LiNi0.5Co0.2Mn0.3O2@WO3复合正极材料的制备与性能

徐琳; 万柳; 祝天喜; 杨楠; 郭隆泉; 任丽

doi:10.13801/j.cnki.fhclxb.20190610.001

LiNi_0.5Co_0.2Mn_0.3O₂@WO₃复合正极材料的制备与性能

河北工业大学化工学院, 天津 300000

基金项目: 国家自然科学基金（51203041）

详细信息

通讯作者:
任丽,博士,教授,博士生导师,研究方向为锂离子电池正极材料,E-mail:liren@hebut.edu.cn

中图分类号: TB332
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出版历程
- 收稿日期: 2019-03-05
- 刊出日期: 2020-03-14

Preparation and properties of LiNi_0.5Co_0.2Mn_0.3O₂@WO₃ composite cathode materials

College of Chemical Engineering, Hebei University of Technology, Tianjin 300000, China

摘要

摘要: 为改善LiNi_0.5Co_0.2Mn_0.3O₂（NCM）锂离子电池三元正极材料的电化学性能，采用液相蒸发法将WO₃包覆于NCM表面，得到NCM@WO₃复合正极材料。通过XRD、SEM和TEM对NCM@WO₃复合材料的结构和形貌进行表征，利用充放电测试、循环伏安及交流阻抗测试对其电化学性能进行表征。结果表明，当WO₃包覆量为3wt%时，NCM@WO₃复合材料性能最佳，在0.5 C下的首次放电比容量为179.9 mA·hg^-1，不可逆容量损失降低至42.4 mA·hg^-1，循环50圈后容量保持率为98.3%。WO₃的包覆提高了锂离子扩散速率，减少了电极材料与电解液的副反应，NCM@WO₃复合材料的电化学性能得到提升。
- LiNi_0.5Co_0.2Mn_0.3O₂ /
- 包覆 /
- WO₃ /
- 液相蒸发法 /
- 复合材料
Abstract: In order to improve the electrochemical performance of LiNi_0.5Co_0.2Mn_0.3O₂ (NCM), WO₃ coated NCM (NCM@WO₃) composite cathode materials were synthesized with a liquid phase evaporation process. The structure and morphology of the NCM@WO₃ composite were characterized by XRD, SEM and TEM. The electrochemical performance of the NCM@WO₃ composite was characterized by charge-discharge test, cyclic voltammetry and electrochemical impedance spectroscopy. The results show that the NCM@WO₃ composite with 3wt% WO₃ has the best performance, it delivers an initial discharge capacity of 179.9 mA·hg^-1 with a low irreversible capacity loss of 42.4 mA·hg^-1 at 0.5 C, and the capacity retention after 50 cycles is 98.3%. The improved electrochemical properties of the NCM@WO₃ composite are mainly attributed to the WO₃ coating, which improves the lithium ions diffusion rate and suppresses the interface reaction between the cathode and the electrolyte.
- LiNi_0.5Co_0.2Mn_0.3O₂ /
- coating /
- WO₃ /
- liquid-evaporation process /
- composite