摘要
采用溶胶凝胶法对原料进行了混合，在氮气保护下利用固相反应烧成了LiFePO4／C复合材料．XRD衍射分析表明，烧成温度和碳源引入量对LiFePO4／C的结晶度有较大的影响，在650～700℃范围内烧成的LiFePO4／C结晶完整；当碳源引入量超过20％时，LiFePO4／C衍射峰强度下降．SEM电镜观察到，烧成的LiFePO4／C晶粒细小，大小均匀，晶粒尺寸为100nm左右．以烧成的LiFePO4／C复合材料作为正极材料进行充放电测试，发现碳源对首次放电容量有较大的影响，分别以乙炔黑、蔗糖和葡萄糖作为碳源时，0．1C倍率下首次放电容量分别为120，135，162mA·h／g．对以葡萄糖为碳源烧成的LiFePO4／C复合材料进行放电倍率测试，研究结果表明，该复合材料具有优异的大电流充放电性能．在1C和3C高倍率下首次放电容量为0．1C倍率下放电容量的90％和80％．
LiFePO4/C was synthesized using solid-state reaction under N2 atmosphere where the reaction precursor was prepared by sol-gel method. XRD analysis proved that the sintering temperature and carbon source play an important role in crystalline of LiFePO4/C. In range of 650-700 ℃, LiFePO4 was crystallizedwell. When the content of carbon source was beyond 20 %, the diffraction intensity was weakened. The particles of LiFePO4/C were homogeneous, about 100 nm sizes. Charge-discharge test was made with LiFePO4/C as cathode material. It was found that carbon sources had close relation to composite＇s initial discharge capacity. At 0.1 C rate, the initial discharge capacity was corresponding 120,135, 162 mA · h/g with acetylene black, sucrose, and glucose as carbon sources. The LiFePO4/ C with glucose as carbon source exhibited large current charge-discharge properties. At 1 C and 3 C rate, the initial discharge capacity was 90%, 80% in 0.1 C, respectively.
出处
《长沙理工大学学报（自然科学版）》
CAS
2007年第2期84-88,共5页
Journal of Changsha University of Science and Technology:Natural Science
基金
湖南省教育厅青年基金科研资助项目(06B002)
长沙理工大学青年基金科研资助项目(1004085)
