(Invited) A Brief Understanding of Conduction Ions Transport Physics in Solid State Electrolytes

Abstract

Solid state electrolytes refer to a type of solid materials whose conductivity is close to (or in some cases exceeds) the molten salt and electrolyte. It refers to a special state with liquid-solid duality where conduction ions have near-liquid mobility, while other ions maintain regular crystal arrangement. This liquid-solid duality is attracting the attention of Condensed Matter Physicists. Typical solid electrolyte materials, as a separate phase with novelty, generally have the following features: high ionic conductivity, low activation energy and open structure crystal. This open structure has a network of interconnected empty sites that the ions can occupy. In addition, fast ion conductors have important dynamic and collective effects: they do not have clear optical lattice modes, but there are diffuse low-energy excitations, frequency-dependent conductivity infrared peak, anomalous pre-NMR, phase transitions and a high probability of finding moving ions between two allowable positions. Considering basic research, the core problem of solid electrolytes is the transport of ions on the bulk phase, surface, and interface. This report will introduce the history of research on transport physics in several typical solid electrolyte systems, focusing on combining the work carried out by myself and partners to introduce the major progress in this area in recent years. At the same time, the role of computational physics/materials in the research of solid electrolyte materials is prospected.