摘要
以磷酸铁、碳酸锂和葡萄糖为原料,钛酸酯偶联剂TC-W t作分散剂及杂源,采用高温固相合成制备磷酸铁锂碳包覆复合材料,考察偶联剂的加入对目标化合物的物理性能及电化学性能的影响。通过XRD、SEM及粒度分布等测试技术对所合成的材料进行了表征,并对所得材料进行对比分析,结果表明:添加偶联剂所制得材料颗粒分散效果良好,粒径分布相对均一,同时材料表现良好的电化学性能,在0.1C、0.5C、1C、3C下的首次放电比容量分别为161.8mAh·g-1、148.6 mAh·g-1、136.0 mAh·g-1、112.1 mAh·g-1,比未添加偶联剂制得的材料在相应倍率下所得放电比容量分别高出13.2 mAh·g-1、16.3 mAh·g-1、9.6 mAh·g-1、1.6 mAh·g-1。此外,该材料表现出良好的循环性能,不同倍率循环10次后,比容量仍保持良好。
Carbon coated LiFePO4 composite materials were synthesized solid-state method under high temperature with iron phosphate,lithium carbonate and glucose as the raw materials,and Titanate coupling agent TC-Wt as the dispersant and dopant.The physical and electrochemical properties of carbon coated LiFePO4 were investigated.The crystalline structure and morphology of particles were investigated by X-ray diffraction,scanning electron microscopy and particle-size distribution.The results show that the addition of coupling agent acquires relatively homogeneous particle size distribution and the Carbon coated LiFePO4 also exhibits better electrochemical properties with the first discharge capacities of 161.8、148.6、136.0、112.1 mAh·g-1 at 0.1C,0.5C,1C and 3C rates,respectively,that is 13.2 mAh·g-1、16.3 mAh·g-1、9.6 mAh·g-1、1.6 mAh·g-1 higher than the material without coupling agent.In addition,the Carbon coated LiFePO4 shows excellent cycle stability at different current densities,and the specific capacity remains good even after 10 cycles.
出处
《功能材料与器件学报》
CAS
CSCD
北大核心
2011年第3期274-278,共5页
Journal of Functional Materials and Devices
关键词
磷酸铁锂
正极材料
偶联剂
碳包覆
掺杂
LiFePO4
cathode materials
coupling agent
carbon-coated
doping
