锂离子电池硅薄膜电极充电膨胀的有限元仿真及其实验验证(英文)

Finite element analysis and experimental verification of Si based composite thin film anodes for Lithum-ion battery

硅基负极锂离子电池材料因其具有高的理论容量(4200mAh/g)而成为最有希望的高容量负极材料之一。但硅负极在充放电过程中的体积效应,将引起电极材料粉化以及循环性能变差。为解决上述问题,将硅与惰性过渡金属材料复合,过渡金属充当体积效应的缓冲层。本文利用有限元软件abaqus对比了三种不同的硅薄膜材料(Si/Si-Mn/Si-Zr)。通过磁控溅射方法制备了上述三种硅薄膜材料,并对其进行了SEM、XRD、循环性能等测试,实验得出的结论与仿真结果一致,加入的过渡金属材料有利于缓解体积效应,且Mn材料的缓解效应更强。

Si is the most promising anode material for high energy lithium ion battteries because of its high specific capacity(4200 mAh·g-1).But its undesirable volume enpansion results in mechanical degration and capacity reduction.It is a promising way to combine Si and inert metal to relieve the expansion during Li^+insertion/extraction.In this article,use Abaqus to compare three different Si thin films(Si,Si-Mn,Si-Zr).Si thin film was deposited on Cu foil by magnetron supttering for use as lithium ion battery anode material.The electrochemical performance of Si film was investgated by cyclic voltammetry and constant current charge/discharge test.The results consistent with simulation.The use of metal material is useful for the electronical performance and Zr is more useful than Mn.