Due to the rapidly growing demand for lithium-ion batteries (LIBs) and the upcoming peak in LIBs decommissioning, there is an urgent need to develop a recycling method suitable for spent LIBs. A pyro-recycling process using hydrogen as a reductant has been recognized as an environmentally friendly method for the recycling of LIBs. However, the complexity of the reaction in the conventional recycling process results in a large amount of energy waste. A novel chemical looping complementary hydrogen reduction (CLHR) strategy has been proposed for the purpose of extracting valuable metals from spent LiCoO₂ batteries. This innovative method utilizes LiCoO₂ as carriers, while eliminates the energy wastage caused by the traditional recycling method. The results of fluidized bed experiments showed that both high temperature and long reduction time contributed to the improvement of LiCoO₂ conversion with high purity of the reduction products (mainly Li₂O and Co monomer). Under the reduction condition of 800 °C and 120 min, the conversion of LiCoO₂ was almost 100%, and the selectivities of Li₂O and Co were 54% and 46%, respectively. Based on the experimental results, a thermodynamic analysis of the chemical looping complementary hydrogen reduction process of LiCoO₂ was carried out. The results demonstrated that there was a complementary matching property between the reduction temperature and H₂ concentration, and 650 °C ~ 900 °C was favorable to avoid the formation of liquid LiOH and the loss of target products.

Lithium-ion batteries,Chemical looping reduction,LiCoO2