A Material Flow Analysis of Electric Vehicle Lithium-ion Batteries: Sustainable Supply Chain Management Strategies

Abstract

The increasing adoption of electric vehicles (EVs) has highlighted the need for sustainable lithium-ion battery (LIB) management. This study presents a material flow analysis (MFA) of EV LIBs in the Republic of Korea (RoK), using both a mass-based MFA and a substance flow analysis (SFA). The analysis defines 33 systems and 170 flows across the manufacturing, consumption, discharge and collection, and treatment stages, based on national statistics and data from 11 commercial facilities. In 2022, about 72,446 t of EV LIBs entered the consumption stage through new vehicle sales and battery replacements. However, domestic recovery was limited, as approximately 76.5% of used EVs were exported, reducing the volume of batteries available for recycling. The SFA, focusing on nickel (Ni), cobalt (Co), manganese (Mn), and lithium (Li), showed recovery rates of 69% for Ni, 80% for Co, 1% for Mn, and 80% for Li. Mn was not recovered because its low market price made the recovery process economically impractical. Additional losses occurred from the incineration of separators containing black mass and lithium discharged through wastewater. These findings offer data-driven insights to improve recovery efficiency, guide policy, and enhance the circularity of EV LIB management in the RoK.

1. Introduction

The global transportation sector is heavily dependent on fossil fuels, such as diesel and gasoline, and the resultant carbon emissions are the main contributors to climate change [1,2]. Accordingly, various policies and technologies have been applied to reduce fossil fuel consumption and carbon emissions globally, and electric vehicles (EVs) have been highlighted as promising alternatives to respond to climate change issues [3].

As EVs have become widely supplied, their battery demand has rapidly increased. Specifically, the global EV battery demand has risen more than tenfold, from approximately 50 GWh in 2016 to approximately 550 GWh in 2022 [4], and is expected to reach a maximum of 5400 GWh by 2030 [5]. The batteries used for EVs are mainly lithium-ion batteries (LIB), which include precious metals such as lithium (Li), nickel (Ni), cobalt (Co), and manganese (Mn). However, supply chain instability has become a major issue because the supply chains for these metals are concentrated in certain countries [6]. For instance, approximately 69% of the global supply of Co is produced in the Democratic Republic of Congo, and 80% of the Li is produced in Australia and Chile [7]. This centralization of resource supply chains results in price volatility and political risk, and effective resource management and recycling strategies are pivotal for the sustainable use of EV LIBs [8].

Material flow analysis (MFA) has been widely applied as an important analytical tool to ensure the sustainable management of EV LIBs. MFA helps utilize resources efficiently and minimizes environmental impacts by quantitatively tracking the pathways of materials within a system (e.g., resources, products, and waste) [9]. MFA plays an important role in identifying material flows throughout the life cycle of EV LIBs and provides essential data for the development of recycling and resource recovery strategies, as well as environmental and policy impact assessments [10,11,12].

According to the International Energy Agency (IEA), the global battery recycling capacity by 2030 is expected to be dominated by China (75%), followed by the United States (10%), the European Union (5%), the Republic of Korea (RoK, 5%), and other countries (5%) [13,14]. Although geographically small, the RoK plays a significant role in the global electric vehicle lithium-ion battery (EV LIB) supply chain [15]. It is a major producer of battery cells, cathode materials, and precursors, and is also emerging as a key hub for recycling infrastructure [4].

However, most existing material flow analyses (MFAs) have focused on China, the United States, and Europe [16,17]. Existing studies provide limited insight into the RoK’s unique context, particularly in terms of policies, collection systems, and processing infrastructure. In addition, most previous MFAs focus solely on the end-of-life (EoL) stage and often overlook substantial manufacturing-phase waste, including defective cells, cathode scraps, and rejected modules [16,17,18].

To address these gaps, this study presents a comprehensive life-cycle MFA of EV LIBs in the RoK. The analysis covers the stages of manufacturing, consumption, discharge, and treatment. It also incorporates waste generated during battery production and evaluates both the recovery efficiency and utilization rates of recycled products, focusing on key valuable metals such as Ni, Co, Mn, and Li. Based on primary industrial data and national statistics, this study supports policy development and contributes to international strategies for sustainable battery resource management.

2. Materials and Methods

2.1. Material Flow Analysis (MFA) Method

2.1.1. Target Items and Scope

The initial target materials for the MFA conducted in this study included the waste generated in manufacturing facilities, such as waste cells and waste cathode materials, as well as EV LIBs. EV LIBs encompass both LIBs assembled on EVs and individual unassembled LIBs. These initial target materials undergo various transformations during treatment, interact with auxiliary materials, such as water and chemicals, and eventually produce recycled products, waste, and wastewater. Thus, in this study, the flows of the initial target materials were analyzed, and the flows of auxiliary material input for the treatment and the generated outputs were analyzed. The spatiotemporal scope of this study was limited to the RoK for 2022.

Unlike previous studies, this study explicitly includes the waste generated during the manufacturing phase to increase the completeness of the analysis. This comprehensive approach enables the holistic evaluation of the resource consumption and environmental impacts associated with the entire life cycle of EV LIBs.

2.1.2. System Boundary

The system boundary of the MFA encompasses four main phases in the RoK, as shown in Figure 1: manufacturing, consumption, discharge and collection, and treatment. The manufacturing phase includes all secondary battery manufacturers, EV importers, and sellers except for lead acid battery manufacturers. The consumption phase encompasses EV purchases and EV LIB repairs owing to malfunctions. In the discharge and collection phase, agencies such as central collection centers (CC), local governments (LG), and private collectors (PC) perform activities such as the collection, storage, performance evaluation, and sale of EV LIBs. The treatment phases are divided into repurposing/remanufacturing (RE), pretreatment (PT), hydrometallurgical recycling (HR), pyro-metallurgical recycling (PR), and other treatments (OT). RE, PT, and HR include subsystems for the detailed treatment phase. The scope of OT refers to EV LIBs used for exhibition and research purposes.

Since this study focused on the physical and chemical conversion of EV LIBs, systems that did not affect the material properties, such as EV dismantling facilities, were excluded. In this study, 33 systems and 170 flows were defined, and the corresponding details are described in Supporting Information (SI) Section S1.

2.1.3. Quantification Method for Material Flow

The recovery rates of valuable metals in a given system were evaluated using Equation (1).

$$R_m={\displaystyle \frac{{\sum }_{i\in recovery}(C_{m,i}\times F_i)}{{\sum }_{i\in input}(C_{m,i}\times F_i)}}\times 100(\%)$$

(1)

where $R_m$ is the recovery rate of valuable metal $m$ (%); $i$ represents each individual flow, $recovered$ refers to the set of flows resulting in recovered materials from the system; $input$ refers to the set of input flows into the system; $C_{m,i}$ is the concentration (wt.%) of valuable metal $m$ in flow $i$; and $F_i$ is the total mass of flow $i$.

To avoid duplicate calculations, the input of the entire treatment process was calculated using the amount of initial target waste that was newly input. For example, crushed materials recovered from the pretreatment process, such as black mass moving to a hydrometallurgical recycling process, were excluded from the new inputs.

The MFA was conducted using STAN software (version 2.7, TU Wien, Vienna, Austria), which adopts a static modeling approach. This software allows for consistent material balance calculations while accounting for uncertainty in flow data [19]. In this study, uncertainty was quantified through Gaussian error propagation implemented in STAN, with standard deviations assigned to each flow based on available data sources.

The main sources of uncertainty included differences in operational conditions across facilities, time lags in data reporting, reliance on secondary national statistics for certain flows, and conservative assumptions applied where direct data were unavailable. These components were systematically incorporated into the model to ensure coherence and transparency in the interpretation of material flow results.

2.2. Data Collection and Assumptions

2.2.1. Data Collection Method

The data for the MFA encompass survey data on EV LIB treatment facilities, data from the sampling and analysis of input and output materials, statistical data related to manufacturing, consumption, discharge and collection, treatments associated with EV LIBs, and data from previous studies. The data collected for the MFA were categorized into primary data (directly collected data) and secondary data (data from the literature and statistical data) based on their sources and reliability. The list of data used for the MFA per cycle stage is presented in

Table 1. Data sources for the material flow analysis of electric vehicle lithium-ion batteries by life cycle. Abbreviations: electric vehicle (EV); lithium-ion battery (LIB); lithium iron phosphate (LFP).

Life Cycle	No.	Type of Data	Data Quality	References
Manufacturing	1-1	Waste generation and treatment	Secondary data (National statistics)	[20]
	1-2	Product sales	Secondary data (Industrial report)	[21]
	1-3	Evaporation, wastewater generation	Secondary data (National statistics)	[22]
Consumption	2-1	EV registration and scrapping	Secondary data (National statistics)	[23]
	2-2	Import and export of used EVs	Secondary data (Industrial report)	[24]
	2-4	EV sales	Secondary data (Industrial statistics)	[25]
	2-5	EV market share	Secondary data (Industrial statistics)	[26]
Discharge and Collection	3-1	EV LIB collection and sales at central collection centers and local governments	Secondary data (National statistics)	[27]
	3-2	Information on EV LIB bidding companies	Secondary data (National statistics)	[28]
	3-3	Scrap performance of vehicles containing LFP batteries	Secondary data (National statistics)	[29]
	3-4	Repair rate for EV LIBs	Secondary data (National statistics)	[30]
Waste battery treatment	4-1	Waste generation and treatment performance	Secondary data (National statistics)	[31,32]
	4-2	Input materials for recycling, waste generation, recycled products	Primary data (Survey)	-
	4-3	Valuable metal content (concentration) in waste (wastewater)	Primary data (Sampling and analysis)	-
	4-4	Evaporation, wastewater generation	Secondary data (National statistics)	[22]
	4-5	Import and export of black mass	Secondary data (National statistics)	[33]
	4-6	Performance report on export and import waste	Secondary data (National statistics)	[34]
Common (unit conversion factors, etc.)	6-1	Tolerance weight and LIB weight by EV	Secondary data (National report, industrial data)	[25,35,36]
	6-2	Component materials by LIB type	Secondary data (Previous study)	[37]
	6-3	Exchange rate	Secondary data (National statistics)	[38]

.

Primary data were collected directly from EV LIB treatment sites in the RoK from July to November 2024 through a survey and analysis of the collected samples. The survey included the facility’s status, treatment capacity, waste inputs and outputs, recycled product outputs, additive inputs, and difficulties. Of the 15 EV LIB treatment facilities nationwide, the 11 participating facilities represented approximately 90% of the national reuse and remanufacturing volume, 58% of the pretreatment volume, and 61% of the hydrometallurgical recycling volume, ensuring that the data are representative at the national scale.

Secondary data were obtained from previous studies, government reports, and industry statistics, and the most recent data were prioritized to quantify flows within the system boundary.

2.2.2. Analysis Items and Methods

The analysis items in the SFA were Ni, Co, Mn, and Li, and 34 samples were collected from 11 waste treatment facilities across the RoK for quantitative analysis. The Ni in the waste was analyzed using inductively coupled plasma optical emission spectroscopy (ICP-OES, PerkinElmer, Waltham, MA, USA) according to the YS/T 1342.1 [39] analysis method. The Co in the waste was analyzed using flame atomic absorption spectrometry (FAAS, PerkinElmer, Waltham, MA, USA) according to the YS/T 1342.2 [40] analysis method. The contents of Mn and Ni in the waste were analyzed using YS/T 1229.3 [41]. The contents of Ni and Mn in the wastewater were analyzed using FAAS according to ES 04400.1e [42], and those of Co and Li were analyzed using ICP-OES according to the ISO 11885:2007 [43] analysis method.

All analyses were performed in triplicate under identical conditions, and the average values were calculated with standard deviations reported for the reliability of the results. A list of the collected samples and the analysis results can be found in SI Section S3.

2.2.3. Assumptions

The MFA was performed based on extensive data ranging from the manufacturing to the treatment of EV LIBs. However, because it is difficult to directly quantify some material flows, reasonable assumptions, which are explicitly described in Section S4, were applied.

3. Results and Discussion

3.1. Mass-Based Material Flow Analysis for Electric Vehicle Lithium-ion Batteries

Figure 2 shows the results of the mass-based MFA, showing the entire process from the manufacturing to the treatment of EV LIBs in the RoK. As of 2022, the total input into the system is 11,526 kt, the total output is 11,453 kt, and the total accumulation amount is 73 kt.

3.1.1. Manufacturing Stage

As of 2022, the total volume of LIBs manufactured in MP in the RoK was analyzed to be 1120 ± 43 kt, of which EV LIBs were assessed to be 99 ± 28 kt. The volumes of EV LIBs imported and exported to the RoK were 131 ± 12 kt and 157 ± 15 kt, respectively. The volumes of imported and exported EV LIBs were 99 kt and 64 kt, respectively. The volumes of EV LIBs imported and exported as part of completed vehicles were assessed to be 32 ± 12 kt and 93 ± 15 kt, respectively. These findings indicate that the RoK plays a major role as a battery producer in the EV LIB supply chain and as an exporter of completed vehicles that utilize imported EV LIBs.

In addition to its role as a key manufacturing and trade hub, the RoK also generates a significant amount of waste during the battery production process. In 2022, more than 18,800 t of waste, including defective cathode materials and waste cells, were generated at secondary battery manufacturing facilities. Unlike previous MFA studies, such as those by Bruno and Fiore (2023) and Shafique et al. (2023), which primarily focused on end-of-life batteries, this study includes waste from the production phase within the analytical scope [17,44]. By addressing upstream material losses, the analysis provides a more comprehensive view of resource inefficiencies and offers deeper insight into the structural challenges facing the circularity of EV LIBs.

3.1.2. Consumption Stage

As of 2022, the number of EV LIBs input into the consumption system due to the sale of EVs and the repair of EV LIBs was 72,446 ± 1790 t. Among them, lithium iron phosphate (LFP) batteries accounted for approximately 12.7% (8962 ± 28 t), and nickel cobalt manganese (NCM) or nickel cobalt aluminum (NCA) batteries accounted for the remaining 87.3%. Although LFP batteries are not manufactured in the RoK, the increased collection of Tesla vehicles with LFP batteries has contributed to the higher share of LFP batteries in the RoK. Considering that the average consumption lifetime of EV LIBs is 10–12 years, most LFP batteries remain in the consumption phase and will be discharged as waste in the future [45]. The volume of EV LIBs discharged from the consumption phase was found to be 1822 t, of which approximately 76.5% were exported to other countries as used vehicles and were not collected in the RoK. Such factors hinder battery recycling and resource recovery opportunities in the RoK and undermine the stability of the battery supply chain.

In this context, it is important to note that this study estimates the average consumption lifespan of EV LIBs based on empirical deregistration and battery replacement data in Korea. This contrasts with previous studies that rely on dynamic MFA frameworks and assumed lifespan distributions. For instance, Shafique et al. (2022) and Kamran et al. (2022) applied Weibull distributions with theoretical shape and scale parameters to project retirement flows over time [16,46]. While dynamic models are useful for long-term scenario analyses, they are often sensitive to parameter assumptions and lack alignment with actual failure data. Similarly, Bruno and Fiore (2023) assumed fixed 10-year lifespans without verification against observed usage patterns in the EU [17].

By contrast, the static MFA applied in this study reflects the real-world conditions of battery usage in the RoK. Although this approach does not capture long-term uncertainty, it improves the accuracy of end-of-life flow quantification in the reference year. As a result, it provides a reliable baseline for evaluating the current recycling capacity, identifying policy gaps, and designing short-term intervention strategies.

3.1.3. Discharge Collection Stage

As of 2022, EV LIBs discharged from the consumption phase will be collected by CCs, LGs, and PCs, with a total collection volume of 428 t. Among these, 58 t were stored in CCs and LGs and were not effectively treated, resulting in a cumulative storage volume of 288 t by 2022.

The stored EV LIBs were found to be relatively lighter than those sent for treatment. According to CC data, the average weight of EV LIBs sold for treatment was 324 kg, whereas the average weight of the stored EV LIBs was 237 kg (See SI Section S5 for detailed data). In general, lighter EV LIBs may be less attractive for market transactions because of their lower energy storage capacity, and smaller EV LIBs may face difficulties in market distribution.

Of the 428 t of collected EV LIBs, 370 t of EV LIBs were transferred for the treatment phase, of which 68% went to repurposing and remanufacturing processes. For repurposing and remanufacturing, EV LIBs must be safely certified, with a certification cost of approximately USD 450 per pack. EV LIBs with large capacities have lower certification costs than those with small capacities. Therefore, economic incentives are required to promote the repurposing and remanufacturing of small EV LIBs.

3.1.4. Treatment Stage

In the RoK, EV LIBs and waste generated during manufacturing are treated through repurposing, remanufacturing, pretreatment, and hydrometallurgical recycling processes. The MFA results for the treatment stages can be found in Figure 3. In 2022, there was no commercial-scale dry recycling process operating in the RoK.

Mass-Based MFA: Repurposing and Remanufacturing Process

The MFA results of the repurposing and remanufacturing processes are shown in Figure 3a. Approximately 26% of the 201 t of EV LIBs introduced into the process were excluded because they did not meet the criteria for repurposing and remanufacturing. This is mainly due to a design limitation in which the failure of a single cell results in the disposal of the entire module.

Waste hierarchy prioritizes reduction, reuse, recycling, energy recovery, and disposal. As repurposing and remanufacturing, which are equivalent to reuse, have less environmental impact than recycling, they should be prioritized in waste management. Therefore, technological improvements are required to reduce the waste generated during repurposing and remanufacturing.

Mass-Based MFA: Pretreatment Process

The pretreatment process serves two main purposes: to recover electrical components, such as battery management systems (BMSs), aluminum, copper, and black mass, and to remove interfering substances, such as electrolytes, to increase the recovery of valuable metals in hydrometallurgical recycling. To this end, the pretreatment process consisted of detailed processes such as electrical discharge, dismantling, crushing, heat treatment, and sorting/separation, as shown in Figure 3b.

As of 2022, the total volume of material input in the pretreatment process was 17,188 t, of which 99% was determined to be waste (e.g., waste cathode materials or waste cells) generated by secondary battery manufacturers, not EV LIBs. This implies that the number of EV LIBs disposed of after use is limited, despite the rapid growth of the EV market.

Pretreatment companies have pointed out that dismantling is a major challenge. As the design of EV LIBs has become more complicated and diverse, their compatibility with previous dismantling methods has decreased, requiring more time and higher costs. For example, the latest battery designs, such as Tesla’s 4680 cylindrical cells, BYD’s blade battery packs, and CATL’s cell-to-pack technology, improve safety and space efficiency. However, they also make it difficult to automate and standardize the dismantling process, which contributes to longer times and higher costs for dismantling [47].

EV LIBs contain electrolytes such as propylene carbonate, dimethyl carbonate, and ethylene carbonate [48,49]. The flammability of these materials presents a fire hazard during the pretreatment process and can hinder material recovery during hydrometallurgical recycling [50]. During the heat treatment (300–400 °C), the electrolyte and binder are volatilized and decomposed. The generated gases are adsorbed by activated carbon or captured by scrubbers, producing 2268 t of electrolyte and binder byproducts. These byproducts generate large quantities of waste-activated carbon or wastewater that cannot be effectively recovered or reused, leading to potential resource losses. Therefore, it is essential to develop resource recovery strategies for these materials.

Mass-Based MFA: Hydrometallurgical Recycling Process

In the hydrometallurgical recycling process, there is no standardized process owing to the unique technology applied by the operator; however, the MFA results based on the commonalities of the three surveyed facilities are shown in Figure 3c.

As of 2022, it will be possible to recover Ni, Co, Mn, and Li from previous hydrometallurgical recycling processes; however, Mn will not be recovered. This is because the prices of Ni, Co, Mn, and Li in 2022 are 25,604 USD/ton, 63,598 USD/ton, 1563 USD/ton, and 69,169 USD/ton, respectively, indicating that the price of Mn is lower than that of other minerals [51].

As of 2022, the main chemical inputs in the hydrometallurgical recycling process were analyzed as sodium hydroxide (3.96 ± 0.93 t 30% NaOH/ton input waste), and sulfuric acid (3.69 ± 0.79 t 70% H₂SO₄/ton input waste). Notably, sulfuric acid is overconsumed during the leaching stage. A minimum of 2.0 kg of sulfuric acid is required to dissolve 1 kg of input waste [52], and 2.55 ± 0.52 kg of sulfuric acid was consumed in the leaching process evaluated in this study, showing an excessive usage of approximately 20%.

The excessive usage of chemicals not only increases operating costs but also generates additional environmental burdens, such as hazardous waste and wastewater discharge. It is essential to develop optimized process conditions for hydrometallurgical recycling to increase resource efficiency and minimize environmental impact.

3.2. Substance Flow Analysis for Electric Vehicle Lithium-ion Batteries

This section presents the results of a substance flow analysis (SFA) focusing on two key aspects: (1) the recovery rates of valuable metals (Ni, Co, Mn, and Li) across different treatment processes, and (2) the extent to which recycled products are reintegrated into the manufacturing of EV LIBs in the RoK. The findings provide insights into both the efficiency of current recycling practices and the degree of circularity achieved within the domestic EV LIB supply chain.

3.2.1. Substance Flow Analysis of Recovery Rates During the Treatment Process

Table 2. Substance flow and recovery rate analysis of EV LIBs by treatment stage. The total values are based on the new input volume to prevent the duplicate accumulation of material flows. Abbreviations: repurposing and remanufacturing (RE); pretreatment (PT); hydrometallurgical recycling (HR).

Valuable Metal	Treatment Type	Input (ton)	Output (ton)						Recovery Rate (B/A)
		Waste (A)	Recycled Products (B)	Secondary Waste				Wastewater
				Recycling	Incineration	Landfill	Others
Ni	RE	32	22	10	0	0	0	0	69.2%
	PT	2284	2256	13	11	0	4	0	98.8%
	HR	2772	1936	815	6	15	0	1	69.8%
	Total	2822	1958	828	17	15	4	1	69.4%
Co	RE	12	8	4	0	0	0	0	69.0%
	PT	348	344	2	1	0	0	0	98.9%
	HR	519	417	98	1	2	0	1	80.4%
	Total	531	425	101	2	2	0	1	80.1%
Mn	RE	10	7	3	0	0	0	0	69.5%
	PT	396	393	2	1	0	0	0	99.2%
	HR	571	0	548	1	22	0	0	0.0%
	Total	581	7	550	2	22	0	0	1.1%
Li	RE	7	5	2	0	0	0	0	69.6%
	PT	569	562	3	3	0	1	0	98.9%
	HR	695	557	7	1	0	0	129	80.2%
	Total	706	562	10	4	0	1	129	79.6%

presents the recovery rates of valuable metals per treatment process according to the SFA. The rates were 69% for Ni, 80% for Co, 1% for Mn, and 80% for Li (See SI Section S6 for the SFA results of each valuable metal). The recovery rates for the three key treatment processes—repurposing and remanufacturing, pretreatment, and hydrometallurgical recycling—were analyzed separately, and limitations and improvements were discussed.

SFA: Repurposing and Remanufacturing Process

The recovery rates of valuable metals (Ni, Co, Mn, and Li) in the repurposing and remanufacturing processes were determined to be approximately 70%. The main factor limiting the recovery rate in this process is the structural design of EV LIBs; if one cell in the module fails, the entire module must be discarded as discussed earlier in the treatment stage (see Section 3.1.4). Thus, an improvement in the EV LIB design and optimization of the dismantling method are crucial for achieving a higher recovery rate of valuable metals in this process.

SFA: Pretreatment Process

The recovery rate of the valuable metals (Ni, Co, Mn, and Li) in the pretreatment process was approximately 99%, implying that the materials were retained at a relatively high level. The pretreatment process effectively transfers the majority of valuable metals to hydrometallurgical recycling, but 30–40% of the valuable metals in the secondary waste generated in the pretreatment process are incinerated, which triggers a resource loss problem. The primary secondary wastes generated during the pretreatment process include copper, aluminum, plastics, and electrical parts. The separator contained a large black mass enriched with valuable metals. The contents of Ni, Co, Mn, and Li in the separator were found to be 6.1 ± 5.1%, 0.7 ± 0.1%, 0.6 ± 0.4%, and 1.4 ± 0.2%, respectively; it was analyzed that more than 90% of the incinerated valuable metals originated from the separator (see SI Section S3). Therefore, it is important to develop technologies that can effectively sort black masses using separators.

SFA: Hydrometallurgical Recycling Process

The recovery rates of Ni, Co, and Li from hydrometallurgical recycling were approximately 70%, 80%, and 80%, respectively, while Mn was not recovered. As shown in Figure 4, these commercial-scale results are significantly lower than the recovery rates reported in laboratory and pilot-scale studies, which often exceed 90% under controlled conditions [53,54,55,56,57]. This discrepancy reflects key differences between experimental and industrial settings, such as variability in waste composition, the presence of impurities, and limited process control. In particular, impurities such as aluminum (Al), iron (Fe), and copper (Cu), which originate from current collectors and casings, interfere with the selective separation of valuable metals and reduce the overall recovery rate [58,59,60].

Mn was not recovered because its low market value makes extraction economically unfeasible in commercial operations. Of the 571 t of Mn input into the hydrometallurgical recycling process, 544 t remained in the sludge and were not further treated. Although the sludge could be recycled, no practical recovery pathway for Mn was implemented. According to Brückner et al. (2020), industrial recycling processes generally prioritize the recovery of high-value metals such as Co, Ni, and Li, while Mn is often neglected or only partially separated through mechanical pretreatment [61]. Furthermore, although recovery targets in industry often exceed 95%, actual performance may fall below 50%, depending on input material characteristics and process limitations [62].

In addition to Mn, Li loss during hydrometallurgical recycling is also significant. Of the 695 t of Li input into the process, 129 t (approximately 18.6%) were discharged in liquid effluents. This underscores the urgent need to improve wastewater treatment and develop selective Li recovery technologies. Enhancing the recovery of both Mn and Li is essential for achieving a circular economy in the EV LIB supply chain.

3.2.2. Utilization of Recycled Products in Electric Vehicle Lithium-ion Battery Manufacturing

The utilization of recycled products in EV LIB manufacturing plays a crucial role in strengthening supply chain resilience and reducing reliance on primary raw materials. In this study, recycled products are quantified based on the amount of recovered valuable metals, specifically Ni, Co, Mn, and Li, within their respective recovered compounds. For instance, if cobalt is recovered in the form of cobalt sulfate, its recycled content is assessed based on the cobalt content within cobalt sulfate.

Table 3. Production and utilization of recycled products in EV LIB manufacturing in the Republic of Korea (2022). Abbreviations: electric vehicle (EV); lithium-ion battery (LIB).

Valuable Metal	Amount of Valuable Metals Used in Domestic EV LIB Manufacturing [A (ton)]	Production and Utilization of Recycled Products
		Recycled Product Production [B (ton)]	Domestic Consumption of Recycled Products [C (ton)]	Potential Substitution Rate of Recycled Products [B/A (%)]	Domestic Utilization Rate of Recycled Products [C/A (%)]
Ni	12,325 ± 4372	1936 ± 293	1101 ± 162	15.7 ± 6.1	8.9 ± 3.4
Co	4565 ± 2259	417 ± 111	416 ± 110	9.1 ± 1.5	9.1 ± 1.5
Mn	3684 ± 2832	0 ± 0	0 ± 0	0.0 ± 0.0	0.0 ± 0.0
Li	2697 ± 562	557 ± 240	119 ± 51	20.6 ± 2.5	4.4 ± 0.5

presents the domestic utilization of recycled products in the RoK as of 2022.

Recycled product utilization is evaluated using two key indicators: recycled product substitution potential and usage rate. The substitution potential refers to the total production of recycled products, encompassing both domestic consumption and exports. It represents the maximum possible domestic utilization if all produced recycled products were retained for internal use. Conversely, the usage rate is determined based on the volume of recycled products directly consumed within the domestic battery manufacturing sector.

In 2022, the usage rates of recycled Ni, Co, and Li in domestic LIB production were 8.9 ± 3.4%, 9.1 ± 1.5%, and 4.4 ± 0.5%, respectively. However, no recycled Mn was utilized, as Mn recovery did not occur within this period. These results indicate that while certain valuable metals are reintegrated into LIB manufacturing, the overall integration of recycled products remains limited, highlighting the challenges in achieving a fully circular battery supply chain.

Under the EU Battery Regulation, mandatory minimum recycled content requirements will be enforced from 2031, specifying 6% Ni, 16% Co, and 6% Li, with further increases by 2036 to 15% Ni, 26% Co, and 12% Li [63]. Compliance with these regulations will be critical for maintaining access to the EU market, necessitating an expansion of the RoK’s recovery and utilization of recycled products.

3.3. Policy and Technical Strategies for a Sustainable EV LIB Supply Chain

Based on the results of the mass-based MFA and SFA, this study proposes three focused strategies to enhance the circularity, recovery performance, and reintegration of critical materials in the EV LIB supply chain in the RoK. These strategies respond directly to empirical bottlenecks identified in the analysis, including limited Mn and Li recovery, low domestic utilization rates, and a lack of legal or technical standards for recycled products.

3.3.1. Policy Incentives and Regulatory Targets

This study reveals that Korea’s EV LIB recycling system faces structural challenges in both collection and recovery performance. While several international studies, including those by Bruno and Fiore (2023) and Shafique et al. (2023), project high-efficiency circular systems by 2030, these projections are often based on assumptions that diverge from the current realities in Korea [17,44]. In practice, significant material leakage persists due to the export of used vehicles, the exclusion of manufacturing-stage waste from regulation, and the absence of an integrated collection framework. These factors limit access to recyclable materials and weaken the foundation for domestic circularity.

In addition, the actual utilization of recovered materials in EV LIB manufacturing remains limited. In 2022, the recycled content rates were 8.9 ± 3.4% for Ni, 9.1 ± 1.5% for Co, and 4.4 ± 0.5% for Li, falling short of the EU Battery Regulation targets for 2036 [63]. This highlights a critical gap between domestic performance and international expectations.

To address this issue, this study proposes a phased regulatory roadmap to increase the use of recycled materials, beginning with modest targets for 2025–2031 and progressing toward full alignment with EU standards by 2036, as shown in

Table 4. Proposed mandatory utilization targets for recycled products in EV LIBs in the Republic of Korea (2022–2036). Abbreviations: electric vehicle (EV); lithium-ion battery (LIB).

Valuable Metal	Baseline (2022)	Short-Term				Long-Term
		2025	2027	2029	2031	2032	2033	2034	2035	2036
Ni	5.5%	-	-	5.5%	6.0%	7.8%	9.6%	11.4%	13.2%	15.0%
Co	7.6%	8.5%	11.0%	13.5%	16.0%	18.0%	20.0%	22.0%	24.0%	26.0%
Li	3.9%	4.2%	4.8%	5.4%	6.0%	7.2%	8.4%	9.6%	10.8%	12.0%

. Supporting policy instruments such as tax incentives, preferential procurement, and certification programs should be introduced to stimulate market demand and ensure compliance. Strengthening both regulatory and economic mechanisms is essential to advance material circularity in Korea’s battery industry.

3.3.2. Technical Standards for Recovery Rates

The efficiency and reliability of metal recovery from spent EV LIBs depend not only on the choice of recycling technology but also on the quality of the input materials. In hydrometallurgical processes, black masses with elevated levels of impurities, including Al, Fe, and Cu, can reduce recovery yields and increase processing costs, as discussed in Section 3.2.1. These impurities interfere with selective leaching and solvent extraction, complicating the separation of valuable metals, including Ni, Co, and Li [64,65,66].

To overcome these technical limitations, the establishment of national standards for black mass quality is essential. These standards should specify maximum allowable concentrations of impurities and minimum thresholds for target metals to ensure consistent material quality for downstream processing. For example, China recently adopted its first national standard (GB/T 45203-2024) [67], which classifies black masses based on battery chemistry and defines specific criteria for metal content, impurity limits, and moisture control.

Implementing a similar certification and grading system in the Republic of Korea would enable more predictable processing outcomes, reduce refining inefficiencies, and strengthen alignment with international trade and environmental standards. Such measures would also support the long-term development of a high-integrity recycling supply chain for EV LIBs.

3.3.3. Process Optimization for Mn and Li Recovery

This study identified significant losses of Mn and Li in the current hydrometallurgical recycling system. Mn was not recovered at all, primarily due to its low market value and the lack of process integration for its separation. Furthermore, 18.6% of the Li input was lost through wastewater discharge, reflecting inefficiencies in aqueous-phase separation.

Rather than developing entirely new technologies, it is more appropriate at this stage to focus on optimizing existing hydrometallurgical processes to improve economic feasibility and recovery performance. For Mn, process adjustments such as improved pH control, impurity management, and selective extraction conditions could enhance recovery without major technological overhauls [68]. For Li, optimization of electrodialysis systems and the integration of zero-liquid-discharge (ZLD) technologies could substantially reduce losses to wastewater [69]. Recent studies have demonstrated that bipolar membrane electrodialysis is effective in recovering LiOH and H₂SO₄ from lithium sulfate solutions, offering a pathway for closed-loop recycling [70,71,72].

These improvements are essential not only for increasing material circularity but also for aligning with future market requirements and reducing the environmental footprint of EV LIB recycling operations.

4. Conclusions

This study presents a data-driven material flow and SFA of EV LIBs in the RoK. The results highlight critical structural limitations in the current recycling framework. In 2022, approximately 72,446 t of EV LIBs entered the consumption phase, yet 76.5% of used vehicles were exported without battery recovery, leading to a substantial loss of recyclable materials. The overall recovery rates were 69% for Ni, 80% for Co, 1% for Mn, and 80% for Li. Furthermore, 18.6% of Li input was lost through wastewater discharge. The actual utilization rates of recovered metals in new battery production remained far below international expectations, with only 5.5% for Ni, 7.6% for Co, and 3.9% for Li as of 2022. These figures fall significantly short of the EU Battery Regulation targets for 2036, which require 15% for Ni, 26% for Co, and 12% for Li.

These inefficiencies originate from three key sources identified through the empirical analysis. First, insufficient policy instruments and weak enforcement contribute to the low reintegration rate of battery materials into domestic recycling loops. Although a nationwide collection system exists in the Republic of Korea, a substantial portion of end-of-life EVs are exported prior to battery recovery, resulting in significant resource loss. To address these issues, a phased regulatory roadmap should be introduced to gradually increase the use of recycled materials in EV LIB manufacturing. This roadmap should be accompanied by tax incentives, preferential public procurement, and certification programs designed to strengthen market demand and promote regulatory compliance.

Second, the absence of technical standards for black mass quality undermines metal recovery performance. Elevated levels of Al, Fe, and Cu in collected materials reduce the efficiency of hydrometallurgical processing and complicate selective extraction. The establishment of national standards specifying impurity thresholds and minimum metal content would enhance downstream predictability, improve processing efficiency, and facilitate international alignment.

Third, significant losses of Mn and Li occur during the hydrometallurgical recycling process because Mn is not recovered due to its low economic value, and Li is partially lost through wastewater discharge owing to the low efficiency of aqueous-phase recovery. Rather than introducing entirely new technologies, optimizing existing hydrometallurgical systems offers a practical solution. Improvements such as enhanced pH control for Mn and the adoption of bipolar membrane electrodialysis for Li can significantly reduce metal losses and support closed-loop recycling.