Provided is a method of preparing a crosslinked sulfonated poly(ether ether ketone) (SPEEK) cation exchange membrane including: preparing a crosslinker mixture of a first crosslinker containing two or more vinyl oxy groups and a second crosslinker containing three or more vinyl groups; preparing a mother liquor containing the crosslinker mixture, a SPEEK polymer substituted with sodium, and a solvent; and casting the mother liquor and then irradiating radiation thereon.

(Problem) To provide an electrolyte film for fuel cells, capable of achieving both low resistance (film thinning) and high dimensional stability.

(Solution) An electrolyte film for fuel cells, the electrolyte film comprising a polymeric electrolyte and a polytetrafluoroethylene (PTFE) porous film, characterized in that a material having an elastic modulus higher than that of the material constituting the PTFE porous film is composited on the inside surfaces of pores of the PTFE porous film, and the composited PTFE porous film has an elastic modulus of at least 150 MPa.

A membrane electrode assembly for fuel cells includes a proton conducting membrane having a first side and a second side. The proton conducting membrane in turn includes a first polymer including cyclic polyether groups and a second polymer having sulfonic acid groups. The membrane electrode assembly further includes an anode disposed over the first side of the proton conducting layer and a cathode catalyst layer disposed over the second side of the proton conducting layer.

A membrane electrode assembly for fuel cells includes a proton conducting membrane having a first side and a second side. The proton conducting membrane in turn includes a first polymer including cyclic polyether groups and a second polymer having sulfonic acid groups. The membrane electrode assembly further includes an anode disposed over the first side of the proton conducting layer and a cathode catalyst layer disposed over the second side of the proton conducting layer.

A process for the recovery of a perfluorosulphonic acid ionomer from a component comprising a perfluorosulphonic acid ionomer is disclosed, the process comprising immersing the component comprising the perfluorosulphonic acid ionomer in a solvent comprising an aliphatic diol and heating. Also disclosed is the use of the recovered perfluorosulphonic acid ionomer, for example in to prepared a proton conducting membrane or a catalyst ink.

A process for the recovery of a perfluorosulphonic acid ionomer from a component comprising a perfluorosulphonic acid ionomer is disclosed, the process comprising immersing the component comprising the perfluorosulphonic acid ionomer in a solvent comprising an aliphatic diol and heating. Also disclosed is the use of the recovered perfluorosulphonic acid ionomer, for example in to prepared a proton conducting membrane or a catalyst ink.

Disclosed are a polymer electrolyte membrane showing high ion conductivity even under the condition of low humidity and high temperature and a method for manufacturing the same. The polymer electrolyte membrane of the present invention comprises a porous substrate, a self proton conducting material dispersed in the porous substrate, and an ion conductor impregnated in the porous substrate. The self proton conducting material comprises an inorganic particle functionalized with an azole ring.

Disclosed are a polymer electrolyte membrane showing high ion conductivity even under the condition of low humidity and high temperature and a method for manufacturing the same. The polymer electrolyte membrane of the present invention comprises a porous substrate, a self proton conducting material dispersed in the porous substrate, and an ion conductor impregnated in the porous substrate. The self proton conducting material comprises an inorganic particle functionalized with an azole ring.

Provided is a polymer electrolyte membrane comprising: (a) a polyelectrolyte having an ion exchange capacity of from 0.5 to 3.0 meq/g; and (b) at least one scandium compound selected from the group consisting of scandium oxide, scandium acetate, scandium sulfate, scandium nitrate, and scandium carbonate, wherein a polyethylene glycol (PEG)-derived compound in the polymer electrolyte membrane has a total content of 10 ppm or less.

Disclosed are: a reinforced composite membrane-type polymer electrolyte membrane which can prevent the loss of an ion conductor even when the ion conductor is chemically deteriorated due to long-term use, and thus has remarkably enhanced mechanical and chemical durability; a method for manufacturing same; and an electrochemical device comprising same. The polymer electrolyte membrane of the present invention comprises: a non-crosslinked ion conductor; and a porous support having a plurality of pores filled with the ion conductor, wherein the porous support comprises a polymer having at least one crosslinking functional group, and the crosslinking functional group is a functional group which, when the ion conductor is deteriorated, can cause crosslinking of the ion conductor by binding to the deteriorated ion conductor.