Abstract: A fuel cell according to the present invention comprises a membrane electrode assembly, a bipolar plate for guiding a reaction gas to the membrane electrode assembly, two layers of coolant flow fields formed on the bipolar plane opposite to another plane on which a reaction gas flow field is formed, and an interlayer separation plate; wherein the interlayer separation plate separates the two layers of coolant flow fields and has permeability or jet orifices so as to allow a coolant to pass through.

Abstract: A separator for a fuel cell includes a metal separator (metal substrate) having projections formed by ribs, and porous members provided in a plurality of flow passages partitioned by the projections, in which a hydrophilic portion is provided in a center part of a cross section orthogonal to a flow direction in the porous member, and a water repellent portion is provided in at least a part of portions in contact with wall surfaces of the flow passage within a range of the cross section. According to the present invention, the mixed phase flow in which the reaction gas and the cooling water inside the flow passages are mixed can be made an even flow in the separator in which the porous members are provided in the gas flow passages.

Abstract: A polymer electrolyte membrane fuel cell of the present invention has a simple structure in a cooling part and is small. The polymer electrolyte membrane fuel cell includes a membrane electrode assembly, a porous gas flow field for anode which is conductive and supplies fuel gas, a porous gas flow field for cathode which is conductive and supplies oxidant gas, and a bipolar plate which separates the fuel gas flow field and the oxidant gas flow field. Channels are formed in a surface of the porous gas flow field for cathode, the surface facing the bipolar plate. Preferably, plural concave portions are provided in at least one surface of flow field walls forming the channels. Preferably, the oxidant gas is mixed with cooling water and the mixture is supplied to the porous gas flow field for cathode.

Abstract: Excellent gas sealing properties were difficult to achieve with a structure that uses a meal material to control material cost and does not increase the number of components. A cell is configured by using a metal separator having at least one protruding structure between a manifold and an electrode channel, and having a communicating channel structure that forms a fluid circulating space by being folded back at the side containing a connection so that the tip of the protruding structure is in contact with a surface of the separator. Accordingly, a gas channel from the manifold to an electrode surface can be easily formed integrally. This can be applied to a metal material easily. Further, the present invention can provide excellent gas sealing properties.

Abstract: A proton exchange membrane fuel cell stack comprises a plurality of stacked unit cells, the unit cells each including: a membrane electrode assembly; an anode side-conductive gas diffusion layer and an anode side-fuel gas flow field to feed a fuel gas to an anode of the membrane electrode assembly; and a cathode side-conductive gas diffusion layer and a cathode side-oxidant gas flow field to feed an oxidant gas to a cathode of the membrane electrode assembly; and a bipolar plate for separating between the anode side-fuel flow field and the cathode side-oxidant gas flow field. Then, the fuel gas flow field and the oxidant gas flow field are constituted by respective porous media flow fields each which is a conductive porous medium, and the porous media flow field for the oxidant gas flow field is configured so that liquid water is supplied mixedly together with the oxidant gas thereto.

Abstract: The object of the present invention is to provide a bipolar plate for a fuel cell, suppressing the stay of condensed water in a gas diffusion layer and improving gas diffusion performance. The bipolar plate supplies reaction gas to a power generating surface and has a channel for the reaction gas. The channel is formed with ribs which are made of a conductive material laminate. The ribs have a porous structure and water repellency. The water repellency of the ribs is set lower than that of an adjacent gas diffusion layer. Thus, the condensed water can be moved from the gas diffusion layer to the ribs in an area where the gas diffusion layer and the ribs are in contact with each other. Therefore, deterioration of the gas diffusion performance due to the stay of the condensed water in the gas diffusion layer can be prevented.

Abstract: Excellent gas sealing properties were difficult to achieve with a structure that uses a meal material to control material cost and does not increase the number of components. A cell is configured by using a metal separator having at least one protruding structure between a manifold and an electrode channel, and having a communicating channel structure that forms a fluid circulating space by being folded back at the side containing a connection so that the tip of the protruding structure is in contact with a surface of the separator. Accordingly, a gas channel from the manifold to an electrode surface can be easily formed integrally. This can be applied to a metal material easily. Further, the present invention can provide excellent gas sealing properties.

Abstract: A fuel cell according to the present invention comprises a membrane electrode assembly, a bipolar plate for guiding a reaction gas to the membrane electrode assembly, two layers of coolant flow fields formed on the bipolar plane opposite to another plane on which a reaction gas flow field is formed, and an interlayer separation plate; wherein the interlayer separation plate separates the two layers of coolant flow fields and has permeability or jet orifices so as to allow a coolant to pass through.