从材料结构特征到功能特征——一种新型锂离子导体设计方法  

From material structural feature to the functional feature—A new designing rule for lithium-ion conductors

作　　者：赵悠曼 黄旸 熊立 林海军 ZHAO Youman;HUANG Yang;XIONG Li;LIN Haijun(Chuangming Battery Technology Co.Ltd.,Dongguan 523808,Guangdong,China;Chongqing Institute of Green and Intelligent Technology,Chinese Academy of Sciences,Chongqing 400714,China)

机构地区：[1]东莞市创明电池技术有限公司,广东东莞523808 [2]中国科学院重庆绿色智能技术研究院,重庆400714

出　　处：《储能科学与技术》2023年第11期3287-3298,共12页Energy Storage Science and Technology

基　　金：国家自然科学基金青年项目(双阳离子氧化还原中心的富锂正极材料的理论设计及多谱学实验研究12004382)。

摘　　要：近年来,有理论研究认为硫系锂离子导体材料的硫阴离子框架都具有类bcc(body-centered-cubic)的体心立方堆叠结构。因此,在探索新的硫系锂离子导体时,应从材料库中优选那些具有类bcc硫阴离子框架结构的材料。然而对于设计新型锂离子导体而言,这种设计准则过于简略。本团队基于前人工作基础,对硫系化合物中锂离子的传输和扩散机制进行了研究,并讨论了影响锂离子局域跳跃的结构环境和影响锂离子宏观扩散的化学环境。研究发现,在硫系化合物中,不与过渡金属配位的0-TM通道对于锂离子在晶位之间的跳跃具有决定性的作用;而要形成宏观扩散网络,晶体结构中必须含有足够多的0-TM通道。基于这一认识,本团队探索并设计了几种新的硫系锂离子导体,验证了硫系化合物结构特征与其功能特征之间的关联性。这一工作深化了bcc结构设计准则,为发展新型锂离子导体提供了更为明确的理论方向。In recent years,body-centered-cubic(bcc)-type anion framework has been considered as a deft structural design descriptor for identifying unexplored potential sulfide lithium-ion conductors(SICs).However,the bcc guidance must be completed,and other factors impacting lithium diffusion must be considered.Therefore,they are not always useful in the design of new lithium-ion conductors.In this study,based on previous works,we investigated the lithium-ion hopping and diffusion mechanisms in sulfides.We discussed how the local structural environment impacts lithium hopping from site to site in a micro-manner and how the chemical composition impacts diffusion in a macro-manner.In conclusion,we proved that the zero-transition-metal(0-TM)coordinated channel is essential for the facile hopping of lithium ions,and macro-diffusion can be expected in the materials only if the contents of 0-TM channels exceed the penetrating thresholds.Our study provides a more thorough interpretation of the sulfides'lithium diffusion mechanism and directly connects the structural and functional features of the material.

关 键 词：锂离子导体 离子框架 锂离子扩散 扩散系数 

分 类 号：TK02[动力工程及工程热物理]