Disclosed are an electro-catalyst composition and a precursor electro-catalyst composition (e.g., ink or suspension) for use in a fuel cell that exhibits improved power output. The electro-catalyst composition comprises: (a) a catalyst un-supported or supported on an electronically conducting carrier (e.g., carbon black particles); and (b) an ion-conducting and electron-conducting coating material in physical contact with the catalyst and/or coated on a surface of the carrier, wherein the coating material has an electronic conductivity no less than 10.sup.-4 S/cm (preferably no less than 10.sup.-2 S/cm) and an ion conductivity no less than 10.sup.-5 S/cm (preferably no less than 10.sup.-3 S/cm). Also disclosed are a fuel cell electrode comprising this composition, a membrane-electrode assembly (MEA) comprising this composition, and a fuel cell comprising this composition.