全固态锂电池正极/电解质界面电阻:从空间电荷层模型到表征及模拟  

All-Solid-State Lithium Cathode/Electrolyte Interfacial Resistance:From Space-Charge Layer Model to Characterization and Simulation

作　　者：王达 殷晓彬 吴剑芳 罗亚桥 施思齐[1,4] Da Wang;Xiaobin Yin;Jianfang Wu;Yaqiao Luo;Siqi Shi(School of Materials Science and Engineering,Shanghai University,Shanghai 200444,China;C Innovation Laboratory(21C LAB),Contemporary Amperex Technology Ltd.,Ningde 352100,Fujian Province,China;College of Materials Science and Engineering,Hunan University,Changsha 410082,China;Materials Genome Institute,Shanghai University,Shanghai 200444,China)

机构地区：[1]上海大学材料科学与工程学院,上海200444 [2]宁德时代21C创新实验室,福建宁德352100 [3]湖南大学材料科学与工程学院,长沙410082 [4]上海大学材料基因组工程研究院,上海200444

出　　处：《物理化学学报》2024年第7期21-35,共15页Acta Physico-Chimica Sinica

基　　金：国家重点研发计划(2021YFB3802104);国家自然科学基金(52372208,U2030206,11874254);宁德时代创新实验室开放基金(21C-OP-202205)资助项目。

摘　　要：采用无机固体电解质的全固态锂电池以其高安全性和长寿命等优点,已经成为动力电池领域的重要发展方向之一。随着高室温离子电导率(大于10^(-3)S·cm^(-1))的固体电解质的涌现,锂离子在其中的迁移动力学问题不再是全固态锂电池发展的主要瓶颈。相比之下,正极和固体电解质界面处因空间电荷层等复杂效应导致的高界面电阻成为当前急需解决的难题。本文从(电)化学势及电势的基本概念出发,对描述正极和固体电解质之间化学势差异所导致的空间电荷层的理论模型进行严格推导,以揭示其影响界面电阻的物理本质。接着,本文从实验表征和理论模拟角度出发,综述了当前在观测空间电荷层状态、计算正极/固体电解质界面及其体相锂离子浓度,以及预测界面电阻等方面存在的问题。在此基础上,本文提出了融合空间电荷层模型、数值模拟以及基于实际正极和固体电解质接触处费米能级状态和位置的方法,从而定量评估界面电阻。最后,本文展望了通过优化正极/固体电解质界面来提升全固态锂电池电化学性能的未来发展趋势。通过深入理解界面电阻的物理机制,未来可以采用新的材料设计、界面工程等策略来改善全固态锂电池的性能。这些研究将有助于推动全固态锂电池技术的发展,实现更高效、更安全的能源存储解决方案。All-solid-state batteries(ASSBs) using inorganic solid electrolytes(SEs) have emerged as crucial components in energy storage applications due to their superior safety and cycle life.In recent years,due to the extensive developments of SEs with high room temperature ionic conductivity(> 10^(-3) S·cm^(-1)),the sluggish diffusion kinetics of lithium ions in SEs are no longer the primary bottleneck impeding the enhancement of ASSBs.On the contrary,the notable resistance at the cathode/SE interface has emerged as a pressing issue demanding immediate resolution.The interfacial resistances arising from various factors,including the formation of the space-charge layer,interfacial chemical reactions,and lack of intimate contact,stand as fundamental reasons for a range of performance deteriorations,such as short cycling life,low coulombic efficiency,and poor power performance.These interconnected aspects further result in differences in the orders of magnitude of the reported interfacial resistances at different fabrication temperatures and/or routes,even within the same material system.Among these factors,the solid-solid contact or chemical reaction degree is closely related to the structural and electronic properties of the selected cathode and SE materials.The observed space-charge layer effect is universal and independent of the specific components or types of ion-conductive materials.Thus,obtaining a comprehensive understanding of the physics governing the space-charge layer at the interfaces of ASSBs is pivotal for researchers to fundamentally address the high interfacial resistance stemming from it.This forms the foundation for incorporating other mechanisms(such as interfacial reactions) to more accurately quantify interfacial resistance and expedite interface research in ASSBs.In this review,we strictly derive the theoretical model of the formation of the space-charge layer caused by the inherent chemical potential difference between the cathode and SE from fundamental concepts of(electro)chemical potential and

关 键 词：正极 固体电解质 空间电荷层 界面电势差 界面电阻 

分 类 号：O646[理学—物理化学]