TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Process: Alternately, the cation-conducting composite membrane is formed by(1) precipitating a mixture of ion conducting oxide and a polymer matrix from solution and fabricating resulting product into membrane;(2) forming a matrix polymer within the solution containing suspension of inorganic proton conductor, separating solids from the solution, and pressing the solids into a composite membrane; and(3) producing a suspension containing both matrix polymer and oxide proton conductor, filtering matrix polymer and oxide proton conductor onto removable filter element, removing filtered mass from removable filter element, and pressing filtered mass in presence of heat, to form composite membrane.The cation-conducting composite membrane conducts monovalent charged cations such as protons and alkali metal cations. The proton conductor is synthesized by sol-gel route or by base hydrolysis of metal salt solution comprising metal chloride and/or metal nitrate. Preferred Composition: The membrane comprises sufficient fraction of inorganic oxide proton conductor to insure oxide particle-to-oxide particle connectivity from one surface of membrane to opposite surface. The inorganic oxide proton conductor possesses easily exchangeable proton, has an open framework structure with channels, and retains proton conductivity at above 200 degrees C. The proton conductor comprises insoluble hydrated or hydrous metal oxides chosen from hydrated precious metal containing oxides, acid oxides of heavy post transition elements, oxides of heavier early transition metals, oxide superacids, phosphates of zirconium, phosphates of cadmium, phosphates of titanium, phosphates of lead, phosphates of tin, tungsten trioxide, molybdenum trioxide, hetero-polymolybdates, homo-polymolybdates, hetero-polytungstates, homo-polytungstates, hetero-polytantalates, homo-polytantalates, hetero-polyniobates, homo-polyniobates, oxoacids of antimony and their mixtures. The hydrated precious metal containing oxides are RuOx(H2O)n or (Ru-Ti)Ox(H2O). The acid oxides of heavy post transition elements are acidic antimony oxides or acidic tin oxides. Oxides of heavier early transition metals comprise molybdenum, tungsten or zirconium. The oxide superacids are sulfonated zirconia, sulfonated titanium oxide, or sulfonated titanium-aluminum oxide. The inorganic proton conductor comprises elements forming insoluble hydrated oxides that are not basic, and comprises oxide particles that form a connected network extending from one phase of membrane to another phase of membrane. Porous polymer matrix is synthetic organic polymer having melting point of more than 300 degrees C, and comprises fully halogenated polymer and/or partially halogenated polymer such as fluorinated polymers. Synthetic organic polymer is resistant to oxidation. The porous polymer matrix comprises perfluorosulfonic acid, polytetrafluoroethylene (PTFE), perfluoroalkoxy derivative of PTFE, polysulfone, polymethylmethacrylate, silicone rubber, sulfonated styrene butadiene copolymers, polychlorotrifluoroethylene (PCTFE), perfluoroethylenepropylene copolymer (FEP), ethylene-chlorotrifluoroethylene copolymer (ECTFE), polyvinylidenefluoride (PVDF), copolymers of PVDF with hexafluoropropene and tetrafluoroethylene, copolymers of ethylene and tetrafluoroethylene (ETFE), polyvinylchloride or their mixtures, preferably perfluorosulfonic acid or porous PTFE. EXAMPLE - Porous PTFE filler and suspension of gelatinous zirconium phosphate produced by rapid addition of solution of hydrated zirconium nitrate (Zr(NO3)4.5H2O) to 85% phosphoric acid, were placed in a filtration funnel, and a vacuum was applied to the outlet of funnel. Fluid moved through the pores in the filter, but the gelatinous zirconium phosphate was retained. The pores are rapidly filtered, and filtration was stopped after 10 minutes. The vacuum was released and portion of original suspension which was not passed into the filter was decanted, and the filter was transferred to a boiling flask containing 85% phosphoric acid. A condenser was placed on top of the flask, and the flask was heated until the acid refluxed. The heating was continued for 7 days to crystallize the gel into alpha-Zr(HPO4)2.H2O. After the flask cooled, the acid was decanted and the membrane was removed. The complete filling of pores was insured, when the filtration steps were repeated, followed by refluxing step. The resulting membrane was washed in deionized water to remove free phosphoric acid. The obtained composite membrane was submitted to a Gurley airflow test to determine its gas permeability properties. The test measures the time in seconds for 100 ml of air to flow through 1 square inch sample at 4.88 inches water pressure. The obtained composite membrane was used for fuel cell for generation of electricity.