阳离子调控对卤化物固态电解质性能的改善  

Improvement of performance of halide solid electrolyte by tuning cations

作　　者：何兵 练宇翔 吴木生[1] 罗文崴[1] 杨慎博 欧阳楚英[1] He Bing;Lian Yu-Xiang;Wu Mu-Sheng;Luo Wen-Wei;Yang Shen-Bo;Ouyang Chu-Ying(College of Physics and Communication Electronics,Jiangxi Normal University,Nanchang 330022,China;Hongzhiwei Technology(Shanghai)CO.LTD.,Shanghai 200120,China)

机构地区：[1]江西师范大学物理与通信电子学院,南昌330022 [2]鸿之微科技(上海)股份有限公司,上海200120

出　　处：《物理学报》2022年第20期305-315,共11页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:12064014,51962010,12174162,12064015);鸿之微项目资助的课题。

摘　　要：三元锂金属卤化物作为极具潜力的固体电解质材料受到人们的广泛关注.本文利用基于密度泛函理论的第一性原理方法研究了一系列具有不同Li离子浓度的Li_(x)YCl_(3+x)(x=2.14,3.00,4.20)和Li_(x)YBr_(3+x)(x=1.8,3.0,5.0)材料的结构、电子性质和迁移特性.研究结果表明,Li离子和Li空位浓度的变化对材料的性能有显著影响,而且随着x值的增加,Li离子的含量增加,相应的Li空位浓度降低,结构的稳定性增强、带隙增大、离子迁移能垒降低,从而可以调控该类材料的性能.此外,计算结果进一步表明,在所有考虑的结构中,具有最佳Li离子与Li空位平衡的Li_(3)YCl_(6)和Li_(3)YBr_(6)组分展现出最高的结构稳定性、最大的带隙和最低的迁移能垒.本文为设计性能更好的卤化物固态电解质提供了一种新策略和新思路.Ternary lithium metal halides have attracted much attention as potential solid electrolytes.In this work,we study the structural,electronic and ionic diffusion properties of a series of Li_(x)YCl_(3+x)(x=2.14,3.00,4.20)and Li_(x)YBr_(3+x)(x=1.8,3.0,5.0)by using first-principles calculation based on density functional theory.The calculation results show that the Li-ion concentration has a significant effect on the properties of the materials,and with the increase of x value,Li-ion number becomes higher,structure turns more stable,band gap gets larger,and migration barrier lowers,thus the performance of the material can be tuned.In addition,the calculation results further show that Li_(3)YCl_(6) and Li_(3)YBr_(6) with the best balance between Li-ion carrier concentration and vacancy concentration exhibit the highest structural stability,the largest band gaps,and the lowest migration barriers in all similar structures.Our study provides a new strategy and idea for designing better-performance halide solid electrolytes.

关 键 词：全固态锂离子电池 三元卤化物 浓度调控 第一性原理计算 

分 类 号：TM912[电气工程—电力电子与电力传动] TQ131.11[化学工程—无机化工] O641.1[理学—物理化学]