Engineering Materials for Progressive All-Solid-State Na Batteries

Following the prevalence of the Li-ion battery for electrical energy storage systems (EESs), the world is looking toward alternative, cost-effective, electrical EESs for portable electronics, electric vehicles, and grid storage from renewable sources. Na-based batteries are the most promising candidates and show similar chemistry as Li-based batteries. All-solid-state sodium batteries (AS³Bs) have attracted great attention due to safe operation, high energy density, and wide operational temperature. Herein, current development of solid-state crystalline borate- and chalcogenide-based Na-ion conductors is discussed together with historically important Na-β-alumina and Na superionic conductors (NASICONs). Furthermore, we report on engineering a ceramic Na-ion electrolyte and electrode interface, which is considered a bottleneck for practical applications of solid-state electrolytes in AS³Bs. A soft Na-ion conducting interlayer is critical to suppress the interfacial Na-ion charge transfer resistance between the solid electrolyte and electrode. Several Na-ion conducting ionic liquids, polymers, gels, crystalline plastics interlayers, and other interfacial modification strategies have been effectively employed in advanced AS³Bs.