Sodium-Sulfur Battery

A sodium-sulfur battery, or NaS battery, is a type of molten-salt battery that uses liquid sodium and liquid sulfur electrodes. It has an energy density similar to lithium-ion batteries and is fabricated from inexpensive, low-toxicity materials, but the high operating temperature it requires and the highly reactive nature of sodium and sodium polysulfides make it primarily suited to stationary energy storage rather than vehicles. Molten sodium-sulfur batteries are scalable in size: installations include a 1 megawatt microgrid support system on Catalina Island in California and a 50 megawatt, 300 megawatt-hour system in Fukuoka, Japan.