A positive electrode (10) for an air cell of the present invention includes: a catalyst layer (11) composed of a porous layer containing electrical conductive carbon (1), a binder (2), and a catalyst component (3); and a fluid-tight gas-permeable layer (12) composed of a porous layer containing an electrical conductive carbon (1a) and a binder (2). The fluid-tight gas-permeable layer is stacked on the catalyst layer. This configuration can facilitate series connection of the air cells while preventing electrolysis solution from leaking out of a positive electrode. It is therefore possible to enhance the manufacturing efficiency and handleability of the air cells.

A device for manufacturing a membrane-electrode assembly for a fuel cell may include top and bottom side bonding rolls respectively disposed above and below a transfer path through which an electrolyte membrane and top and bottom electrode films transferred with a predetermined line speed, one of the top side and bottom side bonding rolls provided reciprocally movable in a vertical direction through a first driving source, and transfer anode and cathode catalyst electrode layers of the top and bottom electrode films to top and bottom sides of the electrolyte membrane while compressing the top and bottom electrode films; film rewinders provided above and below the transfer path to rewind the top and bottom electrode films; and a compulsive driving roll provided in a rewinding path of an electrode film rewound by one of the film rewinders and selectively compulsively feeding the electrode film with a predetermined driving speed.

A method of manufacturing a membrane electrode assembly for hydrogen fuel cells includes mixing an electrode binder with a catalyst, followed by dispersing and thermal treatment, to prepare an electrode slurry, coating release paper with the electrode slurry to produce an electrode, and bonding the release paper-coated electrode to an electrolyte membrane, followed by thermal treatment, to perform electrode-membrane bonding.

Simplified methods are disclosed for preparing a catalyst coated membrane that is reinforced with a porous polymer sheet (e.g. an expanded polymer sheet) for use in solid polymer electrolyte fuel cells. The methods involve forming a solid polymer electrolyte membrane by coating membrane ionomer solution onto a first catalyst layer and then applying the porous polymer sheet to the membrane ionomer solution coating, while it is still wet, such that the membrane ionomer solution only partially fills the pores of the porous polymer sheet. A second catalyst ink is then applied which fills the remaining pores of the porous polymer sheet. Not only are such methods simpler than many conventional methods, but surprisingly this can result in a marked improvement in fuel cell performance characteristics.

A micro porous layer and a catalyst layer are integrated into a sheet so that a fuel cell electrode sheet is formed. The electrode sheet is obtained by applying an MPL ink containing a carbon material and a binder to a supporting sheet and heat-treating the ink, and applying a catalyst ink containing a catalyst to the obtained micro porous sheet and drying it. An electrode assembly in which the electrode sheets is laminated onto both sides of a solid polymer electrolyte membrane, is obtained by laminating the electrode sheets formed on the supporting sheets to the solid polymer electrolyte membrane, and thereafter peeling off the supporting sheets.

A method of producing an assembly including a polymer electrolyte membrane includes a step of preliminary pressure application wherein a pressure is continuously applied to a recipient sheet including a polymer electrolyte membrane and an assembling sheet including an assembling layer to be assembled to at least one surface of the recipient sheet, the pressure being applied to the recipient sheet and the assembling layer of the assembling sheet being in contact with each other, and a step of heated pressure application wherein the recipient sheet and the assembling sheet after the preliminary pressure application step are subjected to continuous pressure application with heating.

The present invention relates to a structure including a layer including titanium (di)oxide nanostructures, such as titania nanotubes, in contact with a membrane layer including a proton-conducting polymer. A process for preparing the structures of the invention is presented wherein titanium (di)oxide nanostructures on a first substrate are transferred to an ion-conducting polymer membrane by pressing using a hot press, and then detaching the nanostructures from the first substrate.

The present invention provides a method for producing a fuel cell electrode which is configured to be able to deliver stable electricity generation performance even if the humidity condition of the external environment is changed. Disclosed is a method for producing a fuel cell electrode comprising a catalyst layer that contains a catalyst composite-carried carbon containing platinum, a titanium oxide and an electroconductive carbon, wherein the method comprises: a first step of decreasing an amount of acidic functional groups on a surface of the catalyst composite-carried carbon by firing the catalyst composite-carried carbon at 250 C. or more; a second step of producing a catalyst ink by mixing the catalyst composite-carried carbon obtained in the first step, an ionomer, and a solvent; and a third step of forming the catalyst layer using the catalyst ink obtained in the second step.

Disclosed are a process for separating an electrode for membrane-electrode assemblies of fuel cells from the decal transfer film and an apparatus for separating the electrode. In particular, during the electrode separating process, only an electrode is separated from the decal transfer film on which the electrode is coated, without any damage, by a freezing method for freezing the specimen on the deionized water surface, and thus, wasting the expensive MEA is prevented. Thus, mechanical properties of the pristine electrode can be rapidly quantified in advance, and therefore, long term durability evaluation period during developing MEA having excellent durability is substantially reduced.

A catalyst layer for a fuel cell, wherein the catalyst layer comprises a catalyst-supporting carbon and an ionomer; wherein, in a particle size distribution obtained by the laser diffraction/scattering method, the catalyst-supporting carbon has at least two aggregate particle size peaks at less than 1 ?m and at 1 ?m or more; wherein, when a thickness of the catalyst layer is divided into three equal parts, the catalyst layer has a first region on a gas diffusion layer side, a second region in a middle part, and a third region on an electrolyte membrane side; and wherein a void ratio V.sub.G of the first region is 5% or more higher than a void ratio V.sub.M of the third region.