Oxide Solid Electrolytes in Solid‐State Batteries

Solid‐state electrolytes (SSEs) have re‐emerged as high‐priority materials for enhancing the safety and power density of electrochemical energy storage devices. However, several challenges, including low ionic conductivity, narrow redox windows, and interface issues, hinder the practical deployment of solid‐state batteries (SSBs). In this review, we evaluate recent advances in the design, synthesis, and analysis of oxide SSEs and identify relevant structural and stability factors, as well as dimensional design concepts, for creating oxide SSEs to meet practical application requirements. We provide an overview of the development and characteristics of oxide SSEs, then analyze bulk and ion transport based on different structures. We summarize the progress made in various synthetic approaches to oxide SSEs and discuss issues related to their stability and factors influencing ionic conductivity. Furthermore, we present the main challenges and future development directions of oxide SSBs to pave the way for the practical applications of oxide SSEs.