( 1. 成都理工大学 材料与生物工程学院, 成都 610059；
2. 成都雷雳高科技公司, 成都 610045)
摘 要: 在空气气氛中合成了LiCo0.3Ni0.7-xSrxO2二元掺杂锂离子电池正极材料， 研究了不同掺Sr2+量对材料的结构与电化学性能的影响， 用XRD、 SEM及电性能测试考察了材料的结构、 形貌及其电化学性能。 结果表明： Sr2+的掺入量对材料的结构与电化学性能影响较大， 随着掺Sr2+量的增加， X射线衍射图中材料的特征峰向低角度飘移， 晶胞参数a和c增大， 晶胞体积增大； 电性能测试结果表明： 适量的掺Sr2+有利于提高材料中Li+的扩散能力， 抑制John-Teller效应， 降低阳离子混排现象， 提高材料的电化学稳定性， 当x=0.003， LiCo0.3Ni0.697-Sr0.003O2显示出较优的电化学性能， 首次放电容量为162mA·h·g-1， 首次放电效率为90.6%； 40次循环后其放电容量仍为153mA·h·g-1， 容量损失为7%， 显示出较好的循环稳定性。
关键字: 锂离子电池； 正极材料； LiCo0.3Ni0.7-xSrxO2；合成
cathode material for lithium ion batteries
（ 1. School of Material and Bioengineering,
Chengdu University of Technology,Chengdu 610059, China;
2. LeiLi High-tech. Development Ltd Co.,
Chengdu 610045, China）
Abstract: The layered LiCo0.3Ni0.7-xSrxO2 cathode materials for lithium ion batteries were synthesized in air. The influence on the structure and electrochemical properties of the materials caused by different contents of Sr2+ was investigated, and XRD analysis, SEM and electrochemical tests were used to study the physical and the electrochemical performances of the materials. With increasing value of x, the characteristic peaks of LiCo0.3Ni0.7-xSrxO2 shift to a lower degree and the lattice parameters increase. The results of electrochemical tests indicate that small content of Sr2+ can stabilize the structure of the material and make the electrochemical properties of the material better. The sample LiCo0.3Ni0.697Sr0.003O2 with doping Sr2+ (x=0.003) has the best electrochemical properties, which has an initial discharge capacity of 162mA·h·g-1 and an initial discharge efficiency of 90.6%. After 40 cycles, this sample remains 153mA·h·g-1 of discharge capacity and the loss ratio of capacity is just 7%, showing perfect cyclic stability.
Key words: lithium-ion battery； cathode material； LiCo0.3Ni0.7-xSrxO2; synthesis
