稀土离子掺杂合成LiFePO_4/C材料低温性能研究  

Low temperature performance of LiFePO_4/C material doped by rare-earth ion

作　　者：李向南[1,2,3] 张会双[1,2,3] 曹朝霞[1,2,3] 张瑾[1] 尹艳红[1,2,3] 

机构地区：[1]河南师范大学化学化工学院,河南新乡453007 [2]动力电源及关键材料国家地方联合工程实验室,河南新乡453007 [3]动力电源及关键材料河南省协同创新中心,河南新乡453007

出　　处：《电源技术》2016年第6期1163-1166,共4页Chinese Journal of Power Sources

基　　金：河南省重点攻关项目(72102230008);河南省基础与前沿技术研究计划项目(102300410256);新乡市科技发展计划(15GY03)

摘　　要：以Gd2O3作为掺杂化合物,分别采用Fe2O3和Fe C2O4·2 H2O作为铁源固相法合成LiFePO_4/C材料。采用X射线衍射(XRD)、扫描电子显微镜(SEM)、能量散射光谱(EDS)、LAND电池测试系统及电化学工作站等对材料的晶体结构、形貌和电化学性能进行测试,重点分析了材料的低温特性。结果表明:以Fe C2O4·2 H2O为铁源合成的LiFePO_4/C展示出较好的电化学性能,尤其是低温性能。25℃下,0.1 C、5 C首次放电比容量分别为146.1、108.8 m Ah/g,-20℃时相同倍率下放电比容量为99.8、73.9 m Ah/g,分别为25℃时放电比容量的68.3%和67.9%,具有较好的低温性能。Fe2O3and Fe C2O4·2 H2 O were used as iron source to synthesize LiFePO_4/C compound materials,respectively.And the Gd2O3 were doped to improve its electrochemical properties.Crystalline structure,morphology and electrochemical performance of the samples were characterized by X-ray diffraction,SEM,EDS,charge-discharge tests and AC impedance techniques.Low-temperature performances of the synthesized material were discussed.Results show that the LiFePO_4/C cathode material using Fe C2O4·2 H2 O as iron source shows improved electrochemical performance,especially low temperature.At 25 ℃,the specific capacities of the sample reach 146.1m Ah/g（0.1 C）,108.8 m Ah/g（5 C）.At-20 ℃,the specific capacities of the sample are 99.8 m Ah/g（0.1 C）,73.9m Ah/g（5 C）,which reach about 68.3%,67.9% of that at room temperature,respectively.

关 键 词：LiFePO_4/C 稀土掺杂 低温性能 锂离子电池 

分 类 号：TM912[电气工程—电力电子与电力传动]