Direct Regeneration of Spent LiCoO<sub>2</sub> Black Mass Based on Fluorenone‐Mediated Lithium Supplementation and Energy‐Saving Structural Restoration
Mingli Xu, Chen Wu, Lang Ye, Yuanteng Zhang, Chenyi Zhang, Jieming Hu, Ran Tan, Dong Gu, Xuanze Wang, Olivier Fontaine, Chun Zhan, Lin Zhuang, Xinping Ai, Jiangfeng Qian
Abstract
Abstract Degraded LiCoO 2 cathode from retired Li‐ion batteries is urgently required to be recycled in a greener way for economic and environmental considerations. The coarse metallurgy technologies for Li/Co extraction with massive CO 2 emission and energy consumption cannot satisfy the requirements of carbon neutralization. Herein, it is proposed that direct regeneration of degraded LiCoO 2 cathode could be realized via 9‐fluorenone‐mediated Li supplementation and follow‐up structural restoration. The 9‐fluorenone‐lithium reagent is elaborately selected to compensate for the missing Li + into lattice with targeted stoichiometry owing to its compatible redox potential of 1.95 V versus Li + /Li, which is located just between the reversible intercalation (3.8 V) and irreversible conversion (1.2 V) potentials of LiCoO 2 electrode. Then, thermal energy‐driven structure reorganization enables Li/Co atoms to occupy the right sites, accomplishing desirable structure healing within a short annealing time of 4 h. The regenerated LiCoO 2 cathode exhibits comparable Li‐storage capability to commercial LiCoO 2 , benefiting from the non‐destructive direct regeneration technology. In addition, the regeneration route is regarded as environmentally (0.13 kg CO 2 kg −1 cell) and economically (10.07 $ kg −1 cell) superior to conventional recycling routes based on life‐cycle analysis. The precise surgery on spent LiCoO 2 cathode provides a promising solution for the forthcoming retirement rush of Li‐ion batteries.