Upcycling of spent LiFePO4 into a high-performance LiFe0.5Mn0.5PO4–V cathode material

Abstract

The development of efficient recycling technologies for large-scale retired lithium-ion batteries (LIBs) can significantly facilitate the sustainable utilization of lithium resources. Herein, a simple and effective strategy is proposed to directly upcycle spent LiFePO₄ to prepare next-generation high-performance LiFe_0.5Mn_0.5PO₄–V cathode materials for LIBs. The product features a doping of V ions in LiFe_0.5Mn_0.5PO₄, as well as a uniform carbon coating for LiFe_0.5Mn_0.5PO₄–V particles. Importantly, the material prepared at 750 °C for 10 h has the best performance; it has a high reversible capacity (150.1 mAh g⁻¹ at 0.1C), long lifespan (0.5C, 94.6% capacity retention ratio after 100 cycles) and high rate performance (64.5 mAh g⁻¹ at 5C). Importantly, the insertion of V ions and Mn ions increases both the electrical conductivity and the diffusion coefficient. This strategy is economically beneficial and environmentally friendly, providing a sustainable approach for the value-added utilization of spent battery materials.