Solid electrolytes and interfaces in all-solid-state sodium batteries: Progress and perspective

All-solid-state sodium batteries are promising candidates for the next generation of energy storage with exceptional safety, reliability and stability. The solid electrolytes are key components for enabling all-solid-state sodium batteries with high electrochemical performances. This Review discusses the current developments on inorganic and organic sodium ions solid electrolytes, including β/β′′-alumina, NASICON, sulfides, polymers and others. In particular, the structures, ionic conductivities and fabrications as well as electrochemical/chemical stabilities of solid electrolytes are discussed. The effective approaches for forming intimate interfaces between solid electrolytes and electrodes are also reviewed. And perspectives on future developments in the field of solid electrolytes and possible directions to improve interfacial contacts for future practical applications of all-solid-state sodium batteries are included. All-solid-state sodium batteries are the promising candidate for the next generation of large-scale energy storage with exceptional safety, reliability and stability. The solid electrolytes are the key components for enabling all-solid-state sodium batteries with high electrochemical performances. The current developments of solid electrolytes were reviewed in this article. In particular, the intrinsic properties of solid electrolytes and the effective approaches for forming intimate interfaces between solid electrolytes and electrodes are deeply discussed. Besides, several directions are also suggested for developing the solid electrolytes and improving the interfacial contacts for future practical applications of all-solid-state sodium batteries. [Display omitted] •The overall picture and intrinsic properties about the solid electrolytes of all solid-state sodium batteries are reviewed.•The effective approaches for forming intimate interfaces between solid electrolytes and electrodes are emphasized.•Several possible directions for developing solid electrolytes and improving the interfacial contacts are suggested as well.