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

Authors

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

Corresponding Author

Yong-feng LIU(mselyf@zju.edu.cn)

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.

Graphical Abstract

Keywords

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

DOI Link

https://doi.org/10.13208/j.electrochem.160541

Publication Date

2016-10-28

Online Available Date

2016-07-28

Revised Date

2016-05-19

Received Date

2016-05-03

Recommended Citation

Ya-xiong YANG, Rui-jun MA, Ming-xia GAO, Hong-ge PAN, Yong-feng LIU. Electrochemical Performance of Crystalline Li₁₂Si₇ as Anode Material for Lithium Ion Battery[J]. Journal of Electrochemistry, 2016 , 22(5): 521-527.
DOI: 10.13208/j.electrochem.160541
Available at: https://jelectrochem.xmu.edu.cn/journal/vol22/iss5/9