F掺杂Li_(2)OHX(X=Cl,Br)固态电解质的界面稳定性和离子输运的第一性原理计算研究  

FIRST-PRINCIPLES COMPUTATIONAL STUDY OF INTERFACIAL STABILITY AND ION TRANSPORT IN F-DOPED LI_(2)OHX(X=CL,BR)SOLID-STATE ELECTROLYTES

作　　者：刘波 廖丕广 喻小香 高天宇 刘思彤 郭海鹏 邵志杰 LIU Bo;LIAO Pi-guang;Yu Xiao-xiang;GAO Tian-yu;LIU Si-tong;GUO Hai-peng;HAO Zhi-jie(School of Mathematics and Physics,Jinggangshan University,Ji'an,Jiangxi 343009,China;Jiangxi Metallurgical Vocational and Technical College,Xinyu,Jiangxi 338015,China;Materials Genome Institute,Shanghai University,Shanghai 200444,China)

机构地区：[1]井冈山大学数理学院,江西吉安343009 [2]江西冶金职业技术学院,江西新余338015 [3]上海大学材料基因组工程研究院,上海200444

出　　处：《井冈山大学学报（自然科学版）》2023年第6期14-21,共8页Journal of Jinggangshan University (Natural Science)

基　　金：国家自然科学基金项目(12004145);江西省自然科学基金项目(20212BAB214032);江西省大学生创新创业训练项目(202210419004)。

摘　　要：全固态结构的关键因素是固态电解质材料,它应具有良好的相稳定性和电化学稳定性,以及在室温下的高锂离子电导率。本研究采用第一原理计算,对F掺杂的Li_(2)OHX(X=Cl,Br)固态材料的相稳定性、电化学稳定性、化学稳定性和电子/离子传输特性进行了系统的研究。计算结果表明,F掺杂的Li_(2)OHX(X=Cl,Br)在0 K时是热力学亚稳态且宽带隙的电子绝缘体,可以通过实验合成。与一些硫化物和氧化物基固体电解质相比,该材料表现出更宽的电化学稳定性窗口(0.80-3.15 V)。此外,当与典型的正极材料(LiCoO_(2),LiMn_(2)O_(4),LiFePO_(4))接触时,F掺杂的Li_(2)OHX(X=Cl,Br)显示出良好的化学稳定性。对于离子输运性质,用F~-替代部分OH~-被证明能有效地降低Li_(2)OHX(X=Cl,Br)的锂离子迁移势垒。这些发现为进一步设计高性能固态电解质提供了一个理论指导。The key enabler for an all-solid-state architecture is a solid-state electrolyte that exhibits excellent phase and electrochemical stability,as well as high Li+conductivity at ambient temperatures.In this work,we performed first-principles computational studies on the phase stability,electrochemical stability,chemical stability and electronic/ionic transport properties of F-doped Li_(2)OHX(X=Cl,Br)materials.The calculation results show that the F-doped Li_(2)OHX(X=Cl,Br)are thermodynamically metastable and wide bandgap electronic insulators at 0 K and can be synthesized experimentally.The materials exhibit wider intrinsic electrochemical stability window(0.80-3.15 V)compared with sulfides-and oxides-based solid electrolyte.Moreover,the F-doped Li_(2)OHX(X=Cl,Br)displays significant chemical stability when in contact with typical cathode materials(LiCoO_(2),LiMn_(2)O_(4),LiFePO_(4)).For the ionic-transport property,the replacement of part of OH-by F-is shown to be effective in decreasing migration barriers in Li_(2)OHX(X=Cl,Br).These findings provide a theoretical guidance for further designing high-performance solid-state electrolyte.

关 键 词：第一性原理计算 电子结构 离子输运 界面稳定性 固态电解质 

分 类 号：O48[理学—固体物理]