Review of Recent Advances in Lithium-Ion Batteries: Sources, Extraction Methods, and Industrial Uses

Abstract

Lithium-ion batteries (LIBs) have become the leading energy storage technology because of their high specific energy, excellent efficiency, and longer lifespan. This review offers a comprehensive overview of the lithium battery industry, covering lithium materials and the global supply chain, as well as examining traditional and sustainable extraction methods. The discussion includes the technical and environmental challenges of each extraction method, with particular emphasis on feedstock selection, which greatly influences lithium recovery efficiency, yield, and ecological impact, and capital and operating expenditures. It also investigates the growth of the global battery recycling industry and provides an outlook on innovations in this area. These innovations include recycling systems, a case study on Biomass Energy Systems Inc., and the battery chemistries needed to support a circular economy. The review highlights industrial applications of LIBs in sectors such as automotive, consumer electronics, and aerospace. Finally, it addresses supply chain and recycling challenges related to LIBs, positioning cost, environmental footprint, and regulatory compliance as central considerations for the future of the battery industry.

1. Introduction

The global dominance of lithium, ranging from smartphones to electric vehicle technologies, traces back to the discovery of the two minerals, namely petalite and spodumene, discovered in Uto, a remote island in Sweden, by Jose Bonifacio de Andrada e Silva in the 1800s [1,2]. Over a decade later, in 1817, Swedish chemist Arfwedson, working in the laboratory of the scientist Berzelius, was able to uncover a new alkali metal, which they named lithion/lithina, in these crystalline minerals that can transform under varying temperatures and pressures. Lithium, the lightest metal in the periodic table, has played crucial roles, first as a psychiatric medicine (mood stabilizers) in the mid-19th century and now as a vital component in digital and sustainable technologies. Lithium’s transition from a laboratory curiosity to a cornerstone of modern technology due to its isolation via electrolysis in 1821 and its electrochemical potential gained significant interest in the mid-20th century, leading to the development of lithium-ion batteries (LIBs) based on the innovative concept of intercalation. Commercialized by Sony with its adoption in portable electronics in 1991, LIB rapidly expanded into Electric vehicles (EVs) and renewable energy storage due to its electrochemical properties [3]. To meet these demands, efficient and sustainable recovery of this element from end-of-life (EOL) batteries and mineral sources became critical.

Figure 1 shows the yearly LIB demand across different sectors and how these sectors provide LIBs through recycling. The global demand for LIB has resulted in a dramatic increase across four distinct phases [4]

Figure 1. (A) Annual LIBs demand in various sectors (B) Lithium battery metals demand. (Source: Bloomberg New Energy Finance) (C) LIBs available for recycling from various sources. Source: Circular Energy Storage. ESS, energy storage systems; EV, electric vehicle; UPS, uninterruptible power supply, © 2025 CC BY 4.0 [5].

• The era of portable electronics in the early 1990s
• Diversification of applications such as drones, medical devices, and stationary energy expanded their demand into new sectors from the late 2000s to early 2010s.
• During this phase, a significant new driver called EVs led to a much sharper and faster increase in demand for LIB, serving as the inflection point from the mid-2010s to early 2020s.
• Phase 4 involves rapid acceleration by 2030 and increased demands in aerospace, defense, mass EV adoption, large grid storage, and circular supply or recycling chains.

According to the United States Geological Survey 2025 (USGS 2025) [6], global lithium production increased by 18% in 2024, and its consumption grew by 29% [7]. Its rapid growth has prompted countries to compete for market influence, global control, and supply chain security. McKinsey (2022) [7], projects that global demand for LIBs will reach 50 TWh by 2040, with 30 TWh required solely for electric mobility. This projected growth highlights the pressing need for the development of scalable, efficient and sustainable lithium extraction and recycling technologies.

This review highlights the global dominance of lithium metal, spanning applications from smartphones to electric vehicles. It provides a detailed overview of how LIB has become crucial for electrifying transportation, renewable energy integration and energy storage. It includes information on geographic distribution and worldwide lithium resources. It offers a comprehensive overview of various lithium extraction methods, such as hardrock deposits, brine deposits, sedimentary deposits, and direct lithium extraction (DLE). Furthermore, comparing DLE technologies with conventional methods in terms of life cycle assessment (LCA), capital and operational expenditures (CAPEX/OPEX), and water footprint to evaluate their scalability and environmental impact. These metrics are essential for identifying commercially viable and sustainable pathways for lithium supply. Additionally, the importance of efficient lithium recovery through recycling processes, with a focus on different feedstock types, is discussed. A case study of Biomass Energy Systems Inc. (BESI) and its proprietary thermal processing method for critical mineral recovery is presented. The report also covers the role of battery chemistry and the key factors influencing battery lifespan and performance. Industrial applications and recent advancements of lithium-ion batteries across sectors like automotive, consumer electronics, and aerospace are explored. Finally, the review concludes by addressing the challenges related to the supply chain and recycling of lithium-ion batteries.

2. Geological Background and Supply

There are three main types of lithium deposits, as shown in Figure 2: (a) Pegmatite (hard rock) deposits, which originate from igneous rocks; (b) Brine deposits, found in salars, salt flats, and evaporative basins; and (c) sedimentary (clay-hosted) deposits, located in volcanic or sedimentary basins [8].

Figure 2. Geological framework for lithium deposits; modified from Credit: Sam Davies © Minex Consulting 2019 [9].

Before 2018, lithium in brine deposits found in the Lithium Triangle was preferred because of its large reserves, lower operational costs, and easier extraction through evaporation ponds [10]. However, the extended project timelines (approximately 6 to 10 years) and increasing environmental and regulatory constraints on brine extraction shifted the industry focus from brine to hard rock mining as demand for lithium skyrocketed. Thus, allowing faster project completion (3–5 years), better scalability for industrial supply chains, and more predictable supply. Australia emerged as the dominant global producer, with the Greenbushes mine holding the largest and highest-grade spodumene deposit [7,11,12]. Table 1 summarizes the geological, economic and environmental influence of deposit types.

Table 1. Comparative Characteristics of Major Lithium Deposit Types [7,13,14,15,16,17,18,19,20,21].

Deposit Type	Medium Li Grade	Impurity Constraints	Lead Time (Years)	CAPEX/t LCE (USD)	Water Footprint (m3/t LCE)	Plant Scale Assumption (Capacity, Method, Water Recycling/Reinjection Assumption)
Pegmatite (Mt Cattlin, Australia)	0.46–0.69% (~1.0–1.4 Li2O ore; SC6 ~6% Li2O)	iron, mica, tantalum, feldspar; concentrate quality limits	~4 (greenfield replicate)	~15,000–20,000	~69–77 cradle-to-gate totals (includes Australia and China for conversion); ~3 (concentrate in Australia mine)	Mid-scale commercial (~30–40 kt/yr LCE); Spodumene concentration only; chemical conversion occurs in China; reinjection not applicable for solid ore mining
Continental Brine (Salar de Atacama)	0.04%–0.2% Li (~400–2000 ppm), raw brine feed; avg. ~0.16–0.20% Li	High Mg, Ca, sulfate, and boron; seasonal variability	~4 (for phase expansion)	~10,500 (intensity at 120 kt/yr)	~2.4–5.9 concentrated brine; ~15–33 (carbonate); 31–50 (hydroxide)	120 kt/yr basin output expanding to 180–250 kt/yr LCE by 2026); Solar evaporation ponds, chemical polishing; brine consumed in ponds; minimal reinjection
Sedimentary Clay (Thacker Pass, USA)	0.2–0.4% Li (avg. ~2540 ppm)	Acid consumption (carbonates), Al/Si dissolution, neutralization solids	~5 (after approval)	~73,250	~84	~40 kt/yr LCE; sulfuric acid leaching, neutralization; Partial recycling via neutralization loop; internal recycling via ZLD; no brine reinjection reported
Geothermal Brine (Salton Sea, USA)	~0.02% Li (avg. ~198 ppm; range 150–350 ppm)	High silica; Mn, boron, scaling/fouling	~3–5	~$9000 (NREL/CEC benchmark)	~15–25	~17 kt/yr LCE; spent brine reinjected underground; freshwater withdrawals for process support
Oilfield Brine (Smackover formation, Arkansans, USA)	0.01–0.02% Li (168 ppm Li; cut off ~100 ppm)	Organics, H2S, Ba/Sr, Fe	~3–5	~21,000	Not reported	$437 M CAPEX for ~20.9 kt/yr LCE; phased build; lithium extracted from tail brine of bromine ops; spent brine reinjected

Note: All intensity values (CAPEX/t, water footprint, land footprint) are normalized to reported plant scale assumptions (capacity, method, and reinjection/recycling practices), as summarized in Table 1. All environmental metrics are normalized per tonne of lithium carbonate equivalent (t LCE). Energy in gigajoules (GJ), water in cubic meters (m³), and emissions in tonnes of CO₂ equivalent (t CO₂e). Conversion factors: 1 acre = 4047 m²; 1 ft² = 0.0929 m²; 1 US gallon = 0.003785 m³.

The rise in hard-rock pegmatites was driven by (a) higher purity of pegmatite-sourced Lithium carbonate (Li₂CO₃), which contains fewer contaminants, and (b) the shift toward lithium hydroxide (LIOH), which is preferred for high-performance EV batteries compared to lithium from brines that require a second conversion step from Li₂CO₃. In addition, hard rock mining expanded because it offered faster project completion (3–5 years), easier scalability for industrial supply chains, and more predictable output.

According to USGS 2024, Recent data in Table 2 show that Australia, Chile, and China accounted for over 74% of global lithium production in 2024. Other emerging producers include Zimbabwe, Argentina, and Brazil. Global reserves are estimated at ~30 million tons, with Chile, Australia, and Argentina holding the largest shares.

Table 2. Global Lithium Production (2024) and Reserves (2025) by Country [6,7].

Country	2024 Production (Metric Tons Li Content)	Global Share (%)	Reserves (Million Tons Li)
Australia	88,000	36.7%	7.0
Chile	49,000	20.4%	9.3
China	41,000	17.1%	3.0
Zimbabwe	22,000	9.2%	0.48
Argentina	18,000	7.5%	4.0
Brazil	10,000	4.2%	0.39
Canada	4300	1.8%	1.2
Portugal	380	0.2%	0.06
Namibia	2700	1.1%	0.014
United States	Withheld (W)	—	1.8
Other countries	—	—	2.8
World Total	~240,000	100%	~30.0

There are many key lithium-bearing minerals for the pegmatite deposit type, and the most commercially important one is Spodumene (LiAlSi₂O₆), with others including Lepidolite, Petalite, and Zinnwaldite, to name a few [13,22,23,24]. On one hand, the lithium triangle, which comprises three South American countries—Argentina, Bolivia, and Chile—holds over 74% of the world’s quality lithium deposits, and on the other hand, major producers by output are Australia (~43%), Chile (~28%), and China (~17%) [25,26,27]. Additionally, LIBs account for over 87% of lithium consumption. According to the International Energy Agency (IEA), demand is projected to grow from 165 kt in 2023 to 530 kt by 2030, and 1.2–1.7 Mt by 2045–2050 [26,27].

3. Lithium as a Critical Mineral

The global demand for lithium has sparked intense geopolitical, economic, and environmental debates across different regions. Some materials or metals needed for transformative technologies and renewable energy are considered critical [28], highlighting their importance from an economic and industrial standpoint, which leads to growing demand amid an unstable supply chain. While discussions and global efforts aim to reduce the strategic vulnerability of critical metals by eliminating longer lead times, bottlenecks, and increasing the security of supply [29,30], developed nations that either produce or hold large reserves treat these metals as geopolitical assets. These countries can influence availability, control access, and create artificial scarcity to gain leverage in geopolitical power dynamics and conflicts. In 2023, Australia and Chile dominated the market, accounting for nearly all global lithium production. According to Garder et al. [22], the criticality of these metals depends on factors such as resource geopolitics, market size, structure and maturity, deposit formation, technological importance, processing, and recyclability [31]. These factors emphasize lithium, a mineral commodity considered essential for energy transition and one of the most critical battery metals [26]. According to the IEA 2020 [32,33], under section 7002(e), a critical mineral is any element, substance, or material identified as high risk in supply chain distribution; it is essential in manufacturing products (such as energy technology, defense, currency, agriculture, consumer electronics, and healthcare- related items), and its absence could have serious consequences, as designated by the Secretary of the Interior. This security framework includes six pillars: diversification of supply sources, advancement of technological innovations, supply chain resilience, scaling up recycling, applying environmental and societal standards in extraction, and fostering strong international cooperation [32,34].

As the geopolitics of lithium become stronger, nations intensify efforts to secure supply chain resilience and reduce environmental impacts, focusing on control of critical mineral production from extraction to recycling. In this section, we discuss lithium brine types, highlighting their various extraction methods, from traditional techniques to direct lithium extraction (DLE), which involves several technologically advanced methods for lithium extraction. Figure 3 illustrates the stages of lithium from exploration to end use.

Figure 3. Stages of lithium from exploration to end use.

While other types of lithium deposits, such as hectorite clay, unconventional brine (lepidolite and petalite), mine waste and tailings, and even seawater, show significant potential, uncertainty exists because these methods have not yet been proven economically viable for industrial-scale exploitation [11,18,29]. Figure 4 illustrates the stages of lithium from exploration to end use.

Figure 4. Hardrock mining process. © 2025 Lithium Harvest [15].

4. Hardrock Mining Extraction Methods

The lithium-rich spodumene ore from pegmatite deposits is mainly mined in Australia, Canada, and emerging regions, and its spodumene concentrates contain about 7% Lithium Oxide (Li₂O [24,35,36]. This type of mining is known for providing high-grade lithium with a shorter development time and is an energy-intensive process, accounting for approximately 60% of lithium production. It is also the most common and one of the oldest methods of lithium extraction [36]. The hardrock mining process is shown in Figure 4. First, the hard rock is drilled, blasted, and the fragmented ore is obtained. Then, the physical beneficiation stages [37] occur, such as comminution (crushing and grinding), separation of spodumene from gangue minerals, magnetic separation [38,39] and finally froth flotation, which results in a finer spodumene concentrate [36,38,40,41].

4.1. Dense Media Separation (DMS)

This stage focuses on the coarse separation of minerals from lithium-bearing minerals, such as feldspars and quartz, which are known as gangue silicates with specific gravities of 2.6 to 3.0 based on density differences [37,42]. In 1949, the Edison plant in the USA was a pioneer and known for processing spodumene-rich pegmatites. Gibson et al. [43] applied heavy liquid separation (HLS) to spodumene samples and found that precise density control is very important, as it helps in mass rejection and improves concentrate grade, thus preventing destabilization of downstream grinding and flotation. Other studies have also shown how small significant changes in specific gravity can lead to substantial differences in recovery and lithium grade [43,44]. Multi-stage DMS analysis was also performed on different size fractions (coarse and fine), resulting in a balanced grade, improved recovery, reduced downstream load, increased media stability, and lower ferrosilicon content compared to single-stage DMS [45,46,47].

4.2. Magnetic Separation

It is a widely used technique that uses magnets to separate different impurities (amphibole, tourmaline) based on their magnetic properties during the extraction of lithium-bearing ores, thereby increasing the purity of lithium concentrates [36,37,48]. According to their magnetic characteristics, these minerals can be broadly classified into these categories.

• Ferrimagnetic minerals (magnetite, maghemite, pyrrhotite) retain strong magnetic attraction even after the magnetic fields are removed [49].
• Paramagnetic minerals (such as hematite and ilmenite) found in iron (Fe) lithium-bearing ores like zinnwaldite and some lepidolites, unlike ferrimagnetic minerals, do not retain their magnetic property after the magnetic field is removed.
• Diamagnetic minerals (spodumene, petalite, quartz) are important lithium carriers. Because of their weak magnetic properties, they generally do not respond to magnetic separation methods.

The magnetic separation process can be used in Pre-DMS, Post-flotation, and inline removal (on conveyor belts to eliminate other impurities before grinding) [37,48,49,50]. While studies demonstrate the significant positive impact on the quality of lithium concentrates, ongoing pilot-scale research is focused on developing novel magnetic separation methods to enhance separation efficiency [36,48,51,52,53,54].

4.3. Froth Flotation

It has been widely used as the beneficiation method for spodumene in ores (pegmatite) due to its high efficiency. This process is known for its effectiveness and flexibility in recovering valuable minerals from complex, low-grade, and costly ores [36,37,55]. It is particularly important in exploiting differences in surface chemistry when specific gravities are insufficient for gravimetric methods [56]. Selective flotation depends on several factors [36,37,57], one of which is the choice of reagents [58,59], playing a vital role. In the froth flotation process, collectors (anionic/cationic) [60,61,62] are used to adsorb the valuable target minerals (spodumene), making them hydrophobic and floatable. Common collectors like sodium oleate (NaOL) [60,61,62], enhanced by cationic or anionic agents, are utilized to improve selectivity and recovery.

After the series of physical beneficiation steps (DMS, magnetic separation, and froth flotation) the downstream process proceeds in this sequence: thermal conversion, chemical extraction, leaching and purification, and finally the product recovery stage (carbonization/causticization).

4.4. Thermal Conversion (Calcination)

After recovering spodumene from the ore using collectors, this refractory and reactive concentrate, which contains α-spodumene, is heated to between 1050 and 1100 °C. This process converts it into β-spodumene, making it more reactive and suitable for chemical processing. Recent studies have explored chemical-assisted conversion, in which experiments conducted by Maliachova et al. [63] showed that carbonizing or calcining with Na₂CO3 (sodium carbonate) and CaO (calcium oxide) lowered the effective conversion temperature and resulted in the formation of soluble lithium phases, leading to a significant redesign of the process. Subsequently, different leaching agents (water, sulfuric acid) and various temperatures were tested. Results showed that 96% lithium extraction was achieved through leaching with H₂SO₄ at 900 °C. Lee et al. experimented with serial calcination using CaO recycling and achieved a lithium yield of 97% with reduced reagent consumption [64]. Other studies discussed emerging methods aimed at reducing residence time and energy demand [65], as well as a thermodynamic framework for selecting calcination conditions [66]. While Maliachova et al. [63] and Lee et al. [64] successfully demonstrated and bypassed the sulfuric acid roasting stage to form soluble lithium phases, many industrial flowcharts still follow the conventional step of roasting.

4.5. Chemical Extraction (Sulfuric Acid Roasting)

At this stage, β-spodumene is mixed with a reagent (concentrated H₂SO₄) and roasted at around 200–250 °C, forming Li₂SO₄, which is water-soluble and achieves high recoveries (>95%). However, it produces acidic residues and requires corrosion-resistant equipment. Isa et al., highlight low-grade lithium resources and their applicability to spodumene. Additionally, high-pressure sodium carbonate (Na₂CO₃) leaching of β-spodumene with a recovery rate of over 94% was reported by Jorjani et al., resulting in a sulfuric-acid-free alternative.

4.6. Product Recovery (Carbonization/Refining)

During the Li₂CO₃ process, the purified Li₂SO₄ reacts with Na₂CO₃, causing Li₂CO₃ to precipitate, which is then filtered, washed, dried, and milled to achieve a purity level greater than 99.5%. To produce LiOH, Li₂CO₃ can be causticized with lime or produced by processing Li₂SO₄ through ion-exchange and membrane-assisted crystallization. The importance of impurity control and crystal engineering during the industrial production of battery-grade Li₂CO₃ and LiOH was reviewed by Gallagher et al. [35]. A life cycle analysis (LCA) comparing brine- and ore-based production was conducted by Kelly et al., which revealed higher greenhouse gas emissions and water footprints for ore-based routes. In another study, Iyer and Kelly [67] extended the LCA to the United States, showing that shifting from spodumene-based Li chemicals to alternative sources, such as sedimentary clay and low-Li-content materials, can support the decarbonization of LIBs. Isa et al. [67] reported that integrating evaporators and crystallizers improves the purity and yield of Li₂CO₃.

5. Brine Extraction Methods

There are three subcategories of brines: closed basin (CB; salar), sedimentary basin (SB; oil field), and geothermal basins (GB).

Salar brines, from their name, are hypersaline and found in closed basins known as salars. According to Munk et al., 2016, accessing these deposit types depends on several features such as the shape and size of the salar, the characteristics of the brine, the nucleus, and the halite’s crust thickness [68]. They are predominantly common in Central and South American countries, and these rich brines are mostly located across the Central Andes region due to their high lithium deposits and reserves, but suffer from a high Mg/Li ratio. Furthermore, they are subjected to evaporation-based extraction processes, which are time and water intensive.

5.1. Sedimentary Brine (Oil Field Brine)

They are also called produced waters, which are by-products generated during the extraction of hydrocarbons from sedimentary formations. They exhibit lithium concentrations ranging from 30 to 500 mg/L, as observed in the Williston Basin, Jurassic Smackover (USA), and Qianjiang Depression (China) [14]. They are characterized by heavy metals, dissolved organics, scaling components (Fe, Ba, Sr), and require several pre-treatment stages before lithium recovery through DLE. Despite these obstacles, the large volume of produced water generated daily worldwide and existing infrastructure make it a viable option for scalable lithium co-production. Several field-scale pilot projects by companies such as E3 Lithium, Lithium Harvest, and Standard Lithium have reported promising results, achieving extraction efficiencies of 95%, low water usage, and lower capital costs [69].

5.2. Geothermal Brine

Subsurface fluids move through deep fractured rocks at high temperatures and are primarily accessed through geothermal energy production. The lithium concentration in geothermal fluids typically varies from 20 to 350 mg/L, depending on the reservoir’s geological and geochemical characteristics [14]. These brines often contain high amounts of silica, boron, and divalent cations, which create technical challenges for lithium selectivity. Recent pilot projects in the Upper Rhine Valley (Germany) and Salton Sea region (California) have shown the feasibility of modular DLE technologies such as ion exchange, membrane-electrochemical trains, and electro-intercalation [70,71,72]. Additionally, the environmental impact remains relatively low due to the reinjection of spent brine and cogeneration of renewable power. Table 3 illustrates the comparative performance of geothermal brine with other lithium extraction methods.

Table 3. Comparative Performance and Environmental Indicators of Major Lithium Extraction Methods.

Raw Material Sites Example	Lithium Yield (Typical Grade)	Recovery Efficiency	Environmental Footprint	Key Notes	Ref
Hard Rock (Spodumene–Greenbushes, Australia)	Ore ~1.9% Li2O; SC6 concentrate ~6–7% Li2O	65–85% (typical commercial operations)	~84–120 m3/t LCE water usage benchmark; very high energy demand (~223 GJ/t LCE); high CO2 emissions (~15–20 t CO2e/t LCE);	World’s largest hard rock mine; supplies >40% of global lithium; stable throughput but high carbon intensity and tailings management issues	[15,73,74]
Brine (Salar de Atacama, Chile)	0.04–0.20% Li (~400–2000 ppm; avg. ~0.16–0.20%)	30–50% via solar evaporation	~2.4–5.9 m3/t LCE (concentrated brine); ~15–33 m3/t LCE (carbonate); ~31–50 m3/t LCE (hydroxide); large land footprint; low direct energy use (solar); CO2 emissions ~2.8–5 t/ton LCE	Lowest-cost production globally, but severe sustainability concerns in hyper-arid regions, with documented aquifer depletion and indigenous rights conflicts	[15,74,75,76,77,78,79]
Brine (Silver Peak, Nevada)	~0.016% Li in brine; Concentrated to ~6% Li via solar evaporation	~40–50% recovery (~51% ponds and 78% plant)	Extreme water consumption ~500 m3/t LCE; evaporation ponds (~61 km2); 76% aquifer depletion; CO2 emissions ~2.8–5 t/ton LCE	Oldest operating lithium brine (USA) documented groundwater depletion in Clayton Valley	[80]
Clay-Hosted (Thacker Pass, USA–Lithium Americas study)	0.2–0.4% Li in ore (avg. ~2450 ppm)	80–85% projected with acid leaching	Average process water demand ~84 m3/t LCE; environmental impact depends on sulfuric acid management and neutralization; potential for lower emissions if integrated with renewables	Largest known lithium clay resource in North America; feasibility study projects, onsite sulfuric acid plant and integration with renewable energy.	[17,81,82]
Geothermal Brine (Salton Sea, USA)	~0.02% Li in brine (~198 ppm; range 150–350 ppm)	~75–91% (pilots/Bench scale)	~15–25 m3/t LCE; reinjection mandatory; scaling (silica, CaSO4)	Co-production with geothermal power; closed-loop reinjection; extraction technology still emerging for large-scale production	[14,83,84]

5.3. Solar Evaporation Method

Over the years, the extraction method known as solar evaporation has been the most widely used [10,68,85,86,87]. Lithium-rich water deposits (brine wells) are pumped to the surface and placed into evaporation ponds for over 12–24 months under intense sunlight and dry conditions, which increases the concentration of dissolved salts. As the lithium-rich brine becomes more concentrated, it is transferred between ponds where calcium oxide (lime) is added to precipitate out the salt and impurities such as calcium, magnesium, and boron. Finally, sodium carbonate is added to the purified brine, which is then refined into Li₂CO₃ or processed further to produce LiOH [88].

Despite its low operational cost and mature technology, the solar evaporation process suffers from long processing times, substantial water loss through evaporation, and variable lithium yields. Commercial operations such as Orocobre (Argentina ~17–20 kt LCE/year) and SQM (Chile, ~120 kt LCE/year, which is expanding to 180–250 kt by 2026) via solar evaporation ponds with minimal reinjection typically consume ~1500–2600 m³ of water per tonne of Li₂CO₃, and require land areas measuring several km². Plant scale assumptions for all deposit types (capacity, method, and recycling/reinjection practices) are summarized in Table 1.

This traditional technological process (Figure 5) has disrupted fragile ecosystems in already arid regions [89,90] causing severe environmental impacts [41]. Additionally, countries are developing policies on brine extraction [91]. This has created a need for shorter, less harmful technological processes known as direct lithium extraction methods: a list of advanced techniques for relatively safe and rapid lithium extraction from brine [92]. Figure 6 shows the classification of lithium extraction processes.

Figure 5. Tradition lithium extraction. © 2025 Flottweg SE [93].

Figure 6. Classification of lithium extraction processes.

6. Direct Lithium Extraction (DLE)

While DLE remains an emerging technology with proven high-efficiency lithium extraction (above 90%) at the laboratory level, only a few countries have advanced these processes to either commercial or non-commercial deployment stages [68,94,95,96,97,98]. Argentina hosts the world’s longest-operating commercial DLE facility. The critical importance and rapidly increasing demand for lithium have driven the development of several recovery and extraction technologies for this essential mineral. This has resulted in successful pilot studies, some of which were scaled up, while others, despite promising recovery rates, have not been widely adopted due to concerns over commercial viability. Current DLE methods include adsorbents, ion exchange, membrane separation, solvent extraction, and electrochemical separation. Among these, adsorption, solvent extraction, and ion exchange technologies have been implemented at commercial and pre-commercial scales [99,100].

The adsorption technique has been used by the company Livent at its Fenix project in Catamarca for over two decades [94], and this operation has continuously produced high-purity LiCO₃ without relying on large evaporating ponds, thus making Argentina a proof of longevity [94,98]. According to Livent’s 2023 resource and reserve report, the Fenix Project site boasts a current nominal capacity of ~20–25 kt/yr LCE and is currently expanding to 40 kt/yr LCE and targeting 100 kt/yr by 2030. The proven and probable reserves total around 0.73 Mt Li, supported by measured and indicated resources of about 1.33 Mt Li. [101]. The process flowsheet combines proprietary selective adsorption (DLE) alongside pre-concentrate and finished salar brine ponds, followed by carbonate conversion to produce battery-grade Li₂CO₃ [101]. After years of pilot studies on adsorption and ion-exchange systems for high-magnesium brines, China began to scale up to commercial production in the late 2010s, establishing plants in Qinghai Province, and, to date, multiple facilities are operational [94]. The Fozhao Lanke Lithium industry project at the Chaerhan (Qarhan) Salt Lake operates with a nominal capacity of ~20 kt/yr LCE [102], combining adsorption-based DLE modules with traditional evaporation ponds for pre-concentration [103]. In the Jintai salt lake project, Sunresin proprietary DLE adsorption resin commenced operation in 2018 with a 3 kt/yr LCE module [104], later expanded to 7 kt/yr, while the Yi Li Ping facility operated by Qinghai Salt Lake Industry Co. targets ~20 kt/yr LCE. These facilities have collectively produced a significant portion of China’s lithium chemicals at multi-thousand-ton capacities by integrating DLE, making this strategy a hallmark of the country’s proof-of-concept scalability [95,98]. While Argentina and China have demonstrated and achieved proven DLE at a commercial scale, other regions including Europe, the United States, and Chile remain in the pilot or pre-commercial phases, testing various techniques on diverse brine chemistries.

Figure 7 shows DLE projects by country and type. DLE is a game changer in lithium recovery technology; however, there is no one-size-fits-all solution because each brine resource has unique characteristics, such as lithium concentrations and impurity ratios. Additionally, factors like cost, water and energy consumption, environmental impact, and scalability are some of the drawbacks [41,105]. In the race toward DLE, over 67 leading companies are driving innovation and commercial-scale deployment [106,107,108,109]. About 124 kt of lithium compounds are projected to be produced by 13 DLE plants in 2024, according to the Benchmarks Lithium forecast [110]. The DLE market share has been growing from a 9% share in 2023 [95] and is projected to contribute over 15% by 2036 [105,110,111], as several emerging technologies and companies continue to open plants at a commercial scale [98]. Table 4 summarizes the comparative evaluation of lithium extraction methods for traditional and DLE methods.

Figure 7. DLE projects by country and type. © Copyright 2025 Columbia CGEP [112].

Table 4. Comparative evaluation of lithium extraction methods.

Method	TRL (2025)	Scalability	Sustainability Index and Trade-offs	Ref
Hard Rock (Spodumene)	9	High	Low: Very high CO2 (~20 t CO2 eq/t LCE), high energy (~223 GJ/t), moderate water use (~80 m3/t) but environmentally intensive (high energy)	[13,25,73]
Brine Evaporation	8	Medium	Low: Extreme water footprint (~500 m3/t), low CO2 (~3–7 t CO2e/t LCE), low energy (~0.04 GJ/t), established and low CAPEX, but long lead times and water intensive	[10,97,113,114,115]
DLE–Adsorption	7–9	Medium	Moderate–High: Low water (~20 m3/t), moderate energy (~50 GJ/t), high recovery (90–95%), compact, selective, but sorbent degradation and requires an additional concentration step	[73,99]
DLE–Ion Exchange	7–9	Medium	Moderate–High: This is akin to adsorption with high-purity eluates, but higher chemical usage and sorbent cost	[73,116,117,118]
DLE–Solvent Extraction	7–8	Medium	Moderate: Continuous and high throughput with moderate energy, but solvent toxicity, waste and corrosion challenges	[13,73,74,118]
DLE–Membrane (Nanofiltration)	4–6	Low	Moderate-High: Effective Mg/Li separation, reduces chemical use; but fouling and scaling	[73,119,120]
DLE–Membrane (Electrodialysis)	5–7	Low–Medium	Moderate-High: Selective lithium concentration, continuous operation, low reagent demand but high energy demand and membrane durability concerns remain	[73,74,120,121]
DLE–Membrane (Capacitive deionization)	3–5	Low–Medium	High: Low chemical input and environmentally friendly, has a potential for seawater, but electrode durability.	[73,122,123]
DLE–Electrochemical	3–8	Low	High (potential): Low water and energy if powered by renewables, minimal reagent consumption, but electrode durability and fouling	[73,124,125,126]

7. Extraction of Lithium from Other Non-Traditional Resources

In addition to continental Salt Lake brines and hard rock spodumene, other unconventional lithium sources such as seawater, oilfield brines, and hectorite deposits have been increasingly studied for lithium recovery. Each of these sources presents unique characteristics and challenges, therefore requiring specialized extraction techniques.

7.1. Seawater

Seawater holds the largest lithium reservoir on Earth (~230 billion tons), but with a very low concentration (~0.17–0.20 mg/L), making extraction difficult due to competing ions (Na⁺, Mg⁺, and Ca²⁺) [127]. Conventional separation methods have been uneconomical, but recent advances in membrane and electrochemical technologies have renewed interest in using seawater as a lithium source. Liu et al. developed a pulsed electrochemical intercalation method with TiO₂-coated FePO₄ electrodes, achieving a Li/Na selectivity ratio of ~1.8 × 10⁴ while processing real seawater over multiple cycles [128]. Similarly, capacity deionization systems that include lithium-ion sieve (LIS) membranes have improved lithium extraction selectivity, especially when optimized rinsing protocols are used in simulated seawater brine [129]. Other innovative approaches, such as solid-state electrolyte membrane “electro-pumping,” have significantly increased lithium concentrations—by over 43,000-fold (~0.21 ppm to >9000 ppm)—in Red Sea seawater samples, with Li/Mg selectivity exceeding 45 million and high purity (99.94%) lithium phosphate (Li₃PO₄) [130]. Yang et al. also reported on a LIS membrane with a Li/Na separation factor of ~2.87 × 10⁷, ionic conductivity of ~6.2 × 10⁻⁵ S/cm, Columbic efficiency of ~98%, and energy consumption of ~17.4 kWh/kg Li [131]. Recently, covalent organic frameworks (COF) membranes have been designed to facilitate lithium transport over sodium, presenting a next-generation method for seawater extraction [132]. Challenges such as membrane and electrode fouling, low flux, durability issues, high energy requirements, and expensive technologies hinder scalability and economic viability.

7.2. Hectorite Clay

Clay deposits contain lithium that is bound within the mineral structure, requiring thermal, chemical, or electrochemical activation to extract it. Traditional extraction methods include acid leaching (such as with sulfuric or hydrochloric acid), roasting followed by leaching, hydrothermal treatments, and alkaline digestion. While effective at releasing lithium, these methods often consume large amounts of reagents, high energy, and generate significant solid waste, which undermines their economic and environmental sustainability [114,133,134]. Recently, electrochemical techniques have been developed to address some of these challenges. For example, Haddad et al., in a proof-of-concept study, used hectorite-carbon black composite electrodes (HCCEs) subjected to anodic polarization, demonstrating they can release about 50.7 ± 4.4% of lithium from hectorite under laboratory conditions [133]. Large clay projects like Thacker Pass in Nevada, known for its mixed smectite/illite clay lithology, where the illite-rich zones contain higher lithium grades (4000–9000 ppm Li in certain intervals), and Rhyolite Ridge are currently the focus of lithium extraction efforts for piloting and demonstrating clay-hosted lithium recovery [17,135,136,137]. Commercial viability for large-scale lithium production from clay is yet to be realized due to issues related to reagent use, energy demand, impurity removal, waste management, and efficiency goals [15]. Table 5 presents the process characteristics and technological readiness (TRL) of unconventional lithium resources.

Table 5. Process characteristics and technology readiness of unconventional lithium resources.

Resources	TRL	Typical Li Concentration	Test Conditions	Limiting Factors	Ref
Seawater (membrane/ electrochemical DLE)	2–3	~0.17–0.21 mg/L; real seawater (Red Sea) and synthetic Na-rich matrices	Lab-scale continuous membrane (LLTO), enrichment 43,000×	Na/Mg competition (~60,000:1), fouling, durability, high energy (~76 kWh/kg Li)	[130]
Hectorite/Sedimentary Clays	5–6	015–0.4% Li (~1500–4000 ppm); higher grade ~0.70% Li (~7000 ppm) and exceptional >1.0% Li (>10,000 ppm)	Pilot sulfuric acid leach trains; lab electrochemical release (~50% recovery)	Acid consumption, neutralization solids, energy demand, waste management	[17,133]
Oilfield Brines (produced Water, DLE)	4–5	100–500 mg/L; Marcellus Shale PW avg. ~127–205 mg/L	Skid-mounted modular pilots; produced water datasets; pretreatment for organics/H2S	Regional variability, Mg/Li ratios (5–18), fouling (organics, Fe, H2S), decline rates, infrastructure reuse	[15,138]
Geothermal Brines (Salton Sea, USA)	4–6	20–350 mg/L typical; ~200 mg/L at Salton Sea	Side-stream pilots; high TDS; reinjection mandatory	Scaling (silica, CaSO4), compatibility with power ops, sorbent/media durability, reinjection requirement	[14,15]

Note: “×” indicates fold increase relative to the lithium concentration in the feed solution. For example, 43,000× enrichment means the lithium concentration was raised from ~0.2 mg/L in seawater to ~9000 mg/L in the product stream. LLTO (lithium lanthanum titanium oxide).

8. Lithium Recycling Processes

The efficient recovery of lithium and its environmental sustainability are heavily influenced by the quality and type of feedstock entering the recycling process [139,140]. These feedstocks differ in purity, chemical composition, and physical form, affecting the processing routes and challenges [141,142]. The design and chemistry of LIBs, used in everything from consumer electronics to EVs, create a heterogeneous waste stream that requires careful classification and pre-processing [143]. Sustainable and efficient lithium recovery from EOL batteries and mineral sources is essential. Although demand for mineral resources is expected to grow, supply security remains uncertain. Trends such as the concentration of production in a few countries, decreasing ore grades, and limited recycling at EOL raise concerns about resource security. These concerns are compounded by the fact that most mineral commodities used in emerging technologies are mainly or solely obtained as by-products, which can lead to inelastic supply. Additionally, opportunities for material substitution are often limited, especially as innovation pushes for better portable and smarter technologies that leverage each commodity’s unique properties for specific functions. The IEA’s 2020 publication [144] states that recycling LIBs can reduce some pressure on mining virgin ores. Table 6 presents the types of feedstocks used in LIB recycling, categorized by purity levels, applications, and associated challenges.

Table 6. Feedstock types for LIB recycling [145].

Feedstock Type	Description	Purity Level	Typical Use/Source	Challenges
Cathode Scrap	Unused, defective, or end-of-life cathode material from manufacturing or batteries	High (≥99%)	Industrial manufacturing, second-life batteries	High purity requirements, sorting needed
Black Mass	Crushed, processed cathode and anode mix after mechanical preprocessing. These are powdered or shredded mixed electrode material.	Variable (moderate)	Post-shredding battery waste	Heterogeneous composition, potential contamination
Lithium-Ion Batteries	Fully disassembled or shredded batteries from second use or disposal	Mixed (variable)	EOL batteries from EVs, electronics	Sorting, safety, and pre-treatment challenges
Soft Coin Cells	Miniature batteries used in wearables, sensors, medical devices	High (≥99%)	Consumer devices	Small volume, specialized handling
Pouch and Prismatic Cells	Larger LIB packs with varied chemistries	Moderate to high	EVs, grid storage	Disassembly complexity, chemical heterogeneity
Mixed Cell Streams	Unsorted batteries with varied chemistries and ages	Low to moderate	Mixed waste streams	Sorting difficulty, process adaptation required

Seventy-four new lithium mines averaging 45 kt will be needed by 2035, according to Benchmark Mineral. However, successful recycling can reduce this need by 40% [146]. It also creates a secondary supply of minerals, which already lessens the pressure on the primary supply from mining and refining. Focusing more on recycling could provide three main benefits: increased primary mineral supply, improved supply for resource-poor regions, and better environmental performance and waste management. Even if recycling does not fully replace the need for new supply, by 2040, scrap copper, lithium, nickel, and cobalt used in carbon-free applications could decrease primary requirements of these critical minerals by 10–30% [147].

8.1. Case Study: Biomass Energy Systems Inc-BESI

Biomass Energy Systems Inc. has developed a unique thermal processing method to recover critical metals, including lithium, from EOL LIBs. Unlike traditional chemical hydrometallurgy or pyrometallurgy, BESI’s process emphasizes direct thermal treatment of the black mass produced from battery crushing and initial metal separation [148]. BESI’s lithium recovery technology is built on its extensive patent portfolio in rotary kiln gasification and thermal conversion systems. Key patents include innovations in gas distribution and mixing within rotary reactors [149,150] and devices for versatile gas–solid reactions and waste-to-energy conversion [151,152]. These patented designs allow precise control of gas flow, reaction temperature, and mixing, ensuring efficient thermal decomposition of organics and consistent recovery of the metallic fraction.

The feedstock for BESI’s process includes black mass containing cathode and anode materials, residual electrolyte, and conductive additives. Initial steps involve mechanically reducing size and separating ferrous from non-ferrous components, resulting in a concentration rich in lithium, cobalt, nickel, manganese, and graphite. This pre-processed black mass is then sent to BESI’s thermal gasification system [148]. In BESI’s rotary kiln–based thermal system, organics and carbon-rich fractions are selectively gasified, producing a clean fuel gas that is burned to generate process heat, steam, or electricity. This integrated energy recovery minimizes parasitic loads and can supply excess electricity to the grid. In a separate high-temperature combustion or melting zone, the remaining metal-rich fraction is fluxed (e.g., with iron oxide) to lower the melting point and facilitate the separation of metals into a molten alloy. After cooling and solidification, this metallic product is sent to specialized smelters and refineries for downstream lithium extraction and purification [148]. This closed-loop design offers significant benefits:

• Volume reduction: nearly complete conversion of organics and carbon.
• Deployability: the compact system can be installed near battery collection points, reducing the need for offshore shipping.
• Energy integration: syngas combustion cuts process energy demands, improving economic viability.
• Compatibility with small and distributed feedstocks: enabling recycling at regional or military locations.

Table 7 provides a comparison of BESI thermal recycling with other extraction methods. Compared to chemical hydrometallurgical recycling, BESI’s process uses fewer unit operations, avoids concentrated acids, and produces minimal liquid effluents. Compared to traditional pyrometallurgy, the BESI method offers modular deployment, better energy recovery, and is suitable for smaller throughput operations. As a result, BESI’s thermal platform connects large-scale centralized smelters with emerging lab-scale direct lithium extraction systems, supporting the growing need for sustainable, distributed, and circular lithium supply chains [148,152]. In addition, as shown in Table 8, there are several pathways for recycling of spent LIBs.

Table 7. Comparison of lithium extraction and recycling methods [15].

Feature	Solar Evaporation	Hardrock Mining	DLE from Brine	BESI Thermal Recycling
Feedstock	Continental brine	Rock/Spodumene	Continental brine	Black mass from EOL LIBs
Timeline	13–15 years	8–10 years	5–7 years	<1 year (modular deployment)
Li2CO3 Production Time	2–3 years	3–6 months	~2 h	Days (including refining)
Lithium Yield (%)	20–50%	40–70%	80–95%	85–95% (metal fraction to refinery)
Avg. Footprint per 1000 mt LCE	~0.57 km2	~0.08–0.1 km2	0.0057 km2	<0.0004 km2 (modular units)
System Design	Stationary	Stationary	Deployable/Stationary	Deployable modular thermal units
Environmental Impact	High water consumption; soil/ brine ecosystem disruption	Tailings, soil and water contamination	Minimal effluents, higher energy use	Minimal liquid effluent; energy self-sufficient; volume reduction
Average Invested Capital per 1000 mt LCE	$35 M	$60 M	$65 M	<$20 M (scalable, modular)

Table 8. Summary of techno-economic and environmental indicators for spent lithium-ion batteries.

Pathway	Feedstock	CAPEX (Order of Magnitude)	OPEX (Key Drivers)	Market Value of Recycled Materials and Quantitative Indicators	Ref
Pyrometallurgy (Smelting)	Mixed LIB scrap, black mass	High: large, centralized furnaces gas treatment systems; Conventional plants ($50–$200 M; 2–5 yrs build)	High energy demand (~1000–1600 °C) fluxes/ slag disposal	Strong Ni/Co credits; Li often lost unless hydrometallurgy step added; cost ~$2.9/kg; GHG ~2.21 kgCO2/kg;	[153,154,155,156]
Hydrometallurgy (Leaching + SX/IX)	Black mass, shredded cells	Medium; modular reactors, SX/IX, (~$165 M for 18.25 kt/yr capacity)	Reagents (H2SO4 ≈ 48%, NaOH ≈ 10%, Ca (OH)2 ≈ 12%), effluent and energy costs; sensitive to reagent recycle	Recovers Li, Ni, Co, Mn as salts (Li2CO3/LiOH, NiSO4, CoSO4); >80% yield, >99% purity; cost ≈ $2.2/kg; GHG ≈ 2.3 kg CO2/kg	[156,157,158,159]
Direct Recycling (Cathode Re-lithiation)	Sorted cathode chemistries (NMC, LCO, LFP)	Low–Medium; modular re-lithiation lines; relatively low CAPEX (pilot scale only).	Sorting, re-lithiation reagents, quality assurance to meet cathode specs	Highest potential value if regenerated cathode active material (CAM) meets spec (premium cathodes); cost ~1.6/kg; GHG ~0.5 kg CO2/kg;	[156,158,160]
Mechanical Pre-processing (Front-end)	Whole packs/modules	Low; shredders, separators, safety systems	Low–Moderate; labor, maintenance, safety	Black mass with ≥80–90% electrode yield; >82% Co recovery; ~99% purity via electrostatic separation; graphite recovery 54–84% (0.04–2.75 kg CO2/kg graphite); disassembly saves 40–80% vs. shredding	[161,162,163,164]
Second Life Repurposing (Stationary Storage)	EV modules ≥ 70–80% capacity	Low–Medium; testing, Battery Management System (BMS) integration	Moderate; labor, testing, warranty	Resale often > scrap; Second-life LIB cost ~70/kWh, new ~142/kWh; LCOS 234–278 $/MWh for second life; new cost ~211$/MWh; 50% GHG savings, graphite (~200–600 mg/g adsorption)	[165,166,167,168,169]

LCOS (Levelized cost of storage), NMC (Nickel Manganese Oxide), LCO (Lithium Cobalt Oxide), LFP (Lithium Iron Phosphate).

In Table 8 above, pyrometallurgy remains the most well-established method, but unless coupled with hydrometallurgy, its high CAPEX and energy requirements will limit sustainability and result in lithium losses. High recovery yields and purity are provided by hydrometallurgy, but reagent expenses and effluent treatments dominate OPEX. Direct recycling, although still in its laboratory and pilot scale phase has the lowest carbon footprint and highest potential value provided regenerated cathodes meet specifications. Mechanical pre-processing as a front-end step is essential for safe handling and high-yield black mass production, with disassembly pathways offering substantial cost savings. Second -life repurpose offers great greenhouse gas savings and economic benefits when modules retain sufficient capacity; nevertheless, viability decreases after about 10 years. These pathways illustrate complementary role in which pyrometallurgy, and hydrometallurgy serve as mature recovery routes, direct recycling as a promising low-carbon innovation, mechanical pre-processing as a universal enabler, and second-life repurposing as a bridge strategy for recycling.

8.2. Byproducts, Effluent Management, and Environmetal Considerations

In addition to differences in lithium yield and energy demand, each extraction and recycling pathway generates distinctive byproducts that influence its environmental footprint. These include salt precipitates, residual brine, mineral tailings, and gas-phase emissions that vary depending on feed composition and processing route. Table 9 summarizes the principal byproducts, their typical management strategies, associated environmental risks, and regulatory benchmarks for discharge or reinjection.

Table 9. Major byproducts and effluent management approaches for lithium production and recycling processes.

Process	Major Byproducts	Typical Management Strategy	Main Environmental Risks	Representative Regulatory/Guideline Limit
Solar evaporation (brine-based)	NaCl−, KCl−, Mg(OH)2, CaSO4 rich precipitates; concentrated residual brine	Sequential ponding; recovery of industrial salts; partial reinjection of depleted brine	Aquifer drawdown, surface salt crusting, brine salinization of wetlands	Effluent discharge guidelines typically recommend TDS pH 6–9 into marine or surface water for protection [170]. International benchmarks suggest TDS < 1000 mg L−1, Cl− ≈ 250 mg L−1, and pH 6–8.5 for taste/acceptability guidance [171]
Hard-rock (spodumene) processing	Silicate tailings, fluorinated residues (LiF, CaF2), SO2/NOx from roasting	Neutralization with lime; tailings impoundment; off-gas scrubbers	Acid drainage, fluoride release, airborne SO2/NOx emissions from thermal conversion	SO2 ~ 50–400 mg Nm−3; NOx ~ 200–500 mg Nm−3 (BAT-AELs for roasting/smelting operations) [172]
Direct lithium extraction (DLE, adsorption/ion-exchange)	Spent sorbent media; Mg/Ca concentrate; NaCl-rich reject brine	Closed-loop regeneration; partial brine reinjection; evaporation of residuals	Ionic imbalance in aquifer, trace-metal accumulation	Ionic balance deviation ± 5% (analytical quality-control guideline) [173]
BESI thermal recycling	Metallic alloy residue, vitrified slag, trace SO2/NOx	Slag recovery for secondary metals; catalytic oxidation and gas filtration; no liquid effluent	Minimal aqueous discharge; potential gaseous emissions if abatement insufficient	SO2 emission levels typically range between 50 and 400 mg Nm−3 for roasting and smelting operations; NOx generally controlled within 200–500 mg Nm−3 [172,174]

Overall, conventional brine and hard-rock processes generate substantial volumes of solid and liquid effluents that require continuous management through containment, reinjection, or neutralization, often posing long-term risks of salinization, leachate generation, or chemical instability. In contrast, the BESI thermal process is inherently designed as a closed-loop, minimum-effluent system. It produces only stable, vitrified solid residues suitable for reuse in secondary metal recovery and construction materials, while all gaseous byproducts (SO₂, NO_x, CO₂) are captured and treated through catalytic oxidation and filtration units. Importantly, no aqueous waste streams are generated, eliminating the need for brine reinjection or tailings storage. This configuration drastically reduces the process’s environmental footprint, particularly in terms of water use, effluent toxicity, and long-term disposal liabilities, positioning BESI’s technology as a benchmark for sustainable, closed-loop lithium recovery relative to all other current production methods.

9. Role of Battery Chemistry

In 2020, China accounted for 60% of global battery cell production, with the US second at about 15% [175]. As more funding goes into battery technologies, the question arises: Are EOL a concern? There are several types and variants of batteries, which simply refer to the elements that perform electrochemical activities to store energy [176]. Major components of the LIBs include the anode, cathode, electrolyte, and separator. In addition, other materials in Table 10, such as cobalt, nickel, manganese, iron, aluminum, copper, graphite, and phosphorus, also influence the performance of these batteries. These materials serve different functions. Table 11 Overview of lithium-ion battery chemistries, limitations and applications.

Table 10. Main chemical components in a battery and its functions.

Battery Materials	Function
Lithium	It has high energy density, and long-life cycle and making it vital for EVs
Graphite	It facilitates charge storage and aids conductivity
Nickel	It supports high-density cathodes and extends EV range
Copper	It is essential for electrical conductivity in battery connections and infrastructure of EV
Phosphorus	It is used in lithium-iron phosphate to improve safety and lifespan
Manganese	It strengthens the structure of the battery resulting into cost-effective alternative

Table 11. Overview of lithium-ion battery chemistries, limitations and applications.

Battery Name	Application	Pros	Cons	Energy Density (Wh/kg)	Ref
Lithium-Cobalt Oxide (LiCoO2)	Smart phones, laptops and Cameras	Extremely high energy density, widely available	High risk when damaged, Cobalt is very expensive and scarce.	150–200	[177,178,179]
Lithium Iron Phosphate (LiFeO4)	Solar storage, electric buses, Evs	Safe to use due to excellent thermal and chemical stability, lower cost, long cycle life	Low energy density, lower nominal voltage	90–160	[179,180,181]
Lithium Nickel Manganese Cobalt Oxide (NMC)	Electric bikes, home energy storage	Balanced energy density, great lifespan	Costly (due to cobalt), moderate thermal stability	150–220	[178,182,183]
Lithium Nickel Cobalt Aluminum Oxide (NCA)	Electric power trains, Power tools, electric bikes.	Very high energy density, long life cycle, high specific power	Costly (nickel and cobalt), lower thermal stability,	200–260	[178,179,183,184]
Lithium Manganese Oxide (LiMn2O4)	Power tools, Medical, hybrid vehicles	Good thermal stability, Lower cost than cobalt, High discharge rates,	Shorter life span, lower energy density, faster fading capacity under high load	100–150	[179,182,185]
Lithium Titanate	Grid Storage, Evs, electric bikes	Great long cycle life, wide temperature tolerance, very fast charging capabilities	Very low energy density, low nominal voltage	50–80	[186,187]

10. Industrial Uses of Lithium-Ion Batteries

LIBs deliver superior electrochemical potential compared to other rechargeable batteries, mainly due to their high energy density and long cycle stability as energy storage technology. They are proven to be the top choice for portable electronics, EVs, and grid-scale energy storage because of their high power, safety, and longer cycle life [188]. Li-ion batteries are compact, lightweight, and reach high energy density levels, typically two to four times greater than lead-acid or nickel-cadmium batteries, which is one of their main advantages [189]. We believe these properties are essential, especially for consumer electronics and electric mobility.

According to some authors [190,191], this high energy density directly results in longer runtimes for devices, such as increased driving ranges for EVs, which greatly appeals to end-users. Additionally, lithium-ion cells can withstand thousands of charge and discharge cycles with minimal capacity or efficiency loss, making them a cost-effective solution for long-term use [192]. Scrosati and Garche [193] also emphasize that the main reason LIBs have become popular is because of their efficiency and versatility—they can power a variety of small devices, large industrial systems, and even serve as renewable energy storage, capturing energy generated by home solar power systems. Figure 8 demonstrates the working principle of rechargeable Li-ion batteries during operation.

Figure 8. Mode of operation of rechargeable Li-ion batteries. [194]. © U.S. Government Accountability Office GAO, 2022.

Recent advances in materials science and engineering have led to rapid improvements in the performance properties of Li-ion batteries, such as power density, charging speed, and safe operation, surpassing other battery technologies like Ni-Cd and Ni-MH. These developments have enhanced the competitiveness of Li-ion-based systems [195]. According to Hwang et al. [196], this progress has greatly contributed to their widespread use in modern society, fueling the growth of most mobile electronic devices. They are increasingly becoming the backbone for the electrification of transportation, as Hill et al.’s [197] recent study discusses. Besides these key features, LIBs also have a low self-discharge rate; that is, they can retain their charge for longer periods when not in use and are generally considered less polluting than older battery types [198]. With their broad applicability and continuously improving properties, they have become the most commercially desirable modern energy storage technology [199,200]. Three major industries have adopted and transformed with this technology: automotive, consumer electronics, and aerospace. In automotive, LIBs are driving the shift toward EVs, providing a practical power source for cars, buses, and trucks. For consumer electronics, their compact size and reusability make them ideal for smartphones, laptops, wearables, and other portable devices used daily. In aerospace, they support advanced technologies like drones, satellites, and electric aircraft, where weight, reliability, and energy density are critical. Collectively, these industries demonstrate how LIBs can power innovation, sustainability, and high performance across various sectors.

10.1. Automotive Applications

Light-duty EVs have become more popular because of the fast development of Li-ion battery technology, which provides a good balance of energy, power, and cycle life for cars. Because of this strong performance, Li-ion batteries are seen as the most promising energy source [201] for solving energy shortages [195,202,203,204] and pollution problems [205].

A typical lithium-ion battery pack for EVs consists of many individual cells organized into modules, which are assembled into a pack (Figure 9), along with advanced thermal management systems and battery management electronics [206]. This intricate connection, as noted by Patel & Patel [207], enhances performance and safety by continuously controlling heat runaway during operation to prevent degradation and unsafe conditions. Additionally, battery management systems monitor and maintain vital parameters such as state-of-charge and state-of-health. The robust design ensures optimal battery lifespan and consistent performance due to the complex interaction between electrochemical reactions and thermal behavior [208].

Figure 9. Solid-state Li-ion battery configuration in an EV [209]. Copyright © 2021 American Chemical Society.

According to Zhang et al. [210], Li-ion batteries, especially lithium nickel-manganese-cobalt oxide and lithium iron phosphate chemistries, are widely used in automotive applications because they provide high performance in terms of specific energy, specific power, safety, and cost. These chemistries satisfy the energy storage and power requirements for EV traction while also offering a safe and durable design with effective thermal management. However, the current energy density of commercial Li-ion batteries (around 300 Wh/kg) is still not enough to match the driving range of gasoline-powered vehicles [211,212]. The effort to achieve higher energy density also aims to reduce space and weight limitations in EVs, where smaller and lighter battery packs can increase vehicle range without cutting into cabin space or adding weight [213].

Therefore, it is vital to install and operate advanced battery management systems (BMS) to improve the performance, lifespan, and safety of Li-ion battery packs in EVs by accurately monitoring and controlling various operational parameters [214]. The BMS primarily monitors and manages the performance of battery packs to ensure their optimal function, safety, and longer service life. This includes comprehensive voltage and current tracking, precise estimation of charge and discharge levels, as well as implementing robust protective measures and efficient cell balancing to extend battery life [215,216]. Li et al. [217] found that such systems oversee the thermal environment, prevent overheating and thermal runaway, maintain consistent voltage levels across cells in a pack, and execute critical safety procedures to avoid hazardous conditions, such as overcharge or deep discharge. These findings were also highlighted by Togun et al. [218] in a more recent study.

The complexity of Li-ion electrochemistry and the high stakes for functional safety in automotive applications have driven a vast research and innovation effort toward algorithmic advancements in all domains of BMS functionality [219]. Since state-of-charge (SoC) is not directly measurable, it must be inferred indirectly via models and estimation algorithms built on input data such as cell voltages, currents, and temperature. According to Jebahi et al. [220], SoC errors can lead to vehicle stranding (overestimated SoC) or excessive battery wear and safety incidents (underestimated SoC). Conventional methods include Coulomb Counting (Ampere-Hour Integration), which works by integrating measured current over time to track charge in/out. It is simple and fast, but accumulates error due to sensor drift and initial SoC dependency [220]. It has also been found to be prone to integration drift as the slightest current sensor errors become substantial SoC deviations over long periods. The other widely used estimation algorithm is the Open Circuit Voltage (OCV) Mapping method, which estimates the SoC by comparing battery terminal voltage at rest (no load) against an OCV-SOC curve. Studies have shown it to be more accurate, but only valid during long rest and affected by hysteresis in Li-ion cells [221,222]. This algorithm however has a limited side-by-side efficacy for real-time BMS due to the idle period requirement.

Due to the inability of these legacy systems to robustly handle the non-linear and dynamic behaviors of modern high-power EV packs, especially under load and varying temperatures, other techniques such as the Equivalent Circuit Models (ECM), the Kalman filter–based methods, and Artificial Neural Networks (ANN) have been used to address this problem. The ECM is the most popular model-based estimation used in commercial BMS [219,223] as they sufficiently balance accuracy and computational efficiency, enabling real-time application in EVs. The Kalman filter–based methods, although not as popular, are the gold standard in automative BMS for real-time, dynamic SoC estimation due to their capability to update in real time, correct for model/measurement noise, and fuse information from noise. Their performance is thus highly dependent on accurate initializations and noise parameter tuning [224].

Like SoC, there are several algorithms that are used to predict the state-of-health (SoH) of li-ion batteries which is crucial for predictive maintenance, warranty, and safe operation. Common model-based SoH estimation techniques are the Empirical/Equivalent Circuit Model–Based (ECM) and the Physics-Based/Electrochemical Models. These models are beneficial due to their interpretability and can easily be linked to known degradation phenomena [223,225,226]. They however adapt poorly to cross-chemistry and are susceptible to modeling errors. Machine learning techniques such as support vector machines (SVM), random forest, XGBoost, and Gaussian process regression are also being used for SoH estimation. These systems, according to Xu et al. [227] employ feature-based machine learning via convolutional networks, which automatically extract aging-sensitive features from raw voltage/current/temperature data. Also, due to the scarcity of labeled SoH data in vehicles, self-supervised and semi-supervised learning have emerged. This approach employs unlabeled operational data for self-supervised learning with generative (masked reconstruction) and contrastive tasks [225]. It is also interesting to note that in recent dual-timescale, self-supervised deep learning frameworks have achieved SoH estimation RMSE of below 1% with less than 2% labeled data, outperforming traditional supervised ML and model-based methods—especially under shallow cycles mirroring real-world EV usage [226,227].

Equipment manufacturers are continuously faced with the challenge of finding the delicate balance between battery performance, safety, and longevity of li-ion batteries. To prevent hazards such as lithium plating, thermal runaway, and premature degradation, manufacturers must work with strict quantitative thresholds regarding charging and discharging currents, operational temperatures, and mechanical limits. According to recent studies [228,229], most manufacturers limit fast-charging rates to ≤ 1C, as going above this rate at room temperature causes lithium plating, especially as the battery ages or deviates from ideal state-of-charge (SoC) conditions. For temperature limits, major manufacturers and industry standards stay within 0 °C to 45 °C for safe charging [230]. Charging below 0 °C increases the chances of plating while going above 45 °C causes SEI layer degradation, electrolyte decomposition, and plating via secondary mechanisms. The structural stiffness of the battery and how well the cell maintains geometrical and structural dimensions as a function of temperature and SoC is quantified by its modulus. According to Krause et al. [228], graphite anodes experience up to 13% volume expansion during full (de)lithiation, corresponding to ~4.2% thickness increase (from fully discharged to fully charged). The effect is however smaller (~1–3% contraction) in nickel manganese cobalt and lithium iron phosphate cathodes.

Due to the high thermal sensitivity of LIBs and their structure, maintaining stable operation and extending the battery’s lifespan is a crucial function of the battery thermal management system [231,232,233]. Therefore, effective thermal management is essential for enhancing battery safety, longevity, and preventing degradation, usually involving heat-resistant materials and reliable cooling technologies [234]. Since the optimal operating temperature range is 20–40 °C, Zhao et al. [201] suggests that this narrow limit requires precise thermal management to avoid productivity loss, accelerated aging, and safety risks. Consequently, ensuring an even temperature distribution across all cells in the battery pack is equally important because significant temperature differences can lead to unbalanced degradation and reduce the pack’s lifespan [235,236]

This section would be incomplete without discussing the innovations and challenges related to fast-charging Li-ion batteries in EVs. The primary goal in fast charging LIBs for EVs is to reduce charging time while maintaining the batteries’ lifespan, safety, and energy storage capacity. This requires a careful balance between higher current densities to enable rapid ion intercalation and the suppression of harmful side reactions, such as lithium plating, which can occur during fast charging [237]. According to Mandrile et al. [238] achieving this balance is essential for consumer acceptance, as drivers expect charging times comparable to those of cars with internal combustion engines.

Therefore, more advanced battery chemistry and thermal management, along with improved charging algorithms, are being developed to address current issues in fast charging. Tackling range anxiety and enhancing user convenience are the primary drivers behind the advancement of fast charging technology in EVs, as charging time remains the primary obstacle to widespread adoption [239,240,241,242]. Additionally, fast charging technology for EVs faces challenges such as harmonics generation, control complexity, and cost [243]. Overcoming these issues requires innovations in power electronics, BMS, and grid integration to support efficient and reliable fast-charging infrastructure.

Lastly, a review by Khan et al. [241] highlights the challenges involved in planning for infrastructure, power quality, and network loading when integrating EV charging into the existing electricity grid. Nonetheless, an integrated energy system also offers opportunities for additional grid services, such as ancillary services, reactive power support, load balancing, and especially vehicle-to-grid technology. However, the strong and stable electrical supply required by large-scale EV charging could strain the current utility grid and potentially lead to overloads in the distribution power system [244]. This has been shown to increase electricity demand, particularly during peak charging times, which can cause voltage instability, reduced reserve margins, and reliability issues in the power grid [245]. To address these grid-level challenges, new charging strategies and advanced energy management systems are being developed to optimize power flow and minimize strain on the infrastructure system [246].

10.2. Consumer Electronics Applications

This section discusses the widespread use of LIBs in various consumer electronic devices, from portable communication tools to high-performance computers. Li-ion batteries have a significant impact on consumer electronics, and with their advent, many battery-powered devices are now cordless and lightweight, making them easier to carry and use. Additionally, their excellent energy storage capacity and efficient power delivery have become essential for the continuous operation and integration of these devices into daily life. This advantage has been explained in some works as being due to their high energy density, long service life, and environmental friendliness, which together meet the urgent needs of modern portable society for reliable, long-lasting power sources. Shinde et al. [190] argue that this technological breakthrough has not only enabled the miniaturization of electronic devices but also greatly extended the operating time on a single charge, creating new milestones in user comfort and gadget autonomy.

The use of Li-ion batteries for commercial purposes has significantly changed daily life, making portable electronic devices popular and transforming communication, entertainment, and medical science. The widespread use of Li-ion batteries in portable electronic devices (e.g., mobile phones, laptops) is due to their high energy density and cycling stability [195,247]. Their pervasive presence in consumer electronics has made the Li-ion battery a key part of modern mobile lifestyles, with billions of units produced each year to satisfy the growing global demand for portable products. As a result, Masias et al. [248] argue that the remarkable development of semiconductors and computers has been equally driven by the parallel evolution of LIBs technology, which has enabled the modern Information Age.

10.2.1. Compact Form Factor and Energy-to-Weight Ratio

With LIBs being widely and increasingly used in consumer electronics, including smartphones and wearables, it is crucial to maximize energy density, especially within limited volumetric and gravimetric constraints [193]. This goal guides research into new and improved electrodes and cell designs that maximize energy storage per unit mass and volume. As some authors [249,250] report in Arote [199], this is particularly important for portable devices, where user acceptance often depends on size and weight; however, this should not compromise the device’s operating life. Engineers are thus challenged to develop cell architectures that optimize volumetric efficiency while satisfying thermal management and safety requirements.

Furthermore, in the quest for higher energy density, it is common to also aim for increased capacity of electrode materials and to optimize operating voltages. However, this approach introduces new challenges related to material stability and electrolyte compatibility [251]. As noted by Chen et al. [252], these considerations have expanded the practical applications of Li-ion batteries, such as for EVs and grid-scale energy storage in emerging markets, where energy density directly impacts range and efficiency. Pursuing higher energy density requires balancing trade-offs between energy capacity, power output, and most importantly, safety—especially as cell and energy levels grow. This has driven significant efforts to develop new anode and cathode materials with high specific capacities to prolong battery life and enhance electrochemical stability. Consequently, research has increasingly focused on creating advanced anode and cathode materials, along with improved electrolytes and separators, to boost the overall performance and safety of batteries [253].

For example, high-nickel cathode materials have high energy density but can experience complex chemical and structural degradation during long-term cycling, which limits their stability [254]. Given these material limitations, Wang et al. [255] shows that a key design guideline for consumer electronics is the selective use of advanced materials, which can address these issues while still providing an acceptable energy density for real-world applications. This includes developing new electrode architectures and electrolyte formulations that accommodate volume changes in high-capacity materials and enhance the stability of the solid electrolyte interphase [256]. These advancements are crucial for unlocking the full potential of Li-metal anodes in next-generation batteries, despite some challenges.

10.2.2. Recent Advancements in Fast Charging and AI-Enabled Battery Optimization

Real-time battery health monitoring, using AI and machine learning, is widely employed for predictive maintenance and energy distribution optimization in complex systems [257]. These advances are essential for meeting consumer demand for fast charging while also extending device lifespan through innovative charging management and predictive maintenance. Burden prediction based on usage and environmental profiles supports real-time charging protocol optimization, reducing degradation pathways and maximizing cell life. This involves applying machine learning to accurately estimate State-of-Health and State-of-Charge, as described by Cavus et al. [257] which is necessary for optimal battery performance and safety throughout its lifespan.

Such predictive capabilities with adaptive charging algorithms enable the optimization of charging cycles based on the condition of batteries, which extends battery life and improves charging efficiency [215]. Zhao et al. [201] consider such advanced data-driven techniques essential not only for predicting battery failure and optimizing charging protocols but also for modeling safety aspects, opening a promising new path for truly predictive, high-fidelity numerical simulations of LIBs. Onyenagubo et al. [258] demonstrate that machine learning-based models are effective in predicting remaining useful life by analyzing the complex relationships between charge/discharge cycles, temperature, and voltage. These factors, which are often not captured by traditional empirical models across different operating conditions, are investigated. Such predictive models are crucial for developing proactive battery management systems that can forecast potential problems before they lead to failures, thereby enhancing battery safety and reliability across various applications [201,258].

This kind of predictability benefits both business and the environment by reducing the environmental impact of battery production and disposal. A key part of this process is the development of battery digital twins, or cyber-physical systems that combine models, data, and artificial intelligence to make batteries smarter and more durable [259]. Several other studies [201,258,260] view this approach as a way to enable real-time monitoring and simulation of battery performance, helping manufacturers and users predict degradation and take preventative measures. These digital twins employ advanced sensing and communication technologies to gather detailed data on the battery’s condition and feed this information into sophisticated AI models for maintenance and operational decisions [261,262,263].

According to Safavi et al. [264], this real-time two-way communication between the physical battery and its digital twin enables a higher level of predictive accuracy in battery behavior across various operational scenarios and optimizes charge strategies to extend battery life. That is to say, by dynamically adjusting charging parameters, identifying potential problems, and addressing them even before incidents occur, the mechanism creates a strong framework for advanced battery management [259]. These advanced digital twins are increasingly integrated with cloud computing platforms to process large datasets from multiple batteries in real-time, which improves prediction models and allows fleet-level optimization schemes [265]. Additionally, these digital twin models are not just predictive tools but also facilitate the coordination of the entire battery value chain, including production, second-life applications, and recycling efforts [266]. Essentially, combining these AI-supported battery management systems enables accurate prediction of their lifespan, which is vital for effective battery development and the transition to zero-emission mobility to ensure sustainability.

10.3. Aerospace Applications

This section discusses common uses of LIBs in aerospace, especially as electric power becomes more prominent in aviation. It includes applications like controlling drones, satellites, and electric aircraft, which use materials that are dense yet lightweight for manufacturing. A separate section is dedicated to drones and UAVs because they are among the fastest-growing and most diverse uses of LIBs in the aerospace industry.

10.3.1. General Aerospace Use-Cases

The significant rise in demand for eco-friendly aviation and improved operational efficiency has made LIBs a key component in the electrification of many aerospace applications. Their high energy density, long cycle life, and fast charge–discharge capabilities make them well-suited for a wide range of demanding aerospace uses, from commercial planes to unmanned aerial vehicles (UAVs) [188,267,268]. As Zubi et al. [191] point out, this widespread applicability highlights their potential to significantly reduce carbon emissions and lower costs in the air transport industry. However, some authors [269,270] raise safety concerns about LIBs, particularly regarding thermal runaway and fire risks, which necessitate strict safety measures and advanced thermal management for use in aerospace systems.

Ensuring the safety and reliability of these batteries under normal and abnormal conditions remains a major concern, requiring advanced thermal management to prolong their lifespan and prevent catastrophic failures. Lamb & Jeevarajan [271] consider this a critical issue in aerospace due to limited space, high power demands, and the serious consequences of system failure. This calls for multidisciplinary solutions to mitigate risks at the component, cell, and system levels. Additionally, the high energy stored in large battery packs—ranging from tens of kilowatt-hours in urban air mobility to thousands in commercial aircraft—requires careful attention to safety issues specific to aviation. According to Bhatt & O’Dwyer [272], this high energy potential is vital for aeronautical applications because it directly affects an aircraft’s range and payload. Meanwhile, its lightweight nature is key to improving efficiency and reducing fuel consumption. The substantially higher energy density per weight of modern batteries compared to older chemistries has enabled their use in contemporary aircraft, such as the Boeing 787 Dreamliner, where batteries perform functions ranging from engine starting to emergency backup power [268].

Currently, many of the above applications rely on auxiliary power as ongoing advancements in LIBs, especially in energy density and safety, are progressing for use in electric and hybrid-electric aircraft propulsion systems [273]. These large battery packs are vital in a wide range of modern aircraft designs, from “more electric” to “fully electric” configurations. According to Sripad et al. [274], this raises significant safety concerns specific to aviation, mainly involving exothermic heat events and the risk of partial or total loss of a safety-critical power supply. Therefore, designing advanced battery management systems with precise state-of-charge (SoC) and state-of-health (SoH) estimation, along with advanced thermal management technologies, is crucial for ensuring safe and reliable operation throughout the aircraft’s operational regime [271].

10.3.2. Drones and UAVs

Unlike satellites or manned aerial vehicles, drones and UAVs significantly differ in size, payload, and mission types. This includes photo quadcopters, large-scale military UAVs, and air-delivery drones. These applications have unique battery requirements, such as high power-to-weight ratios, rapid charging, and stable performance amid environmental changes like temperature, wind, and altitude. The growing need for extended endurance and high power-to-weight ratios in UAVs (Unmanned Aerial Vehicles) has further promoted the use of lithium batteries as a key technology for small and medium-sized drone platforms. This is mainly due to their high energy density, high voltage, and wide operational temperature range—important factors for aerial platforms [268,275]. According to Fei et al. [276], the longer lifespan and low self-discharge rate of Li-ion batteries also significantly enhance operational performance and maintenance cycles, surpassing those of traditional chemistries such as lead-acid or nickel-metal hydride batteries.

However, their use in drones also faces significant challenges, particularly regarding safety, as the cell could easily experience thermal runaway under extreme conditions (e.g., rapid charge/discharge cycles or mechanical stress) [267,270]. Other applications, such as monitoring and delivery, highlight the need to maximize flight time—usually between 20 and 40 min—by improving battery performance [277]. Dost et al. [278] found that ambient temperature significantly affects the drone’s operating range, especially in extreme cold or heat, which impacts battery performance by reducing capacity, increasing internal resistance, and speeding up self-discharge rates. This is especially crucial for missions in diverse climates since a battery’s failure to perform optimally greatly reduces flight endurance and increases the risk of mission failure [277]. For instance, cold temperatures notably hinder the electrochemical processes in Li-ion cells, temporarily lowering available capacity and power [279].

On the other hand, high temperatures initially seem to boost performance by reducing internal resistance. As Li et al. [280], this significantly accelerates degradation by opening pathways such as SEI growth and active material dissolution, which also shortens the overall device lifespan. These environmental sensitivities highlight the need for smart and adaptable thermal systems that keep the battery within its ideal temperature range, regardless of external conditions, thus ensuring optimal performance and durability. Efficiency and lifespan can also decline due to natural responses to temperature changes, making effective thermal management essential [281]. The high-power demands of UAVs require batteries capable of delivering over 100 A for extended periods, as noted by Pernía et al. [282] which further complicates thermal management strategies. This necessitates advanced battery management systems that precisely monitor cell temperatures and voltages to prevent overheating and maintain an optimal discharge rate, thereby reducing fire hazards.

Additionally, the rapid recent advancements in onboard computing and AI in drones demand more reliable power delivery systems, since these advanced functions consume energy intensively [283]. Boroujerdian et al. [284] argue that designing effective power management units capable of automatically adjusting to changing computational workloads and external conditions will be crucial for optimizing drone utility and reducing mission failure risks. However, due to the inherent high energy and power density, as well as the long cycle life of Li-ion batteries, they continue to be the most commonly used energy storage devices for current UAVs, despite ongoing thermal management and weight challenges.

10.4. Comparative Analysis Across Industries

This comparative study highlights (Table 12) the applications of LIBs, focusing on industry-specific customization in the automotive, consumer electronics, and aerospace sectors. While sharing common principles of electrochemistry, each sector has unique performance needs: high energy density and fast charging for EVs, compactness and long life for consumer electronics, lightweight design and high reliability for aerospace applications. The comparative requirements analysis reveals the technological innovations and breakthroughs driving progress in each area, as well as synergistic opportunities where advances can be combined and integrated. Table 12 summarizes these findings.

Table 12. Lithium-ion battery comparison across industries.

Parameter	Automotive (EVs)	Consumer Electronics	Aerospace
Capacity (kWh)	Approx. 20–100+ kWh packs (e.g., Nissan Leaf ~24 kWh; Tesla Model S ~85 kWh) [285]	Approx 10–15 Wh for smartphones and ~50 Wh for laptops [285]	Ranges between 10 and 100 kWh (small satellite), 10–500 kWh (electric Aircraft/UAVs) [286,287]
Energy density (Wh/kg)	Between 120 and 220 [288,289,290]	Approx. 150–330 [291]	Between 130 and 250 (current Li-ion cells) [292]
Cycle life (cycles)	Approx 1000–2000 cycles [293]	Approx 300–800 cycles [294]	Between 9000 and 26,000 cycles, depending on cell type and test duration [295]
Safety	Robust BMS and cooling are used, but thermal runaway (fire) risk remains [296]	Devices are limited to <100 Wh (FAA limit) and include protective circuitry, but overheating/short-circuit hazards exist [296]	Highest safety standards and qualification; NASA guidelines emphasize hazard control for Li-ion (flammable electrolyte) [287]
Cost ($/kWh)	Estimated at $130/kWh for EV packs (2023 data) [297]	Estimated at $200/kWh for small-scale cells [285]	Specialized (often >> $1000/kWh) Varies based on qualification testing, safety protocols, and mission-specific design constraints [287]
Weight (kg/kWh)	Between 6 and 8 kg/kWh (EV pack) [298]	Mostly between 0.1 and 0.2 kg, depending on size and capacity [299]	Between 4 and 7.7 kg/kWh in specific energy, depending on design and cell chemistry [292]

11. Supply Chain and Recycling Challenges of LIBs

LIBs are crucial in modern technology, powering consumer devices, energy systems, and EVs. However, the rapid global demand has revealed supply chain challenges that hinder scalability, sustainability, and resilience. A key issue is securing and sourcing essential raw materials, including lithium. The global demand for lithium increased by 500% between 2007 and 2022, mainly driven by electric vehicle growth, with 75% of its mine production concentrated in Australia and Chile. China also dominates over 65% of refining and cell manufacturing capacity [26,300]. This regional dominance poses systemic risks of supply chain disruption and vulnerability to geopolitical tensions and trade restrictions for nations heavily reliant on these sources, representing a significant strategic risk [301,302]. Despite initiatives like the Inflation Reduction Act (IRA) and the Bipartisan Infrastructure Law (BIL), scale-up and assurance of cost and quality remain ongoing challenges [303,304]. Extracting lithium from hard-rock deposits and brines is water and energy-intensive and has been linked in the literature to aquifer depletion and ecological disruption in arid regions.

On the manufacturing scale, bottlenecks from mining to cell manufacturing and pack assembly remain a major concern. From a logistics standpoint, strategic placement of manufacturing facilities is crucial, but threats such as resource availability, transportation issues, safety measures, permits, and production delays are significant—especially when supply chain disruptions extend across multiple continents [305]. Additionally, recycling offers another opportunity to lessen raw material dependency. However, high costs, variable recovery efficiencies, regulatory uncertainties, lack of standardization, and the fact that only a small percentage of EOL batteries are efficiently recovered into battery-grade materials [306,307].

Ensuring a resilient and sustainable LIB supply chain requires a multi-pronged strategy that addresses the geographical concentration of resources, environmental and ethical risks, manufacturing bottlenecks, policy coordination, logistical constraints, and technological innovations—key factors in maintaining a resilient and sustainable global battery industry [308].

Direct recycling needs to address several challenges such as various material inputs, stability issues, and the quality of LIBs recovered, before being fully implemented in practice. Future investments and research efforts will play a crucial role in accomplishing efficient and sustainable solutions because recycling of EOL LIBs is still in early stages. This not only recovers valuable metals such as Co, Ni, and Li from the electrode materials but also properly disposes of other substances that are averse to the ecosystem. This consequently maximizes recovered components and minimizes environmental pollution. Some of the other non-technical factors such as retired batteries storage, transportation, lack of regulations, and standards also have a significant impact on the LIBs recycling.

Recent policy frameworks highlight five policies mechanisms as particularly crucial to accelerate this transition. The transition to a circular battery economy over the next decade requires coordinated policy actions that address the design, production and end-of-life management (value chain of lithium-ion batteries).

To begin with, Extended Producer Responsibility (EPR) mandates that manufacturers fund and manage collection, recycling, and safe disposal thereby internalizing and incentivizing design improvements that facilitate recyclability [309]. The U.S Environmental Protection Agency 2023 (EPA) recognizes EPR as a fundamental element in its sustainable battery management framework [310]. Comparable EPR programs within the electronics industry have demonstrated potential to enhance collection efficiency by 30–40% within five years [309]. Second, mandatory collection and recycling targets offer regulatory certainty and drive investment in recycling infrastructure. The European Union’s Batteries Regulation (2023) projects binding collection rates of 63% and 73% by 2027 and 2030, respectively, along with minimum recycling efficiencies for lithium (50% and 80% by 2027 and 2031, respectively), nickel and cobalt [311,312].

Third, eco-design and carbon footprint standards are essential for embedding circularity at the design stage. Standardized battery datasheets and digital passports enhance traceability and logistics by providing details regarding battery chemistry, manufacturer, state-of-health (SoH) which facilitates safer disassembly and more efficient recycling processes. The EU regulation mandates disclosure of carbon footprint and recycles content thresholds (such as 6% lithium, 16% cobalt, 6% nickel) by 2031, hence driving innovation in low-impact chemistries and recycling-friendly designs [312].

Fourth, supply chain transparency and due diligence are essential to ensure circularity does not compromise social and environmental sustainability. Uniform quality standards for black mass such as ≥95% metal-oxide purity and <2% moisture content, facilitate industrial scalability, global trade, and interoperability among recycling facilities. The IEA emphasizes transparent reporting frameworks to secure critical minerals while upholding fair competition and public trust which also help mitigate unsustainable mining practices and human right violations in resource-high regions [313].

Finally, public investment and incentives accelerate commercialization of circular technologies. Policy incentives aimed at DLE with brine reinjection can reduce water consumption by up to 90% in arid salars while maintaining lithium recovery rates at above 80% thereby aligning primary production with environmental, social, and governance (ESG) objectives. In the US, the Infrastructure Investment and Jobs Act under the DOE designated in March 2024 funding for 17 projects in the area of battery recycling, reprocessing, and collection initiatives and research and development innovations [314]. These policies (EU, IEA, U.S. EPA) are implemented from a coherent policy framework thereby facilitating the scaling of circularity in the battery sector within the next decade. In summary, these cohesive policy frameworks strengthen supply chain transparency, bolster material security, diminish environmental impacts, and position lithium circular management as important in the global transition towards sustainable energy.

Safety measures for secondary use of LiB are closely tied to national or regional policy frameworks as shown in Table 13. The EU battery regulation (2023) requires conformity assessment, mandatory collection targets, recycling efficiencies, carbon-footprint disclosure, standardized information exchange via digital battery passports, and reporting obligations. This provision ensures that repurposed batteries meet verified state-of-health, module compatibility, safety, performance standards and traceability of prior use which are core determinants if second-life safety [312,315]. In the United States, asides from prescriptive regulation, its policies also promote programmatic instruments. The EPA and DOE emphasize safety through initiatives under the Infrastructure Investment and Job Acts, by funding demonstrations projects that integrate end-of-life EV batteries into stationary storage and guidance, refurbishments and installation supported by the National Blueprint for Lithium Batteries 2021–2030. In addition, achieving certification under UL 1973, UL 9540, and UL 9540A are essential for companies in the battery repurposing market [316]. In the Asia region, China, through the Ministry of Industry and Information Technology (MIIT) of the People’s Republic of China (MIIT Interim Measures 2018), (GB/T 36276,36545;2023) mandated automakers to establish collection channels and ensure safe reuse, or recycling which is supported by national standards which requires, dismantling protocols, fire safety, state-of-health testing and transport compliance [317,318]. Other countries, such as Japan, under the Act on the Promotion of Effective Utilization of Resources and Ministry of Economy, Trade and Industry (METI) guidelines [319,320,321], and South Korea, through its Resource Recycling Act, emphasize refurbishment standards, safe reuse, recycling, conformity, fire codes and traceability [322,323]. In the African continent, Nigeria and other African countries, in partnership with United Nation Environment Programme (UNEP), support circular economy for electronics and battery initiatives, focusing on safe electronic waste handling, controlled imports of used EVs, and financing circular economy projects under the Africa Circular Economy Facility, which aligns with the African Development Bank’s ten-year strategy (2024–2033) [324,325,326]. These regions and nations converge on core safety enablers such as standardized state-of-health testing, safe refurbishment protocols, diagnostic verification, interoperable battery management system integration and system-level hazard mitigation (such as emergency response, fire codes, ventilation) [314,315].

Table 13. Global Safety measures and policies for secondary use of LiB.

Region	Policy Mechanism	Safety Measures	Ref.
European Union	EU Batteries Regulation (2023)	Conformity assessment, mandatory collection/recycling targets, carbon-footprint disclosure, digital battery passports, reporting obligations	[312]
United States	Infrastructure Investment and Jobs Act; EPA/DOE initiatives; National Blueprint for Lithium Batteries 2021–2030	Funded pilots for second-life storage; refurbishment and installation guidance; certification under UL 1973, UL 9540, UL 9540A	[310,314,327]
China	MIIT Interim Measures (2018); national standards GB/T 36276,36545;2023	Mandatory collection/reuse by automakers; SOH testing; dismantling protocols; fire safety; transport compliance	[317,318]
Japan	Act on the Promotion of Effective Utilization of Resources; METI guidelines	Diagnostics and refurbishment standards; conformity to JIS safety codes; integration into renewable energy storage	[319,320,321]
South Korea	Resource Recycling Act; Korea Energy Agency pilots	Extended Producer Responsibility; SOH testing; fire codes; traceability and liability frameworks	[322,323]
Nigeria/Africa	UNEP Circular Electronics Initiative (2019); AfDB Africa Circular Economy Facility (2022); ACEA regional alliance	Safe e-waste handling; controlled imports of used EVs; financing circular economy projects; emerging battery reuse pilots	[324,325,326]

12. Conclusions

LIBs are essential for the global energy transition, supporting the rapid growth of consumer electronics, EVs, and energy grid storage systems. The review underscores the importance of accessing lithium from diverse sources such as Salar, geothermal waters, oilfield brines, hard-rock deposits, and clay-hosted resources for LIB success. It explains how extraction technologies have progressed from traditional methods like evaporation and acid leaching to innovative, sustainable techniques such as direct lithium extraction (DLE) and electrochemical methods, which reduce water use, speed up processing, and lessen environmental impacts. This paper reviews recent developments in LIBs and advances in recycling methods and techno-economic considerations (CAPEX/OPEX), impurity management, and regulatory benchmarks for effluent emissions. In the industry, LIBs are now widespread at an unprecedented scale, with a market exceeding $400 billion. Their extensive applications have highlighted significant vulnerabilities in the supply chain, which are complex and multifaceted. A case study details an emerging lab-scale direct lithium extraction system developed by BESI. BESI’s thermal recycling method offers modular deployment, improved energy recovery, and supports circular lithium supply chains. The role of battery chemistry plays a vital role for the LIB’s future as it regulates the key attributes such as energy density, longevity, cost, and safety. Researchers are also exploring other alternatives for LIBs, such as sodium-ion (Na-ion) batteries that offer lower cost, higher abundance, lower cost, and superior cold-weather performance. Nevertheless, advances in battery chemistry improvements, which include, development of novel cathode materials, advances in additives and electrolytes (solid state and gel-based), and integration of nanomaterials can address the challenges of conventional LIBs and further enable LIBs to remain as a cornerstone of the global battery industry. The review also emphasizes the urgent need to address challenges like raw material shortages, geopolitical control of refining, inadequate recycling infrastructure, and environmental concerns. It discusses the critical role of technological innovation in extraction, large-scale deployment, and coordinated policy efforts. Ultimately, creating a circular battery economy prioritizing recycling and secondary use is vital to reducing resource demands and strengthening supply chain resilience. This review offers valuable insights for researchers, policymakers, and industry leaders aiming to advance LIB technology sustainably economically and responsibly.