Abstract: A hydrophilic porous carbon electrode which has excellent hydrophilicity, which has high reaction activity when used for a battery, and with which excellent battery characteristics is able to be obtained is provided. A hydrophilic porous carbon electrode is a sheet-form hydrophilic porous carbon electrode in which a carbon fiber is bonded using a resin carbide and has a contact angles ?A of water on both surfaces in a thickness direction being 0 to 15° and a contact angle ?B of water in a middle portion in the thickness direction being 0 to 15°. The hydrophilic porous carbon electrode is obtained by forming the carbon fiber and a binder fiber into a sheet, impregnating the sheet into a thermosetting resin, subjecting it to heat press processing, and then subjecting it to carbonization at 400 to 3000° C. in an inert atmosphere. The hydrophilic porous carbon electrode is transported and is subjected to a heat treatment while an oxidizing gas flows at 400 to 800° C.

Abstract: A hydrophilic porous carbon electrode which has excellent hydrophilicity, which has high reaction activity when used for a battery, and with which excellent battery characteristics is able to be obtained is provided. A hydrophilic porous carbon electrode is a sheet-form hydrophilic porous carbon electrode in which a carbon fiber is bonded using a resin carbide and has a contact angles ?A of water on both surfaces in a thickness direction being 0 to 15° and a contact angle ?B of water in a middle portion in the thickness direction being 0 to 15°. The hydrophilic porous carbon electrode is obtained by forming the carbon fiber and a binder fiber into a sheet, impregnating the sheet into a thermosetting resin, subjecting it to heat press processing, and then subjecting it to carbonization at 400 to 3000° C. in an inert atmosphere. The hydrophilic porous carbon electrode is transported and is subjected to a heat treatment while an oxidizing gas flows at 400 to 800° C.

Abstract: A hydrophilic porous carbon electrode which has excellent hydrophilicity, which has high reaction activity when used for a battery, and with which excellent battery characteristics is able to be obtained is provided. A hydrophilic porous carbon electrode is a sheet-form hydrophilic porous carbon electrode in which a carbon fiber is bonded using a resin carbide and has a contact angles ?A of water on both surfaces in a thickness direction being 0 to 15° and a contact angle ?B of water in a middle portion in the thickness direction being 0 to 15°. The hydrophilic porous carbon electrode is obtained by forming the carbon fiber and a binder fiber into a sheet, impregnating the sheet into a thermosetting resin, subjecting it to heat press processing, and then subjecting it to carbonization at 400 to 3000° C. in an inert atmosphere. The hydrophilic porous carbon electrode is transported and is subjected to a heat treatment while an oxidizing gas flows at 400 to 800° C.

Abstract: A hydrophilic porous carbon electrode which has excellent hydrophilicity, which has high reaction activity when used for a battery, and with which excellent battery characteristics is able to be obtained is provided. A hydrophilic porous carbon electrode is a sheet-form hydrophilic porous carbon electrode in which a carbon fiber is bonded using a resin carbide and has a contact angles ?A of water on both surfaces in a thickness direction being 0 to 15° and a contact angle ?B of water in a middle portion in the thickness direction being 0 to 15°. The hydrophilic porous carbon electrode is obtained by forming the carbon fiber and a binder fiber into a sheet, impregnating the sheet into a thermosetting resin, subjecting it to heat press processing, and then subjecting it to carbonization at 400 to 3000° C. in an inert atmosphere. The hydrophilic porous carbon electrode is transported and is subjected to a heat treatment while an oxidizing gas flows at 400 to 800° C.

Abstract: A porous base material and a porous electrode having both gas permeability suitable for a gas diffusion layer for a fuel cell vehicle and mechanical strength capable of withstanding continuous processing in a roll-to-roll manner, and a porous electrode which is suitable for an electrode for a redox flow cell and has excellent diffusibility of an electrolyte are required. Provided is a porous base material containing a carbon fiber (A) having an average fiber diameter of 10 to 20 ?m, an average fiber length of 2 to 30 mm, a tensile modulus of elasticity of 200 to 600 GPa, and a tensile strength of 3,000 to 7,000 MPa and a carbon binder (D), in which the carbon fiber (A) is bound with the carbon binder (D).

Abstract: Provided is a porous electrode substrate having excellent thickness precision, gas permeability and conductivity, handling efficiency, low production costs and a high carbonization rate during carbonization. Also provided are a method for manufacturing such a substrate, a precursor sheet and fibrillar fiber used for forming such a substrate, along with a membrane electrode assembly and a polymer electrolyte fuel cell that contain such a substrate. The method for manufacturing a porous electrode substrate includes step (1) for manufacturing a precursor sheet in which short carbon fibers (A) and carbon fiber precursor (b) are dispersed, and step (2) for carbonizing the precursor sheet, and the volume contraction rate of carbon fiber precursor (b) in step (2) is 83% or lower.

Abstract: According to the present invention, a porous electrode substrate with greater sheet strength, lower production cost, and excellent gas permeability and conductivity as well as its manufacturing method are provided. Also provided are a precursor sheet for forming such a substrate, and a membrane electrode assembly and a polymer electrolyte fuel cell containing such a substrate. The method for manufacturing such a porous electrode substrate includes the following steps [1]˜[3]: [1] a step for manufacturing a sheet material in which short carbon fibers (A) are dispersed; [2] a step for manufacturing a precursor sheet by adding a water-soluble phenolic resin and/or water-dispersible phenolic resin to the sheet material; and [3] a step for carbonizing the precursor sheet at a temperature of 1000° C. or higher.

Abstract: Provided is a porous electrode substrate having excellent thickness precision, gas permeability and conductivity, handling efficiency, low production costs and a high carbonization rate during carbonization. Also provided are a method for manufacturing such a substrate, a precursor sheet and fibrillar fiber used for forming such a substrate, along with a membrane electrode assembly and a polymer electrolyte fuel cell that contain such a substrate. The method for manufacturing a porous electrode substrate includes step (1) for manufacturing a precursor sheet in which short carbon fibers (A) and carbon fiber precursor (b) are dispersed, and step (2) for carbonizing the precursor sheet, and the volume contraction rate of carbon fiber precursor (b) in step (2) is 83% or lower.

Abstract: A process of producing a porous electrode substrate, including: dispersing first short carbon fibers and producing a first precursor sheet not having a three-dimensional entangled structure of the first short carbon fibers; treating the first precursor sheet such that the first short carbon fibers in the first precursor sheet are entangled and that a second precursor sheet having a three-dimensional entangled structure of the first short carbon fibers is obtained; dispersing second short carbon fibers on the second precursor sheet such that a porous electrode precursor sheet including the second precursor sheet and a third precursor sheet not having a three-dimensional entangled structure of the second short carbon fibers and stacked on the second precursor sheet is obtained; and carbonization treating the porous electrode substrate precursor sheet at a temperature of at least 1000° C. to obtain the porous electrode substrate.

Abstract: According to the present invention, a porous electrode substrate with greater sheet strength, lower production cost, and excellent gas permeability and conductivity as well as its manufacturing method are provided. Also provided are a precursor sheet for forming such a substrate, and a membrane electrode assembly and a polymer electrolyte fuel cell containing such a substrate. The method for manufacturing such a porous electrode substrate includes the following steps [1]˜[3]: [1] a step for manufacturing a sheet material in which short carbon fibers (A) are dispersed; [2] a step for manufacturing a precursor sheet by adding a water-soluble phenolic resin and/or water-dispersible phenolic resin to the sheet material; and [3] a step for carbonizing the precursor sheet at a temperature of 1000° C. or higher.

Abstract: Provided is a porous electrode substrate having excellent thickness precision, gas permeability and conductivity, handling efficiency, low production costs and a high carbonization rate during carbonization. Also provided are a method for manufacturing such a substrate, a precursor sheet and fibrillar fiber used for forming such a substrate, along with a membrane electrode assembly and a polymer electrolyte fuel cell that contain such a substrate. The method for manufacturing a porous electrode substrate includes step (1) for manufacturing a precursor sheet in which short carbon fibers (A) and carbon fiber precursor (b) are dispersed, and step (2) for carbonizing the precursor sheet, and the volume contraction rate of carbon fiber precursor (b) in step (2) is 83% or lower.

Abstract: According to the present invention, a porous electrode substrate with greater sheet strength, lower production cost, and excellent gas permeability and conductivity as well as its manufacturing method are provided. Also provided are a precursor sheet for forming such a substrate, and a membrane electrode assembly and a polymer electrolyte fuel cell containing such a substrate. The method for manufacturing such a porous electrode substrate includes the following steps [1]˜[3]: [1] a step for manufacturing a sheet material in which short carbon fibers (A) are dispersed; [2] a step for manufacturing a precursor sheet by adding a water-soluble phenolic resin and/or water-dispersible phenolic resin to the sheet material; and [3] a step for carbonizing the precursor sheet at a temperature of 1000° C. or higher.

Abstract: The provision of a porous electrode substrate that has large sheet strength, low production costs, high handling properties, high thickness precision and surface smoothness, and sufficient gas permeability and electrical conductivity. A porous electrode substrate including a three-dimensional entangled structure including short carbon fibers (A) dispersed in a three-dimensional structure, joined together via three-dimensional mesh-like carbon fibers (B). A method for producing a porous electrode substrate, including a step (1) of producing a precursor sheet including short carbon fibers (A), and short carbon fiber precursors (b) and/or fibrillar carbon fiber precursors (b?) dispersed in a two-dimensional plane; a step (2) of subjecting the precursor sheet to entanglement treatment; and a step (3) of subjecting this sheet to carbonization treatment at 1000° C. or higher. It is preferable to include a step (4) of subjecting the sheet to hot press forming at lower than 200° C.

Abstract: Provided are: a porous electrode substrate which has excellent handling properties and surface smoothness and satisfactory gas permeability and electrical conductivity, and enables the reduction of damage to a polymer electrolyte membrane when integrated into a fuel cell; and a process for producing the porous electrode substrate.

Abstract: The purpose of this invention is to provide a porous electrode substrate that has a low manufacturing cost, has sufficient conductivity and gas diffusion characteristics, and shows favorable power generation ability with minor structural changes in the porous electrode substrate. This invention is: a method for manufacturing a porous electrode substrate that comprises a step (1) in which a dispersion fluid comprising a carbon powder (C) and a fluorine-based resin is applied to one or both surfaces of a precursor sheet wherein carbon short cut fibers (A1) are dispersed in planar orientations with the fiber orientations being substantially within the same plane, and as a result the fluorine-based resin that contains the carbon powder (C) in the vicinity of the surface layer of one side or both sides of the precursor sheet is distributed unevenly to form a precursor sheet with unevenly-distributed fluorine-based resin.

Abstract: Provided are: a porous electrode substrate which has excellent handling properties and surface smoothness and satisfactory gas permeability and electrical conductivity, and enables the reduction of damage to a polymer electrolyte membrane when integrated into a fuel cell; and a process for producing the porous electrode substrate.

Abstract: A method for manufacturing a porous electrode substrate, comprising: step (1) of dispersing the pieces of a short carbon fiber (A) and a fiber (b) containing a polymer having a softening point of 250° or higher but lower than 400° C. and a particulate substance having a melting point of 400° C. or higher, in a planar direction, and thereby obtaining a precursor sheet; step (2) of impregnating the precursor sheet with a carbon powder (C2) containing powdered carbon, and a fluorine-based resin containing elemental fluorine and a resin component; and step (3) of heat treating the impregnated precursor sheet at a temperature of 250° C. or higher but lower than 400° C. in the presence of oxygen.

Abstract: Provided is a porous electrode substrate having high mechanical strength, good handling properties, high thickness precision, little undulation, and adequate gas permeability and conductivity. Also provided is a method for producing a porous electrode substrate at low costs. A porous electrode substrate is produced by joining short carbon fibers (A) via mesh-like of carbon fibers (B) having an average diameter of 4 ?m or smaller. Further provided are a membrane-electrode assembly and a polymer electrolyte fuel cell that use this porous electrode membrane. A porous electrode substrate is obtained by subjecting a precursor sheet, in which short carbon fibers (A) and short carbon fiber precursors (b) having an average diameter of 5 ?m or smaller have been dispersed, to carbonization treatment after optional hot press forming and optional oxidization treatment.

Abstract: Provided is a porous electrode substrate having high mechanical strength, good handling properties, high thickness precision, little undulation, and adequate gas permeability and conductivity. Also provided is a method for producing a porous electrode substrate at low costs. A porous electrode substrate is produced by joining short carbon fibers (A) via mesh-like of carbon fibers (B) having an average diameter of 4 ?m or smaller. Further provided are a membrane-electrode assembly and a polymer electrolyte fuel cell that use this porous electrode membrane. A porous electrode substrate is obtained by subjecting a precursor sheet, in which short carbon fibers (A) and short carbon fiber precursors (b) having an average diameter of 5 ?m or smaller have been dispersed, to carbonization treatment after optional hot press forming and optional oxidization treatment.

Abstract: According to the present invention, a porous electrode substrate with greater sheet strength, lower production cost, and excellent gas permeability and conductivity as well as its manufacturing method are provided. Also provided are a precursor sheet for forming such a substrate, and a membrane electrode assembly and a polymer electrolyte fuel cell containing such a substrate. The method for manufacturing such a porous electrode substrate includes the following steps [1]˜[3]: [1] a step for manufacturing a sheet material in which short carbon fibers (A) are dispersed; [2] a step for manufacturing a precursor sheet by adding a water-soluble phenolic resin and/or water-dispersible phenolic resin to the sheet material; and [3] a step for carbonizing the precursor sheet at a temperature of 1000° C. or higher.