Disclosed is a catalyst layer for a fuel cell that has good gas diffusion properties in the entire catalyst layer and in which coarsening of catalyst particles can be suppressed. The catalyst layer for a fuel cell includes fibrous conductive members and catalyst particles. The fibrous conductive members are inclined relative to the surface direction of the catalyst layer, and the length L of the fibrous conductive members and the thickness T of the catalyst layer satisfy the relational expression: L/T≤3. Each of the catalyst particles includes a core portion and a shell portion that covers the core portion, and contains a component different from that of the core portion.

A bonding device of a fuel cell part is disclosed. The bonding device of the fuel cell part may bond an upper gas diffusion layer and a lower gas diffusion layer to top and bottom surfaces of an MEA base material through adhesive layers, while disposing the MEA base material between the upper gas diffusion layer and the lower gas diffusion layer, and may include: a lower die that supports the MEA base material, the upper gas diffusion layer, and the lower gas diffusion layer to be bonded with each other; an upper die installed in an upper side of the lower die; and an ultrasonic wave vibration source that is installed to be capable of moving in a vertical direction at opposite sides of the upper die, compressing the upper gas diffusion layer, and applying ultrasonic wave vibration energy to the adhesive layer.

The present invention provides a novel and improved metal-air battery in which a lot of catalyst can be disposed in a triple phase boundary, and further, battery properties can be improved. In the metal-air battery according to the present invention, a catalyst layer of an air electrode of a metal-air battery contains a catalyst element and a carbon material, the carbon material comprises two materials of a carbon material A supporting thereon the catalyst element and a carbon material B not supporting the catalyst element, the catalyst layer comprises an agglomerate X containing the catalyst element, the carbon material A and the carbon material B as main components and an agglomerate Y containing the carbon material B as a main component, and the agglomerate X is a continuum and the agglomerate Y is dispersed in the agglomerate X.

Provided is a carbon-fiber nonwoven cloth with low resistance to gases or liquids passing through, and low resistance in the thickness direction to heat or electricity, which is particularly appropriate for a gas diffusion electrode of a polymer electrolyte fuel cell; the cloth having an air gap with a diameter of at least 20 μm, at least some of the carbon fibers being continuous from one surface to the other surface, and the apparent density being 0.2-1.0 g/cm.sup.3, or, having an air gap with a diameter of at least 20 μm and at least some of the carbon fibers being mutually interlaced, and further, at least some of the carbon fibers being oriented toward the thickness direction and the apparent density being 0.2-1.0 g/cm.sup.3.

A membrane electrode assembly and a method of manufacturing an electricity generating assembly include a pair of gas diffusion layers disposed on both surfaces of the membrane electrode assembly. Coupling agents are applied on surfaces of the gas diffusion layers, modifying surfaces of the gas diffusion layers. A coupling agent-friendly adhesive is applied to the surfaces of the gas diffusion layers to which the coupling agents are applied, forming adhesion layers on surfaces of the gas diffusion layers. The gas diffusion layers are stacked on the surfaces of the membrane electrode assembly, causing the adhesion layers to come into contact with the first and second surfaces of the membrane electrode assembly.

Provided is a low-cost electrochemical element that includes a high-performance electrode layer. The electrochemical element includes an electrode layer, and the electrode layer contains small particles and large particles. The small particles have a particle diameter of 200 nm or less in the electrode layer, and the large particles have a particle diameter of 500 nm or more in the electrode layer.

The invention relates to a method for depositing a metal M1 onto a carbon layer, as well as to a method for manufacturing an electrode for fuel cells and to a method for manufacturing a fuel cell. The method for depositing a metal M1 onto a porous carbon layer according to the invention includes a step of depositing said metal M1 by means of the electrochemical reduction of an electrolytic solution of a salt of the metal M1, and, prior to said step of depositing the metal M1 by means of electrochemical reduction, a step of depositing a metal M2 by means of chemical reduction using a reducing gas of a salt of the metal M2, the thermodynamic equilibrium potential between the ionic form of the salt of M2 and M2, E.sup.eq.sub.ionic form of the salt of M2/M2 being greater than the thermodynamic equilibrium potential between the ionic form of the salt of M1 and M1, E.sup.eq.sub.ionic form of the salt of M1/M1. The invention can be used, in particular, in the field of fuel cells.

A cell stack includes a plurality of single cells, wherein each single cell includes a membrane electrode assembly having a cathode, an anode, an interposed membrane, and an anode gas diffusion layer wherein a) in a single cell, the anode gas diffusion layer and a cathode gas diffusion layer are arranged in relation to one another such that a first thickness gradient of the anode gas diffusion layer and a second thickness gradient of the cathode gas diffusion layer run opposite to one another or b) in two or more single cells, the anode gas diffusion layers are arranged in relation to one another such that an overall thickness gradient of the anode gas diffusion layers is minimized and/or wherein in two or more single cells, the cathode gas diffusion layers are arranged such that an overall thickness gradient of the cathode gas diffusion layers is minimized.

An embodiment gas diffusion layer unit for a fuel cell includes a gas diffusion layer disposed on a surface of a membrane electrode assembly and a sub-gasket, the sub-gasket surrounding and supporting an edge of the membrane electrode assembly, and an elastic member provided in a predetermined area of an edge of the gas diffusion layer, the elastic member being integrated with the gas diffusion layer and being in contact with the sub-gasket.

A microporous layer for use in a fuel cell includes a first carbon black having carboxyl groups at a concentration less than 0.1 mmol per gram of carbon, a hydrophobic additive and a hydrophilic additive. A method for producing a membrane electrode assembly includes preparing a microporous layer ink, applying the microporous layer ink to a first side of a gas diffusion substrate, sintering the gas diffusion substrate to form a gas diffusion layer having a first side with a microporous layer, and thermally bonding the first side of the gas diffusion layer to an electrode layer. The microporous layer ink includes a suspension medium, a first carbon black having carboxyl groups at a concentration less than 0.1 mmol per gram of carbon, a hydrophobic additive and a hydrophilic additive.