Microcapsule and microsphere controlled release forms of antioxidants such as cerium oxide to improve durability, and extend the lifetime of fuel cells are disclosed. Membrane electrode assemblies (MEAs) and polymer electrolyte membrane fuel cells (PEMFCs) employing the controlled release forms and methods of mitigating or suppressing cerium migration in fuel cells are also disclosed.

Microcapsule and microsphere controlled release forms of antioxidants such as cerium oxide to improve durability, and extend the lifetime of fuel cells are disclosed. Membrane electrode assemblies (MEAs) and polymer electrolyte membrane fuel cells (PEMFCs) employing the controlled release forms and methods of mitigating or suppressing cerium migration in fuel cells are also disclosed.

A thermoplastic resin (thermosetting resin) for forming a microporous layer of a polymer electrolyte fuel cell has a melt viscosity at 350? C. of less than or equal to 200 Pa.Math.s. In an instance where 2 g of the thermoplastic resin (thermosetting resin) is immersed in 100 ml of hot water having a temperature of 100? C. for 6 hours, an amount of metal ions dissolved from the thermoplastic resin (thermosetting resin) is less than or equal to 65 ppm.

A thermoplastic resin (thermosetting resin) for forming a microporous layer of a polymer electrolyte fuel cell has a melt viscosity at 350? C. of less than or equal to 200 Pa.Math.s. In an instance where 2 g of the thermoplastic resin (thermosetting resin) is immersed in 100 ml of hot water having a temperature of 100? C. for 6 hours, an amount of metal ions dissolved from the thermoplastic resin (thermosetting resin) is less than or equal to 65 ppm.

Disclosed is a method of producing an antioxidant that has excellent antioxidant ability and is well dispersed when applied to a membrane-electrode assembly (MEA). The method includes a step of preparing a powder including reduced metal oxide and a step of mixing the powder with a powdery ionomer to obtain an antioxidant in which the ionomer is bound to the surface of the reduced metal oxide.

An anion exchange resin capable of producing an electrolyte membrane, a binder for forming an electrode catalyst layer and a fuel cell electrode catalyst layer, which have improved chemical properties and mechanical properties; an electrolyte membrane and a binder for forming an electrode catalyst layer produced from the anion exchange resin; and a fuel cell having the electrolyte membrane or the electrode catalyst layer.

An electrolyte membrane laminate including: a first electrolyte membrane having a first main surface and a second main surface; and a first interlayer and a second electrolyte membrane in this order on the first main surface of the first electrolyte membrane; wherein the first electrolyte membrane contains a hydrocarbon-based polymer electrolyte, the first interlayer contains a polymer electrolyte and particles, and the second electrolyte membrane contains a polymer electrolyte and particles containing a transition metal element. Provided is an electrolyte membrane laminate having an excellent hydrogen-proof barrier property and a good durability.

A method is disclosed for improving the durability of membrane electrode assemblies in solid polymer electrolyte fuel cells by reducing the amount of halogen ion contaminants present. Silver carbonate is dissolved in an ionomer dispersion and incorporated into an appropriate component in the fuel cell where it reacts with halogen ion present to form silver halides. The component is then exposed to a suitable light source that decomposes the halide into halogen gas which is then removed prior to final assembly of the fuel cell.

A method is disclosed for improving the durability of membrane electrode assemblies in solid polymer electrolyte fuel cells by reducing the amount of halogen ion contaminants present. Silver carbonate is dissolved in an ionomer dispersion and incorporated into an appropriate component in the fuel cell where it reacts with halogen ion present to form silver halides. The component is then exposed to a suitable light source that decomposes the halide into halogen gas which is then removed prior to final assembly of the fuel cell.

The present specification provides a method for preparing a polymer electrolyte membrane including reducing a ketone group of a polyarylene ether ketone polymer of a polymer electrolyte membrane; and treating the polymer electrolyte membrane with sulfuric acid, a polymer electrolyte membrane prepared using the same, a membrane electrode assembly including the polymer electrolyte membrane, and a fuel cell including the membrane electrode assembly.