Room temperature sodium-sulfur (Na-S) batteries, known for their high energy density and low cost, are one of the most promising next-generation energy storage systems. However, the polysulfide shuttling and uncontrollable Na dendrite growth as well as safety issues caused by the use of organic liquid electrolytes in Na-S cells, have severely hindered their commercialization. Solid-state electrolytes instead of liquid electrolytes are considered to be the most direct and effective solution to solve the above problems. However, its practical application is still greatly challenged due to the poor interfacial compatibility between the all-solid-state electrolytes and the anode/cathode, ionic conductivity, and the shuttle effect caused by the presence of liquid phase in the quasi-solid-state electrolytes. This paper presents a comprehensive review of solid-state Na-S batteries from the perspective of regulating interfacial compatibility and improving ionic conductivity as well as suppressing polysulfide shuttle. According to different components, solid-state electrolytes were divided into five categories: solid inorganic electrolytes, solid polymer electrolytes, polymer/inorganic solid hybrid electrolytes, gel polymer electrolytes, and liquid–solid inorganic hybrid electrolytes. Finally, the prospect of developing high performance solid-state electrolytes to improve the cycling stability of room temperature Na-S cells is envisaged.

Sodium metal is one of the ideal anodes for high-performance rechargeable batteries because of its high specific capacity (~ 1166 mAh·g⁻¹), low reduction potential (−2.71 V compared to standard hydrogen electrodes), and low cost. However, the unstable solid electrolyte interphase, uncontrolled dendrite growth, and inevitable volume expansion hinder the practical application of sodium metal anodes. At present, many strategies have been developed to achieve stable sodium metal anodes. Here, we systematically summarize the latest strategies adopted in interface engineering, current collector design, and the emerging methods to improve the reaction kinetics of sodium deposition processes. First, the strategies of constructing protective layers are reviewed, including inorganic, organic, and mixed protective layers through electrolyte additives or pretreatments. Then, the classification of metal-based, carbon-based, and composite porous frames is discussed, including their function in reducing local deposition current density and the effect of introducing sodiophilic sites. Third, the recent progress of alloys, nanoparticles, and single atoms in improving Na deposition kinetics is systematically reviewed. Finally, the future research direction and the prospect of high-performance sodium metal batteries are proposed.