Abstract:Resource utilization of spent LiCoO2 batteries is of great significance to solve the problem of shortage of lithium and cobalt resources in China. Thermodynamic process of selective sulfurization of LiCoO2 by sulfur gas was analyzed. Effects of temperature, amount of sulfur, total pressure and additives on sulfidation transformation behavior and phase transformation of LiCoO2 were discussed. The results show that stable regions of different phases in Li-Co-S-O system can be regulated by controlling partial pressure of oxygen P(O2) and sulfur P(S2) of the atmosphere when temperature is ≤600 ℃, LiCoO2 can be selectively sulfurized and sulfur products can be controlled without causing generation of gases such as SO2. Dropping of total pressure P can reduce the reaction temperature of selective sulfide LiCoO2, and the addition of solid carbon, iron and iron oxide will significantly affect the existing forms of lithium and cobalt in sulfide products. The addition of FeS2 or SO2 gas can replace the sulfidation of S2 gas, and has no obvious effect on existence of lithium and cobalt in sulfide products. The experimental results of gas selective sulfidation of LiCoO2 verifies the thermodynamic calculation results, and SO2 utilization rate at initial stage of mass increment during sulfidation of LiCoO2 is about 75%.