高等学校化学学报 ›› 2023, Vol. 44 ›› Issue (11): 20230223.doi: 10.7503/cjcu20230223

• 物理化学 • 上一篇    下一篇

Mo2C/PE隔膜对锂硫电池性能的影响

王前1,2, 魏祎2, 贾洪声2()   

  1. 1.通化师范学院, 通化 134002
    2.吉林师范大学功能材料物理与化学教育部重点实验室, 四平 136000
  • 收稿日期:2023-05-05 出版日期:2023-11-10 发布日期:2023-08-10
  • 通讯作者: 贾洪声 E-mail:iop84041@163.com
  • 作者简介:目前在《通化师范学院学报》编辑部工作.
  • 基金资助:
    吉林省自然科学基金(20200201236JC);吉林省发展和改革委员会产业技术研究与开发项目(2022C040-6)

Effect of Mo2C/PE Separator on the Performance of Lithium Sulfur Batteries

WANG Qian1,2, WEI Yi2, JIA Hongsheng2()   

  1. 1.Tonghua Normal University,Tonghua 134002,China
    2.Key Laboratory of Functional Materials Physics and Chemistry,Ministry of Education,Jilin Normal University,Siping 136000,China
  • Received:2023-05-05 Online:2023-11-10 Published:2023-08-10
  • Contact: JIA Hongsheng E-mail:iop84041@163.com
  • Supported by:
    the Natural Science Foundation of Jilin Province, China(20200201236JC);the Industrial Technology Research and Development Foundation of Jilin Provincial Development and Reform Commission, China(2022C040-6)

摘要:

为了提升对锂金属负极的保护作用, 抑制多硫化物的穿梭效应, 选择成本低且地球丰富度高的钼基材料合成球壳结构的碳化钼(Mo2C), 并制备了碳化钼修饰的聚乙烯隔膜(Mo2C/PE), 分析了Mo2C/PE隔膜对锂硫电池性能的影响. 结果表明, Mo2C良好的亲锂性可以诱导Li+均匀沉积, 抑制锂枝晶生长. Mo2C/PE隔膜具有较大的比表面积和孔隙率, 碳化钼可以促进多硫化物在其附近的碳球内沉积成硫化锂, 增加的形核位点和沉积空间对充放电过程中引起的体积变化有一定的改善效果. 制备的Li-Li对称电池在较高的电流密度下, 与不使用PE隔膜的电池相比, 使用Mo2C/PE隔膜电池的极化电压起伏更小, 可以稳定循环. 装有Mo2C/PE隔膜的锂硫电池在0.2C的倍率下, 放电比容量为1235.3 mA·h/g, 经过500次循环后, 放电容量可以维持在652.4 mA·h/g.

关键词: 碳化钼, 碳化钼/聚乙烯隔膜, 锂硫电池, 锂负极, 电化学性能

Abstract:

In order to enhance the protective effect of lithium metal negative electrodes and suppress the shuttle effect of polysulfides, the molybdenum based materials with low-cost and high Earth abundance were selected to synthesize molybdenum carbide(Mo2C) with spherical shell structure, and the molybdenum carbide modified polyethylene separators(Mo2C/PE) was prepared. The influence of Mo2C/PE separators on the performance of lithium sulfur batteries was analyzed. The results indicate that the good lithium affinity of Mo2C can induce uniform deposition of Li+ and inhibit the growth of lithium dendrites. The Mo2C/PE separator has a large specific surface area and porosity, which has a certain improvement effect on the volume changes caused by the charging and discharging process. Compared to the battery without PE separator, Li-Li symmetric battery using Mo2C/PE separator has smaller polarization voltage fluctuations and can stably cycle at higher current density. Lithium sulfur batteries equipped with Mo2C/PE separators have a specific discharge capacity of 1235.3 mA·h/g at a rate of 0.2C, and after 500 cycles, the discharge capacity can be maintained at 652.4 mA·h/g.

Key words: Mo2C, Mo2C/PE separator, Lithium sulfur battery, Lithium negative electrode, Electrochemical performance

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