Abstract: The present invention is a grafted polymer electrolyte membrane prepared by first preparing a precursor membrane comprising a polymer which is capable of being graft polymerized, exposing the surface of the precursor membrane to a plasma in an oxidative atmosphere, then graft-polymerizing a side chain polymer to the plasma treated precursor membrane and introducing a proton conductive functional group to the side chain. The resulting grafted polymer electrolyte membrane has excellent stability and performance when used in a proton-exchange membrane fuel cell or for electrolysis of water.

Abstract: A solid polyelectrolyte fuel cell has (a) a positive electrode, (b) a negative electrode, and (c) a solid polyelectrolyte membrane containing water, between the positive electrode and the negative electrode, where the water content of portions of the solid polyelectrolyte membrane adjacent to the negative electrode is greater than the water content of portions of the solid polyelectrolyte membrane adjacent to the positive electrode. The cell outputs high voltage and has good properties.

Abstract: A solid polyelectrolyte fuel cell has (a) a positive electrode, (b) a negative electrode, and (c) a solid polyelectrolyte membrane containing water, between the positive electrode and the negative electrode, where the water content of portions of the solid polyelectrolyte membrane adjacent to the negative electrode is greater than the water content of portions of the solid polyelectrolyte membrane adjacent to the positive electrode. The cell outputs high voltage and has good properties.

Abstract: A solid polymer electrolyte fuel cell includes a solid polymer electrolyte membrane and a fuel cell electrode. The solid polymer electrolyte membrane and/or the fuel cell electrode can contain at least one catalyst selected from oxide catalysts, macrocyclic metal complex catalysts, transition metal alloy catalysts and inorganic salt catalysts. The catalyst decomposes hydrogen peroxide formed during fuel cell operation and prevents the hydrogen peroxide from decomposing the solid polymer electrolyte membrane. As a result, a solid polymer electrolyte fuel cell is formed that is excellent in durability and available at a reduced cost.

Abstract: The present invention is a grafted polymer electrolyte membrane prepared by first preparing a precursor membrane comprising a polymer which is capable of being graft polymerized, exposing the surface of the precursor membrane to a plasma in an oxidative atmosphere, then graft-polymerizing a side chain polymer to the plasma treated precursor membrane and introducing a proton conductive functional group to the side chain. The resulting grafted polymer electrolyte membrane has excellent stability and performance when used in a proton-exchange membrane fuel cell or for electrolysis of water.

Abstract: A solid polyelectrolyte membrane for a fuel cell, comprises a synthetic resin comprising main chains and side chains, the main chains having a copolymer structure of a first olefin hydrocarbon and an olefin perfluorocarbon, the side chains having a sulfonic acid group containing crosslinked copolymer structure of a second olefin hydrocarbon and a diolefin hydrocarbon. The solid polyelectrolyte membrane is an inexpensive, solid polyelectrolyte membrane for fuel cells, of which the water content is controlled so that it does not cause too much wetting of electrode catalysts.

Abstract: A solid polyelectrolyte membrane for a fuel cell includes (a) a hydrocarbon polymer grafted fluorine polymer, which contains sulfonic acid groups, and (b) whisker fibers, fixed to the grafted fluorine polymer. The fiber may be surface-treated with a silane coupling agent which reacts with the fluorine polymer and the fibers, prior to graft-copolymerization.