High-efficiency regeneration of spent LiCoO2 battery by constructing a layer intermediate

Abstract

Lithium-ion batteries have been widely used given the rapid development of intelligent communication devices and new energy vehicles in the 21st century. The recycling of spent lithium-ion batteries has emerged as a pressing environmental concern. The regeneration of cathode materials has garnered widespread attention as the most promising approach for the recovery of lithium cobalt oxide (LCO). However, the significant impact of phase transformation layers on the regeneration efficiency of LCO has been rarely addressed. In this study, we investigated the effects of phase transformation layers on the relithiation process, demonstrating that the phase transformation layers structure impedes lithium-ion transport along its primary pathways. We further proposed using layered hydroxide oxides as structural intermediates to reconstruct the phase transformation layers on the surface of spent LCO materials. This approach mitigates the negative effects of phase transformation layers, promoting lithium-ion transport. The regenerated materials processed through this method exhibited a specific capacity after 100 cycles that was 139% of that achieved by directly regenerated materials. These results validate the method's effectiveness in enhancing the recovery efficiency and regeneration capability of spent materials.