Direct regeneration of spent LiFePO4 cathodes based on broaden of Li+ compensation channels by argon plasma ball milling

The wide application of LiFePO 4 (LFP) batteries in energy storage equipment inevitably produces a large number of spent LFP batteries. However, the existing direct regeneration technology usually only pays attention to the compensation of Li + , ignoring the problems of poor conductivity, binder residue, and slow compensation channels of Li + in spent LFP. Here, we introduce a direct, efficient, and environmentally sustainable regeneration method of spent LFP cathodes, which utilizes argon plasma ball milling to effectively decompose the residual binder on the surface, induce the construction of vacancies in the carbon layer, and broaden the Li + compensation channels. Through argon plasma ball milling pretreatment, the Fe (III) phase can be more effectively transform into the Fe (II) phase during the calcination stage, achieving structural repair of spent LFP. The regenerated LFP exhibits excellent electrochemical performance, with the discharge capacity of 142.9 mAh g −1 at 1C, with no significant capacity loss after 200 cycles, and nearly 100 % capacity retention after 500 cycles at 5C. Economic analysis indicates that the proposed regeneration method offers significant economic benefits and low energy consumption, providing a novel reference for the efficient direct regeneration of spent lithium-ion batteries.