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以聚丙烯酸为碳源,用低温还原-插锂与聚合物高温分解相结合的方法制备LiFePO4/C复合正极材料;FePO4被还原插锂与含碳聚合物化学包覆同时进行,简化了制备工艺,降低了制备成本。经X射线粉末衍射(XRD)、扫描电镜(SEM)以及恒电流充/放电测试,研究了不同焙烧温度对合成产物的物相、晶胞参数、表面形貌及电化学性能的影响。研究发现,焙烧温度为600℃时,合成产物的0.1 C倍率放电具有最高的放电容量和最好的循环稳定性。在0.1 C下LiFePO4/C复合材料的首次放电容量高达141.3 mAh/g,库伦效率为98.0%,100次循环后,其容量保持率为108.3%。
LiFePO4 / C composite cathode material was prepared by the combination of low temperature reduction-insertion lithium and pyrolysis of polymer with polyacrylic acid as carbon source. FePO4 was reduced and inserted into lithium simultaneously with the chemical coating of carbon-containing polymer, which simplified the preparation process , Reducing the preparation cost. The effects of calcination temperature on the phase, unit cell parameters, surface morphology and electrochemical properties of the synthesized products were investigated by X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and galvanostatic charge / discharge test. The results show that the 0.1 C rate discharge of the synthesized product has the highest discharge capacity and the best cycling stability when the calcination temperature is 600 ℃. The initial discharge capacity of LiFePO4 / C composites was as high as 141.3 mAh / g at 0.1 C and the coulombic efficiency was 98.0%. After 100 cycles, the capacity retention rate was 108.3%.