锂离子电池正极材料Li2MnO3的合成及改性  

Synthesis and modification of cathode material Li2MnO3 for lithium ion battery

作　　者：宋丹丹 曾艳红 SONG Dan-dan;ZENG Yan-hong(Yueyang Vocational Technical College,Yueyang Hunan 414000,China)

机构地区：[1]岳阳职业技术学院,湖南岳阳414000

出　　处：《电源技术》2020年第6期815-817,870,共4页Chinese Journal of Power Sources

摘　　要：采用固相法合成Li2MnO3,粒子纳米化对Li2MnO3的性能有很大的影响,通过扫描电子显微镜法(SEM)测试发现样品颗粒大小在100 nm左右,通过电化学工作站测试发现未处理的Li2MnO3材料的首次充电比容量为169.4 mAh/g,放电比容量为117.8 mAh/g,比用普通的固相法合成Li2MnO3的比容量(51 mAh/g)要高很多.用不同浓度的过硫酸铵处理Li2MnO3,通过X射线衍射光谱法(XRD)、SEM测试发现过硫酸铵处理并没有破坏Li2MnO3的结构,过硫酸铵处理后的样品颗粒尺寸比未处理的要小一些,通过电化学工作站测试发现:处理后材料的首次效率、比容量、循环性能、倍率性能都大有改善.处理后的Li2MnO3在2C以下充放电时,30%-Li2MnO3、40%-Li2MnO3的倍率性能明显优于Li2MnO3.Li2 MnO3 was synthesized by solid-state method.The nanoparticle has a great influence on the performance of Li2 MnO3.The SEM test result shows that the sample particle size is around 100 nm.The electrochemical workstation test results show that the initial charge special capacity of the untreated Li2 MnO3 is 169.4 mAh/g,and the discharge specific capacity is 117.8 mAh/g,much higher than that of Li2 MnO3 synthesized by ordinary solid-state method.The synthesized Li2 MnO3 was treated in different concentration ammonium persulphate solution.The XRD and SEM test results show that the ammonium sulfate treatment does not destroy the structure of Li2 MnO3,and the particle size of the ammonium persulfate treated sample is smaller than that of the untreated sample.The electrochemical workstation test results show that the initial columbic efficiency,specific capacity,cycling performance and rate performance of the treated sample are improved.The rate performance of 30%-Li2 MnO3 and40%-Li2 MnO3 are better than the untreated Li2 MnO3 during charging and discharging at 2 C.

关 键 词：锂离子电池 正极材料 LI2MNO3 优化 

分 类 号：TM912.9[电气工程—电力电子与电力传动]