TECHNOLOGY FOCUS - ELECTRICAL POWER AND ENERGY - Preferred Process: The heat-treated carbon is ground, prior to step (i). The polyoxometalate is co-crushed with the heat-treated carbon. The metal oxide and the polyoxometalate are co-crushed prior to step (i). The process further comprises a step of immersing the electrode obtained in step (iv) in a solution of an inorganic acid. Preferred Components: The conductive material having positive charge is a carbon material obtained by heat treatment of carbon at a temperature of at least 900 degrees C. The carbon subjected to heat treatment is in the form of carbon black, carbon nanotube, graphite, glassy carbon, carbon felt, or carbon nanoparticles.    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The polyoxometalate is constituted by a cation and a polyanion, where the polyanion has the structure of formula ((MmOy)(p-)) or ((XxMmOy)(q-)); and the cation is hydrogen ion (H+), ammonium ion (NH4+), alkali metal cations, alkaline earth metal cations, and transition metal cations. The polyoxometalate is preferably (H3PW12O40), (H4SiW12O40) or ((NH4)6H2W12O40). The solvent in step (i) is an organic solvent. The solvent in step (i) is an aqueous acid solution at a pH less than or equal to 5. The mass content in polyoxometalate is at least equal to the mass content of carbon in the suspension obtained in step (i). The conductive material having positive charges is a metal oxide bearing positive charges. The metal oxide is partially oxidized titanium, titanium dioxide in powder or mass, indium oxide doped with tin, or tin oxide. The mass content of polyoxometalate is at least greater than or equal to 25% than the mass concentration of the metal oxide. The volume content of binder is at least 25-50% or at least 75% of the suspension obtained in step (i). The metal oxide is coated with a polymer having positive charges. The polyoxometalate is stable in acid and the binder is a fluoropolymer comprising copolymers of sulfonated or hydrogenated tetrafluoroethylene. The polyoxometalate is stable in neutral or basic medium, and the binder is non-sulfonated copolymers of non sulfonated or hydrogenated tetrafluoroethylene.M = a transition metal;X = a transition metal or a nonmetallic element comprising P, As, Sb, Bi, Si, Ge, Se, or Te; andm, x, y, p, q = greater than or equal to 1.    TECHNOLOGY FOCUS - POLYMERS - Preferred Components: The polymer having positive charges is polyvinylpyridine, polyaniline, polythiophene, polypyrrole or poly (diallyldimethylammonium). The binder is an organic binder, which is a fluoropolymer.