Hitachi, Ltd.

Hitachi Chemical Company, Ltd.

Mitsubishi Petrochemical Company Limited

Babcock-Hitachi Kabushiki Kaisha

Jinichi Imahashi

Toshiki Kahara

Seizi Takeuchi

Tomoichi Kamo

Fumito Nakajima

Katsunori Nishimura

Masato Takeuchi

Akio Honji

Shimpei Matsuda

Kenzo Ishii

Masahiro Komachiya

Kohki Tamura

Shigeo Uno

Akira Kato

Tatsuo Horiba

Shinpei Matsuda

Hideo Okada

Toshikatsu Mori

Kenji Yamaga

Yasushi Muranaka

Tohru Koyama

Sigeru Okabe

Makoto Imanari

Makoto Morishima

Yoshihisa Watanabe

Shigeoki Nishimura

Ko Takahashi

Norio Yamada

Masanori Yoshikawa

Hiroshi Tobita

Kunko Kitami

Yuki Okuda

Youichi Sakuta

Hirosi Tobita

Otane Hitomi

Syuichi Oohara

A fuel cell system for power generation comprising a solid polymer type fuel cell having a solid polymer electrolyte membrane for separating an anode gas and a cathode gas, a resistor, an inverter, a switch for switching the inverter and the resister with respect to the fuel cell, the switch and the inverter, a supply conduit and discharge conduit for the anode gas and the cathode gas, and a supply vale and a discharge valve. When a molar ratio of the hydrogen contained in the anode gas to oxygen contained in the cathode gas becomes 2/1 or less at the time of the stop of the fuel cell, the supply valve for air is closed.

Method of stopping a solid polymer type fuel cell system

The fuel cell assembly disclosed includes at least one unit fuel cell comprising a separator having flow channels for oxidizing gas, a cathode to which the oxidizing gas is fed, a membrane electrolyte of proton conductivity, an anode to which fuel gas is fed, and a separator having flow channels for the fuel gas, the above members being arranged in order. The fuel cell assembly further comprises a humidifier having a porous member to humidify at least the fuel gas to be fed to the anode. The porous member of the humidifier is so disposed as to face at least the flow channels for the oxidizing gas so that water is supplied to the flow channels from part of the surface of the porous member opposite to the water supplying face and/or from the outer periphery of the porous member.

Fuel cell with humidifier

A polymer electrolyte fuel cell comprises a fuel cell stack and a humidifier. The fuel cell stack includes plural cells in which each cell has a pair of electrodes and a proton-conductive electrolyte membrane arranged between the pair of electrodes, wherein an oxidant gas or a fuel gas passes through the humidifier before being fed to the fuel cell stack, and wherein a wet gas containing water or water vapor also passes through the humidifier. In the fuel cell, the humidifier includes a porous separating layer and a hydrophilic water-releasing layer, wherein the separating layer is configured to separate the wet gas from the oxidant gas or the fuel gas in the humidifier, and wherein the hydrophilic water-releasing layer is disposed in a side of the oxidant gas or the fuel gas to the separating layer in the humidifier.

Polymer electrolyte fuel cell system

This invention provides an electrode for a polymer electrolyte fuel cell which fuel cell contains: a solid polymer electrolyte membrane; electrode layers formed respectively on both faces of the electrolyte membrane; two reinforcing members which cover respective outer surfaces of the electrode layers; and a sealing member which covers, extending from respective end faces to respective end parts of the reinforcing members, whole peripheries of the two reinforcing members, wherein the electrolyte membrane, the electrode layers and the reinforcing members are integrally formed by the sealing member.

Polymer electrolyte fuel cell

The object of this invention is to provide an electrode for a polymer electrolyte fuel cell, a separator therefor, a polymer electrolyte fuel cell and a generating system, which electrode is simplified in structure, have high handling property, can be transferred precisely to a predetermined position, and enables automation of a production process. This invention provides an electrode for a polymer electrolyte fuel cell which electrode contains: a solid polymer electrolyte membrane; electrode layers formed respectively on both faces of the electrolyte membrane; two reinforcing members which cover respective outer surfaces of the electrode layers; and a sealing member which covers, extending from respective end faces to respective end parts of the reinforcing members, whole peripheries of the two reinforcing members, wherein the electrolyte membrane, the electrode layers and the reinforcing members are integrally formed by the sealing member.

Electrode for polymer electrolyte fuel cell, separator therefore, and polymer electrolyte fuel cell, and generating system using them

To provide a compact power source best suited for portable use, which uses no separator and has no auxiliary equipment such as a fluid supply mechanism, and portable electronic equipment using the power source. A fuel cell, a fuel cell generator, and electric equipment using these have a construction such that the fuel cell, having an anode for oxidizing liquid fuel, a cathode for reducing oxygen, and an electrolyte membrane for insulating the anode from the cathode, has a construction of a hollow support, the anode, electrolyte membrane, and cathode are disposed on the outer peripheral surface of the hollow support to form a generator section, and the fuel is brought into contact with the inside of the hollow support and gas containing the oxygen is brought into contact with the outside of the generator section.

Fuel cell, fuel cell generator, and equipment using the same

The polymer electrolyte type hydrogen-oxygen fuel cell of the present invention comprises an oxygen electrode and a hydrogen electrode, a polymer electrolyte membrane provided between the oxygen electrode and hydrogen electrode and electron conductors provided on the side of the electrodes which is opposite to the electrolyte side and the oxygen electrode comprises a catalytically active component, a carrier for the catalytically active component and a binder and has such a gradient in water repellency across the thickness that the water repellency is highest in the area adjacent to the electrolyte and lowest in the area adjacent to the conductor. In this fuel cell, flooding of water at the interface between the oxygen electrode and the electrolyte can be prevented.

Polymer electrolyte hydrogen-oxygen fuel cell where the polymer

Provided is a solid polymer electrolyte type fuel cell which is improved in cell output characteristics by preventing the flooding phenomenon at the interface between the oxygen electrode and the electrolyte membrane, accelerating the gas diffusion and effective utilization of the active surface of the catalyst. This solid polymer electrolyte type fuel cell comprises solid polymer electrolyte membrane 1 and gas diffusion electrodes 2 and 3 provided on both sides of the membrane, said gas diffusion electrodes comprising catalyst layers 6 and 8 and gas diffusion layers 7 and 9 being provided on the outer side of the respective catalyst layers and a hydrogen-containing gas and an oxygen-containing gas being fed to the respective electrodes. In this cell, the water-repellency of the hydrogen electrode 2 is higher than that of the oxygen electrode 3 and furthermore, a gradient of water-repellency is provided in the catalyst layer of each electrode so that the water-repellency in the portion facing to the electrolyte membrane is higher than that in the portion facing to the gas diffusion layer in each catalyst layer. The output density of the cell according to the present invention is as high as 2-3 times that of conventional cells.

Solid polymer electrolyte type fuel cell

In a fuel cell comprising a pair of counterposed gas-diffusible electrodes, an electrolyte-retaining, porous matrix provided between and in contact with the electrodes, a fuel chamber for feeding a gaseous fuel to the anode of the pair of the electrodes and an oxidizing agent chamber for feeding a gaseous oxidizing agent to the cathode of the pair of the electrodes, the cell performance is remarkably prevented from lowering by making the electrolyte saturated absorption amount of the cathode smaller than that of the anode, thereby preventing migration of the electrolyte in the electrolyte-retaining matrix.

Fuel cell

In a fuel cell comprising an electrolyte-retaining matrix interposed between a pair of gas-diffusion electrodes, the matrix comprises particles or fibers of a substance unreactive with phosphoric acid and having electron-insulating properties and an inorganic binder.

Method of making fuel cell

In operating a fuel cell comprising an oxidizing agent chamber subject to supply of an oxidizing agent gas and a fuel chamber subjected to supply of a fuel gas, sintering of noble metal particles such as platinum black as an electrode catalyst can be prevented from sintering by connecting the fuel cell to an outside auxiliary load circuit and controlling the unit cell voltage to not more than 0.80 V at start or discontinuation to operate the fuel cell or during the operation of the fuel cell when an outside load becomes too low due to fluctuation of the outside load. The fuel cell performance can be improved thereby.

Method for operating fuel cell

A fuel cell comprising a pair of gas diffusion electrodes, an electrolyte retaining matrix disposed between said gas diffusion electrodes, and a phosphoric acid electrolyte disposed within said matrix, characterized by using as matrix that comprising one or more metal oxides having electronic insulation and insolubility in phosphoric acid and a binder is excellent in phosphoric acid retaining ability and can be used for a long period of time without degradation of the performance of fuel cell.

A fuel cell electrode being substantially free from cracks on the surface of catalyst layer on the electrode and having a good electrode performance under the atmospheric pressure or under pressure when assembled into a fuel cell, which comprises a gas-diffusing electroconductive substrate with continued pores and a water-repellent catalyst layer comprising electroconductive submicron particles having a catalyst, electroconductive materials each having a volume 10.sup.3 -10.sup.10 as large as the volume of the largest particle of the submicron particles and, if necessary, having a catalyst, and a water-repellent polymer as a binder, the electroconductive submicron particles and the electroconductive materials being provided in a mixing ratio by volume of the former to the latter of 95-50 to 5-50.

Fuel cell electrode

Fuel cell with improved and stabilized electrode performance having at least one gas diffusion electrode, where the gas diffusion electrode comprises an electronconductive, gas-permeable substrate and an electrode catalyst uniformly distributed on the substrate, the electrode catalyst comprising colonies each consisting of not more than 20 primary particles of noble metal each having a size of 10-30 A and being uniformly distributed and deposited on carrier powder.

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Hitachi, Japan

Jinichi Imahashi