Sb掺杂对Li_(7)La_(3)Zr_(2)O_(12)固体电解质离子电导率和稳定性影响的第一性原理  

Effects of Sb Doping on the Ionic Conductivity and Stability of Li_(7)La_(3)Zr_(2)O_(12)Solid Electrolyte:A First-principles Investigation

作　　者：曹星 倪磊[1] 段理[1] 傅茂森 钟宏[2] CAO Xing;NI Lei;DUAN Li;FU Maosen;ZHONG Hong(School of Materials Science and Engineering,Chang’an University,Xi’an 710064,China;State Key Laboratory of Solidification Processing,Northwestern Polytechnical University,Xi’an 710072,China)

机构地区：[1]长安大学材料科学与工程学院,陕西西安710064 [2]西北工业大学凝固技术国家重点实验室,陕西西安710072

出　　处：《材料科学与工程学报》2025年第1期16-22,共7页Journal of Materials Science and Engineering

基　　金：西北工业大学凝固技术国家重点实验室开放课题(SKLSP202416)。

摘　　要：石榴石型固态电解质Li_(7)La_(3)Zr_(2)O_(12)是实现全固态锂离子电池关键技术中最具潜力的电解质材料之一。本研究采用第一性原理方法研究了Sb掺杂对Li_(7)La_(3)Zr_(2)O_(12)电解质材料离子电导率和稳定性的影响。计算结果表明,Sb的加入可以稳定Li_(7)La_(3)Zr_(2)O_(12)的立方相结构,并在结构中引入一定数量的Li空位,形成均匀的扩散网络。随着Sb含量进一步提升,晶胞中产生过量的锂空位会削弱离子间的相互作用,造成局部少量结构畸变和迁移路径阻滞,导致离子电导率降低。在所研究的体系中Li_(52)La_(24)Zr_(12)Sb_(4)O_(96)具有最大的离子电导率(σ_(300k)=10.776 mS·cm^(-1))。通过第一性原理计算,加深了人们对Sb掺杂Li_(7)La_(3)Zr_(2)O_(12)电解质材料中锂离子扩散机制的理解。The garnet-based solid-state electrolyte Li_(7)La_(3)Zr_(2)O_(12)is one of the most promising electrolyte materials for realizing the key technology of all-solid-state lithium-ion batteries.In this paper,the effect of Sb doping on the ionic conductivity and stability of Li_(7)La_(3)Zr_(2)O_(12)electrolyte material is investigated using a firstprinciples approach.The calculated results show that the addition of Sb can stabilize the cubic phase structure of Li_(7)La_(3)Zr_(2)O_(12),and the doping of a small amount of Sb elements introduces a certain number of Li vacancies in the structure,forming a uniform diffusion network.With further elevation of the doping content,the generation of excessive Li vacancies in the crystal cell weakens the inter-ion interactions,resulting in a small number of local structural distortions and migration path blockage,which leads to a decrease in the ionic conductivity.The Li_(52)La_(24)Zr_(12)Sb_(4)O_(96)compounds have the largest ionic conductivities in the studied system(σ_(300k)=10.776 mS·cm^(-1)).The first-principles calculations have deepened the understanding of the lithium diffusion mechanism in Sb-doped Li_(7)La_(3)Zr_(2)O_(12)electrolyte materials.

关 键 词：固体电解质 密度泛函理论 分子动力学 离子电导率 

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]