Trends in the Development of Room-Temperature Sodium-Sulfur Batteries

This review examines research reported in the past decade in the field of the fabrication of batteries based on the sodium-sulfur system, capable of operating at an ambient temperature (room-temperature sodium-sulfur (Na-S) batteries). Such batteries differ from currently widespread lithium-ion or lithium-sulfur analogs in that their starting materials are cheaper and more readily available. One of the key problems to be resolved on the way to room-temperature Na-S batteries with high energy density and long-term cycling stability is transport of cell reaction products (sodium polysulfides) to the opposite electrode, which leads to an appreciable battery self-discharge and loss of the active material as a result of redox reactions that are not accompanied by energy generation. This review is aimed at examining approaches to improving the electrochemical performance of the room-temperature Na-S batteries. Particular attention is paid to potential applications of cation-exchange materials capable of suppressing polysulfide anion transport, with a high sodium cation transport rate retained.