Green and efficient method for the realization of full-component recovery of LiFePO4 black powder

Abstract

With regard to retired LiFePO₄ batteries, resource treatment has become a matter of public concern. The currently used wet recycling process causes secondary environmental pollution and has the difficulty of full-component recovery. Therefore, a green and efficient recovery process for the realization of full-component recovery of LiFePO₄ black powder is proposed in this work. In this closed-loop process with liquid flow circulation, no waste liquid and gas emission is generated, and the purity of recycled Li₂CO₃ can reach up to 99.4%. Moreover, battery-grade FePO₄ can be obtained after simple treatment, solving the problem of lithium tailings and slag in the traditional wet recycling process. The performances of recycled Li₂CO₃ and FePO₄ are similar to commercialization products according to electrochemical tests. More importantly, the resynthesized LiFePO₄ cathode displays high-capacity retention of 97.5% after 200 cycles at 0.5 C, indicating the superiority of our strategy. Furthermore, the pouch cell with 5.2 A h presents outstanding performance, and high-capacity retentions of 96% and 95.2% can be observed after 500 cycles at 0.5 C and 1 C, respectively. The aforementioned results indicate the attractive prospects of this green and efficient lithium extraction and full-component recovery process.