Co5O8

Co₅O₈ is a mixed-valence cobalt oxide ceramic compound that exists as part of the cobalt oxide family, where cobalt exists in both +2 and +3 oxidation states. This material is primarily investigated in research and development contexts for electrochemical and catalytic applications rather than as an established engineering commodity. Its notable applications include energy storage devices (supercapacitors, battery electrodes), oxygen evolution catalysis for water splitting and fuel cells, and magnetic oxide systems—areas where its electrical conductivity and redox activity offer advantages over simpler cobalt oxide phases like CoO or Co₃O₄.