Enhanced leaching of metals from spent lithium-ion batteries by catalytic carbothermic reduction

Spent Li-ion battery (LIB) recycling has become a challenge with the rapidly developing electric vehicle (EV) industry. To address the problems of high cost and low recovery of Li in the recycling of spent LIBs using traditional hydrometallurgical processes, we developed an alkali metal catalytic carbothermic reduction method to recover spent LiNixCoyMnzO2 (NCM). Using alkali metal catalysts, such as NaOH, significantly reduced the temperature required for carbothermic NCM material reduction and realized targeted control of the phase of the reduction product, where Li was first separated by prior water leaching, followed by Ni, Co, and Mn recycling by acid leaching. The optimized carbothermic reduction conditions were a reaction time of 3 h, temperature of 550 °C, NaOH dosage of 15 wt%, and graphite dosage of 15 wt%. The Li leaching efficiency reached 78.5 wt% during water leaching. And during acid leaching, the Ni, Co and Mn leaching efficiencies were 99.8 wt%, 99.7 wt%, and 99.5 wt%, respectively. This study provides strong technical support for the development of LIB industry.