Recycling Valuable Metals from Spent Lithium-Ion Batteries Using Carbothermal Shock Method

Pyrometallurgy technique is usually applied as a pretreatment to enhance the leaching efficiencies in the hydrometallurgy process for recovering valuable metals from spent lithium-ion batteries. However, traditional pyrometallurgy processes are energy and time consuming. Here, we report a carbothermal shock (CTS) method for reducing LiNi0.3Co0.2Mn0.5O2 (NCM325) cathode materials with uniform temperature distribution, high heating and cooling rates, high temperatures, and ultrafast reaction times. Li can be selectively leached through water leaching after CTS process with an efficiency of >90 %. Ni, Co, and Mn are recovered by dilute acid leaching with efficiencies >98 %. The CTS reduction strategy is feasible for various spent cathode materials, including NCM111, NCM523, NCM622, NCM811, LiCoO2, and LiMn2O4. The CTS process, with its low energy consumption and potential scale application, provides an efficient and environmentally friendly way for recovering spent lithium-ion batteries.

Automated summary

Pyrometallurgy technique is commonly used as a pretreatment to improve leaching efficiencies in the hydrometallurgy process for recovering valuable metals from spent lithium-ion batteries. Traditional pyrometallurgy processes are time and energy consuming. In this study, a carbothermal shock (CTS) method was developed for reducing LiNi0.3Co0.2Mn0.5O2 (NCM325) cathode materials with uniform temperature distribution, high heating and cooling rates, high temperatures, and ultrafast reaction times. The CTS process showed high efficiencies in selectively leaching Li (>90%) and recovering Ni, Co, and Mn (>98%) in dilute acid leaching. The CTS reduction strategy was also applicable to various other spent cathode materials. This low energy consumption and potentially scalable CTS process provides an efficient and environmentally friendly approach for recovering spent lithium-ion batteries.