In-situ selective leaching and closed-loop recovery from waste LiFePO4 batteries by reusable succinic acid

Recovering lithium from waste LiFePO 4 (LFP) cathode is not only an economical solution to resource constraints but also a key step toward achieving a green and circular energy industry. In this study, experiments are designed through thermodynamic analysis to determine the initial pH of the reaction. By comparing and analyzing six different organic acid leaching agents, eco-friendly succinic acid based leaching system is proposed to achieve best selective separation of 98.5% Li and 2.5% Fe respectively. The leaching mechanism of the reaction is investigated through thermodynamic analysis and structural characterizations: LiFePO 4 is converted into FePO 4 via in-situ oxidation, while the original olivine structure remains unchanged. In addition, high-purity Li 3 PO 4 is recovered through chemical precipitation method. LiFePO 4 is regenerated through the high-temperature solid-phase method and exhibits excellent electrochemical performance. Succinic acid is recycled as leaching agent, enabling the full recycling and utilization of entire process. This study provides an efficient and sustainable closed-loop recovery approach for waste LiFePO 4 cathode materials.