ELECTROLYTE MEMBRANE OF A MEMBRANE-ELECTRODE ASSEMBLY HAVING IMPROVED CHEMICAL DURABILITY AND A MANUFACTURING METHOD THEREOF

An electrolyte membrane of a membrane-electrode assembly is formed by a manufacturing method yielding a membrane with improved chemical durability. The manufacturing method includes preparing an antioxidant solution, mixing the antioxidant solution and a first ionomer dispersion solution, drying the mixture to produce a composite having an antioxidant and a first ionomer surrounding the antioxidant, introducing and mixing the composite with a second ionomer dispersion solution, and applying that mixture to a substrate and drying the mixture to manufacture an electrolyte membrane. The resulting electrolyte membrane includes the composite having an antioxidant in an ionic state and a first ionomer surrounding the antioxidant.