NaOH-Assisted Roasting for Corecovery of Spent LiFePO<sub>4</sub> and LiCoO<sub>2</sub> Batteries
Xiangyun Li, Shuaibo Gao, Fengyin Zhou, Xin Qu, Yuqi Cai, Dihua Wang, Huayi Yin
Abstract
Additive-assisted roasting has proven to be an effective strategy to improve metal recovery and decrease pyrometallurgical temperatures in the recycling of spent lithium-ion batteries (LIBs). However, excessive usage of additives and polluting exhaust emissions still need to be resolved. Here, a corecovery approach based on NaOH-assisted roasting is proposed for the recovery of valuable metals from spent LiFePO 4 and LiCoO 2 batteries, wherein NaOH is used as a roasting agent to destroy the structure of LiFePO 4 and generate Fe(OH) 2 to reduce LiCoO 2, separating Fe and Co from Li that is in the form of phosphates (Li x Na y PO 4 ). Hence, 94.8% of Li can be selectively separated by water leaching and recovered as Li 3 PO 4 by stepwise evaporation and crystallization. By Everbatt model analysis, the NaOH-assisted roasting process is a promising candidate for the economic, environmental, and efficient recovery of LIBs with high utilization of additives and low emissions.