High Temperature Sodium - Zinc Chloride Batteries With Sodium Beta - Alumina Solid Electrolyte

Abstract

High Temperature energy storage systems are widely explored due to the increasing need of storage systems in the electric utility industry. With the use of such systems, load leveling can be achieved. The energy storage system of interest here is based on Sodium - β alumina solid electrolyte (BASE) with liquid sodium as anode and molten ZnCl2 as cathode. BASE is an excellent sodium ion conductor with a very high conductivity at 300oC. The discharge reaction: 2Na + ZnCl2 à 2NaCl + Zn OCV (350oC) = 2.4V Unlike sodium sulfur batteries, the volumetric power density of Na - ZnCl2 battery is higher due to the planar cell construction. If a cell fails, it develops a low resistance so that the other cells continue to deliver power in a normal manner. This paper will compare the Na - ZnCl2 batteries: planar design, construction and testing, with other high temperature storage batteries.