不同锂源对LiFePO_4正极材料电化学性能的影响  

Effect of Different Li Sources on Electrochemical Performance of LiFePO_4 Cathode Material

作　　者：卜立敏[1] 秦秀娟[1] 孙学亮[1] 吴伟[1] 

机构地区：[1]燕山大学环境与化学工程学院,河北秦皇岛066004

出　　处：《有色金属（冶炼部分）》2011年第7期56-60,共5页Nonferrous Metals（Extractive Metallurgy)

基　　金：河北省自然科学基金资助项目(B2008000758)

摘　　要：采用不同锂源用碳热还原法合成LiFePO4正极材料,利用TG-DTA、XRD和SEM对前驱体、材料的晶体结构及表面形貌进行表征,通过充放电和循环伏安测试电化学性能。结果显示,以乙酸锂为锂源制得的样品颗粒粒径最小、电化学性能最佳。以C/20倍率充放电,首次放电比容量达到143.3 mA.h/g。该样品具有稳定的循环行为,以C/10倍率循环15次后放电容量为初始值的98%。循环伏安曲线显示以乙酸锂为锂源合成的LiFePO4材料具有良好的可逆性,极化小。The LiFePO4 cathode material is synthesized with different Li sources by carbothermal reduction methods,and the crystalline structure and morphology of the precursor and cathode material are characterized by TG-DTA and X-ray powder diffraction and the electrochemical properties are investigated by charge-discharge and CV tests.The results show that the finest particle size and the optimal electrochemical performance are achieved for the sample synthesized with CH3COOLi·2H2O.And a high capacity of 143.3 mA·h/g is delivered at the C/20 rate.The sample also displays a stable cycle-life,and even after 15 cycles,the discharge capacity is still 98% of initial capacity at C/10 rate.It is shown by CV tests that the reversibility and the polarization of the sample synthesized with CH3COOLi·2H2O are the best and the smallest.

关 键 词：无机非金属材料 磷酸铁锂 乙酸锂 碳热还原 正极材料 

分 类 号：TM911.3[电气工程—电力电子与电力传动]