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 gas diffusion electrode substrate has an electrically conductive porous substrate and a microporous layer-1 on one side of the electrically conductive porous substrate. The microporous layer-1 includes a dense portion A and a dense portion B. The dense portion A is a region containing a fluorine resin and a carbonaceous powder having a primary particle size of 20 nm to 39 nm. The dense portion A has a thickness of 30% to 100% with respect to the thickness of the microporous layer-1 as 100% and a width of 10 ?m to 200 ?m. The dense portion B is a region containing a fluorine resin and a carbonaceous powder having a primary particle size of 40 nm to 70 nm.

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 gas diffusion electrode substrate has an electrically conductive porous substrate and a microporous layer on one side of the electrically conductive porous substrate. The microporous layer includes a dense portion A and a dense portion B. The dense portion A is a region containing a fluorine resin and a carbonaceous powder having a primary particle size of 20 nm to 39 nm. The dense portion A has a thickness of 30% to 100% with respect to the thickness of the microporous layer as 100% and a width of 10 ?m to 200 ?m. The dense portion B is a region containing a fluorine resin and a carbonaceous powder having a primary particle size of 40 nm to 70 nm.

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.