Polymer electrolyte membrane, method for fabricating same, and membrane-electrode assembly comprising same

A method for producing a composite polymer electrolyte membrane, the method comprising:

• preparing a first solution by dissolving a precursor of a first hydrocarbon-based ion conductor in a first solvent, the first hydrocarbon-based ion conductor being a sulfonated polyether ketone-based crystalline polymer which is insoluble in the first solvent;
• producing a nanoweb structure by electric spinning and subsequently heat treating the first solution;
• eliminating protective groups from the precursor of the nanoweb structure, thereby converting the precursor into the first hydrocarbon-based ion conductor and producing a porous support of the nanoweb structure containing the first hydrocarbon-based ion conductor;
• and
• filling pores of the porous support with a second hydrocarbon-based ion conductor by (i) applying a second solution prepared by dissolving the second hydrocarbon-based ion conductor in a second solvent in which the first hydrocarbon-based ion conductor is insoluble to the porous support and (ii) removing the second solvent.