Minimal Salt-Assisted Sulfuric Acid Oxidation Roasting for Selective Lithium Extraction from Spent LiFePO ₄ Batteries

Recovering lithium from spent LiFePO4 batteries presents a significant opportunity to address the issue of lithium scarcity. However, current technology requires many strong oxidants to achieve precise lithium selectivity, which is costly and inevitably causes secondary pollution. In this paper, a minimal salt-assisted sulfuric acid oxidative roasting technique is proposed to achieve 93.5% lithium recovery and nearly 100% selectivity. Meanwhile, the addition of sodium salt is reduced by 95.6%, reducing solid waste production and lowering the sodium content in the lithium leach solution. In addition, the process reduces energy consumption and greenhouse gas emissions by about 35% compared to the previously reported sulfate roasting process. This study provides new insights into the recovery of lithium resources by using a multioxidation to front-end selectively extract lithium from spent LiFePO4 cathodes.