固相补锂法再利用废旧 LiFePO4正极材料及电化学性能

以废旧磷酸铁锂（LiFePO4）正极材料为原料，经过热处理除杂和固相补锂后，利用碳热还原反应重新获得了电化学性能优异的LiFePO4/C正极材料。测试结果表明，补加物质的量分数为10%的Li2CO3和质量分数为25%的葡萄糖可获得结晶度良好、无杂质的LiFePO4/C正极材料，且能有效弥补其可循环锂的损失。在0.1C和20C倍率下，其放电比容量分别为159.6 mA·h/g和86.9 mA·h/g，在10C倍率下，经1 000次循环后，再生LiFePO4正极材料的容量保持率为91%。说明该方法可有效处理废旧LiFePO4电池，为大规模循环再利用废旧LiFePO4正极材料提供了一条可行的途径。

Reusing of spent LiFePO4 cathode materials by solid phase lithium refilling method and electrochemical performance there of

The spent LiFePO4 cathode materials were re-synthesized by adding different amount-of-substance fraction of Li2CO3 in solid phase method after high temperature purification treatment.The electrochemical test results showed that the re-synthesized cathode materials can effectively make up for the loss of reversible lithium by adding suitable amount of 10% （amount-of-substance fraction） of Li2CO3 and 25%（mass fraction） glucose and exhibited excellent electrochemical performance as cathode materials.Their specific discharge capacity can reach 159.6 mA·h/g at 0.1C，and 86.9 mA·h/g even at 20C.After 1 000 cycles at 10C，they still have a high capacity retention rate of 91%.This work showed that this method can effectively improve the electrochemical performance of spent cathode material and provided an effective route for large scale recovery and reuse of spent LiFePO4 cathode materials in lithium-ion batteries.