Hitachi, Ltd.

Hitachi Chemical Company, Ltd.

Kohki Tamura

Tatsuo Horiba

Toshiki Kahara

Masato Takeuchi

Hideo Okada

Sigeru Okabe

Kazuo Iwamoto

Jinichi Imahashi

Seizi Takeuchi

Kazunori Fujita

Fumito Nakajima

Shimpei Matsuda

Noboru Ebato

Hidejiro Kawana

Tomoichi Kamo

Shinpei Matsuda

Tetsuichi Kudo

Akio Honji

Toshikatsu Mori

Hiroshi Tobita

Kenzo Ishii

Kunko Kitami

Hirosi Tobita

Seiji Takeuchi

Hidehito Obayashi

Osamu Asai

Fumio Sato

Teruo Kumagai

Munehiko Tonami

Tomio Yoshida

Go Kawamura

Yoshio Iwase

Go Kikuchi

Tatuo Horiba

Noboru Ebata

In a fuel cell having a fuel electrode, an oxidant electrode, and an electrolyte which is located between both the electrodes, a methanol concentration control device is disposed, at a pipe which supplies the fuel to the fuel cell for controlling the amount of the methanol in the pipe by detecting the open-circuit voltage of the unit cell or the open-circuit potential of the oxidant cell at the methanol concentration control device.

Fuel cell comprising a device for detecting the concentration of methanol

A unit cell is formed by a plurality of sub-unit cells as a result of dividing each of the electrodes and electrolytic plate into a plurality of parts. That is, the electrodes and the electrolytic plate are each divided into two parts by electrolytic plate support portions projected from the surfaces of separators. The support portions are pressed in contact with the end portions of the electrolytic plate so as to support the electrolytic plate and seal the reaction gas, preventing it from leaking. The electrolyte support portions of the separators can be provided with electrolyte supply paths, through which the electrolyte is supplied and impregnated into the electrolytic plate. The electrolyte can be supplied via the apertures provided in the separators, to the electrolyte supply paths.

Fuel cell

A fuel cell provided with an electrolyte retaining plate made of electrical insulating long fibers such as lithium aluminate long fibers which have preferably a length of 100 to 400 .mu.m and a diameter of 1 to 4 .mu.m, are interlocked each other and have vacant spaces for filling an electrolyte can be constructed and operated safely without damaging the electrolyte retaining plate for a long period of time.

Process for producing an electrolyte retaining matrix of electrical

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.

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

The disclosure is concerned with a secondary cell comprising a positive electrode, a negative electrode, a liquidous electrolyte layer interposed between the electrodes, said electrolyte containing a dopant consisting of an anion and a cation, means for electrically insulating the electrodes, and an envelope for enclosing and for air-tightly sealing the electrodes and the electrolyte. The positive electrode or the negative electrode is made of a material, such as, phthalocyanine complexes, metal porphyrin complexes, chalcogenides of transition metals and an electrically conductive polymeric material such as polyacetylene. The secondary cell of the present invention has a long service life because of its good durability to charge and discharge operations.

Secondary battery

This invention is a fuel element for liquid fuel cell characterized in that a liquid fuel is rendered to assume a non-fluidized state by either physical means or chemical means, and is returned back to the initial liquid fuel at any time by physical means or chemical means.

Fuel element for liquid fuel cell and a liquid fuel cell

A methanol fuel cell with an electrolyte ion exchange membrane integrated with an oxidizer electrode containing water-repellent particles on one side of the membrane and with a hydrophilic fuel electrode containing no water-repellent particles on the other side thereof and with less contact resistance between the ion exchange membrane and the electrodes and a three-phase boundary readily formable in the oxidizer electrode.

A liquid fuel cell including an anode made of carbon powders, which contains therein an electrode catalyzer and is adapted to be supplied with a liquid fuel, a cathode supplied with oxygen, and a separator interposed between the anode and the cathode. In order to improve cell performance, the anode is formed from carbon powders bonded with a binder, the carbon powders having particle sizes passing through a 50 Tyler mesh screen, in which at least thirty percent by volume of the carbon powders are unable to pass through a 100 Tyler mesh screen.

Liquid 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

In a molten carbonate fuel cell, an anode or cathode is made of a sintered material containing a nickel oxide and/or cobalt oxide and a rare earth element oxide. This anode or cathode has a high activity and is stable at high temperatures.

Molten carbonate fuel cell

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.

A methanol fuel cell wherein a positive electrode and a negative electrode are disposed in contact with a solid film which exhibits a hydrogen ion- and/or hydronium ion-conductivity. The methanol permeability coefficient of the solid film of the methanol fuel cell is at most 1.times.10.sup.-6 mol/(mol/l).min.cm.sup.2.

Methanol fuel cell

A positive plate composite agent consisting of a mixture of manganese dioxide, carbon powder and polytetrafluoroethylene powder is press-molded at a pressure in the range of 1 to 5 t/cm.sup.2. The resulting molded article is then pulvertized into massive particles having a particle size ranging from 0.03 to 15 mm.sup.3. The massive particles are then press-molded into a positive plate having a predetermined shape at a pressure in the range of 0.2 to 1 t/cm.sup.2. There is thus obtained a positive plate of an enclosed type battery which comprises a portion consisting of the compactly formed massive particles of the positive plate composite agent and a portion consisting of the coarsely formed small particles of the composite agent interposed between the massive particles so as to define paths or voids for the passage of an electrolyte.

Structure of positive plate of enclosed type battery

Disclosed is a process for producing a positive electrode for a non-aqueous electrolytic cell. Manganese dioxide is heat-treated at a temperature between 250.degree. and 400.degree. C. The heat-treated manganese dioxide is next mixed with a conducting agent and binder. The binder is suspended in water by means of non-ionic surface active agent, and the mixture is heat-treated at a temperature between 180.degree. and 350.degree. C. and then pressured molded into a positive electrode. This production process allows the provision of a positive electrode for a non-aqueous electrolytic cell of excellent discharge characteristics.

Growing community of inventors

Hitachi, Japan

Kohki Tamura