The exponential growth of electric vehicles (EVs) will lead to the large-scale retirement of lithium iron phosphate (LFP) batteries in the future. This work proposes an environmentally friendly solid-phase strategy for regenerating waste LFP cathode materials. The regeneration mechanism is also investigated through characterizations. The method involves lithium supplementation, crystal structure repair and Cu doping. Glucose is used as a reducing agent to reduce a large amount of Fe in waste LFP to Fe, while the addition of Li is used to fill the lithium vacancy in waste LFP. Notably, Cu doping increases the vibrational density and conductivity of the regenerated material and expands the ion diffusion channel, which significantly enhances the electrochemical performance of the regenerated LFP cathode. Moreover, the specific capacity of regenerated LFP (Cu@R-LFP) at 0.05C is 160.15 mAh/g, about 97.65 % of that of new LFP (N-LFP). The capacity retention rate of Cu@R-LFP can be as high as 81.19 % even after 1,000 cycles at 1C rate. The method proposed in this study provides a simple and scalable strategy for recycling waste LFP cathode materials.

中文翻译：

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Cu掺杂改性有效再生废旧LiFePO4正极材料

电动汽车（EV）的指数级增长将导致未来磷酸铁锂（LFP）电池的大规模退役。这项工作提出了一种环保的固相策略来再生废弃的磷酸铁锂正极材料。还通过表征研究了再生机制。该方法包括补锂、晶体结构修复和Cu掺杂。采用葡萄糖作为还原剂，将废磷酸铁锂中大量的Fe还原为Fe，同时添加Li来填充废磷酸铁锂中的锂空位。值得注意的是，Cu掺杂增加了再生材料的振动密度和电导率，并扩大了离子扩散通道，从而显着增强了再生LFP正极的电化学性能。此外，再生LFP（Cu@R-LFP）在0.05C下的比容量为160.15 mAh/g，约为新LFP（N-LFP）的97.65%。 Cu@R-LFP在1C倍率下循环1000次后容量保持率仍高达81.19%。本研究提出的方法为回收废磷酸铁锂正极材料提供了一种简单且可扩展的策略。