NaCrO2 MATERIAL, MOLTEN SALT BATTERY, AND METHOD FOR PRODUCING THE NaCrO2 MATERIAL

摘要

PROBLEM TO BE SOLVED: To provide an NaCrOmaterial which enhances discharge capacity of a molten salt battery when used as a positive electrode active material, a molten salt battery, and a method for producing the NaCrOmaterial.SOLUTION: The molten salt battery includes a positive electrode 1 with the NaCrOmaterial comprising secondary particles in which primary particles of NaCrOaggregate as an active material. The primary particles of NaCrOhave an average particle diameter of 0.1 m and the secondary particles are in a granular shape with a filling rate of 80%. The granular secondary particles are formed in such a manner that aqueous solutions of Cr(OH)and NaOH are sprayed and dried, whereby Cr(OH)and NaOH react with each other to yield NaCrOand primary particles of NaCrOaggregate. When charging the molten salt battery, sodium ions which reach the positive electrode 1 diffuse quickly in the granular secondary particles and intrude into the primary particles, and accordingly discharge capacity at a high discharge rate is further enhanced as compared with the conventional one.