Facile and sustainable recovery of spent LiFePO4 battery cathode materials in a Ca(ClO)2 system

Abstract

Spent LiFePO₄ batteries are gradually increasing in popularity and interest, and their stable and insoluble olive-shaped structure poses a great challenge for the sustainable recycling of Li. In this study, a simple and sustainable Ca(ClO)₂ system was proposed for the recovery of spent LiFePO₄ battery cathode materials. The effects of both mechanochemical activation and hydrometallurgical enhanced leaching on the deconstruction of LiFePO₄ and the leaching rates of Li and Fe in the Ca(ClO)₂ system were studied. Compared with mechanochemical activation, Ca(ClO)₂-assisted hydrometallurgical enhanced leaching can simultaneously achieve the separation and enrichment of the target components Li⁺ and Fe³⁺ and the Ca²⁺ impurities. The transformation path and reaction mechanism of LiFePO₄ in the Ca(ClO)₂ system were proposed based on the phase composition and micromorphology of the reaction products. In addition, the economic evaluation results show that Ca(ClO)₂-assisted hydrometallurgical enhanced leaching has a high recovery economy. The developed Ca(ClO)₂ system realizes the strong dissolution of spent LiFePO₄ battery cathode materials and the sustainable comprehensive recovery of valuable components.