Anisotropically Electrochemical–Mechanical Evolution in Solid‐State Batteries and Interfacial Tailored Strategy

• Published in: Angewandte Chemie (International ed.) Vol. 58; no. 51; pp. 18647 - 18653
• Main Authors: Sun, Nan, Liu, Qingsong, Cao, Yi, Lou, Shuaifeng, Ge, Mingyuan, Xiao, Xianghui, Lee, Wah‐Keat, Gao, Yunzhi, Yin, Geping, Wang, Jiajun, Sun, Xueliang
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 16.12.2019; Wiley
• Edition: International ed. in English
• Subjects: Batteries; Contact loss; Electrochemistry; Electrolytes; ENERGY STORAGE; Evolution; Flux density; Interface reactions; Interfaces; lithium; Phase transitions; solid-state batteries; sulfide electrolyte; lithium; solid-state batteries; interfaces; sulfide electrolyte; electrochemistry
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.201910993

All‐solid‐state batteries have attracted attention owing to the potential high energy density and safety; however, little success has been made on practical applications of solid‐state batteries, which is largely attributed to the solid–solid interface issues. A fundamental elucidation of electrode–electrolyte interface behaviors is of crucial significance but has proven difficult. The interfacial resistance and capacity fading issues in a solid‐state battery were probed, revealing a heterogeneous phase transition evolution at solid–solid interfaces. The strain‐induced interfacial change and the contact loss, as well as a dense metallic surface phase, deteriorate the electrochemical reaction in solid‐state batteries. Furthermore, the in situ growth of electrolytes on secondary particles is proposed to fabricate robust solid–solid interface. Our study enlightens new insights into the mechanism behind solid–solid interfacial reaction for optimizing advanced solid‐state batteries. Solid as a rock: The unsatisfactory electrochemical performance in solid‐state batteries originates from internal strain‐induced contact loss, heterogeneous phase transformation, and the augmentation of metallic surface passivation layers. With in situ growth of solid sulfide electrolyte into 3D FeS2 microstructure, these issues can be significantly inhibited and superior electrochemical performance can be achieved.