Recycling of mixed cathode lithium‐ion batteries for electric vehicles: Current status and future outlook

TLDR

The rapid growth of electric vehicles is projected to generate up to 4 million metric tons of lithium‑ion battery waste by 2040, creating economic and environmental pressures that recycling must address, yet current infrastructure mainly recovers cobalt and is ill‑prepared for cobalt‑deficient mixed‑metal cathodes. This review surveys recycling strategies for recovering metals from mixed‑metal LIB cathodes and mixed‑chemistry scrap. Hydrometallurgical methods, involving pretreatment, reductive acid leaching of the cathode, and subsequent selective precipitation or solvent extraction of Li, Ni, Mn, Co, and impurities, can recover metals or enable direct cathode resynthesis.

Abstract

Abstract Worldwide trends in mobile electrification, largely driven by the popularity of electric vehicles (EVs) will skyrocket demands for lithium‐ion battery (LIB) production. As such, up to four million metric tons of LIB waste from EV battery packs could be generated from 2015 to 2040. LIB recycling directly addresses concerns over long‐term economic strains due to the uneven geographic distribution of resources (especially for Co and Li) and environmental issues associated with both landfilling and raw material extraction. However, LIB recycling infrastructure has not been widely adopted, and current facilities are mostly focused on Co recovery for economic gains. This incentive will decline due to shifting market trends from LiCoO 2 toward cobalt‐deficient and mixed‐metal cathodes (eg, LiNi 1/3 Mn 1/3 Co 1/3 O 2 ). Thus, this review covers recycling strategies to recover metals in mixed‐metal LIB cathodes and comingled scrap comprising different chemistries. As such, hydrometallurgical processes can meet this criterion, while also requiring a low environmental footprint and energy consumption compared to pyrometallurgy. Following pretreatment to separate the cathode from other battery components, the active material is dissolved entirely by reductive acid leaching. A complex leachate is generated, comprising cathode metals (Li + , Ni 2+ , Mn 2+ , and Co 2+ ) and impurities (Fe 3+ , Al 3+ , and Cu 2+ ) from the current collectors and battery casing, which can be separated and purified using a series of selective precipitation and/or solvent extraction steps. Alternatively, the cathode can be resynthesized directly from the leachate.