Systematic Review of Battery Life Cycle Management: A Framework for European Regulation Compliance

Abstract

Batteries are fundamental to the sustainable energy transition, playing a key role in both powering devices and storing renewable energy. They are also essential in the shift towards greener automotive solutions. However, battery life cycles face significant environmental challenges, including the harmful impacts of extraction and refining processes and inefficiencies in recycling. Both researchers and policymakers are striving to improve battery technologies through a combination of bottom–up innovations and top–down regulations. This study aims to bridge the gap between scientific advancements and policy frameworks by conducting a Systematic Literature Review of 177 papers. The review identifies innovative solutions to mitigate challenges across the battery life cycle, from production to disposal. A key outcome of this work is the creation of the life cycle management framework, designed to align scientific developments with regulatory strategies, providing an integrated approach to address life cycle challenges. This framework offers a comprehensive tool to guide stakeholders in fostering a sustainable battery ecosystem, contributing to the objectives set by the European Commission’s battery regulation.

1. Introduction

The development of the lithium-ion battery (LIB), which originated in the 1960s and was commercialized in 1991, represents decades of targeted research and development activities that form the basis of today’s information technology systems [1] and that allow for their progress and for the opening up of new scenarios in many sectors. As a result, it is easy to understand how the demand for batteries has grown exponentially worldwide and will continue to do so in the coming years. LIBs, together with lead–acid and nickel-based batteries, make up almost 95% of the market. It is a market that was worth more than 60 billion in 2014, doubled in value in the following 5 years [2], and is estimated to be worth more than EUR 300 billion by 2027, with an average annual growth rate (CAGR 2021–2027) expected to reach +10%, with peaks of +15% in Europe [3]. Initial estimates from 2018 projected that the European production capacity of cell factories would reach 120 GWh by 2030, which is sufficient to produce 2.2 million Electric Vehicles (EVs). However, updated projections from recent years indicate that by 2022, this capacity increased to 789.2 GWh (sufficient for 15 million EVs), reflecting approximately 14% of the expected global production capacity of 5452 GWh by 2030. Although early predictions have evolved significantly, these numbers underscore the rapid scaling of EV production capacity in response to growing demand. Currently, there are seven manufacturers of LIBs in Europe, of which the top three by capacity are LG Chem (Poland, 32 GWh), Samsung SDI (Hungary, 20 GWh), and Northvolt (Sweden, 16 GWh). By 2030, it is estimated that there will be 27 battery factories in 18 different companies, 8 of which will be built through agreements with car manufacturers such as Volkswagen, Stellantis, Nissan, Volvo, and Renault [4]. This because it is estimated that by 2030, the demand for batteries in the automotive sector will constitute 60% of the market, while the percentage contribution to the demand for consumer electronics will gradually decrease from 21% to 3%, even if it doubles in terms of quantities [2].

Nevertheless, batteries cannot become one of the central pillars of the green revolution unless their sustainability is clearly defined and achieved. A sustainable battery can be defined as an energy storage solution that optimizes the use of eco-friendly materials, which are preferably abundant, accessible, or derived from secondary raw materials, and that minimizes its environmental impact throughout its entire life cycle, from production to end-of-life recycling [5,6]. Additionally, Zanoletti et al. [6] emphasize the importance of integrating batteries into low-carbon energy production and charging technologies, thereby contributing to a cleaner and more sustainable energy system.

Currently, the entire life cycle of batteries is affected by critical issues [7,8] that undermine the sustainability definition outlined above. Upstream processes, such as the extraction of raw materials and, in particular, battery manufacturing, which generates roughly 64% of the carbon footprint of the entire life cycle [9], are highly polluting [10]. Downstream processes are inefficient, recycling does not allow for a high recovery rate of materials [11], and circular business models are rarely adopted [12]. Finally, from a technical point of view, batteries need improvements in terms of performance, safety, control [13], and design to favor their end-of-life management [14].

The European Commission has acknowledged the strategic importance of batteries within the framework of the Green Deal Industrial Plan for the Net-Zero Age [15]. As a response to the evolving requirements of sustainability and industrial trends, the legislation on batteries was updated in Regulation (EU)2023/1542 [16]. This new regulatory framework is the first proposed initiative under the Circular Economy Action Plan (CEAP [17]) and the first piece of European legislation to take a comprehensive life cycle approach. Indeed, key aspects of this regulation include introducing stringent standards and requirements from cradle to grave. This includes setting ambitious recycling targets, mandating the declaration of carbon footprints, and implementing a digital passport system for better traceability and due diligence in the supply chain. The final aims are as follows: (1) ensuring the creation of an internal and sustainable market for batteries, aiming to position Europe as the second leading global power in this sector, after China; (2) promoting the circularity of batteries and the materials that constitute them; (3) reducing the environmental and social impacts related to battery life cycle management. To achieve this, the legal bases of the new regulation are based on Article 114 of the TFEU, whose objective is the establishment and functioning of the internal market, rather than relying on Article 175, which concerns environmental protection.

The primary aim of this study is to conduct a thorough Systematic Literature Review (SLR) to identify and examine innovative solutions capable of addressing the various challenges encountered throughout the battery life cycle. These solutions are instrumental to achieving the ambitious objectives set by the European Commission. In contrast to previous related studies, this research takes a unique approach by structuring the analysis according to the phases of the European regulation. It covers the entire battery life cycle, starting from the extraction phase and extending to the second-life phase. While many of the sustainability challenges and solutions discussed are broadly applicable across battery types, certain approaches are tailored to the unique characteristics of the most prevalent chemistries. This study, therefore, presents a wide array of sustainable solutions spanning technical advancements and strategies to enhance environmental, economic, and social sustainability.

The main outcome of this study is the development of a life cycle management framework, which is presented and elaborated in Section 4. The framework serves as a comprehensive and structured guide that seamlessly integrates scientific research insights and policy instruments. Its purpose is to steer the battery industry and all stakeholders towards sustainable practices in adherence to the regulation’s ambitious targets. By offering a holistic approach, the framework addresses the challenges and opportunities encountered at each stage of the battery life cycle, ultimately promoting a sustainable battery ecosystem.

The methodology utilized in this study, outlined in Section 2, involves the meticulous selection and analysis of 177 scientific papers that lay the foundation for the development of the life cycle management framework. In Section 3, this paper dissects the contents of these papers, providing an in-depth exploration of the diverse and innovative solutions proposed across various phases of the battery life cycle. In conclusion, Section 5 summarizes the analysis outcomes providing several conclusions.

2. Materials and Methods

The PSALSAR methodology, aligned with the PRISMA Checklist (Supplementary Materials), was utilized to attain a precise SLR realization [18]. This methodology is composed of the following steps: (i) the Protocol, which consists in the definition of this study’s purpose; (ii) the Search, to define the best strategy to follow in the paper collection phase; (iii) the AppraisaL, aimed at defining the criteria and selecting the papers; (iv) the Synthesis, to catalog the papers; (v) the Analysis of the papers; and (vi) the Report phase, to provide a clear picture of the performed SLR for a wide range of interested stakeholders. The application of steps (i)–(iv) is described hereafter, while step (v) is reported in Section 3, and finally step (vi) is discussed in Section 4 and Section 5.

For the identification and definition of the purpose of this study (Protocol step), the CIMO methodology was used [19], allowing for an understanding of the general framework of the research and orienting this study (

Table 1. Study’s protocol definition with CIMO methodology.

Context	Intervention	Mechanism	Outcomes
Batteries need further technological developments to ensure the green energy transition. From a regulatory point of view, the European Commission has established medium–long term objectives in the new battery regulation, which is currently being approved.	Systematic Literature Review on battery sustainability in their entire life cycle, with a phase-by-phase analysis based on the objectives indicated in the new European regulation on batteries.	Translation of the objectives of the new European Regulation in terms of technological developments. Subdivision of the various steps of the life cycle according to the subdivision made by the European regulation. Analysis of the state of the art of technology and issues addressed in the regulation.	Indication of the strengths and weaknesses of scientific research on each phase of the battery life cycle in terms of technological developments and sustainability for a better orientation of future scientific research aimed at ensuring the achievement of European objectives and facilitating the green energy transition.

).

As regards the collection of papers (Search step), two of the main scientific databases, Scopus and Science Direct, were consulted using 20 different strings defined by using a series of keywords cited within the European regulation (

Table 2. Summary of the Search phase.

Database	Search Strings and Search Terms	Articles (#)	Research Date
Scopus	“Responsible sourcing” AND “Battery”	9	19 August 2022
	“Sustainable mining” OR “Green mining”) AND “Battery”	18	19 August 2022
	“Hazardous Substances” AND “Battery”	161	22 August 2022
	“Carbon Footprint” OR “Process optimization” OR “Sustainable manufacturing”) AND “Battery” AND “Manufacturing”	103	22 August 2022
	“Recycled Content” AND “Battery”	9	22 August 2022
	“Design for” AND (“Sustainability” OR “Disassembly” OR “Remanufacturing” OR “Recycling”) AND “Battery”	116	22 August 2022
	“Safety” AND “Manufacturing” AND “Battery”	639	22 August 2022
	“EV battery” AND (“Use phase” OR “LCA”) AND (“Duration” OR “Performance” OR “Sustainability”)	46	23 August 2022
	“End of Life management” OR “EOL management” AND “Battery”	62	23 August 2022
	“Extended producer responsibility” AND “Battery”	41	23 August 2022
	“Lead Acid” AND “Battery recycling”	131	23 August 2022
	“lithium” AND “battery recycling” AND “Efficiency”	93	23 August 2022
	“Sustainable Recycling” AND “Battery”	67	23 August 2022
	“Refurbishment” AND “Battery”	61	25 August 2022
	“Second Life” AND “Battery”	498	25 August 2022
	“Battery Management System” AND “Sustainability”	106	25 August 2022
	“Digital Passport” OR “Passport” AND “Battery”	22	25 August 2022
	“Sustainable Supply Chain” AND “Battery”	20	25 August 2022
Science Direct	“Responsible sourcing” AND “Battery”	91	19 August 2022
	“Sustainable mining” OR “Green mining”) AND “Battery”	1133	19 August 2022
	“Hazardous Substances” AND “Battery”	3102	22 August 2022
	“Carbon Footprint” AND “Battery” AND “Manufacturing”	2823	22 August 2022
	“Recycled Content” AND “Battery”	359	22 August 2022
	(“Design for Disassembly” OR “Design for Recycling” OR “Design for Remanufacturing” OR “Design for Sustainability”) AND “Battery”	1408	22 August 2022
	“Safety Improvement” AND “Manufacturing” AND “Battery”	246	22 August 2022
	“EV battery” AND (“Use phase” OR “LCA”) AND (“Duration” OR “Performance” OR “Sustainability”)	2042	23 August 2022
	“End of Life management” OR “EOL management” AND “Battery”	1918	23 August 2022
	“Extended producer responsibility” AND “Battery”	788	23 August 2022
	“Lead Acid” AND “Battery recycling”	638	23 August 2022
	“lithium” AND “battery recycling” AND “Efficiency”	944	23 August 2022
	“Recycling efficiency” AND “Battery”	630	23 August 2022
	“Refurbishment” AND “Battery”	2992	25 August 2022
	“Second Life” AND “Battery”	885	25 August 2022
	“Battery Management System” AND “Sustainability”	1447	25 August 2022
	“Digital Passport” AND “Battery”	8	25 August 2022
	“Sustainable Supply Chain” AND “Battery”	429	25 August 2022

). This allowed us to the collect 24,085 potentially useful papers for this SLR.

Once these data had been collected and stored in files (.res format) containing the basic information of each paper and the related abstracts, they were uploaded to the Rayyan platform to facilitate the Appraisal step [20]. This phase opened with the definition of the eligibility criteria (

Table 3. Eligibility criteria defined in the Appraisal phase.

Eligibility Criteria	Decision
The chosen keywords exist at least in the title or abstract section of the paper	Inclusion
The paper is published in a peer-reviewed scientific journal	Inclusion
The paper is written in the English language	Inclusion
The paper studies the use of alternative materials in batteries	Exclusion
The paper is duplicated within the search documents	Exclusion
The full paper is not available or accessible	Exclusion
The paper was published before 2013	Exclusion

) to be used for the preliminary inclusion and exclusion of the papers. The selection criteria included studies published in the last 10 years, specifically from 2013 to 2022, to provide a snapshot of the scientific landscape up to the period immediately preceding the introduction of the new European battery regulation, allowing for an assessment of how prepared the field was for this regulatory milestone. Papers concerning the study of alternative materials were not included, as it is a very broad scientific field of application, not mentioned in the European regulation and deserving of a dedicated SLR.

Through the eligibility criteria, it was possible to proceed to the operational phase of selecting the papers that constitute the basis of this SLR in the Rayyan platform following the procedure proposed by the PRISMA 2020 flow chart (Figure 1). The screening process took place in several steps:

• Removal of duplicates identified both automatically by Rayyan and manually. At the end of the process, there were 13,145 papers left.
• Exclusion of papers through the platform’s AI and manual operations based on the interpolation of keywords, which brought the number of papers to 2302.
• Analysis of the remaining papers based on titles and abstracts and manual exclusion.
• Paper retrieval.

Subsequently, the SLR inclusion criteria were defined (

Table 4. SLR inclusion criteria defined in the Appraisal phase.

Life Cycle Phase	Battery Regulation	SLR Inclusion Criteria
Extraction phase	Contribution to responsible sourcing; extra-territorial aspect aimed at regulating the methods of extraction and processing of raw material by operators; also valid in third countries to lower environmental and social impacts.	The paper analyzes the impacts of the raw materials present in batteries and/or proposes sustainable solutions for green mining and/or deals with the issue of responsible sourcing.
Manufacturing phase	Hazardous substance restriction; carbon footprint declaration (2024); battery performance classes (2026); maximum CO2 threshold (2027); declaration of recycled content of lithium (Li), cobalt (Co), lead (Pb), and nickel (Ni) (2027); growing minimum recycled content (2030, 2035); obligation of removability and replaceability; safety requirements.	The paper analyzes the impacts of or proposes innovative and sustainable solutions regarding the content of hazardous substances in batteries, the optimization of production processes, reducing the carbon footprint in the manufacturing phase, recycled content, end-of-life design, and safety issues.
Use Phase	Minimum performance and durability requirements.	The paper analyzes the environmental and technical performance of EVs and portable batteries, in particular their durability and efficiency.
Collection Phase	Growing targets of portable battery collection (2025, 2030); 100% EV batteries collected by certified operators; Extended Producer Responsibility (EPR) requirements.	The paper proposes systems to improve end-of-life management and/or analyzes Extended Producer Responsibility.
Recycling Phase	Growing recycling efficiency targets for lead, lithium, and other types of batteries (2025, 2030); Growing recycling recovery targets for Li, Co, copper (Cu), Pb, and Ni (2026, 2030).	The paper analyzes the current battery recycling systems, in particular those of lead–acid and lithium batteries, and proposes alternative and better solutions to optimize the recovery of materials.
Second-Life Phase	Requirements for repurposing and remanufacturing; reuse indicated as a priority in the waste hierarchy.	The paper analyzes the status and improvement of battery repurposing and remanufacturing processes and second-life solutions.
Transversal Aspects	Obligation to have a battery management system (BMS) inside EVs and industrial batteries; mandatory supply chain due diligence focusing on social and environmental impacts; ensuring the traceability of batteries through a digital passport, mandatory from 2027.	The paper analyzes BMS status and improvements and solutions for the application of the digital passport and studies the optimization of battery supply chains to make them more sustainable.

). This consisted in translating the goals of the European regulation into a technical–scientific language, allowing for an in-depth analysis of the 245 remaining papers and for their exclusion or cataloging along the various stages of the life cycle (

Table 5. Summary of the Synthesis stage.

Phase	Regulation Topic	Total (n°)	Screened (n°)	Selected (n°)	Included (n°)
Extraction		1251	397	31	21
	Natural resources			9	6
	Responsible sourcing			9	7
	Sustainable mining			13	8
Manufacturing		8966	308	45	34
	Hazardous substances			3	2
	Carbon footprint			13	10
	Recycled content			5	4
	Design for			8	5
	SESS safety			16	13
Use Phase		2088	288	28	21
Collection		2809	460	9	8
	End-of-life management			5	4
	EPR			4	4
Recycling		2503	108	48	38
	Lead–acid recycling			3	2
	Lithium recycling			39	31
	Other recycling			6	5
Second Life		5989	493	28	23
	Repurposing/remanufacturing			8	5
	Second-life applications			20	18
Transversal Phases		479	248	36	32
	Battery management system			21	18
	Electronic exchange system and digital passport			4	4
	Sustainable supply chain			11	10
Total		24,085	2302	233	177

) for the Synthesis stage.

At the end of the screening process, the 177 papers forming part of this SLR were identified, corresponding to 1.35% of the total number of starting papers (excluding duplicates).

In the analysis of the included papers, the Journal of Cleaner Production was the international journal that published the highest number of articles cited in this SLR, with 19 articles, followed by the Journal of Energy Storage, with 10 (

Table 6. Most cited international journals in this SLR.

Journal	n°
Journal of Cleaner Production	19
Journal of Energy Storage	10
Resources, Conservation and Recycling	7
Energies	6
Resources Policy	6

). Regarding the years of publication, the data indicate that two-thirds of the selected publications come from the last two years (2021 and 2022), meaning the issues addressed have acquired importance and relevance in recent years (Figure 2).

3. Results

3.1. Extraction Phase

The reserves of raw materials for the production of batteries are scarce and are struggling to meet the demand. Weil et al. [21] produced a dynamic model for studying the demand for LIBs for vehicles, indicating that Li, Co, Ni, and Cu are of particular concern as their demand is projected to surpass the capacity of existing reserves by 2050. Hodgkinson and Smith [22] investigated risk mitigation and resilience strategies aimed at reducing environmental impact in the extraction phase.

Lithium procurement methods, including its recovery from brine, are being explored. According to Khalil et al. [23] and Y. Sun et al. [24], innovative brine-based methods for Li recovery offer improved productivity and efficiency compared to traditional methods but also come with a higher environmental impact and cost due to their low technology readiness level (TRL). Hence, hybrid solutions are considered the most sustainable option for increasing lithium supply. Y. Sun et al. [24] found that the most promising method is adsorption, especially when combined with electrochemical techniques. An effective approach to primary production in the European market is the exploitation of Li-rich geothermal fields, which would ensure low-impact supply and processing. Sanjuan et al. [25] evaluated six such fields and determined that the Upper Rhine Graben (URG) between France and Germany is the most favorable. The economic viability of investing in this form of extraction, which entails high initial costs but also offers multiple extracted products and flexible operating costs based on volume, hinges on the pace at which it is implemented relative to traditional low-cost methods and the market appeal it generates [26].

To secure the supply of scarce resources such as cobalt (Co) and maintain their sustainability, monitoring the market and utilizing production forecasting models are crucial. Co’s primary production is often a by-product of copper and nickel mining and the majority of its deposits are located in countries with political and socio-economic imbalances, such as the Democratic Republic of the Congo [27] which holds 51% of the world’s reserves [28], with unsustainable supply chains, particularly in regard to local health and environmental degradation [29]. Currently, the most environmentally friendly method of Co extraction is hydrometallurgy, but it generates substantial amounts of acid waste with high disposal costs, making pyrometallurgy the preferred option, despite it being more energy-intensive and polluting. Sprecher and Kleijn [30] evaluated alternative methods and found deep-sea extraction to be the most promising, despite its currently high cost. Alvarenga et al. [31] compared the impacts of land-based and deep-sea mining focusing on three midpoint impact categories and found that transitioning to the latter could result in a reduction in climate change of up to 38% and a 72% reduction in acidification, with photochemical oxidant formation remaining stable or increasing by a maximum of 7%.

Among the natural resources utilized in battery production are rare earth elements (REEs), including lanthanum. The development of green energy technologies contributes to an unsustainable consumption of REEs. Golroudbary et al. [32] pointed out that a 1% increase in green energy production led to a 0.18% decrease in REE reserves and a 0.90% increase in GHG emissions during the manufacturing phase. This is due to the energy-intensive production processes and the low recycling rate, which is currently only 1% due to the small amounts of REEs utilized in each battery [33,34].

The European Commission has a focus area of responsible sourcing, which entails the integration of social, ethical, and environmental factors in the supplier selection process. Deberdt and Billon [35] provided a worldwide mapping of the various responsible sourcing initiatives, including pilot projects, traceability solutions, blockchain implementation, and the participation of downstream companies. Deberdt et al. [36] specifically studied the Entreprise Générale du Cobalt (EGC), established in Congo in 2018, which aims to centralize the purchasing and sales of artisanal products while ensuring responsible sourcing. Their study revealed the lack of accountability of companies in ensuring due diligence and inadequate knowledge of the EGC program among supply chain actors. Mancini et al. [37] conducted a due diligence assessment using a Social Life Cycle Assessment (S-LCA) approach for two pilot projects in Congo and proposed a set of tools for consideration, requiring replication and scaling. Lastly, W. Liu et al. [38] emphasized the general lack of consumer awareness regarding the environmental and social impacts of the extraction phase.

3.2. Manufacturing Phase

The manufacturing phase is the most critical and the most impactful phase of the battery life cycle, strongly conditioning the other phases [39].

The topic of hazardous substances in batteries has received limited attention in scientific research. Melchor-Martínez et al. [40] investigated the effects of hazardous substances on the environment and their ecotoxicological impact, as well as the potential impact of emerging metals whose end-of-life fate is unclear. Recknagel et al. [41] demonstrated that roughly two-thirds of the portable batteries evaluated had amounts of Pb above the threshold, and over half also contained levels of mercury (Hg) and Pb above the threshold. Additionally, only 50% of the batteries were properly labeled, with some button cells being found to contain no mercury.

In regards to the CF of the manufacturing phase, the scientific community has acknowledged the magnitude of the problem and developed several solutions. Ellingsen et al. [42] conducted a life cycle analysis of batteries and found that the manufacturing phase is the most energy-intensive and impactful stage, advocating for the utilization of renewable energy during this stage. Reducing the CF of battery manufacturing requires the optimization of processes. Niri et al. [43] produced a predictive model to minimize production waste resulting from failures by predicting cell characteristics with a 5% margin of error and electrode characteristics with a 3% threshold. Silva et al. [44] presented a strategy for identifying manufacturing limitations and strategies for enhancing energy efficiency. Machinery used in the cutting, annealing, and formation processes was identified as a bottleneck. Assad et al. [45] developed a framework to predict energy-related key performance indicators (e-KPIs) of production processes to improve energy efficiency while maintaining production targets and designing sustainable processes. Lander et al. [46] conducted a study to evaluate the environmental impacts of an effective thermal management system, leading to an improvement in life cycle cost (LCC) by 27% and a decrease in the carbon footprint by 25%. Babu Sanker and Baby [47] proposed the utilization of phase change material (PCM)-based thermal management with a melting point between 32° and 40° in combination with thermal conductivity enhancers, as well as modifications in the design of pins, type of metal foam coatings, graphene-enhanced hybrid PCMs, and the use of machine learning.

In addition to process optimization, reducing the environmental impact of various components also offers potential solutions. Rui et al. [48] analyzed the environmental impact of natural graphite, a crucial material for battery production, and determined that it has a greater impact than synthetic graphite. The production of cathode active material (CAM) is both cost-expensive and inefficient. Therefore, Kurzhals et al. [49] proposed an alternative production process with two calcination phases instead of one to determine optimal parameters for higher productivity, lower carbon footprint per unit, and equivalent performance. Silicon-based anodes have gained attention due to their higher theoretical capacity compared to graphite anodes. D. Zhang et al. [50] conducted research on the sustainable production of silicon anodes using fly ash generated in combustion processes, which was fixed to carbon micro-sheets, MXene, and graphite nanosheets, resulting in an improved performance and reduced environmental impact of fly ash. The production of graphite anodes accounts for 55% of the environmental impact of the manufacturing of lead–acid batteries according to the Global Warming Indicator [51]. Moreover, the emission of sulfuric acid mist during the plate production constitutes another significant environmental challenge. In an effort to mitigate this issue, Peram et al. [52] tested the impact of Sodium Lauryl Sulfate (SLS) at 2.0 mL/cell in the electrolyte, which reduced the emissions by 40% without affecting battery performance.

Recycled content is another policy adopted by Europe as a means of promoting sustainability and innovation. This stands in contrast to the lack of policies regarding recycling and end-of-life management in the United States [53]. According to projections by Abdelbaky et al. [54], Europe’s waste stream of spent batteries in 2040 may surpass the demand for raw materials needed to produce batteries. The proposed base scenario forecasts that these percentages will exceed the ones imposed by the regulation due to an increased recycling capacity and a reduction in the use of Co, Ni, graphite, and Cu in batteries. J. Liu et al. [55] presented several methods for conducting a Life Cycle Assessment (LCA) analysis and evaluating recycled content within it.

Eco-design is one of the pillars of the Circular Economy Action Plan. The results of a statistical analysis reveal that batteries are a significant contributor to the aging of portable devices such as laptops, making eco-design crucial [56]. The study of K. Liu, Wang, et al. [57] presents a series of crucial parameters to be considered throughout the entire life cycle in the eco-design phase. Tan et al. [58] introduced design criteria for cathode material recycling, focusing on material structure without modifying the elemental composition. Thompson et al. [59] noted that the design of batteries poses significant challenges in the recycling process. They found that separating materials from the electrodes can result in significant savings of up to 70% and improve the environmental impact. The use of robotics in the design of easy-to-open module-less packs, the elimination of adhesives, improved labeling, and alternative electrode and connector design can facilitate disassembly and promote recycling. Mao et al. [14] proposed several design-for-recycling solutions, including anode-less cells, soluble binders for cathode materials, self-supporting electrodes without binders, and water-based electrolytes. Tornow et al. [60] created a methodology to design and select multi-material components in new battery systems by considering the impact of assembly and disassembly stages, achieving an average of 10% improvement in disassembly compared to traditional designs.

The European Commission has also taken on the responsibility of regulating battery safety. S. Zhang et al. [61] emphasized the problem of flammable electrolytes and suggested alternatives in the form of non-flammable or flame-retardant electrolytes. They closely examined the properties of these options, including eutectic solvents and aqueous electrolytes, which boast excellent characteristics and low costs. Li et al. [62] focused on separators and the importance of adding reversible shutdown functions to instantly block current circulation or thermal protection, suggesting solutions such as the use of shape memory polymers (SMPs). Zhong et al. [63] highlighted that thin separators can improve energy density-worsening mechanical properties and therefore safety. Chen et al. [64] recommended internal and external strategies for LIB safety improvements, such as the use of additives, selecting materials, and design optimization, as well as cooling and cell balance. B. Liu et al. [65] provided a comprehensive framework to avoid safety issues in LIBs under mechanical abuse, while Xu et al. [66] reviewed the latest methods and technology for safety testing under mechanical, electrical, and thermal abuse. Xiong et al. [67] performed a detailed analysis of short-circuit diagnosis and prognosis, identifying indicators to monitor. Cavers et al. [68] introduced a guide exploring the impact of electrolytes on the safety of high voltage LIBs, also probing cost and environment impacts. They found that aquatic electrolytes are the optimal technology, but they need further development, and solid-state electrolytes are currently the safest technology, but they are expensive and have performance issues. Kong et al. [69] reproduced the phenomenon of spontaneous combustion of batteries in the laboratory, concluding that avoiding foreign bodies during battery construction is crucial. Kirkels et al. [70] addressed the problem of safety from a socio-economic point of view that involves all stakeholders. Longchamps et al. [71] proposed a revised thermal management scheme based on the use of thermally stable materials and self-heating structures. Altarabichi et al. [72] explored a machine learning approach to predict the State of Health (SOH) of batteries. Finally, Cai et al. [73] examined prismatic cells, showing how aging mechanisms also vary with temperature.

3.3. Use Phase

According to the LCA conducted by Shafique et al. [74], in terms of Global Warming Potential, the power grid is the most impactful factor during the use phase. In regions with high-carbon-intensity power grids, hybrid vehicles are less impactful than plug-in or fully electric ones [75]. Dik et al. [76] reviewed trends in car batteries, examining both technological advancements and environmental impacts. Among LCA studies, Dhanasekar et al. [77] found that lithium iron phosphate (LFP–LiFePo4) batteries offer superior performance but at a higher cost than lithium–cobalt oxide (LCO–LiCoO2) batteries, while solid-state batteries perform best overall but have a lower technology readiness level (TRL). For industrial use, LFP batteries are more sustainable than sodium sulfur (NaS) batteries, despite having approximately double the manufacturing impact [78]. According to Feng et al. [13], LFP batteries are more sustainable than lithium–nickel–cobalt–manganese oxide (NCM) batteries due to the absence of nickel and cobalt, although LFPs have lower efficiency and recyclability. In contrast, an LCA by Quan et al. [79] shows that NCM batteries may have a lower impact when considering refurbishment and secondary use as energy storage systems (ESSs). However, NCM batteries also have a shorter overall lifespan than LFP batteries. NCM batteries, compared to LiMn2O4 (LMO), consume more energy over their life cycle but emit fewer greenhouse gases [80]. The studies of Ma and Deng [81], Sandrini et al. [82], and Wu et al. [83] emphasize that LCA results for batteries are significantly influenced by variables such as the functional unit, partly due to limited accessible data for battery design. To mitigate subjectivity, Ma and Deng [81] developed a parameterized model for EV batteries focusing on CO₂ emissions, offering guidelines for sustainable design. Additionally, S. Zhao and You [80] proposed an integrated hybrid LCA model that combines LCA with an Economic Input–Output System to assess environmental impact. Although promising, this approach remains limited by data availability, restricting comprehensive use across all impact categories. Garcia et al. [75] proposed an innovative approach for the evaluation of EV battery environments during the use phase, aimed at supporting car manufacturers in the selection phase. In general, Koroma et al. [84] showed the variation of national energy mix is the most influential parameter in hypothetical future scenarios, followed by recycling. On the other hand, Wu et al. [83] identified the cathode, battery management system, and packaging as the most impactful components in batteries.

X. Hu et al. [85] addressed the issue of battery performance deterioration at low temperature, concluding the external pre-heating solutions need to increase efficiency while internal ones have a low TRL. Sanfélix et al. [86] proposed a novel dual-cell battery system for full EVs, a hybrid energy storage system (HESS), which increases the drive range per cycle by 10% compared to standalone batteries. HESS’s efficiency during the use phase compensates the higher impacts in the manufacturing phase, resulting in an overall more environmentally sustainable system compared to traditional ones. Spitthoff et al. [87] showed that reducing the anode potential or increasing the cathode potential could improve battery performance by increasing cell voltage. Wassiliadis et al. [88] investigated the battery performance of the Volkswagen ID.3 Pro Performance. Its electric range is limited by external causes, powertrain materials, and thermal management strategies. The loss of energy can be reduced through a better integration of the cell, module, and pack, and also by avoiding the use of modules. To improve the power capacity, the study recommended pre-heating strategies and a design that reduces overpotential and improves thermal stability.

The behavior of battery duration was examined by Lehtola and Zahedi [89], who indicated that as time, temperature, and the state of charge impact calendar age, cycle aging is affected by factors such as the number of cycles, depth of discharge, and charging rate. They found that optimal battery management can result in an improvement in battery life, particularly in vehicle-to-grid (V2G) operations. Kostopoulos et al. [90] established that the optimal state of charge range lies between 20% and 80%, beyond which energy losses during recharging double, slowing it down, while the consumption increases by approximately 2 kWh/100 km, the battery degrades more readily, and its lifespan is reduced.

In regards to lead–acid batteries, Davidson et al. [91] assessed their environmental impact, demonstrating that the negative effects of lead extraction and battery production are significantly offset by the employed technologies and high recycling rates.

3.4. Collection Phase

Battery collection is the first phase of battery EOL; thus, any issue can congest subsequent stages and overall sustainability. Given the projected increase in the number of end-of-life batteries from 2018 to 2040 from 192 to 423 times, it is crucial to optimize this phase [92]. Moreover, the collection phase should ensure a consistent supply of EoL batteries even to justify recovery processes. Although this challenge is expected to resolve autonomously over time [93], currently, the collection phase should guarantee more collection pathways, reducing inadequate disposal or non-disposal [94]. Jayant et al. [95] modeled and simulated a reverse logistics system for collecting EoL batteries and determined that factors such as the capacity of the disassembly site, the supplier’s capacity, cost of reprocessing, remanufacturing, and cost of new modules, linked to demand, production processes, and environmental impacts, must be considered. Slattery et al. [96] focused on the logistical transport of EoL batteries, frequently neglected in most studies, resulting in a shortage of data, which impacts between 1 and 3.5% of life cycle greenhouse gas emissions and 41% of recycling costs.

The EPR system is a crucial aspect in the successful management of end-of-life batteries. Turner and Nugent [97] pointed out that implementing only EPR practices regarding single-use batteries may not bring the desired environmental outcomes and that alternative approaches such as bans on single-use batteries and the promotion of rechargeable batteries may be more effective. The choice of the various EPR channels depends on independent recycling and commissioning alliance recycling costs and reuse costs [98]. Lin and Chiu [99] evaluated different EPR schemes in Taiwan, finding that the most effective scheme is a combination of an organized producer responsibility scheme (PRO) and a deposit system. Conclusively, Compagnoni [100] evaluated the state of the art in EPR for electronic and electrical equipment (EEE) and provided recommendations for improvement, both politically and in terms of macro-area interactions.

3.5. Recycling Phase

This chapter addresses recycling problems and solutions to enhance efficiency and increase the rate of recovery. As various batteries necessitate distinct methods, the chapter examines the literature on lead–acid batteries, lithium-ion batteries, and other battery types separately. The recycling approaches outlined are tailored to the specific needs and optimal processes for each battery chemistry, with dedicated methods highlighted to maximize material recovery and efficiency across different battery types.

Examining the lead–acid battery industry first, in 2020, China produced 227.36 million KVAh of lead–acid batteries, surpassed by the number that reached the EOL, 233.32 million KVAh, creating both a challenge and an opportunity [98]. X. Tian et al. [101] compared five lead–acid battery recycling methods, including three traditional pyrometallurgical methods and two innovative hydrometallurgical methods. The environmental analysis showed that the QSL furnace had the best overall performance, while the citrate leaching process, despite having minimal direct impacts, uses citric acid, which is energy-intensive and has significant indirect impacts on Global Warming Potential (GWP) and eutrophication. Pyrometallurgy methods were also more economically profitable; hence, they are the most prevalent methods. W. Zhang et al. [102] identified a promising technology at TRL6-7 for recovering Pb paste: the paste-to-paste leaching method tested by Kumar and Yang.

Focusing on LIB recycling, Gao et al. [103], Jin et al. [104], Pražanová et al. [105], Gianvincenzi et al. [106], and G. Tian et al. [107] have emphasized that pyrometallurgy contributes to the recovery of Co, but it is not effective for Li and manganese (Mn), and therefore, it must be combined with hydrometallurgy. According to Makuza et al. [108], the replacement of Co in commercially available batteries will make pyrometallurgical processes obsolete unless they are integrated into a flexible structure with various technologies. Hydrometallurgy has high recovery efficiency through the acid leaching process, recovering more than 99% of Li and Co and over 98% of high-purity Cu with low energy consumption. However, it requires optimization, as it is time-consuming and generates a substantial amount of wastewater [109,110]; in the end, it is more impactful than pyrometallurgy in terms of carbon footprint [111]. The LCA conducted by Y. Wang et al. [112] showed any LIB recycling methodology has the potential to save a minimum of 30% of metals. Moreover, utilizing end-of-life LIBs as energy storage systems (ESSs) as a second life before recycling can bring substantial environmental benefits. Indeed, if 50% could be used in ESSs, it could offset the environmental impact of upstream processes of LIBs. Tao et al. [113] found that replacing Co with Ni can increase sustainability. Furthermore, they demonstrated that the higher the energy density, the lower the environmental impact, while the higher the specific capacity, the higher the environmental impact.

Several studies have aimed to enhance the hydrometallurgical recycling process. Fahimi et al. [111] proposed an immediate improvement by replacing deionized water with distilled water and using tap water for the washing process. Peeters et al. [114] suggested an alternative leaching method in a single step, exploiting current collectors as reducing agents for the extraction of Co from LCOs, decreasing the chemicals used and the wastewater produced. They demonstrated that Cu is an excellent reducing agent. J. Kumar et al. [115] focused on the recycling of LFPs, investigating selective Li leaching methodologies. These methodologies could also be applicable to NCM-based cathode materials, which are layered compounds. Among these perspectives, J. Kumar et al. [115] and Roy et al. [116] identified bioleaching using biomass waste as cost-effective and eco-friendly alternative leaching agents which generate less process waste and reduce biomass impacts. Golmohammadzadeh et al. [117] deepened the study of using organic-based acids as leaching reagents, recommending the use of reducing agents based on glucose, sucrose, lactose, alcohol, phenolic aromatics, citric acid, oxalic acid, sodium borohydride, pyrite, sodium sulfite, sodium bisulfite, carbon, ammonium thiosulfate, sulfite of ammonium, corn stalk, sawdust, molasses, and corncob. Among the promising recycling processes, Gao et al. [103] identified the high potential of ion sieving and ion imprinting for selective separation and purification. Roy et al. [116] and Morina et al. [118] focused on cathode material recovery, identifying electro-deposition and deep eutectic solvent (DES)-based green solvo-metallurgical processes.

Hydrometallurgy and pyrometallurgy are prevalent and commonly used technologies; however, they are not the only options available. Gao et al. [103], Pražanová et al. [105], and Zhou et al. [119] evaluated the potential of direct recovery without chemical use, determining subcritical CO₂ extraction electrolytes to be the most promising approach. The primary challenge facing direct recovery processes is their high cost. Velázquez-Martínez et al. [120] compared ten innovative technologies and identified the OnTo technology as the most potential due to its capability to recover anode and cathode material from end-of-life lithium-ion batteries (EoL LIBs) to be reused in new LIBs. Waterjet-based recycling is another excellent alternative that enables the recovery of cathode material ready for reuse. Kurz et al. [121] the GWP of waterjet-based recycling is between 8 and 26 times lower than that of conventional methods. Wolf et al. [122] demonstrated the efficacy of the semi-continuous centrifugation process in separating battery active materials and aqueous multi-component agglomerate dispersions for direct recycling, thereby enhancing subsequent hydrometallurgical stages. Perez-Antolin et al. [123] proposed a potentially revolutionary methodology for replacing spent EoL LIB electrode active materials using the Regenerative Electrochemical Ion-Pumping Cell (REIPC) with semi-solid electrodes. This method reduces costs by 95% compared to conventional manufacturing, providing a sustainable alternative to precipitation and ion exchange resin processes.

Successful recycling requires proper pre-treatment. Mechanical crushing is the most widely used due to its high productivity, but it nevertheless suffers from the heterogeneity of EoL LIBs [124]. To discharge exhausted LIBs, the short circuit is the fastest method, but it poses fire or explosion risks, making controlled discharge a safer option while also capturing heat. Controlled discharge, however, has its own limitations in terms of discharge and cost. Thermal deactivation is a promising alternative, which, however, has a low TRL. Garg et al. [125] and Meng et al. [126] asserted that intelligent disassembly through machine learning (ML) and artificial intelligence (AI) can improve efficiency and manage diversity, lowering risks, costs, and times. Dos Santos et al. [127] presented a cost-effective and sustainable closed-loop process for Co and Li recovery from portable electrical devices using green smoothing for Co and an innovative evaporation–calcination and water dissolution method for the recovery of Li, resulting in a recovery rate of 97.6–99.6% for Co and 75% for Li.

In conclusion, the management aspect of LIB recycling is equally crucial as the recycling processes themselves. Fahimi et al. [111] employed the ESCAPE method to assess the impacts of recycling processes, showing that it can be utilized as effective pre-screening and LCA comparison tool. S. Sun et al. [128] and W. Zhang et al. [129] provided recommendations for public decision makers based on the management of EoL LIBs, suggesting closed-loop recycling solutions primarily utilizing mechanical pre-treatment followed by hydrometallurgical processes.

The recycling of non-Li batteries was also explored. Assefi et al. [130] studied the recycling of nickel–cadmium (Ni-Cd) and nickel–metal hydride (Ni-MH) through the thermal reduction of pyrometallurgy processes. Assefi et al. [131] proposed an alternative method for recycling Ni-Cd batteries by converting them into highly porous NiO nano-cuboids through selective isolation and hydrothermal treatment. Yao et al. [132] developed a technique for the recovery of rare earth elements in EoL Ni-MH batteries through Supercritical Fluid Extraction. Zinc-based EoL battery recycling was approached by Maryam Sadeghi et al. [133], using hydrometallurgical processes for Mn and Zinc (Zn) recovery.

3.6. Second-Life Phase

The potential for second-life applications varies by battery type, with lithium-ion batteries, for example, being particularly suited for ESSs due to their durability and remaining capacity after initial use, whereas other chemistries present different second-life viability.

To ensure a second life, it is necessary for a battery to go through refurbishing and remanufacturing processes. Cong et al. [134] published a reference paper on battery refurbishing, detailing its four phases: disassembling, testing, regrouping, and second use. The disassembling process should be performed at the level of modules or cells without causing damage, so understanding the limits and constraints that differentiate the various cells is important. The cells are then regrouped based on similar electrochemical performance as determined by SOH tests and designated for a second life based on the destination requirements. Refurbishing is more energy-efficient and uses fewer materials than recycling, but the disassembling and reassembling phase must consider emissions and toxic substances. Further study is needed in this area. Other critical factors in the process include manual work, risks, and process timing. According to Foster et al. [135], Kampker et al. [136], and Standridge and Hasan [93], the terms “repurposing” and “refurbishing” are interchangeable. Huster et al. [137], however, used “repurposing” to refer to the “second life destination”. The process of remanufacturing differs from refurbishing as it involves replacing degraded cells instead of regrouping them. This results in restoring the SOH to its original level, but it also requires new cells and materials. Both processes begin similarly; therefore, Foster et al. [135] and Standridge and Hasan [93] suggested the use of a flexible structure to manage case by case. Kampker et al. [136] provided a decision-making framework for remanufacturing and repurposing/refurbishing for EoL LIBs. Standridge and Hasan [93] created a mathematical model to determine the production capacities required for remanufacturing, repurposing/refurbishing, and recycling. Currently, remanufacturing is more cost-effective than repurposing/refurbishing. While remanufacturing costs are about 60% of a new battery, repurposing/refurbishing becomes viable only at certain R&D expenses and minimum sales price levels [135]. Huster et al. [137] highlighted the impact of production and raw material costs on the future feasibility of these processes, making it challenging to predict their future.

EV batteries are warranted for 8–10 years; subsequently, despite having 80% capacity, they are not considered suitable for the traction of cars [138], but their potential is adequate for other uses. Shahjalal et al. [139] emphasize the importance of evaluating the economic value of using second-life batteries (SLBs) considering the decreasing cost of new LIBs, the shorter lifespan and refurbishing costs of SLBs, as well as the heterogeneity of SLBs, which may hinder their compatibility with a specific use. Vu et al. [140] stated that the feasibility of using SLBs through refurbishing or remanufacturing depends on the applicant company’s requirements. SLBs can be used, in particular, for grid stationary applications, peak shaving, reducing renewable energy intermittence, off-grid electricity supply, and mobile fast-charging stations. Casals et al. [138] studied the remaining useful life of SLBs in different scenarios, with results showing that fast EV charging stations can use SLBs for over 30 years, off-grid applications for 12 years, and grid services for 6 to 12 years. X. Hu et al. [141] and Toorajipour et al. [12] explored the current business models and interviewed key players in the value chain to determine the elements that promote circular businesses. These elements include political support, coordination and communication across the value and supply chain, the development of V2G, improved energy production from renewable sources, and the integration of advanced technologies like AI, blockchain, IoT, cloud computing, big data, and smart manufacturing. According to Lee et al. [142], using SLBs not only supports a circular economy but also helps reduce costs: a new battery accounts for 70% of the total cost of an ESS. Silvestri et al. [143] demonstrated that the use of SLBs combined with photovoltaic (PV) panels results in a roughly 22% reduction in both environmental and economic impacts compared to relying solely on the national grid. Obrecht et al. [144] predict that by 2040, between 6.27% and 21.68% of the electricity generated by photovoltaic systems will be stored in batteries, thus making the adoption of SLBs in this application environmentally and economically beneficial. Ioakimidis et al. [145] demonstrated the sustainability of the second use of EV LFPs in smart buildings; however, they did not consider EoL LFP recycling scenarios. Casals et al. [138] and Cusenza et al. [146] found that the use of SLBs in smart buildings can increase battery lifespan by 35% and reduce the systems’ overall impacts by 4% in terms of energy demand and 17% in terms of abiotic depletion potential. S. Hu et al. [147] confirmed the technical feasibility of using SLBs as flexible loads in economic power dispatch, with estimated savings of 12%. Horesh et al. [148] evaluated the use of a Heterogeneous Unifying Battery (HUB) for SLBs and showed its effectiveness in frequency regulation. Lacap et al. [149] studied a real-life case application of SLBs in microgrids with a SOH of 71%, which was stable and achieved a 60% reduction in peak periods and a 39% decrease in energy consumption. White et al. [150,151] provided an analysis model for SLB performance. In grid frequency regulation, they found that batteries with active thermal management are more efficient and that higher energy efficiency corresponds to lower density; therefore, there was more space and fewer frequency regulation services were offered. Nedjalkov et al. [152] explained the application and decision-making phases of SLBs in off-grid projects. Reinhardt et al. [153] presented a framework for building sustainable models using SLBs.

3.7. Transversal Phase

The last issues addressed in this SLR are crucial for the entire battery life cycle. An optimized BMS enhances performance and safety and offers circular opportunities in the EoL phases. The digital passport and sustainable supply chains are central topics in all key industries that need to improve their sustainability for competitiveness and compliance with regulations.

Battery management systems (BMSs) are making significant progress towards effective battery management. Huang et al. [154], K. Liu, Wang, et al. [57], Pattnaik et al. [155], and Y. Wang et al. [156] have shown that advanced sensors are necessary for monitoring multiple internal states and parameters. New technologies, such as fiber-optic sensing, buckled membrane sensors, ultrasonic transmission-based state of charge (SOC) probes, acousto-ultrasonic guided waves, and high-precision contact-type displacement sensors are emerging. Current technology relies on trained data sets rather than the internal electrochemical processes, thermal field prediction, and behavioral characteristics analysis, resulting in several limitations. Single-state estimation is also limited, so joint state estimation increases accuracy. BMS fault diagnosis currently relies on detection thresholds and simple fault diagnosis, which are not adequate for thermal or sensor faults. The advent of 5G will drive the evolution of BMSs, taking advantage of big data and cloud computing, as explored by K. Liu et al. [157]. They specifically delved into AI, offering valuable information for the implementation and optimization of the BMS through it. Bordes et al. [158], Hossain et al. [159], and Kassim et al. [160] analyzed algorithms for estimating SOH and SOC. Girijaprasanna and Dhanamjayulu [161] specifically reviewed methodologies for accurate SOC estimation, considering internal and external factors that impact electrochemical reactions. Intelligent sensors were also studied by Hossain Lipu et al. [162], along with BMS control schemes. Their study showed how thermal management control systems using particle swarm optimization (PSO)-based fuzzy logic controllers (FLCs) and model predictive control can effectively map the battery system in complex situations. W. Wang et al. [163] analyzed the use of Digital Twins (DTs) in BMSs and found that research is still in its early stages but has produced promising results in SOC and SOH estimation. Lamoureux et al. [164] examined the BMS application of an adaptive power-mix control strategy for second-life management, which reduced battery degradation and increased second-life duration by 56% in an off-grid system. Basia et al. [165] proposed the use of a Failure Modes, Mechanisms, and Effects Analysis (FMMEA)-based fusion approach to estimate remaining useful life (RUL). D’Arpino et al. [166] aimed to reduce battery degradation through optimal control using a dynamic programming algorithm, which has the potential to greatly benefit second-life batteries (SLBs). Hong et al. [167] used variable-length-input long short-term memory neural networks capable of estimating SOH in real time and, if trained, predicting battery capacity degradation trajectories. Bordes et al. [158] demonstrated the results of the DEMOBASE project, including the application of a neural network to estimate battery parameters, streamlining some operations such as periodic SOC recalibration and reducing the need for complex electrochemical models with a bridge between the neural network and the BMS platform. Tete et al. [168] reviewed the impact of temperature management on battery performance and lifespan. Siddique et al. [169] focused on using phase change materials (PCMs) and thermoelectric coolers (TECs) for thermal management, while Zare et al. [170] evaluated various types of solid–liquid PCM in the automotive sector and proposed PCM organic as eco-friendly alternatives. Al Qubeissi et al. [171] demonstrated the effectiveness of N-heptane as a dielectric hydrocarbon coolant.

The battery passport (BP) is a critical tool in the regulation of batteries and a cornerstone of the Global Battery Alliance. It is also included in the Circular Economy Action Plan and proposed by the World Economic Forum. The BP involves collecting data throughout the product’s life cycle, covering aspects from materials and chemicals to components and end-of-life information. The BP promotes the transparency, standardization, environmental benchmarking, validation, and traceability of all materials and processes, supporting decision-making for second life battery (SLB) applications [172,173]. Berger et al. [174] have developed a theoretical framework for the necessary information to be included in a digital battery product to aid policymakers and serve as a model for other digital passports. Cheng et al. [175] suggest the use of blockchain for traceability, which can drive the adoption of formal recycling channels.

To attain a sustainable supply chain, multiple challenges must be addressed by implementing forecasting systems for raw material demand and supply, cutting production costs and time, enhancing production efficiency and longevity, reducing environmental impact during recycling, optimizing material extraction methods, and implementing cost-reducing measures [176]. Weimer et al. [177] provided an integrated definition of the raw material value chain. The challenges in the value and supply chain vary from country to country; for example, in the USA, only LIB cells and separator materials are produced, and other components are imported. However, their growing vehicle sales market could lead to the internalization of components using recycled materials from EoL LIBs in the future. In the short term, issues such as scarce EoL battery collection mechanisms, low volumes, and high costs in the recycling phase must be addressed. In the long term, the composition of the next-generation battery and how it will impact the entire value chain remains uncertain [178]. P. Kumar et al. [179] developed a methodology to analyze the supply chain in each territorial situation, identifying 17 key sustainability factors using the Delphi technique and the Best–Worst Method (BWM), and tested it using India as a case study. A. Amato et al. [180] focused on the sustainability of the Li supply chain and concluded that the secondary raw material can replace the primary material no more than 30%. Furthermore, they found that decentralized end-of-life management by small and medium-sized enterprises has a lower impact on the environment compared to centralized management. Subulan et al. [181] employed the fuzzy goal programming model as a decision-making tool for lead–acid battery sustainable supply chains to achieve objectives while providing flexibility. Gu et al. [182] mathematically investigated the role of governments in sustainable supply chains and found that governments will be more inclined to use subsidies for secondary use if the rate of remanufacturing of discarded batteries is higher than the quality of reusable batteries. Their study also provided all the decision combinations that can be made by SLB users. X. Wang et al. [183] dealt with consumer behavior and its positive impact on circular businesses, also described by Mosconi et al. [184]. Matos et al. [185] developed a multilayer system approach by intertwining the flows of Co, Li, Mn, natural graphite, and Ni in Europe to identify and solve bottlenecks in the main raw material supply chain of Co, Li, Mn, natural graphite, and Ni in Europe. The analysis revealed that the supply chain of these materials is heavily dependent on imports, especially Li and graphite, which are recycled outside of Europe.

4. Life Cycle Management Framework

The developed framework for sustainable life cycle management is based on the objectives set forth in the new European regulation, offering a holistic and structured approach to meet the stringent demands of the regulation and guide the implementation of sustainable practices throughout the battery life cycle, incorporating various activities, frameworks, and technologies derived from the results of this SLR. Figure 3 consists of distinct elements, including elliptical-shaped box terminators representing the actors responsible for specific phases or processes in the battery life cycle. Processes in rectangular boxes indicate various activities, and diamond-shaped decision boxes are used for evaluating compliance with regulatory requirements. Post-it boxes are employed to group the outcomes of the SLR and contain summarized information on the proposed solutions from existing research papers. For ease of reading and clarity, each phase of the battery life cycle is associated with a distinct color in the framework. Indigo is attributed to the extraction and refining phase of raw materials. Amber represents the manufacturing phase. Peacock blue is assigned to the use and collecting phase. Violet is associated with the refurbishing, remanufacturing, and second-life phase. Lastly, fuchsia is used for the recycling phase. In the following subsections, the framework will be explained, and to aid the reader, the text present in the diagram blocks will be provided in italics.

4.1. Extraction Phase Management

The extraction and refining phase of the battery life cycle plays a pivotal role in ensuring the sustainable supply of raw materials, making it a critical stage that demands meticulous attention. Within this phase, the responsibility lies with the supplier, who may either be directly engaged in upstream processes starting from extraction or be associated with a Tier 2 supplier. The supplier’s role becomes twofold: first, to comply with the stringent requirements of responsible sourcing, and second, to exercise vigilance in verifying that the raw materials have been extracted and processed sustainably. In cases where sustainability standards are not met, the supplier must promptly seek alternative sources that align with eco-friendly practices. Responsible sourcing best practices are illustrated by Deberdt and Billon [35]. Drawing insights from a comprehensive analysis of the literature, a myriad of techniques for the alternative extraction of lithium (Li) and cobalt (Co) have emerged, each presenting a unique approach to address sustainability concerns. For lithium extraction, researchers have explored methods aimed at reducing environmental impact, such as optimizing adsorption efficiency using highly efficient adsorbents, combined with the integration of adsorption–electrochemical methods, offering a potentially eco-conscious alternative [24]. In cobalt extraction, advancements focus on deep-sea extraction, which requires careful consideration of environmental and regulatory factors, as well as coordinated investments to educate all value chain actors, particularly local communities and artisanal and small-scale mining beneficiaries, who may benefit from more responsible initiatives [37,38,184]. Additionally, proactive investments in Li-rich European geothermal fields have been proposed to enable lithium extraction while simultaneously harnessing heat and energy generation—a promising approach to optimize resource use [25]. Despite the numerous advancements in alternative extraction techniques, the literature analysis revealed an absence of specific studies focusing on improving existing extraction processes. As such, future research endeavors should aim to optimize cobalt recovery processes as a valuable by-product during nickel (Ni) and copper (Cu) extraction, propose cost-effective disposal or recovery systems for cobalt derived from hydrometallurgy acid waste, develop forward-looking demand and supply predictive models to ensure the sustainable primary production of raw materials, and update comprehensive databases for LCA to garner a holistic understanding of the environmental impacts involved [27,28,30,31,32,33,34]. Addressing these research gaps promises to bolster the practice of responsible sourcing during the extraction and refining phase, fostering sustainability at the very foundation of the battery industry.

4.2. Manufacturing Phase Management

The manufacturing phase is under the responsibility of the manufacturer/producer, who must first focus on the battery design. The design process must consider various factors related to eco-design, an area of particular focus by the European Commission.

Regarding the restriction of substances, the regulation mandates that all batteries must not contain more than 0.0005% of mercury, and portable batteries shall not contain more than 0.002% of cadmium. From mid-2024, portable batteries, whether or not they are incorporated into appliances, shall not contain more than 0.01% of lead by weight, with a 5-year derogation for portable zinc–air button cells. However, the challenge lies in finding solutions to reduce hazardous substances. Studies on batteries made with alternative materials have been excluded from the SLR as their technology readiness levels (TRLs) are low, and their implementation may not have significant impacts on the regulation.

Enhancing the removability and replaceability of batteries necessitates the application of eco-design principles. From 2027, any natural or legal person placing products with large-format lithium-, manganese-, or nickel-based batteries (LMT batteries) on the market shall ensure that those batteries, as well as individual battery cells included in the battery pack, are readily removable and replaceable by an independent professional at any time during the lifetime of the product. While frameworks exist for designing cathode materials for recycling [58], a comprehensive framework encompassing design for assembly, disassembly, recycling, remanufacturing, and reuse is needed, alongside the implementation of mandatory tools like the digital passport.

Addressing the carbon footprint challenge, industrial batteries (above 2 kWh), EV, and LMT batteries must comply with CF requirements. A staged approach involves first declaring the CF, then implementing performance classes, and lastly setting maximum thresholds. The CF declaration is calculated as kgs of CO₂ equivalent per one kWh of the total energy provided by the battery over its expected service life, per battery model, per manufacturing plant. The methodology for CF calculation is to be detailed by the Commission, and a feasibility study to extend this to all batteries is expected before the end of 2030. To reduce the CF impacts, optimizing cutting, annealing, and formation processes [44], and adopting decision-making tools for sustainable battery manufacturing [43,45] are critical. Additionally, managing the thermal issues of LIBs [47] and utilizing synthetic graphite [48], two-phase calcination for CAM production [49], fly ashes for silicon anodes [50], and SLS in lead–acid battery electrolytes [52] are promising solutions.

Furthermore, the design phase should consider the subsequent stages of the life cycle, including performance and durability requirements. The regulation introduces minimum requirements for factors such as rated capacity, capacity fade, power, power fade, internal resistance, internal resistance increase, and energy round trip efficiency. Additionally, batteries must have an expected lifetime in terms of cycles and calendar years under the reference conditions for which they have been designed. To optimize performance, improvements in pre-heating systems and sensor integration are crucial research areas [85,154]. Environmental performances can be optimized through the exclusive use of renewable energy and a unified, accessible database for accurate Life Cycle Assessments [75,80,81,82,83,84]. The durability aspect is essential, with HESS showing advantages over traditional systems [86]. Moreover, introducing an eco-charging mode to maintain SOC between 20% and 80% and exploring V2G operations hold promise [89,90].

Additionally, in this phase, it is necessary to consider the challenges related to recyclability and remanufacturing, which will be discussed in more detail later. Designing batteries for easy disassembly, with a focus on Design for Disassembling and Refurbishing [134], is vital as battery volumes increase and disassembly becomes a bottleneck. Advancing technologies in this area are essential to ensure sustainable and efficient processes.

Subsequently, the inclusion of a BMS must be considered. As mandated by the regulation, a BMS must be integrated into LMT batteries, EV batteries, and stationary battery energy storage systems (SBESSs) by mid-2024. The BMS will provide read-only access to authorized parties for various purposes, such as facilitating battery availability through energy storage, evaluating remaining lifetime based on health estimation, and supporting battery reuse, repurpose, or remanufacturing. In the literature, BMS development requires real-time data sensors, multi-sensor information fusion technology, and accurate battery modeling [156]. Research should focus on hybrid algorithms for SOC and SOH estimations [158,161], embedded systems, and high-performance processors [155,157,160,162,167]. Additional areas of interest include thermal abuse analysis [157], organic phase change materials (PCMs) [168], and dielectric thermal (DT) technologies [170]. Challenges like data management, privacy, and AI integration need further attention [157].

After planning and designing, the assembly phase begins, with manufacturers adhering to the European regulation’s obligations on recycled content. By mid-2031, minimum recycled content targets are set for cobalt (16%), lead (85%), lithium (6%), and nickel (6%), and they are expected to increase by mid-2036 (cobalt: 26%; lead: 85%; lithium: 12%; nickel: 15%). To achieve these targets, manufacturers must utilize valid sources of recovered material, including battery manufacturing and post-consumer waste. However, higher recycled content largely relies on advancements in the recycling stage, promoting batteries with increased recycled materials.

Afterwards, following battery production, the testing phase ensues, where ensuring safety is of paramount importance. The European regulation mandates stationary battery energy storage systems to possess technical documentation attesting to their safety and hazard mitigation measures to be ready for the market. From a technological standpoint, battery safety remains a major concern, and various solutions have been proposed to enhance it. One such solution is improving thermal stability and flame resistance of the electrolyte using eutectic solvents and aqueous electrolytes [61]. Incorporating a reversible shutdown function or thermal protection in the separators has also shown potential to enhance battery safety, although its impact on performance must be carefully evaluated [62]. Moreover, several authors have proposed solutions to mitigate safety issues stemming from mechanical, thermal, and electrical abuse. These solutions should be analyzed and consolidated into a unified safety design framework [63,64,65,66,67,68,69]. Lastly, improvements in the detection technologies used in security tests are also needed [67].

4.3. Use and Collecting Phase Management

Once the battery is prepared, it reaches the end users, either directly or through a series of distributors, depending on the manufacturer’s network channels. This marks the usage phase of the battery, eventually leading to the collecting phase as the batteries reach their EOL. Producers of batteries must follow EPR regulations when introducing batteries to the market in a Member State. This includes financial contributions to cover expenses like separate collection, transport, and treatment of waste batteries, conducting compositional surveys of mixed municipal waste, providing information on battery waste prevention and management, and data reporting to competent authorities. Additionally, activities like preparing for reuse, repurpose, repurposing, or remanufacturing invoke additional EPR obligations for economic operators. Producers can also delegate these responsibilities to a Producer Responsibility Organization (PRO), subject to additional requirements. The EOL manager plays a crucial role in collecting batteries to meet the Commission’s imposed targets. The regulation mandates collection targets based on different categories of batteries and different years. For waste portable batteries, the collection targets are set at 45% by 2023, 63% by 2027, and 73% by 2030. For waste large-format lithium-, manganese-, or nickel-based batteries (LMT), the targets are 51% by 2028 and 61% by 2031 [16]. To optimize the EPR process and enhance its efficiency, proactive management of demand and supply for second use is crucial, including addressing the transportation phase, which often goes unaddressed in LCA analyses despite its impact [96]. Establishing a sustainable supply chain requires better communication along the entire value chain, which can be achieved through blockchain-based platforms with modules for automatic reporting, certification control, and support of circular businesses [181,182,183,184,185]. Decentralizing EOL management is also considered crucial in reducing environmental impact [180].

Once collected, the batteries undergo a thorough evaluation to determine their second-life suitability. Depending on their condition, batteries may be selected for remanufacturing or refurbishing, where they are restored and prepared for second life. Alternatively, if a battery is deemed unrecoverable, it will be directed towards recycling processes to recover valuable materials and reduce environmental impact.

4.4. Remanufacturing, Refurbishing, and Second-Life Management

To validate that a waste battery subject to preparing for second life or remanufacturing/refurbishing is no longer waste, the battery holder must provide evidence of a state-of-health evaluation or testing, demonstrating its capability to deliver the required performance. Additionally, documentation of further use of the battery, supported by an invoice or a contract for sale or ownership transfer, is necessary. Proper protection during transportation, loading, and unloading, achieved through adequate packaging and stacking, is also required. From a scientific perspective, eco-design and automated, intelligent disassembly play a significant role in promoting refurbishing and remanufacturing [134,136]. Although LCA studies highlight the benefits of second-use batteries, more data and exploration are needed in this area, which can be gathered from BMSs and digital battery passports. Developing a precise second-life battery degradation model and integrating cutting-edge technologies and technical–economic–territorial analysis are essential for optimizing second-life battery applications [12,85,134,140,142,150,151].

Consequently, the life cycle diagram illustrates that after the second-life phase, the battery is returned to the end user for further usage, which may involve different applications and sectors. This second-life stage offers an additional opportunity for battery utilization, prolonging their functionality and value before proceeding to the subsequent phase, which involves recycling.

4.5. Recycling Phase Management

In the final stage of the battery life cycle, recycling plays a pivotal role, aligning with the ambitious targets set by the European Commission for recycling efficiencies and material recovery. By 2025 and 2030, the targets are set at 75% and 80% for lead–acid batteries, 65% and 70% for lithium-based batteries, and 80% for nickel–cadmium batteries. For other waste batteries, the target is 50%. In terms of material recovery targets, the Commission aims for 90% recovery of cobalt, copper, and lead by 2031, along with 50% recovery of lithium by the same year. Nickel, on the other hand, is targeted for 90% recovery by 2031. From a chemical and scientific standpoint, significant progress is being made to improve recycling processes. The QSL furnace process is recommended for primary lead–acid battery smelters, while the rotary furnace process is suggested for secondary Pb plants. Hydrometallurgy technologies are being improved with innovative techniques like leaching paste-to-paste [102]. For LIB recycling, a wide range of solutions are available, and detailed LCAs are recommended for evaluating recycling methodologies [116]. To increase recycling rates, designing batteries for recycling and implementing industrial-scale intelligent disassembly using AI and ML are crucial [108,111,119,129]. Short-term strategies include using alternative one-step leaching methods and substitution of ultrapure water, while long-term solutions involve investigating the impact of leaching on organic-based acid reagents [111,114]. To enhance the recycling process, frameworks combining metallurgical, mechanical, and chemical methods are being developed [111,128]. Future studies should focus on the quality of recycled output, systemic pathways for the recovery of anodic materials, and the improvement of mechanical crushing. The integration of eco-design principles can further enhance the flexibility and efficiency of recycling methods, ensuring the achievement of recycled content requirements and contributing to a sustainable battery industry [12,85,140,142,150,151].

Notably, the circular nature of the life cycle diagram demonstrates that the output of the recycling process will be reintroduced into the battery production phase during manufacturing, contributing to the achievement of the recycled content targets.

4.6. Battery Passport Management

The battery passport plays a pivotal role in the sustainable life cycle management framework, ensuring traceability and transparency across the entire battery life cycle. Represented by a dashed line encompassing the entire cycle in the diagram, the BP’s scope extends from material extraction through recycling and reuse. By 2027, the European regulation mandates that LMT batteries, EV batteries, and large industrial batteries with a capacity above 2 kWh must be equipped with a DPP accessible through a QR Code. The BP is envisioned to encompass various levels of information accessibility, catering to different stakeholders. At the public level, it will provide essential details such as manufacturer information, battery specifications, and material composition. For interested parties and the Commission, the BP will include compliance test reports and other relevant data. At a more restricted level, authorized bodies will have access to performance parameters, battery status, usage data, and environmental conditions. The successful implementation of the BP poses both opportunities and challenges. One of the primary challenges lies in standardizing formats, metrics, measurements, and data definitions to ensure consistency and interoperability across the battery industry [173]. Additionally, ensuring data protection, including intellectual property and confidential information, is paramount. Establishing mechanisms for data accessibility throughout the entire value chain while safeguarding sensitive data is a delicate balance. To address these challenges, researchers and industry players have proposed innovative approaches. Berger et al. [174] put forth a theoretical framework which requires further technological and industrial development to be fully realized. Blockchain technology, with its decentralized and secure nature, shows promise in ensuring data integrity and confidentiality in the BP [174,175]. Other methods, such as point-to-point transmission, consensus mechanisms, and encryption algorithms, can also contribute to bolstering data security and accessibility.

5. Conclusions

In this paper, 177 articles have been analyzed to collect solutions and highlight gaps in the state of the art of battery management throughout the life cycle. The analysis reveals that most of the topics have been addressed, with the regulation issue of recycling LIBs garnering the largest number of proposed solutions. These solutions range from simple techniques such as substituting deionized water to more complex and resource-intensive innovative technologies. The scientific community is also directing their efforts towards enhancing the efficiency of BMS and reducing the CF during the manufacturing phase.

In Section 4, the life cycle management framework was presented, offering a comprehensive approach to address the challenges and opportunities in the battery life cycle. This framework serves as a bridge, aligning research efforts with the policy tools established by the new European regulation, guiding future studies and aiding all actors in the battery value chain to prepare for the ambitious goals set forth by the regulation. Designed to offer a flexible yet specific approach, the framework acknowledges the unique challenges and optimal practices across different battery types, ensuring tailored solutions for sustainable battery applications throughout the life cycle.

Table 7. Technology solutions clustered (E = extraction, M = manufacturing, U = use, C = collecting, S = second life, R = recycling).

Solutions	E	M	U	C	S	R
Law harmonization	✓	✓	✓	✓	✓	✓
Eco-design		✓	✓	✓	✓	✓
Actor involvement	✓			✓	✓	✓
Complete and unified databases			✓	✓	✓	✓
Intelligent and automized disassembling					✓	✓
Cutting-edge tech integration			✓	✓	✓	✓

summarizes solutions that appear in multiple phases and can address various regulation issues, thus serving as potential starting points for achieving a more sustainable battery life cycle and meeting regulation goals. Among these, law harmonization is the only one that would guarantee benefits in every single phase of the life cycle, but it is a high-level solution that can be applied at the governmental and supranational levels. The other solutions, on the other hand, can be applied at the scientific level, starting from eco-design solutions that would favor all the phases ranging from manufacturing to the second life of the battery, contributing to the achievement of regulation issues such as removability and replaceability, safety increase, performance increase, durability, recycling efficiency and recovery increase, refurbishing, and remanufacturing. Similarly, the involvement and communication between all the value chain actors, the presence of complete and unified databases, and the integration with cutting-edge techs would support the development of optimal and sustainable strategies. All these solutions should be enhanced with the implementation of the BP which currently is at embryonic level.

Since the introduction of the regulation, there has been a notable increase in scientific publications addressing battery life cycle management and sustainability. This surge in research reflects the proactive response of the scientific community to the regulatory requirements and highlights the acceleration in developing solutions aligned with the ambitious sustainability goals. Future reviews could thus focus on these recent contributions to capture the ongoing advancements prompted by this regulatory framework.