Hitachi, Ltd.

Hitachi Maxwell, Ltd.

Takayuki Hirashige

Makoto Morishima

Mikio Kishimoto

Yuko Sawaki

Kazutaka Matsuo

Hiroshi Sasaki

A composite electrolyte membrane uses a metal-oxide hydrate which has a number of hydration water molecules of 2.7 or more and 10 or less and/or which is in the form of particles having a particle diameter of 1 nm or more and 10 nm or less. The composite electrolyte membrane exhibits its expected original performance, has both a high proton conductivity and a low methanol permeability, and provides a high-output membrane electrolyte assembly for a fuel cell.

Composite electrolyte membrane, production method thereof, membrane-electrode assembly, and fuel cell

A membrane-electrode assembly comprising a cathode catalyst layer for reducing an oxidant gas, a polymer electrolyte membrane and an anode catalyst layer, the polymer electrolyte membrane being sandwiched between the catalyst layers, wherein the cathode catalyst layer exhibits super-water-repellency. The disclosure is also concerned with a method of manufacturing the membrane-electrode assembly and a fuel cell using the membrane-electrode assembly.

Catalyst for fuel cell, membrane-electrode assembly, method of manufacturing the assembly, and fuel cell using the assembly

The zirconium oxide hydrate particles of the present invention are represented by the formula ZrO.nHO and have a mean primary particle size of 0.5 nm or more and 5 nm or less, and 'n' in the formula represents a number greater than 2.5. Moreover, the method for producing of zirconium oxide hydrate particles of the present invention includes the step of preparing zirconium oxide hydrate particles by adding an aqueous zirconium salt solution to an aqueous alkaline solution while controlling the pH to 7.0 or more and 13.0 or less, and the step of subjecting the zirconium oxide hydrate particles to a hydrothermal treatment in the presence of water at a temperature of 50&#xb0; C. or more and less than 110&#xb0; C. for 3 hours or more.

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Hitachi, Japan

Takayuki Hirashige