Strategies to Stabilize the Sodium metal anode for High-energy Room-temperature Sodium-Sulfur Batteries

Abstract

Room temperature sodium-sulfur batteries possess higher specific energy and improved inherent safety compared to their high-temperature analogs used in stationary grid storage. The viability of room temperature sodium batteries depends critically on the mechanical and ionic transport properties of the solid electrolyte interphase. Solid electrolyte interphases address a number of concomitant challenges, including large volume change, low ionic conductivity, rapid dendrite growth, and high chemical reactivity, which limit the viability of sodium anodes. In this presentation, novel strategies to stabilize the sodium metal anode are discussed that enable a high-rate cycling of sodium anodes. A solid-vapor growth approach is developed to fabricate a variety of artificial interphases directly on the surface of the sodium metal anode. As a result, the metal anode could be cycled for over 600 cycles at relatively higher currents. A room-temperature sodium-sulfur cell comprising modified sodium metal anode and sulfur cathode could be cycled for over 500 cycles with minimal capacity decay per cycle.