Abstract: A low-cost gas diffusion electrode is described that overcomes defects of conventional techniques, that achieves both dry-up resistance and flooding resistance, and that has satisfactory power generation performance, where the gas diffusion electrode includes a conductive porous substrate, and a microporous layer containing conductive fine particles and provided on at least one surface of the conductive porous substrate. The gas diffusion electrode has, based on the number of fine pores having an area of 0.25 ?m2 or more that are observed in a cross section of the microporous layer in a thickness direction, a percentage of fine pores having a circularity of 0.5 or more of 50% or more and 100% or less.

Abstract: A low-cost gas diffusion electrode is described that overcomes defects of conventional techniques, that achieves both dry-up resistance and flooding resistance, and that has satisfactory power generation performance, where the gas diffusion electrode includes a conductive porous substrate, and a microporous layer containing conductive fine particles and provided on at least one surface of the conductive porous substrate. The gas diffusion electrode has, based on the number of fine pores having an area of 0.25 ?m2 or more that are observed in a cross section of the microporous layer in a thickness direction, a percentage of fine pores having a circularity of 0.5 or more of 50% or more and 100% or less.

Abstract: A gas diffusion electrode including: a conductive porous substrate and a microporous layer on at least one side of the conductive porous substrate; in which the total of regions passing through the microporous layer in the thickness direction has an area ratio of 0.1% or more and 1% or less; and in which the microporous layer has a portion that has penetrated into the conductive porous substrate (hereinafter referred to as penetration portion), the penetration portion having a thickness ratio of 30% or more and 70% or less with respect to 100% of the thickness of the microporous layer. The gas diffusion electrode used for fuel cells affords fuel cells having high water removal performance and high power generation performance.

Abstract: A precursor fiber sheet includes short carbon fibers having an average length of 3 to 10 mm, natural pulp having an ash content of 0.15 mass % or less, and a heat-carbonizable resin, and a porous carbon sheet is obtained by carbonizing the precursor fiber sheet. This enhances gas diffusibility and water removal properties of the porous carbon sheet and has high mechanical strength and few appearance defects even when the bulk density of the porous carbon sheet is lowered.

Abstract: A gas diffusion electrode in which a microporous layer is provided on at least one surface of a conductive porous substrate, wherein the areas obtained by dividing the cross section perpendicular to the plane of the microporous layer into three equal parts in the thickness direction are a first area, a second area, and a third area, with respect to the conductive porous substrate side, the fluorine strength of the third area being 0.8 to 1.2 times the fluorine strength of the second area.

Abstract: A gas diffusion electrode substrate that is used in a fuel cell and is constituted by an electrode substrate and microporous parts, in which a microporous part (A) is formed on one surface of the electrode substrate with a thickness in the range of 10 ?m or more and 60 ?m or less, and in the gas diffusion electrode substrate, the pore volume of pores with a pore size of 0.1 ?m or more and less than 10 ?m is within the range of 0.9 times or more and 5 times or less of the pore volume of pores with a pore size of 10 ?m or more and less than 100 ?m.

Abstract: A gas diffusion electrode includes a porous carbon electrode substrate and a microporous layer(s) provided at least on one surface of the porous carbon electrode substrate. The porous carbon electrode substrate is composed of carbon short fibers bonded with a resin carbide. When the region of the porous carbon electrode substrate, extending from a plane that has a 50% filling rate and is closest to one surface of the substrate to a plane that has the 50% filling rate and is closest to the other surface thereof, is trisected in the through-plane direction to obtain three layers, a layer located closer to one surface has a layer filling rate different from the layer filling rate of the layer located closer to the other surface. The microporous layer has a thickness under an added pressure of 0.15 MPa of from 28 to 45 ?m, and has a thickness under an added pressure of 2 MPa of from 25 to 35 ?m.

Abstract: A gas diffusion electrode including: a conductive porous substrate and a microporous layer on at least one side of the conductive porous substrate; in which the total of regions passing through the microporous layer in the thickness direction has an area ratio of 0.1% or more and 1% or less; and in which the microporous layer has a portion that has penetrated into the conductive porous substrate (hereinafter referred to as penetration portion), the penetration portion having a thickness ratio of 30% or more and 70% or less with respect to 100% of the thickness of the microporous layer. The gas diffusion electrode used for fuel cells affords fuel cells having high water removal performance and high power generation performance.

Abstract: A fuel cell gas diffusion layer includes: a porous carbon fiber base substrate containing discontinuous carbon fibers bonded to each other with carbide, and a porous layer containing at least carbonaceous particles, the porous carbon fiber base substrate having a porous layer (A) with a mean thickness t1 of 10 to 55 ?m deposited on one surface A thereof, the porous carbon fiber base substrate being impregnated with porous layer (J) at least part of which is exposed at an opposite surface B, the porous carbon fiber base substrate having internal pores with a cross-sectional area accounting for 5% to 40% of the total cross section in a through-plane direction, at least porous layer (A) and porous layer (J) both having a void percentage of 50% to 85%, the porous carbon fiber base substrate having a thickness of 60 to 300 ?m, and the porous carbon fiber base substrate having a bulk density of 0.20 to 0.45 g/cm3.

Abstract: A gas diffusion electrode includes a porous carbon electrode substrate and a microporous layer(s) provided at least on one surface of the porous carbon electrode substrate. The porous carbon electrode substrate is composed of carbon short fibers bonded with a resin carbide. When the region of the porous carbon electrode substrate, extending from a plane that has a 50% filling rate and is closest to one surface of the substrate to a plane that has the 50% filling rate and is closest to the other surface thereof, is trisected in the through-plane direction to obtain three layers, a layer located closer to one surface has a layer filling rate different from the layer filling rate of the layer located closer to the other surface. The microporous layer has a thickness under an added pressure of 0.15 MPa of from 28 to 45 ?m, and has a thickness under an added pressure of 2 MPa of from 25 to 35 ?m.

Abstract: A gas diffusion electrode in which a microporous layer is provided on at least one surface of a conductive porous substrate, wherein the areas obtained by dividing the cross section perpendicular to the plane of the microporous layer into three equal parts in the thickness direction are a first area, a second area, and a third area, with respect to the conductive porous substrate side, the fluorine strength of the third area being 0.8 to 1.2 times the fluorine strength of the second area.

Abstract: A precursor fiber sheet includes short carbon fibers having an average length of 3 to 10 mm, natural pulp having an ash content of 0.15 mass % or less, and a heat-carbonizable resin, and a porous carbon sheet is obtained by carbonizing the precursor fiber sheet. This enhances gas diffusibility and water removal properties of the porous carbon sheet and has high mechanical strength and few appearance defects even when the bulk density of the porous carbon sheet is lowered.

Abstract: A gas diffusion electrode substrate that is used in a fuel cell and is constituted by an electrode substrate and microporous parts, in which a microporous part (A) is formed on one surface of the electrode substrate with a thickness in the range of 10 ?m or more and 60 ?m or less, and in the gas diffusion electrode substrate, the pore volume of pores with a pore size of 0.1 ?m or more and less than 10 ?m is within the range of 0.9 times or more and 5 times or less of the pore volume of pores with a pore size of 10 ?m or more and less than 100 ?m.

Abstract: A fuel cell gas diffusion layer includes: a porous carbon fiber base substrate containing discontinuous carbon fibers bonded to each other with carbide, and a porous layer containing at least carbonaceous particles, the porous carbon fiber base substrate having a porous layer (A) with a mean thickness t1 of 10 to 55 ?m deposited on one surface A thereof, the porous carbon fiber base substrate being impregnated with porous layer (J) at least part of which is exposed at an opposite surface B, the porous carbon fiber base substrate having internal pores with a cross-sectional area accounting for 5% to 40% of the total cross section in a through-plane direction, at least porous layer (A) and porous layer (J) both having a void percentage of 50% to 85%, the porous carbon fiber base substrate having a thickness of 60 to 300 ?m, and the porous carbon fiber base substrate having a bulk density of 0.20 to 0.45 g/cm3.

Abstract: A composite shaped article with uneven configuration junction face, comprising a resin member and a plate member composed of topside and underside arranged surface layer base materials integrated with a core layer base material interposed therebetween, the plate member and the resin member joined together with an uneven configuration at the side end faces facing each other. In the composite shaped article, the length of actual junction line formed along the unevenness of the uneven configuration is 1.05 mm or greater per mm of a protrusion passage line consisting of a continuity of line segment linking neighboring protrusion tops with each other in the uneven configuration drawn by the surface layer base materials.

Abstract: A composite shaped article with uneven configuration junction face, comprising a resin member and a plate member composed of topside and underside arranged surface layer base materials integrated with a core layer base material interposed therebetween, the plate member and the resin member joined together with an uneven configuration at the side end faces facing each other. In the composite shaped article, the length of actual junction line formed along the unevenness of the uneven configuration is 1.05 mm or greater per mm of a protrusion passage line consisting of a continuity of line segment linking neighboring protrusion tops with each other in the uneven configuration drawn by the surface layer base materials.