A SiCl4-Assisted Roasting Approach for Recovering Spent LiCoO2 Cathode

Efficiently recycling end-of-life lithium-ion batteries (LIBs) has been pursued in recent years to reduce energy consumption and secondary waste. In this paper, silicon tetrachloride (SiCl4)-assisted roasting was developed to recover LiCl, CoCl2, and Co3O4 from spent lithium cobalt oxide (LiCoO2) batteries. At 500 °C and a SiCl4/LiCoO2 mass ratio of 3:1, 95.6% of Co was recovered as CoCl2 and 98.4% of Li was recovered as LiCl. When the mass ratio was 0.7:1, 24.6% of Co was in the form of CoCl2, and the remaining was Co3O4, accompanied by the Li leaching rate of 95.6%. LiCoO2 resynthesized from recycled Li2CO3 and Co3O4 exhibits good electrochemical performance, with a capacity of over 142.5 mAh g–1 at 1C and a capacity retention rate of 93% after 100 cycles. According to the EverBatt model analysis, the SiCl4-assisted roasting method exhibits lower energy consumption and greenhouse gas emission, as well as more considerable revenue. Since SiCl4 is a byproduct of the polysilicon production process, the SiCl4-assisted chlorination at medium temperatures not only reduces the cost, but also achieves the disposal of SiCl4 and spent LIBs in a green manner.