Microwave hydrothermal renovating and reassembling spent lithium cobalt oxide for lithium-ion battery

With the growing number of lithium-ion batteries (LIBs) that are consumed by worldwide people, recycling is necessary for addressing environmental problems and alleviating energy crisis. Especially, it is meaningful to regenerate LIBs from spent batteries. In this paper, the microwave hydrothermal method is used to replenish lithium, assemble particles and optimize the crystal structure of the spent lithium cobalt oxide. The microwave hydrothermal process can shorten the reaction time, improve the internal structure, and uniformize the particle size distribution of lithium cobalt oxide. It helps to construct a regenerated lithium cobalt oxide (LiCoO₂) battery with high-capacity and high-rate properties (141.7 mAh g^-1 at 5C). The cycle retention rate is 94.5% after 100 cycles, which is far exceeding the original lithium cobalt oxide (89.7%) and LiCoO₂ regenerated by normal hydrothermal method (88.3%). This work demonstrates the feasibility to get lithium cobalt oxide batteries with good structural stability from spent lithium cobalt oxide batteries.