METHOD FOR PRODUCING IRON OXYFLUORIDE POSITIVE ELECTRODE ACTIVE SUBSTANCE

Provided is a technology for producing a positive electrode active substance mainly composed of FeOF having a sufficient charge-discharge capacity, in the short-time and easy manner. Also provided is a positive electrode active substance mainly composed of FeOF. The method for producing the positive electrode active substance mainly composed of FeOF comprises the steps of admixing iron oxide FeOand iron fluoride FeFboth in solid states, and melt-quenching the mixture in an atmosphere of inert gas. The positive electrode active substance mainly composed of FeOF is composed of not less than 50% by weight of FeOF with a remainder being iron fluoride FeFand/or iron oxide FeO.