Abstract: A fuel battery system of the present invention includes: an alkaline fuel battery; a fuel supply device for supplying a fuel to an anode of the fuel battery; an oxidizing agent supply device for supplying an oxidizing agent to a cathode of the fuel battery; a liquid supply device which supplies a liquid to the cathode; a valve which switches between fluids to be supplied to the cathode; and a control device which controls the switching of the valve. The fuel battery system suppresses the neutralization of an anion-exchange electrolyte due to carbon dioxide in the air, by supplying the liquid from the liquid supply device to the cathode and making the cathode in the state of being immersed in the liquid when the fuel battery stops power generation.

Abstract: A membrane-electrode-assembly contains two or more types of solid polymer electrolytes having different acid dissociation constants in an electrode catalyst layer, a solid polymer electrolyte of small acid strength covers the surface of a catalyst, and a solid polymer electrolyte of large acid strength is disposed to the periphery thereof, which makes the resistance to dissolving of the catalyst metal and the ion conductivity in the catalyst electrode layer compatible.

Abstract: A fuel cell power generation system of the invention includes a hydrogen supply unit for reforming hydrocarbon fuel to generate reformed gas including hydrogen or generating reaction gas including the hydrogen from a hydrogen material, an oxygen supply unit, a fuel cell for receiving the hydrogen from the hydrogen supply unit and oxygen from the oxygen supply unit, for power generation, temperature sensors each for detecting a temperature of the hydrogen supply unit, and a temperature control unit for adjusting generated power, thereby controlling the temperature of the hydrogen supply unit, based on the detected temperature. The temperature control unit includes a target power setting unit for setting first and second target powers as generated power target values, and a target power switching unit for performing target value switching between the first and second target powers according to a predetermined change in the detected temperature.

Abstract: Disclosed is a bipolar plate for a fuel cell including a bipolar plate substrate; and a byproduct-decomposing layer covering the bipolar plate substrate, the bipolar plate has channels for transport of a reactant gas, the channels being arranged on a surface of the bipolar plate substrate, and the bipolar plate has a first side to face an anode catalyst layer of the fuel cell and a second side to face a cathode catalyst layer of the fuel cell. The byproduct-decomposing layer is arranged on at least one of the first side and the second side, includes a catalyst, and is capable of decomposing a byproduct formed as a result of a reaction of the fuel cell. The bipolar plate enables long-term control of discharge of formic acid and other byproducts without deterioration in system efficiency of the fuel cell.

Abstract: A membrane electrode assembly for a fuel cell comprises a solid polymer electrolyte membrane, an anode being formed on one side of the solid polymer electrolyte membrane and containing a catalyst and a solid polymer electrolyte, a cathode being formed on another side of the solid polymer electrolyte membrane and containing a catalyst and a solid polymer electrolyte, an anode gas diffusion layer formed on one side of the anode, and a cathode gas diffusion layer formed on one side of the cathode. In addition, a formic acid oxidation electrode containing palladium and a solid polymer electrolyte is formed between the anode gas diffusion layer and the anode.

Abstract: A fuel cell comprising a unit cell, in which an anode for oxidizing a fuel and a cathode for reducing oxygen disposed to sandwich a solid polymer electrolyte membrane; the anode is an electrode catalyst layer formed by mixing microbubbles controlled in particle diameter to an electrode catalyst slurry including the anode materials; and the cathode is an electrode catalyst layer formed by mixing microbubbles controlled in particle diameter to an electrode catalyst slurry including the cathode materials, can achieve a high power generation by controlling the capillary structure of the electrode catalyst layer, by improving the diffusion of matters to be consumed and the rejection of created water in the electrode catalyst layer, and by enhancing use efficiency of the catalyst metal.

Abstract: A fuel cell comprises an anode oxidizing a fuel, a cathode reducing an oxidizing agent, a polymer electrolyte disposed between the anode and the cathode, whereby an assembly is constituted by the anode, cathode and polymer electrolyte, a pair of gas diffusion layers disposed at both sides of the assembly of the anode, and the cathode, a bipolar plate for providing the fuel to the gas diffusion layer, and another bipolar plate for providing the oxidizing agent to the gas diffusion layer, wherein at least one of the gas diffusion layers includes a porous gas diffusion layer substrate having a hydrophilic surface layer, and wherein particles of a water-repellent material are dispersed in pores of the porous gas diffusion layer substrate. This results in a higher cell voltage and a higher power at a high current density, prevention of a flooding and a longer cell lifetime.

Abstract: A fuel cell comprises an anode oxidizing a fuel, a cathode reducing an oxidizing agent, a polymer electrolyte disposed between the anode and the cathode, whereby an assembly is constituted by the anode, cathode and polymer electrolyte, a pair of gas diffusion layers disposed at both sides of the assembly of the anode, and the cathode, a bipolar plate for providing the fuel to the gas diffusion layer, and another bipolar plate for providing the oxidizing agent to the gas diffusion layer, wherein at least one of the gas diffusion layers includes a porous gas diffusion layer substrate having a hydrophilic surface layer, and wherein particles of a water-repellent material are dispersed in pores of the porous gas diffusion layer substrate. This results in a higher cell voltage and a higher power at a high current density, prevention of a flooding and a longer cell lifetime.

Abstract: A fuel cell comprising a unit cell, in which an anode for oxidizing a fuel and a cathode for reducing oxygen disposed to sandwich a solid polymer electrolyte membrane; the anode is an electrode catalyst layer formed by mixing microbubbles controlled in particle diameter to an electrode catalyst slurry including the anode materials; and the cathode is an electrode catalyst layer formed by mixing microbubbles controlled in particle diameter to an electrode catalyst slurry including the cathode materials, can achieve a high power generation by controlling the capillary structure of the electrode catalyst layer, by improving the diffusion of matters to be consumed and the rejection of created water in the electrode catalyst layer, and by enhancing use efficiency of the catalyst metal.

Abstract: During a time zone where a power demand is smaller than an average value of the entire power demands of homes, an excess portion obtained by subtracting a power demand from a base power portion supplied by PEFC (1) is charged in a capacitor (7) and a lead storage battery (8) in advance; and during a time zone where a power demand is larger than the average value, a peak power portion exceeding this average value is discharged from the capacitor (7) and the lead storage battery (8); thereby enabling the system to sufficiently meet daily home-use demand with requisite minimum equipment while effectively using surplus power. Thus, energy efficiency can be enhanced without wasting energy, and also cost efficiency can be improved.

Abstract: A fuel cell power generation system of the invention includes a hydrogen supply unit for reforming hydrocarbon fuel to generate reformed gas including hydrogen or generating reaction gas including the hydrogen from a hydrogen material, an oxygen supply unit, a fuel cell for receiving the hydrogen from the hydrogen supply unit and oxygen from the oxygen supply unit, for power generation, temperature sensors each for detecting a temperature of the hydrogen supply unit, and a temperature control unit for adjusting generated power, thereby controlling the temperature of the hydrogen supply unit, based on the detected temperature. The temperature control unit includes a target power setting unit for setting first and second target powers as generated power target values, and a target power switching unit for performing target value switching between the first and second target powers according to a predetermined change in the detected temperature.

Abstract: During a time zone where a power demand is smaller than an average value of the entire power demands of homes, an excess portion obtained by subtracting a power demand from a base power portion supplied by PEFC (1) is charged in a capacitor (7) and a lead storage battery (8) in advance; and during a time zone where a power demand is larger than the average value, a peak power portion exceeding this average value is discharged from the capacitor (7) and the lead storage battery (8); thereby enabling the system to sufficiently meet daily home-use demand with requisite minimum equipment while effectively using surplus power. Thus, energy efficiency can be enhanced without wasting energy, and also cost efficiency can be improved.