Abstract: Batteries employing an oxygen (air) electrode, particularly those in which the oxygen electrode is combined with an alkali metal or alkaline earth metal negative electrode useful I for bulk energy storage, particularly for electric utility grid storage, as well as for electric vehicle propulsion. Batteries have an electrochemically reversible oxygen positive having a porous mixed metal oxide matrix for receiving and retaining discharge product and a dense (non-porous) separator element which conducts oxygen ions and electrons in contact with a source of oxygen.

Abstract: Cell and batteries containing them employing a transition metal chalcogenide positive electrode (cathode) in combination with a liquid alkali metal haloaluminate. At operating temperatures, the positive electrode (cathode) of the invention comprises a solid matrix comprising electroactive cathode material permeated with and in physical and electrical contact with liquid alkali metal haloaluminate electrolyte. The positive and negative electrodes are separated with a solid alkali metal conducting electrolyte. The transition metal chalcogenide is not in direct physical contact with the solid electrolyte. Electric and ionic conductivity between the solid electrolyte and the positive electrode is mediated by the liquid alkali metal haloaluminate electrolyte. More specifically, the cells are sodium/iron sulfide cells. Batteries of the invention are useful for bulk energy storage, particularly for electric utility grid storage, as well as for electric vehicle propulsion.