Si基锂离子电池负极材料的纳米化和合金化<br />-中国材料进展

文章信息/Info

作者:: 曲晓雷; 蒲凯超; 高明霞; 刘永锋; 潘洪革; (浙江大学材料科学与工程学院，硅材料国家重点实验室，浙江省电池新材料与应用技术研究重点实验室

Author(s):: Qu Xiaolei; Pu Kaichao; Gao Mingxia; Liu Yongfeng and Pan Hongge; School of Materials Science and Engineering of Zhejiang University

Keywords:: Li-ion battery; anode; Si-based materials; nanostructuring; alloying

摘要:: Si作为一种新型锂离子电池负极材料，具有理论比容量高、来源丰富、成本低廉、安全性能好等优点，近年来备受关注。但其在充放电过程中巨大的体积变化使得材料粉化严重，导致循环过程中容量迅速衰退，难以满足实用化的需求。纳米化和合金化是改善Si负极材料的有效途径，纳米化能够有效缓解材料嵌脱锂过程中体积变化所造成的机械应力，缩短锂离子的迁移距离，从而明显改善Si基材料的电化学循环稳定性能；合金化可以减小材料在脱嵌锂过程的体积变化率，提高材料的电导率，也可以延长Si基材料的循环寿命，此外，Si合金的振实密度高，制备工艺简单，有利于规模化应用。本文简要综述了最近5年在Si基锂离子电池负极材料的纳米化和合金化方面的研究进展，重点关注了不同纳米结构和合金化方法对其电化学储锂容量、倍率性能和循环稳定性能的影响。

Abstract:: As a new-type anode material of Lithium-ion batteries, silicon (Si) has attracted much attention in recent years, due to its high theoretical capacity, abundance on earth, low cost and good safety. However, the huge volume change during charge/discharge process induces severe pulverization and fast capacity fading, which prevents Si-based anode from practical applications. Nanostructuring and alloying are effective approaches to improve the electrochemical performance of Si-based anode materials. Nanostructure can help release the mechanical stress caused by volume expansion, and shorten migration distance of Li-ion, consequently improving the electrochemical stability of Si. Alloying can reduce the volume change rate of Si-based materials during charge/discharge, and enhance the conductivity, which also extends the lifetime of Si anode. Furthermore, the preparation process of Si-based alloys with high tap density is simple and scalable for mass production. In this paper, the development of Si nanostructures and alloys in recent 5 years is briefly summarized by focusing on their effects on electrochemical capacity, rate performance and cycling stability.