Halide solid electrolytes in all-solid-state batteries: Ion transport kinetics, failure mechanisms and improvement strategies

Halide solid electrolytes (SEs) have emerged as a prominent area of research interest due to their exceptional properties. Currently, there is growing interest in halide SEs, driven by optimized structural frameworks, advanced synthesis methods, and enhanced physico-mechanical deformability rooted in halogen chemistry. In this paper, we devote to describing the mechanism of ion transport kinetics in halide SEs, while also presenting an overview of the current research status and future development prospects in halide-based all-solid-state batteries (ASSBs). The application of modeling and theoretical calculations has provided a significant impetus to the field. In addition, it presents a summary of the potential sources of ion transport failure in halide SEs and the electrode|SE interface, and proposes effective strategies to address these issues. Ultimately, this paper provides a forward-looking perspective on prospective avenues of research in halide SEs, drawing insights from investigations into cycle stability and rapid ion conduction in this field. The review promotes our understanding on the dynamics of fast ion conduction in halide SEs, which offers valuable insights to guide the development of innovative halide SEs.