Abstract: A fuel-cell electrode and a method of manufacturing the fuel-cell electrode achieves a high catalyst utilization ratio and makes it possible to obtain higher output characteristics with a smaller amount of catalyst. The fuel-cell electrode includes a catalytic layer composed of an ion conductive substance, an electron conductive substance and catalytic activation substances. The catalytic activation substances are electrolytically deposited on the electron conductive substance.

Abstract: An electrochemical fuel cell includes an electrolyte membrane, a first electrode on one side of the electrolyte membrane and a second electrode on another side of the electrolyte membrane, a first separator and a second separator, and a seal. The first and second separators sandwich the first and second electrodes. The seal is provided between the electrolyte membrane and one of the first and second separators for sealing a path of a fuel gas or an oxidative gas, and between the first and second separators for sealing a coolant path. The softer layer in the seal elastically deforms and absorbs a surface roughness of the electrolyte membrane or the electrode. The harder layer supports the electrolyte membrane or the electrode. The seal can respond to and follow a length of the electrolyte membrane or the separator changed by varying temperature.

Abstract: A fuel cell according to an embodiment of the invention includes a separator on which a gas passage groove is formed. A cross sectional area of a gas passage changes in a direction in which the gas passage groove extends, while each of an opening width of the gas passage groove and a depth of the gas passage groove remains substantially constant.

Abstract: An aspect of the invention for achieving the aforementioned objects relates to a fuel cell including at least one unit cell. The unit cell includes a first separator which is disposed on one side of an MEA, and which includes a first concave groove which constitutes a first gas passage, and a first convex rib whose rear surface constitutes a first refrigerant passage, and on which a first gas cross groove is formed; and a second separator which is disposed on the other side of the MEA, and which includes a second concave groove which constitutes a second gas passage, and a second convex rib whose rear surface constitutes a second refrigerant passage, and on which a second gas cross groove is formed.

Abstract: An improved fuel cell makes uniform partial gas pressure of a fuel gas flowing through a gas passage formed between an electrode and a separator of a fuel cell, activating an electrode reaction in a whole region of the electrode surface along the gas passage. The inlet and outlet for the fuel gas are disposed on a diagonal line of the separator to define a gas passage such that fuel gas smoothly flows even though portions of the passage away from the diagonal line. This may reduce the separator size and improve the volumetric efficiency of the fuel cell and the diffusibility of fuel gas as well as the drainage of water produced by the electrode reaction.

Abstract: The method of the present invention enhances the adhesive strength of a polymer electrolyte film via an adhesive and thereby manufactures a fuel cell having a high reliability for a gas sealing property. The method provides a pair of separators and applies an adhesive on specific areas of the separators, which are directly joined with the polymer electrolyte film. The adhesive used here is a modified rubber adhesive that is a mixture of epoxy resin and modified silicone and has a modulus of elasticity of not greater than 10 MPa and a durometer A hardness of not greater than 90 after cure. The method subsequently lays the pair of separators upon the joint body and cures the adhesive for bonding the separators directly to the polymer electrolyte film.

Abstract: The invention improves operability in forming a catalyst electrode, and improves performance of a fuel cell. A catalyst-loaded carbon is dispersed in a mixed solution of an azeotropic solvent and ion exchanged water. An electrolyte solution is added to the dispersed solution. A solvent, such as ethanol or the like, is added to adjust the viscosity and the water content of the solution, thereby providing an electrode catalyst solution. The use of the obtained solution as an ink for forming a catalyst layer through printing improves printing characteristic and drying characteristic.

Abstract: A control system for a fuel cell to output an electric energy by a reaction between a fuel gas and an oxidizing gas. The control system comprises a humidifier for decreasing the humidification of the fuel cell when the pressure in the fuel cell is high, and for increasing the humidification of the fuel cell when the pressure in the fuel cell is low.

Abstract: A fuel-cell electrode and a method of manufacturing the fuel-cell electrode achieves a high catalyst utilization ratio and makes it possible to obtain higher output characteristics with a smaller amount of catalyst. The fuel-cell electrode includes a catalytic layer composed of an ion conductive substance, an electron conductive substance and catalytic activation substances. The catalytic activation substances are electrolytically deposited on the electron conductive substance.

Abstract: Separators for unit cells of a fuel cell each have a plurality of through holes extending therethrough and a recessed portion formed in a surface thereof. In a fuel cell incorporating such separators, the recessed portion of each separator forms an in-cell oxidative gas passage, together with an adjacent cathode. An oxidative gas, supplied from an external device into the fuel cell, is distributed from an oxidative gas supply manifold formed by holes of the separators, to the in-cell oxidative gas passages. The oxidative gas is then collected in an oxidative gas discharge manifold formed by holes of the separators, and conveyed out of the fuel cell by the discharge manifold. During the passage through each in-cell oxidative gas passage, the oxidative gas flows via an oxidative gas transit manifold formed by holes of the separators.

Abstract: A seal in an electrochemical fuel cell prevents fluid in a space from leaking. The seal includes a first layer and a second layer having different coefficients of elasticity. The seal is made of rubber. An electrochemical fuel cell includes an electrolyte membrane, a first electrode on one side of the electrolyte membrane and a second electrode on another side of the electrolyte membrane, a first separator and a second separator, and the seal. The first and second separators sandwich the first and second electrodes. The seal is not only provided between the electrolyte membrane and one of the first and second separators for sealing a path of a fuel gas or an oxidative gas, but is also between the first and second separators for sealing a coolant path. Since the softer layer in the seal elastically deforms and absorbs a surface roughness of the electrolyte membrane or the electrode, the sealing ability of the seal is high.

Abstract: A seal in an electrochemical fuel cell prevents fluid in a space from leaking. The seal includes a first layer and a second layer having different coefficients of elasticity. The seal is made of rubber. An electrochemical fuel cell includes an electrolyte membrane, a first electrode on one side of the electrolyte membrane and a second electrode on another side of the electrolyte membrane, a first separator and a second separator, and the seal. The first and second separators sandwich the first and second electrodes. The seal is not only provided between the electrolyte membrane and one of the first and second separators for sealing a path of a fuel gas or an oxidative gas, but is also between the first and second separators for sealing a coolant path. Since the softer layer in the seal elastically deforms and absorbs a surface roughness of the electrolyte membrane or the electrode, the sealing ability of the seal is high.

Abstract: A seal in an electrochemical fuel cell prevents fluid in a space from leaking. The seal includes a first layer and a second layer having different coefficients of elasticity. The seal is made of rubber. An electrochemical fuel cell includes an electrolyte membrane, a first electrode on one side of the electrolyte membrane and a second electrode on another side of the electrolyte membrane, a first separator and a second separator, and the seal. The first and second separators sandwich the first and second electrodes. The seal is not only provided between the electrolyte membrane and one of the first and second separators for sealing a path of a fuel gas or an oxidative gas, but is also between the first and second separators for sealing a coolant path. Since the softer layer in the seal elastically deforms and absorbs a surface roughness of the electrolyte membrane or the electrode, the sealing ability of the seal is high.

Abstract: Separators for unit cells of a fuel cell each have a plurality of through holes extending therethrough and a recessed portion formed in a surface thereof. In a fuel cell incorporating such separators, the recessed portion of each separator forms an in-cell oxidative gas passage, together with an adjacent cathode. An oxidative gas, supplied from an external device into the fuel cell, is distributed from an oxidative gas supply manifold formed by holes of the separators, to the in-cell oxidative gas passages. The oxidative gas is then collected in an oxidative gas discharge manifold formed by holes of the separators, and conveyed out of the fuel cell by the discharge manifold. During the passage through each in-cell oxidative gas passage, the oxidative gas flows via an oxidative gas transit manifold formed by holes of the separators.

Abstract: A separator for an electrochemical fuel cell provides a path for a fuel gas or an oxidative gas to an electrode and functions as a wall of a unit cell of the electrochemical fuel cell. The separator comprises a conductive metal plate, a conductive coating membrane, and a tight coating membrane. The conductive coating membrane coats the conductive metal plate where the separator contacts the electrode. The tight coating membrane coats the conductive metal plate where the conductive coating membrane does not coat the conductive metal plate. A conductivity of the conductive coating membrane is higher than the tight coating membrane, and the tight coating membrane has a tighter adhesion to the conductive metal plate than the conductive coating membrane. The conductive coating membrane comprises carbon, a precious metal, or an alloy of nickel and chromium. The tight coating membrane comprises a close-grained resin.

Abstract: Separators for unit cells of a fuel cell each have a plurality of through holes extending therethrough and a recessed portion formed in a surface thereof. In a fuel cell incorporating such separators, the recessed portion of each separator forms an in-cell oxidative gas passage, together with an adjacent cathode. An oxidative gas, supplied from an external device into the fuel cell, is distributed from an oxidative gas supply manifold formed by holes of the separators, to the in-cell oxidative gas passages. The oxidative gas is then collected in an oxidative gas discharge manifold formed by holes of the separators, and conveyed out of the fuel cell by the discharge manifold. During the passage through each in-cell oxidative gas passage, the oxidative gas flows via an oxidative gas transit manifold formed by holes of the separators.

Abstract: A separator for a fuel cell is manufactured by preparing a raw material powder, uniformly mixing the prepared raw material to be formed into a slurry, and charging the raw material powder derived from granulation into a metal mold for heat press forming. The raw material is obtained by adding to carbon powder a binder containing a mixture of phenolic resin and epoxy resin. Therefore the heat press forming step does not cause the binder to generate gas, thus allowing manufacturing of a separator exhibiting sufficient gas-impermeability.

Abstract: The method of the present invention enhances the adhesive strength of a polymer electrolyte film via an adhesive and thereby manufactures a fuel cell having the high reliability for the gas sealing property. The method exposes a joint body, which has been prepared by interposing a polymer electrolyte film between an anode and a cathode and bonding them, to an atmosphere having a temperature of 25° C. and a humidity of 50% over one hour (S110). The method then provides a pair of separators and applies an adhesive on specific areas of the separators, which are directly joined with the polymer electrolyte film (S120). The adhesive used here is a modified rubber adhesive that is a mixture of epoxy resin and modified silicone and has a modulus of elasticity of not greater than 10 MPa and a durometer A hardness of not greater than 90 after cure.

Abstract: The invention improves operability in forming a catalyst electrode, and improves performance of a fuel cell. A catalyst-loaded carbon is dispersed in a mixed solution of an azeotropic solvent and ion exchanged water. An electrolyte solution is added to the dispersed solution. A solvent, such as ethanol or the like, is added to adjust the viscosity and the water content of the solution, thereby providing an electrode catalyst solution. The use of the obtained solution as an ink for forming a catalyst layer through printing improves printing characteristic and drying characteristic.

Abstract: An improved fuel cell makes uniform partial gas pressure of a fuel gas flowing through a gas passage formed between an electrode and a separator of a fuel cell, activating an electrode reaction in a whole region of the electrode surface along the gas passage. The inlet and outlet for the fuel gas are disposed on a diagonal line of the separator to define a gas passage such that fuel gas smoothly flows even though portions of the passage away from the diagonal line. This may reduce the separator size and improve the volumetric efficiency of the fuel cell and the diffusibility of fuel gas as well as the drainage of water produced by the electrode reaction.