Assessment of recycling methods and processes for lithium-ion batteries

A facile and efficient recovery method of valuable metals from spent lithium-ion batteries via simultaneous leaching and separation strategy

Traditional hydrometallurgical recycling methods present challenges including complex processes, significant metal loss, and high costs. To address these issues, this work introduces a facile and efficient recycling method for spent ternary cathode materials, which combines acid leaching and oxidation as well as ammonia leaching. Firstly, careful control of the phosphoric acid concentration and sodium persulfate dosage allows for the selective leaching of Li and Ni in the process of acid leaching and oxidation, and thus their leaching efficiencies can reach as high as 99.3 % and 97.2 % respectively. Meanwhile, Co and Mn can be separated in the form of Co3O4 and MnO2 remaining in the waste residues. Secondly, based on the stability difference of complexes formed by cobalt and manganese with ammonia, Co can be selectively leached from waste residue through ammonia leaching, with the leaching efficiency reaching 93.2 %, while Mn is separated via reacting with CO32- in the solution to form MnCO3. Moreover, the mechanisms of selectively leaching Li and Ni during acid leaching and oxidation processes are revealed using characterization techniques such as XRD, ICP, SEM-EDS, and thermodynamic analysis. Finally, economic analysis shows that the benefits of this approach in terms of battery reuse are considerable, and there are clear advantages in terms of process simplification and operational safety. Compared to traditional hydrometallurgical recovery methods, which typically involve sequential separation after metal leaching, the proposed method achieves simultaneous leaching and separation of metals, thereby simplifying the recovery process and reducing metal losses.

High-Selective Separation Recovery of Ni, Co, and Mn from the Spent LIBs Via Acid Dissolution and Multistage Oxidation Precipitation

For recovering Ni, Co, and Mn from lithium-ion batteries, traditional chemical precipitation methods demonstrate low selectivity and significantly contribute to environmental pollution. This study proposes a separation recovery technique for transition metals, specifically Ni, Co, and Mn, from spent LIBs, involving "acid dissolution" and "multistage oxidation precipitation". More than 98 % of transition metals can be extracted from spent LIBs using a low acid concentration (0.5 M) without reducing agents. The feasibility of separating different metals via multistage oxidation precipitation, based on their different electrode potentials for oxidizing Me2+ (Me=Mn/Co/Ni), was confirmed. The combination of oxidizing agent S2O8 2- and the precipitant OH- was universally applied to the fractional precipitation of Mn, Co, and Ni respectively. About 99 % of Mn, 97.06 % Co, and 96.62 % Ni could be precipitated sequentially by changing the concentrations of S2O8 2- and the pH value of solution. XRD, XPS, XRF, ICP-MS and other methods were employed to elucidate the mechanism behind the multistage oxidation precipitation of target metal compounds, exploiting the differential electrode potentials for oxidizing Me2+ ions. This technique surpasses traditional solvent extraction in cost-effectiveness and selectivity, showing promise for large-scale industrial applications in recovering Mn, Co, and Ni.

A Comprehensive Review on Reductive Recycling of Cathode Materials of Spent Lithium-Ion Batteries

The prosperity of the lithium-ion battery market is inevitably accompanied by the depletion of corresponding resources and the accumulation of spent batteries in a dialectical manner. Spent lithium-ion batteries are harboring the characteristics of hazardous waste and high-value resources, so efficient recycling is of great significance. The cathode material is considered as an interesting target for repurposing. Despite some important reviews give commendable emphasis to recycling technologies, there is still a dearth of exploration of recycling mechanisms. This deficiency of awareness highlights the need for further research and development in this area. This review aims to systematically review and thoroughly discuss the reduction reaction mechanism of each method regarding different cathode materials. And systematically digest the selection of reducing agent and the effect of reduction reaction on material regeneration are systematically digested, as well as the impact of the reduction reaction on the regeneration of materials. This review emphasizes the importance of balancing efficiency, economic and environmental benefits in reuse technologies. Finally, the review proposes an outlook on the opportunities and challenges facing the reuse of key materials for next-generation spent batteries aimed at promoting the green and sustainable development of lithium-ion batteries, circular economy and ecological balance.

Environment-friendly, efficient process for mechanical recovery of waste lithium iron phosphate batteries

Technology for recycling retired lithium batteries has become increasingly environment-friendly and efficient. In traditional recovery methods, pyrometallurgy or hydrometallurgy is often used as an auxiliary treatment method, which results in secondary pollution and increases the cost of harmless treatment. In this article, a new method for combined mechanical recycling of waste lithium iron phosphate (LFP) batteries is proposed to realize the classification and recycling of materials. Appearance inspections and performance tests were conducted on 1000 retired LFP batteries. After discharging and disassembling the defective batteries, the physical structure of the cathode binder was destroyed under ball-milling cycle stress, and the electrode material and metal foil were separated using ultrasonic cleaning technology. After treating the anode sheet with 100 W of ultrasonic power for 2 minutes, the anode material was completely stripped from the copper foil, and no cross-contamination between the copper foil and graphite was observed. After the cathode plate was ball-milled for 60 seconds with an abrasive particle size of 20 mm and then ultrasonically treated for 20 minutes with a power of 300 W, the stripping rate of the cathode material reached 99.0%, and the purities of the aluminium foil and LFP reached 100% and 98.1%, respectively.

Life cycle thinking and safe-and-sustainable-by-design approaches for the battery innovation landscape

Developments in battery technology are essential for the energy transition and need to follow the framework for safe-and-sustainable-by-design (SSbD) materials, chemicals, products, and processes as set by the EU. SSbD is a broad approach that ensures that chemicals/advanced materials/products/services are produced and used in a way to avoid harm to humans and the environment. Technical and policy-related literature was surveyed for battery technologies and recommendations were provided for a broad SSbD approach that remains firmly grounded in Life Cycle Thinking principles. The approach integrates functional performance and sustainability (safety, social, environmental, and economic) aspects throughout the life cycle of materials, products, and processes, and evaluates how their interactions reflect on SSbD parameters. 22 different types of batteries were analyzed in a life cycle thinking approach for criticality, toxicity/safety, environmental and social impact, circularity, functionality, and cost to ensure battery innovation has a green and sustainable purpose to avoid unintended consequences.

A Minireview on the Regeneration of NCM Cathode Material Directly from Spent Lithium-Ion Batteries with Different Cathode Chemistries

Research on the regeneration of cathode materials of spent lithium-ion batteries for resource reclamation and environmental protection is attracting more and more attention today. However, the majority of studies on recycling lithium-ion batteries (LIBs) placed the emphasis only on recovering target metals, such as Co, Ni, and Li, from the cathode materials, or how to recycle spent LIBs by conventional means. Effective reclamation strategies (e.g., pyrometallurgical technologies, hydrometallurgy techniques, and biological strategies) have been used in research on recycling used LIBs. Nevertheless, none of the existing reviews of regenerating cathode materials from waste LIBs elucidated the strategies to regenerate lithium nickel manganese cobalt oxide (NCM or LiNixCoyMnzO2) cathode materials directly from spent LIBs containing other than NCM cathodes but, at the same time, frequently used commercial cathode materials such as LiCoO2 (LCO), LiFePO4 (LFP), LiMn2O4 (LMO), etc. or from spent mixed cathode materials. This review showcases the strategies and techniques for regenerating LiNixCoyMnzO2 cathode active materials directly from some commonly used and different types of mixed-cathode materials. The article summarizes the various technologies and processes of regenerating LiNixCoyMnzO2 cathode active materials directly from some individual cathode materials and the mixed-cathode scraps of spent LIBs without their preliminary separation. In the meantime, the economic benefits and diverse synthetic routes of regenerating LiNixCoyMnzO2 cathode materials reported in the literature are analyzed systematically. This minireview can lay guidance and a theoretical basis for restoring LiNixCoyMnzO2 cathode materials.