An assembly of electrochemical cells for an electrochemical reactor, including a first electrochemical cell, including a first membrane/electrode assembly including a first anode and a first cathode on either side of a proton exchange membrane; first and second flow guides positioned on either side of the first assembly; a second electrochemical cell, including a second membrane/electrode assembly including a second anode and a second cathode on either side of a proton exchange membrane; third and fourth flow guides on either side of the second membrane/electrode assembly; the first and third flow guides have one and the same geometry; the first anode and the second anode have different distributions of surface densities of electrocatalytic material on respective faces of the first and second proton exchange membranes.

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 .sub.A of water on both surfaces in a thickness direction being 0 to 15 and a contact angle .sub.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. in a direction perpendicular to a direction in which the hydrophilic porous carbon electrode is transported to be subjected to hydrophilization.

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.

A fuel cell FC includes a cell structure 1 in which an anode electrode layer 11, an electrolyte layer 13 and a cathode electrode layer 15 are stacked. The anode electrode layer 11 is arranged in the middle, and has an electrode reacting part 11 having a thermal expansion coefficient greater than a thermal expansion coefficient of the electrolyte layer, and an outer peripheral part 113 arranged adjacent to the electrode reacting part 111 on an outer periphery of the electrode reacting part 111, the outer peripheral part 113 having a thermal expansion coefficient smaller than the thermal expansion coefficient of the electrode reacting part 111. The fuel cell FC is arranged on the anode electrode layer side of the cell structure 1, and further includes a metallic supporting plate 2 that supports the cell structure 1.

A reforming element for a molten carbonate fuel cell stack and corresponding methods are provided that can reduce or minimize temperature differences within the fuel cell stack when operating the fuel cell stack with enhanced CO.sub.2 utilization. The reforming element can include at least one surface with a reforming catalyst deposited on the surface. A difference between the minimum and maximum reforming catalyst density and/or activity on a first portion of the at least one surface can be 20% to 75%, with the highest catalyst densities and/or activities being in proximity to the side of the fuel cell stack corresponding to at least one of the anode inlet and the cathode inlet.

Electrochemical cells, such as those present within flow batteries, can include at least one electrode with one face being more hydrophilic than is the other. Such electrodes can lessen the incidence of parasitic reactions by directing convective electrolyte circulation toward a separator in the electrochemical cell. Flow batteries containing the electrochemical cells can include: a first half-cell containing a first electrode with a first face and a second face that are directionally opposite one another, a second half-cell containing a second electrode with a first face and a second face that are directionally opposite one another, and a separator disposed between the first half-cell and the second half-cell. The first face of both the first and second electrodes is disposed adjacent to the separator. The first face of at least one of the first electrode and the second electrode is more hydrophilic than is the second face.

The purpose of the present invention is to provide a carbon sheet that is suitably employed in a gas-diffusion-electrode substrate that has excellent flooding resistance and with which it is possible to suppress internal peeling of the carbon sheet. In order to achieve the aforementioned purpose, the present invention has the following configuration. Specifically, provided is a porous carbon sheet containing carbon fibers and a binder, wherein, in a section between a surface on one side of the carbon sheet and a surface on the other side thereof, when layers obtained by dividing, under compression, the carbon sheet into six equal parts in the thickness direction are assumed to be layer 1, layer 2, layer 3, layer 4, layer 5, and layer 6, in order starting from the layer including the surface on the one side to the layer including the surface on the other side, the layer in which the packing ratio under compression is the greatest is layer 2, and the relationships of the packing ratios under compression among layer 2, layer 3, layer 4, layer 5, and layer 6 are such that layer 2 has the greatest packing ratio, and layer 3 has the second-greatest packing ratio.

A membrane electrode assembly for a fuel cell, with a membrane, a catalyst layer (16) and a gas diffusion layer. The catalyst layer (16) has a first side facing the membrane and a second side facing the gas diffusion layer. In the catalyst layer (16) an ionomer content increases towards the membrane. The catalyst layer (16) has a first sublayer (22) in which catalyst particles (26) are coated with a first ionomer (28). The catalyst layer (16) further has a second sublayer (24) with a second ionomer (32) which is closer to the membrane than the first sublayer (22). Pores (30) are present at least between the coated catalyst particles (26). Further, a method for preparing such a membrane electrode assembly, a fuel cell system and a vehicle with a fuel cell system.

Electrochemical cells, such as those present within flow batteries, can include at least one electrode with one face being more hydrophilic than is the other. Such electrodes can lessen the incidence of parasitic reactions by directing convective electrolyte circulation toward a separator in the electrochemical cell. Flow batteries containing the electrochemical cells can include: a first half-cell containing a first electrode with a first face and a second face that are directionally opposite one another, a second half-cell containing a second electrode with a first face and a second face that are directionally opposite one another, and a separator disposed between the first half-cell and the second half-cell. The first face of both the first and second electrodes is disposed adjacent to the separator. The first face of at least one of the first electrode and the second electrode is more hydrophilic than is the second face.

The present disclosure relates to liquid solutions which include particulates that can function as an electrode, thereby forming an electrode solution, useful in the fabrication of liquid flow electrochemical cells and liquid flow batteries. The electrode solutions of the present disclosure may include an electrolyte comprising a liquid medium and at least one redox active specie, wherein the electrolyte has a density, De; and a core-shell particulate (202, 204) having a core, a shell and a density Dp, wherein at least a portion of the shell of the core-shell particulate includes an electrically conductive first metal and wherein 0.8DeDp1.2De; and wherein a first redox active specie of the at least one redox active specie and the electrically conductive first metal are different elements. The present disclosure also provides electrochemical cells and liquid flow batteries comprising an electrode solution according to the present disclosure.