欢迎访问《电化学(中英文)》期刊官方网站,今天是

电化学(中英文) ›› 2016, Vol. 22 ›› Issue (5): 521-527.  doi: 10.13208/j.electrochem.160541

• 能源电化学材料近期研究专辑(南开大学 陈军教授) • 上一篇    下一篇

晶态Li12Si7锂离子电池负极材料的电化学性能研究

杨亚雄,马瑞军,高明霞,潘洪革,刘永锋*   

  1. 硅材料国家重点实验室,浙江省电池新材料及应用技术重点实验室,浙江大学材料科学与工程学院,浙江杭州 310027
  • 收稿日期:2016-05-03 修回日期:2016-05-19 出版日期:2016-10-28 发布日期:2016-07-28
  • 通讯作者: 刘永锋 E-mail:mselyf@zju.edu.cn
  • 基金资助:

    国家自然科学基金资助项目(51471152),教育部创新团队项目(IRT13037)和中组部拔尖人才支持

Electrochemical Performance of Crystalline Li12Si7 as Anode Material for Lithium Ion Battery

YANG Ya-xiong, MA Rui-jun, GAO Ming-xia, PAN Hong-ge, LIU Yong-feng*   

  1. State Key Laboratory of Silicon Materials, Key Laboratory of Advanced Materials and Applications for Batteries of Zhejiang Province and School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, China
  • Received:2016-05-03 Revised:2016-05-19 Published:2016-10-28 Online:2016-07-28
  • Contact: LIU Yong-feng E-mail:mselyf@zju.edu.cn

摘要:

通过加热摩尔比为12:7的LiH/Si球磨混合物,避免了Li与Si之间巨大的熔点差异,成功制备了晶态Li12Si7合金,研究了其电化学性能和储锂机制. 发现Li12Si7在0.02 ~ 0.6 V的嵌脱锂过程中,只发生晶胞体积的变化,而不产生相变,呈现出明显的固溶储锂机制. 该固溶储锂机制的存在,有效抑制了Si基负极材料嵌脱锂过程中由于相变导致的体积效应,使得晶态Li12Si7在0.02 ~ 0.6 V电压范围内具有显著改善的电化学性能,其首次库伦效率高达100%,30次循环后的可逆容量保持率约为74%,分别优于相同条件下原始Si电极的55%和37%.

关键词: 锂离子电池, 负极材料, 锂硅合金, 电化学性能, 储锂机制

Abstract:

Crystalline Li12Si7 is successfully synthesized by heating the mixture of LiH and Si with a molar ratio of 12:7, which avoids the huge difference of the melting points between Li and Si. The electrochemical performance and lithium storage mechanism of the as-prepared Li12Si7 are studied in this work. It is found that only a change in cell volume takes place without a phase change during the lithiation/delithiation of Li12Si7 at a voltage range of 0.02 ~ 0.6 V, exhibiting a solid-solution lithium storage mechanism. Such a lithium storage process effectively retards the volume effect caused by the phase change during lithiation/delithiation of Si-based anode. This induces significantly the improved electrochemical properties of crystalline Li12Si7 while cycling at 0.02 ~ 0.6 V. The first Coulombic efficiency of crystalline Li12Si7 is determined to be as high as 100%, and the capacity retention is 74% after 30 cycles, which are distinctly higher than those of Si anode (55% and 37%, respectively) under identical conditions.

Key words: lithium-ion batteries, anode materials, Li-Si alloys, electrochemical properties, lithium storage mechanism

中图分类号: