Directly-regenerated LiCoO2 with a superb cycling stability at 4.6 V

The exponential growth of “3C” (computer, communication, and consumer electronics) market generates an ever-increasing demand on recycling materials from the end-of-life LiCoO2 (LCO) batteries with ecological and efficient methods. Herein, we present a direct and scalable approach to recycle the degraded LCO by healing and stabilizing their damaged structure via solid reactions. The as-proposed approach constructs a protective layer onto the regenerated LCO particles to suppress the O3 to H1–3 phase transition at 4.55 V. Benefiting from the unique design, superb electrochemical performance was achieved for the regenerated LCO, exhibiting a high specific capacity retention of 85.9% after 100 cycles with a charging cut-off voltage of 4.6 V and a superb rate capability, which are even superior to those of the pristine commercial LCO. In addition, compared with the LCO production with raw chemicals, the as-proposed healing-stabilizing strategy reduces the total energy consumption by 68.5%, bringing noteworthy economic and environmental benefits. This work provides not only new understandings to stabilize LCO at high voltage, but also a practical solution to the closed-loop development of LCO batteries.