The purpose of the present invention is to provide: a method for producing a gas diffusion electrode base which enables the achievement of a gas diffusion electrode base that has a microporous layer with small surface roughness and is not susceptible to damaging an electrolyte membrane; and a gas diffusion electrode base that has a microporous layer with small surface roughness and is not susceptible to damaging an electrolyte membrane. For the purpose of achieving the above-described purpose, the present invention has the configuration described below. Namely, a specific gas diffusion electrode base which has a carbon sheet and a microporous layer, and wherein the carbon sheet is porous and the DBP oil absorption of a carbon powder contained in the microporous layer is 70-155 ml/100 g.

Realized are an electrochemical element and a solid oxide fuel cell that have a dense electrolyte layer and that have excellent durability and robustness, and methods for producing the same. An electrochemical element includes: a metal substrate 2 having a plurality of through holes 21; an electrode layer 3 provided over a front face of the metal substrate 2; and an electrolyte layer 4 provided over the electrode layer 3, wherein the through holes 21 are provided passing through the front face and a back face of the metal substrate 2, the electrode layer 3 is provided in a region larger than a region, of the metal substrate 2, in which the through holes 21 are provided, and the electrolyte layer 4 has a first portion 41 coating the electrode layer 3, and a second portion 42 that is in contact with the front face of the metal substrate 2.

An electrode (10) includes a first diffusion layer (1) having water repellency, a second diffusion layer (2) supporting a catalyst (4) thereon, and an oxygen-permeable layer (3) having oxygen permeability and interposed between the first diffusion layer and the second diffusion layer. The second diffusion layer includes a sheet-like carbon material. A fuel cell (100) includes an anode (20) supporting microorganisms, an ion transfer layer (30) permeable to hydrogen ions, and a cathode (40) being the electrode (10) and separated from the anode with the ion transfer layer interposed therebetween.

A catalyst layer (20) for a fuel cell and to a method suitable for producing the catalyst layer (20). The catalyst layer (20) includes a catalyst material (22) containing a catalytic material (24) and optionally porous carrier material (23) on which the catalytic material (24) is supported. The catalyst layer also includes mesoporous particles (21) made from hydrophobic material.

Provided is a carbon substrate for a gas diffusion layer of a fuel cell. The carbon substrate has a structure, in which a plurality of unit carbon substrates are stacked. Each of the unit carbon substrates is a plate type substrate having a first surface and a second surface opposite to the first surface. Carbon fibers are randomly arranged on the first surface of the each unit carbon substrate. The number of the carbon fibers arranged in a machine direction of the unit carbon substrate is greater than the number of carbon fibers arranged in a transverse direction of the unit carbon substrate from the first surface to the second surface along a thickness direction of the unit carbon substrate; and, accordingly, an orientation gradient, in which the orientation in the machine direction increases from the first surface to the second surface, is shown.

The present invention relates to an electrode catalyst for a fuel cell that includes a carbon support (11) having pores (13) and catalyst particles containing platinum or a platinum alloy supported on the carbon support (11). The pores (13) of the carbon support (11) have a mode size of pores (13) in a range of 2.1 nm to 5.1 nm. A total pore volume of the pores (13) of the carbon support (11) is in a range of 21 cm.sup.3/g to 35 cm.sup.3/g. A distance between the catalyst particles and a surface of the carbon support (11) is in a range of 2.0 nm to 12 nm as a distance of a 50% cumulative frequency.

The present invention concerns a method for preparing a catalyst coated membrane including the steps of: coating a substrate with a first catalyst dispersion thereby obtaining a first catalyst dispersion coated substrate, providing a second side of a membrane with a support film, coating a first side of the membrane with a second catalyst dispersion, thereby obtaining a second catalyst dispersion coated first side of the membrane, drying the first catalyst dispersion thereby obtaining a first catalyst coated substrate or drying the second catalyst dispersion coated first side of the membrane thereby obtaining a second catalyst coated first side of the membrane, laminating the first catalyst coated substrate to the second catalyst dispersion coated first side of the membrane or laminating the first catalyst dispersion coated substrate to the second catalyst coated first side of the membrane so that the first catalyst and the second catalyst superimpose, thereby forming a laminate including a membrane comprising a first catalyst layer, drying the laminate, removing the support film from the second side of the membrane, coating a third catalyst dispersion on the second side of the membrane, drying the third catalyst dispersion, thereby obtaining a second catalyst layer on the membrane, and removing the substrate from the first catalyst coated substrate.

A method of manufacturing a membrane electrode assembly, includes: forming catalyst coated membrane using an electrode catalyst layer containing an ionomer having a sulfonic acid group and a catalyst carrier, and an electrolyte membrane; applying an ionization accelerator having a low molecular weight component represented by a chemical formula C.sub.lH.sub.mO.sub.n (where l, m, and n are natural numbers) for accelerating generation of sulfate ions, to the catalyst coated membrane; performing UV irradiation on the ionization accelerator applied to the catalyst coated membrane; heating the catalyst coated membrane having the ionization accelerator subjected to the UV irradiation; and bonding a gas diffusion layer containing a radical inhibiting substance to an outer surface of at least one of the ionization accelerator subjected to the UV irradiation or the catalyst coated membrane.

Embodiments of the invention include fuel cells incorporating sheets and/or powders of silica fibers and methods for producing such devices. The silica fibers may be formed via electrospinning of a sol gel produced with a silicon alkoxide reagent, such as tetraethyl ortho silicate, alcohol solvent, and an acid catalyst.

A metal-air battery includes an anode portion including a metal; a cathode portion including a porous layer, wherein the porous layer includes a reduced non-stacked graphene oxide; and an electrolyte disposed between the anode portion and the cathode portion.