Sodium metal anode battery technologies have revolutionized energy storage research. In recent years, new insights have been gained regarding the solid electrolyte interphase (SEI) on sodium metal anode; however, several questions remain to be answered, in particular, the impact of electrolyte structure on the composition and physicochemical stability of the SEI. In addition, the impact of ion-solvation chemistry on the crystallinity of the SEI warrants a more detailed understanding. This review discusses the crucial aspects of sodium-ion solvation chemistry and its impact on the stability of the SEI. The core principles guiding the design of electrolytes through additives, ion-solvent interaction, and ion-pair formation are highlighted. Future research directions necessary to design a stable sodium metal anode are also discussed.
Prof. Vipin Kumar