Search Results (127)

The exponential growth of lithium-ion batteries (LIBs) in electric vehicles and energy storage systems has amplified the urgent need for sustainable recycling strategies. Conventional pyrometallurgical and hydrometallurgical methods for LIB recycling are energy-intensive, chemically demanding, and fail to preserve the structural integrity of cath-ode materials. Closed-loop recycling, in contrast, enables the recovery of layered oxides with minimal processing steps, reducing environmental footprint and supporting a circular economy. This study provides a systematic comparison of two regeneration approaches—sol–gel synthesis and hydroxide co-precipitation—for closed-loop recycling of layered NCM (LiNi_xCo_yMn_zO₂) cathode materials recovered from spent LIBs. Spent cells were mechani-cally processed and leached using malic acid to recover Ni, Co, Mn, which were subsequently used to synthesize NCM622 cathode powders. The regenerated materials were characterized using SEM/EDX, XRD, and electrochemical testing in CR2032 coin cells. Both methods successfully produced phase-pure layered oxides with the R-3m structure, with distinct differences in structural ordering and electrochemical behavior. The sol–gel-derived NCM622 displayed higher crystallinity and reduced cation mixing, evidenced by an I(003)/I(104) ratio of 1.896 compared to 1.720 for the co-precipitated sample, and delivered a high initial discharge capacity of 170 mAh/g at 0.1 C. However, it exhibited significant capacity fade, retaining only 60 mAh/g after 40 cycles. In contrast, the co-precipitation route produced hierarchical porous spherical agglomerates that offered superior cycling stability, maintaining ~150 mAh/g after 40 cycles with lower polarization (ΔE_p = 0.16 V). Both materials demonstrated electrochemical performance comparable to commercial NCM. Overall, hydroxide co-precipitation emerged as the most industrially viable method due to scalable processing, compositional robustness, and improved long-term stability of regenerated cathodes. This work highlights the critical influence of synthesis route selection in LIB closed-loop recycling and provides a technological framework for industrial recovery of high-value NCM cathode materials. Full article

The recycling of spent lithium-ion batteries (LIBs) requires efficient and sustainable methods for recovering critical metals. In this study, the leaching behavior of LiCoO₂ cathode material obtained from spent LIBs was investigated in phosphoric acid, using copper powder recovered from waste LIBs as a reducing agent. Leaching experiments were conducted under various conditions (temperature, solid-to-liquid ratio, agitation rate) and compared with systems without copper. In the absence of copper, lithium and cobalt, recoveries after 30 min were approximately 77% and 23%, respectively. The addition of copper significantly enhanced leaching, achieving >96% recovery for both metals at 80 °C, with most extraction occurring within the first 30 min. Kinetic analysis using the shrinking core model indicated a mixed-control mechanism involving both surface chemical reaction and product layer diffusion. The calculated activation energies were 20.2 kJ·mol⁻¹ for lithium and 16.1 kJ·mol⁻¹ for cobalt. Solid residues were characterized by X-ray diffraction (XRD) and scanning electron microscopy with energy-dispersive spectroscopy (SEM-EDS). XRD results revealed that the composition of the residues varied with leaching temperature: Co₃O₄ was consistently detected, whereas Cu₈(PO₃OH)₂(PO₄)₄·7H₂O appeared only when leaching was performed above 50 °C. Thermodynamic calculations supported the reductive role of copper and provided insight into possible reaction pathways. These findings confirm the effectiveness of copper-mediated leaching in phosphoric acid and demonstrate that temperature strongly influences residue phase evolution, thereby offering valuable guidance for the design of sustainable LIB recycling processes. Full article

The growing demand for lithium-ion batteries (LIBs) is driving a rapid increase in the volume of spent cells which—as hazardous waste—must be managed effectively in accordance with circular-economy principles. Hydrometallurgical recycling allows the recovery of critical metals at far lower environmental cost than primary mining. This paper presents a method for obtaining metallic nickel from sulfate leach solutions produced by leaching the so-called “black mass” derived from shredded LIBs. Nickel electrodeposition was performed on a stainless-steel cathode with Ti/Ru-Ir anodes at 60 °C and pH 3.0–4.5. Two process variants were examined. Variant A—with a decreasing Ni²⁺ concentration (49 → 25 g L⁻¹)—achieved a current efficiency of 60–88%, but the deposits were non-uniform and prone to flaking. Variant B—in which the bath was stabilized by the continuous dissolution of Ni(OH)₂ (maintaining Ni²⁺ at 35–40 g L⁻¹) and amended with PEG-4000, H₃BO₃ and Na₂SO₄—reached higher efficiency (78–93%) and produced uniform, bright deposits up to 0.5 mm thick with a purity >90%. The results confirm that keeping the nickel concentration constant and appropriately modifying the electrolyte significantly improve both the qualitative and economic aspects of recovery, highlighting electrolysis as an efficient way to process LIB waste and close the nickel stream within the material cycle. Full article

The escalating production and use of lithium-ion batteries (LIBs) have led to a pressing need for efficient and sustainable methods for recycling valuable metals such as cobalt, nickel, manganese, and lithium from spent cathode materials. Traditional hydrometallurgical leaching approaches, based on mineral acids, face significant limitations, including high reagent consumption, secondary pollution, and poor selectivity. In recent years, deep eutectic solvents (DESs) and ionic liquids (ILs) have emerged as innovative, environmentally benign alternatives, offering tunable physicochemical properties, enhanced metal selectivity, and potential for reagent recycling. This review provides a comprehensive analysis of the current state and prospects of leaching LIB cathode materials using DES and ILs. We summarize the structural diversity and composition of common LIB cathodes, highlighting their implications for leaching strategies. The mechanisms, efficiency, and selectivity of metal dissolution in various DES- and IL-based systems are critically discussed, drawing on recent advances in both laboratory and real-sample studies. Special attention is given to the unique extraction mechanisms facilitated by complexation, acid–base, and redox interactions in DES and ILs, as well as to the effects of key operational parameters. A comparative analysis of DES- and IL-based leaching is presented, with discussion of their advantages, challenges, and industrial potential. While DES offers low toxicity, biodegradability, and cost-effectiveness, it may suffer from limited solubility or viscosity issues. Conversely, ILs provide remarkable tunability and metal selectivity but are often hampered by higher costs, viscosity, and environmental concerns. Finally, the review identifies critical bottlenecks in upscaling DES and IL leaching technologies, including long-term solvent stability, metal recovery purity, and economic viability. We also highlight research priorities that emphasize applying circular hydrometallurgy and life-cycle assessment to improve the sustainability of battery recycling. Full article

The recovery of critical metals from spent lithium-ion batteries (LIBs) is essential to reduce environmental impacts and promote circular economy strategies. This study developed a sustainable and scalable process for the recovery and complete valorization of lithium, cobalt, and other valuable components from end-of-life LIBs. Hydrometallurgical treatment using biodegradable citric and oxalic acids was employed as a green alternative to conventional inorganic acids, achieving high selectivity and reduced environmental impact. Experimental work was conducted on 3 kg of LIBs from discarded laptop batteries (Dell and HP). After safe discharge and dismantling, the cathode materials were thermally treated at 300 °C to detach active components, followed by acid leaching in 1 M citric acid at 30 °C, pH 2.5, and 6 h of reaction. Lithium and cobalt were recovered as oxalates with efficiencies of 90% and 85%, respectively, while copper, aluminum, and graphite were separated through mechanical and thermal processes. Beyond metal recovery, the process demonstrates a circular upcycling approach, transforming recovered materials into functional products such as aluminum keychains, copper jewelry, and graphite-based pencils. This integrated strategy connects hydrometallurgical extraction with material reuse, advancing toward a zero-waste, closed-loop system for sustainable LIB recycling and local resource valorization. Full article

During the recycling process of spent lithium-ion batteries (LIBs), there is a large number of fluoride ions in the leaching solution. These fluoride ions not only affect the quality of lithium products, but they also have adverse effects on the environment. Therefore, the efficient and deep removal of the characteristic pollutant fluoride ions is currently a hot topic in the field of recycling spent LIBs. In this study, a porous zirconium-based adsorbent was prepared and its adsorptive properties were characterized. Due to the excellent affinity between zirconium and fluorine, the zirconium-based adsorbent exhibited excellent adsorption performance in the leaching solution of spent lithium iron phosphate (SLFP) batteries. Under the optimal adsorption conditions, the adsorption capacity reached 113.78 mg/g, and it surpassed most commercial adsorbents. The zirconium-based adsorbent followed the Langmuir isotherm model for fluoride adsorption with correlation coefficients consistently exceeding 0.95, and exhibited pseudo-second-order kinetics, demonstrating goodness-of-fit values above 0.998. The negative Gibbs free energy change thermodynamically confirms the spontaneous nature of the adsorption process. The structure of the adsorbent before and after adsorption was characterized, and the adsorption mechanism was elaborated in detail. Furthermore, the influence of the coexistence of different anions on the adsorption of fluoride ions by zirconium-based adsorbent was studied in a real leaching solution from SLFP calcine. This study provides a feasible approach to deep defluoridation for leachate from spent LIBs, and has the advantages of simple operation and high adsorption capacity. Full article

With the increasing adoption of lithium-ion batteries (LIBs) as the batteries of choice in electromobility, personal electronic devices, and so on, comes the challenge of ageing, which prevents the batteries from performing optimally and meeting the design intent. This is observed in the form of declining power capability due to the increase in resistance and the reduction in capacity that can be stored or discharged from them. Unfortunately, the cost of assessing batteries after the first use remains a daunting challenge. In our work, we propose an approach that carries out fast preliminary grading based on resistance and capacity by first connecting old cells of the same chemistry and model in series with resistors to limit the branch current, then connecting the branches in parallel to equalise the voltages. A Simulink model of NCR18650PF Panasonic cells with adaptive-series resistance is compared with a fixed-series resistance and found to improve the balancing time from over 24 h to just 8 h. Electrochemical impedance spectroscopy (EIS) was carried out on the individual balanced cells between 0.1 Hz and 5 kHz so that the real impedance, imaginary impedance, absolute impedance, and phase were compared with the SOH of the cells at each frequency. Results show that the imaginary impedance in the 6.6 Hz frequency range shows a good correlation coefficient > 0.98 with the SOH, especially with a state of charge (SOC) of about 75–85% for the LCO cells. By selecting only a sample from all the cells that covers a wide range of ages and carrying out a full-capacity checkup on them, a simple correlation with the SOH and the EIS measurements for different frequencies can be used to estimate the SOH of the other cells that were connected in the same parallel connection. This is a considerable time saving in the charge and discharge time on the other cells in facilities that lack the capacity for simultaneous cycling of all cells. There are also huge energy savings in not having to cycle all the cells. Therefore, it offers a more efficient approach to grading spent cells than carrying out full capacity tests. Full article

Near-complete (>99%) dissolution of lithium and cobalt was achieved by the leaching of black mass from spent (end-of-life) lithium-ion batteries (LiBs) using 4 M H₂SO₄ or HCl at 60 °C. Raising the temperature to 90 °C did not increase the overall extraction of lithium or cobalt, but it increased the rate of extraction. At 60 °C, 2 M H₂SO₄ or 2 M HCl performed similarly to the 4 M H₂SO₄/HCl solution, although extractions were lower using 1 M H₂SO₄ or HCl (~95% and 98%, respectively). High extractions were also observed by leaching in low pulp density (15 g/L) at 60 °C with 2 M CH₂ClCOOH. Leaching was much slower with hydrogen peroxide reductant concentrations below 0.5 mol/L, with cobalt extractions of 90–95% after 3 h. Pulp densities of up to 250 g/L were tested when leaching with 4 M H₂SO₄ or HCl, with the stoichiometric limit estimated for each test based on the metal content of the black mass. Extractions were consistently high, above 95% for Li/Ni/Mn/Cu with a pulp density of 150 g/L, dropping sharply above this point because of insufficient remaining acid in the solution in the later stages of leaching. The final component of the test work used leaching parameters identified in the previous experiments as producing the largest extractions, and just sulphuric acid. A seven-stage semi-continuous sulphuric acid leach at 60 °C of black mass from LiBs that had undergone an oxidising roast (2h in a tube furnace at 500 °C under flowing air) to remove binder material resulted in high (93%) extraction of cobalt and near total (98–100%) extractions of lithium, nickel, manganese, and copper. Higher cobalt extraction (>98%) was expected, but a refractory spinel-type cobalt oxide, Co₃O₄, was generated during the oxidising roast as a result of inefficient aeration, which reduced the extraction efficiency. Full article

The rapid growth of the electric vehicle (EV) market has highlighted the critical importance of securing a stable supply chain for lithium-ion battery (LIB) resources, thereby increasing the need for efficient recycling technologies. Among these, lithium recovery remains a major challenge due to significant losses during conventional processes. In this study, a chlorination roasting process was introduced to convert Li₂O in spent LIBs into LiCl, which was subsequently evaporated for selective lithium extraction and recovery. Roasting experiments were conducted under air, vacuum, and N₂ conditions at 800–1000 °C for 1–5 h, with Cl/Li molar ratios ranging from 0.5 to 8. The optimal condition for lithium evaporation, achieving 100% recovery, was identified as 1000 °C for 5 h, with a Cl/Li molar ratio of 6 under vacuum. Following lithium removal, residual valuable metals were extracted through H₂SO₄ leaching, and the effects of acid concentration and H₂O₂ addition on leaching efficiency were examined. The air-roasted samples exhibited the highest leaching performance, while the vacuum- and N₂-roasted samples showed relatively lower efficiency; however, the addition of H₂O₂ significantly enhanced leaching yields in these cases. Full article

Driven by the growing demand for sustainable resource utilization, the recovery of valuable constituents from spent lithium-ion batteries (LIBs) has attracted considerable attention, whereas conventional recycling processes remain energy-intensive, inefficient, and environmentally detrimental. Herein, an efficient and environmentally benign separation strategy integrating dielectrophoresis (DEP) and magnetophoresis (MAP) is proposed for isolating the primary components of “black mass” from spent LIBs, i.e., lithium iron phosphate (LFP) and graphite microparticles. A coupled electric–magnetic–fluid dynamic model is established to predict particle motion behavior, and a custom-designed microparticle separator is developed for continuous LFP–graphite separation. Numerical simulations are performed to analyze microparticle trajectories under mutual effects of DEP and MAP and to evaluate the feasibility of binary separation. Structural optimization revealed that the optimal separator configuration comprised an electrode spacing of 2 mm and a ferromagnetic body length of 5 mm with 3 mm spacing. Additionally, a numerical study also found that an auxiliary flow velocity ratio of 3 resulted in the best particle focusing effect. Furthermore, the effects of key operational parameters, including electric and magnetic field strengths and flow velocity, on particle migration were systematically investigated. The findings revealed that these factors significantly enhanced the lateral migration disparity between LFP and graphite within the separation channel, thereby enabling complete separation of LFP particles with high purity and recovery under optimized conditions. Overall, this study provides a theoretical foundation for the development of high-performance and environmentally sustainable LIBs recovery technologies. Full article

Waste lithium-ion batteries (LIBs), which usually contain dangerous organic electrolytes and transition metals, including nickel, cobalt, iron, and manganese, can hurt the environment and human health. Substantial advancements have been achieved in employing high-efficiency, economical, and environmentally sustainable techniques for the recycling of spent LIBs. Converting exhausted LIBs into efficient energy conversion catalysts straightforwardly is a good strategy for addressing metal resource constraints and clean energy concerns. This transforms waste cathodes, anodes, binders, and separators from depleted LIBs into electrocatalysts free of platinum group metals for the oxygen evolution reaction (OER) and the oxygen reduction reaction (ORR). The composite, including transition metal oxide, graphene oxide, and carbon mass, will be synthesized from spent LIBs, demonstrating enhanced electrocatalytic activity. Utilizing “waste-to-energy” methods for used LIBs as catalysts would provide substantial benefits in environmental preservation and the effective production of functional materials in metal–air batteries. Full article

The growing demand for lithium-ion batteries (LIBs) has led to an urgent need for sustainable recycling strategies for spent cathode materials. In this study, a mechanochemical approach was developed for the recovery of lithium and cobalt from end-of-life LiCoO₂ cathodes using high-energy ball milling. For the first time, aluminum and carbon were employed as internal reducing agents, facilitating the in situ decomposition of LiCoO₂ into CoO, Li₂O, and metallic Co. X-ray diffraction analysis confirmed significant structural disorder, phase transitions, and the formation of CoO, AlCo, and spinel-like CoAl₂O₄. The Taguchi method was applied to optimize milling parameters, identifying 800 rpm, 60 min, and a ball-to-powder ratio of 50:1 as the most effective conditions for structural activation. Subsequent ammonia leaching under fixed conditions (3.0 M NH₃·H₂O, 1.0 M (NH₄)₂CO₃, 60 °C, 25 mL/g, 6 h) demonstrated high recovery efficiencies: up to 94.6% for lithium and 83.7% for cobalt in the best-performing samples. These results highlight the synergistic benefits of mechanical activation and reductant-assisted phase engineering for enhancing metal recovery. The proposed method offers a simple, scalable, and eco-friendly route for the hydrometallurgical recycling of LIB cathodes without requiring extensive chemical pretreatment. Full article

The surging demand for lithium-ion batteries (LIBs) has intensified the need for sustainable recovery of critical metals such as lithium, manganese, cobalt, and nickel from spent cathodes. While conventional hydrometallurgical and pyrometallurgical methods are widely used, they involve high energy consumption, hazardous waste generation, and complex processing steps, underscoring the urgency of developing eco-friendly alternatives. This study presents a novel, water-enhanced deep eutectic solvent (DES) system composed of choline chloride and D-glucose for the efficient leaching of valuable metals from spent LiMn-based battery cathodes. The DES was synthesized under mild conditions and applied to dissolve cathode powder, with leaching performance optimized by varying temperature and duration. Under optimal conditions (100 °C, 24 h), exceptional recovery efficiencies were achieved: 98.9% for lithium, 98.4% for manganese, and 71.7% for nickel. Material characterization using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and inductively coupled plasma mass spectrometer (ICP-MS) confirm effective phase dissolution and metal release. Although this DES system requires relatively higher temperature and longer reaction time compared to traditional acid leaching, it offers clear advantages in terms of non-toxicity, biodegradability, and elimination of strong oxidizing agents. These results demonstrate the potential of water-enhanced choline chloride–glucose DES as a green alternative for future development in sustainable battery recycling, supporting circular economy objectives. Full article

The sustainable recycling of valuable metals from spent lithium-ion batteries (LIBs) is critical for resource conservation and environmental protection but remains challenging due to the complex coexistence of target and impurity metals. This study systematically investigates the selective leaching behaviors of metals (Co, Li, Cu, Fe, Al) in phosphoric acid media, revealing that lithium could be preferentially extracted in mild acidic conditions (0.8 mol/L H₃PO₄), while complete dissolution of both Li and Co was achieved in concentrated acid (2.0 mol/L H₃PO₄). Kinetic analysis demonstrated that metal leaching followed a chemically controlled mechanism, with distinct extraction sequences: Li > Cu~Co > Fe > Al in dilute acid and Cu > Al~Li > Fe > Co in concentrated acid. Furthermore, we developed a closed-loop process wherein oxalic acid simultaneously precipitates Co/Li while regenerating H₃PO₄, enabling acid reuse with minimal efficiency loss during cyclic leaching. These findings establish a single-step phosphoric acid leaching strategy for selective metal recovery, governed by tunable acid concentration and reaction kinetics, offering a sustainable pathway for LIBs recycling. Full article

The traditional recycling process of spent lithium-ion battery(LIB) with high Mn content faces the defects of high cost of neutralization and precipitation, poor economics of Mn extraction, and serious Li loss. Therefore, this paper introduces a comprehensive hydrometallurgical method for extracting valuable metals from high-Mn spent LIB. Particularly, directional precipitation of Mn was achieved by utilizing its redox properties, and shot-process extraction and enrichment of Li was realized by using the extractant HBL121. In a sulfuric acid system, control of the oxidant dosage to 0.8% resulted in high leaching efficiencies for Li, Ni, Co, and Mn, with values of 96.58%, 96.13%, 95.22%, and 94.24%, respectively, under optimal conditions which were C(H₂SO₄) of 3.5 mol/L, V(H₂O₂) of 0.8% (v/v), L/S of 10:1, temperature of 60 °C, and time of 60 min. Subsequently, the addition of KMnO₄ dosage (K_p/K_t) in a ratio of 1:1 resulted in the precipitation of 98.47% of Mn as MnO₂, with Ni and Li precipitation efficiencies of 0.2% and 0.1%, respectively. Cascade extraction of Ni and Co was reached by using Cyanex272 extractant from the solution after Mn precipitation. At an organic-to-aqueous phase ratio (O/A) of 1:5, the Co extraction efficiency reached 98.68%, whereas the loss efficiency of Ni was 5.53%, and Li was less than 0.1%. Adjusting the O/A to 1:1 increased the Ni extraction efficiency to 89.99% and Li loss to 8.95%. Finally, the HBL121 extractant was utilized to extract Li from the Li-rich solution, achieving 95.08% extraction efficiency. The Li was stripped with 2 mol/L H₂SO₄ from the load organic phase, realizing a Li concentration of 11.44 g/L. Thus, this process facilitates the comprehensive and efficient recovery of valuable metals such as Li, Ni, Co, and Mn from spent high-Mn LIB. Full article