共晶Ga-Sn与10Li-GaSn的第一原理分子动力学研究  

Ab initio molecular dynamics study on eutectic Ga-Sn and 10Li-GaSn

作　　者：丁安 王建川[1] DING An;WANG Jianchuan(State Key Laboratory of Powder Metallurgy,Central South University,Changsha 410083,China)

机构地区：[1]中南大学粉末冶金国家重点实验室,长沙410083

出　　处：《粉末冶金材料科学与工程》2022年第4期345-350,共6页Materials Science and Engineering of Powder Metallurgy

基　　金：中德合作研究小组资助项目(GZ1528)。

摘　　要：液态共晶Ga_(91.6)Sn_(8.4)可作为锂离子电池的负极。本文采用第一原理分子动力学方法对Ga_(91.6)Sn_(8.4)和嵌锂10%(摩尔分数,%,下同)的Ga_(91.6)Sn_(8.4)(10Li-Ga_(91.6)Sn_(8.4))的结构和动力学特性进行对比分析。结果表明,Ga_(91.6)Sn_(8.4)与10Li-Ga_(91.6)Sn_(8.4)在结构上没有明显差异,为短程有序,但Li的嵌入使得10Li-Ga_(91.6)Sn_(8.4)径向分布函数的第二峰出现“劈裂”,表明体系有序度增加,熔化温度提高。10Li-Ga_(91.6)Sn_(8.4)中,Li的嵌入使得体系中各原子的扩散系数减小,Li-Sn原子间相互吸引力明显强于Li-Ga,充电过程中,Ga_(91.6)Sn_(8.4)液态金属锂离子电池呈现液体向固体转变的趋势。The eutectic Ga_(91.6)Sn_(8.4) liquid metal can be served as the anode in Li-ion batteries. In this paper, the structure and kinetic properties of Ga_(91.6)Sn_(8.4) and Ga_(91.6)Sn_(8.4) with 10%(mole fraction, %, the same below) lithium intercalation(10Li-Ga_(91.6)Sn_(8.4)) were compared and analyzed by ab initio molecular dynamics. Calculation results show that there is no obvious differences in liquid structure between Ga_(91.6)Sn_(8.4) and 10Li-Ga_(91.6)Sn_(8.4), both of them exhibit short-range order.The introduction of Li induces the second peak of the radial distribution function of 10Li-Ga_(91.6)Sn_(8.4) appear “split”,indicating that the order of the system increases and the melting points increases. In 10 Li-Ga_(91.6)Sn_(8.4), the intercalation of Li reduces the diffusion coefficient of each atom in the system, and the attraction between Li-Sn atoms is significantly stronger than that of Li-Ga. Therefore, during the charging process, the Ga_(91.6)Sn_(8.4) Li-ion liquid metal battery exhibits the tendency of liquid-to-solid transition.

关 键 词：Li-Ga-Sn体系 第一原理分子动力学 液态结构 扩散系数 黏度 

分 类 号：O756[理学—晶体学]