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采用喷雾干燥-高温固相法制备纳米LiFePO_4与LiFePO_4/C正极材料,用X-射线衍射,扫描电镜等对合成材料进行了表征,并对以LiFePO_4为正极的电池进行了电化学性能测试。结果表明:材料合成最佳煅烧温度为600℃;合成过程中由于碳对LiFePO_4晶型的生长有一定的抑制作用,相对于纯LiFePO_4材料,LiFePO_4/C材料粒径更小;并且,在此最佳合成温度下合成的LiFePO_4/C正极材料具有良好的电化学性能,在C/5,1C,5C,10C等不同倍率放电情况下,首次放电比容量分别为139.4,137.2,133.5与127.3mAh·g~(-1);表现出良好的循环性能,10C循环50次后,比容量仍保持为117.7mAh·g~(-1)(相当于首次放电容量的92.4%),即每个循环容量衰减仅为0.15%。
The nano-LiFePO 4 and LiFePO 4 / C cathode materials were prepared by spray drying and high temperature solid-state method. The synthesized materials were characterized by X-ray diffraction and scanning electron microscopy. The electrochemical performance of LiFePO 4 cathode was tested. The results show that the optimal calcination temperature is 600 ℃. Due to the carbon inhibited the growth of LiFePO_4 crystal in the synthesis process, the particle size of LiFePO_4 / C is smaller than that of pure LiFePO_4. The synthesized LiFePO 4 / C cathode material with good synthesis temperature has good electrochemical performance and the first discharge specific capacity is 139.4, 137.2, 133.5 and 127.3 mAh · at the different discharge rates of C / 5, 1C, 5C and 10C g -1, showing a good cycling performance. After 50 cycles of 10C, the specific capacity still maintained 117.7mAh · g -1 (equivalent to 92.4% of the initial discharge capacity), that is, the capacity per cycle Attenuation is only 0.15%.