The auto-oxidative relithiation of spent cathode materials at low temperature environment for efficient and sustainable regeneration

The reasonable recycling of spent lithium ions batteries is urgently required and beneficial to new energy industry development to approach the "carbon neutral" target. It is urgent to understanding the structural evolution of spent lack lithium cathode materials during direct regeneration technology with low temperatures condition to avoid deficiencies of complex operation in existing technology. Herein, a novel approach was developed for direct regeneration of spent LiCoO2 materials with a successful structural repair and electrochemical performance recovery, which are composed of auto-oxidative process followed by pre-treatment process of dismantling, soaking and sintering. The auto-oxidative system was composed of LiBr as lithium source and dimethyl sulfoxide as solvent and oxygen donor. The recycled LiCoO2 material shows significantly close to capacity retention of 90.79% than that of the commercial LiCoO2 material. Based on the structural evolution mechanism analysis, the novel approach is still expected to be applied into regeneration of other spent cathode materials and guide an efficient and sustainable direction for the recycling of spent lithium ions batteries.