Kabushiki Kaisha Toyoda Jidoshokki Seisakusho

Kabushiki Kaisha Toyota Chuo Kenkyusho

Toyota Jidosha Kabushiki Kaisha

Shinya Morishita

Hiroshi Kawase

Kenichi Suzuki

Shin-ichi Towata

Katsushi Abe

Masahiko Nakada

Yasuhito Kondo

Shinichi Towata

Kazuhiko Itoh

Masae Oohori

Yutaka Ohya

Shunsuke Yamakawa

Steam is contacted with a hydrogen absorbing alloy in a temperature range from 200.degree. C. to 400.degree. C. With a contact catalytic reaction of water, a metal contained in the hydrogen absorbing alloy is changed to an oxide or a hydroxide. Hydrogen produced causes the Ni compound to be reduced and thereby the Ni metal that is catalytically active is produced. Thus, the surface of the hydrogen absorbing alloy is activated. The steam is contained in an inert gas or a reductive gas. This treatment method is suitable as an activation treatment for a hydrogen absorbing alloy used as an active material of a negative electrode of a secondary battery.

Surface treatment method of hydrogen absorbing alloy

An electrode for a sealed nickel/metal hydride battery and a method of manufacturing the same, which is capable of suppressing a decrease in the charging reserve of a hydrogen-storage alloy electrode (negative electrode) and an increase in the internal pressure of the battery, is provided. The hydrogen-storage alloy electrode is formed using a tackifier or a binder which is prepared from an organic polymer material containing the ether linkage (--O--), for example, polyethylene oxide, polypropylene oxide , or polybutylene oxide. The specified material is suitably hydrophilic, and it exhibits an oxidation resistance which is much higher than that of a conventional material containing the hydroxyl group (--OH). Therefore, the specified material is especially resistant to oxidation and decomposition at the positive electrode of the battery and can significantly reduce the production of hydrogen attributed to the oxidation and decomposition.

Sealed

A method of manufacturing a nickelous positive-electrode active material for an alkaline battery has a formation process in which nickel hydroxide and cobalt hydroxide are formed by adding an alkali metal hydroxide to a reaction system containing nickel ions and cobalt (II) ions. The method comprises at least one step of removing any oxidant which oxidizes the cobalt (II) ions into cobalt (III) ions, during or before the formation process. An expedient for the removal of the oxidant is, for example, to reduce and remove the oxidant by adding a reductant, such as L-ascorbic acid, to the reaction system. The reductant should preferably have an oxidation potential which is lower than the reduction potential of oxygen. Besides, the method should preferably comprise the step of removing the cobalt (III) ions, during or before the formation process.

Method of manufacturing nickelous positive-electrode active material for

An electroless metal or alloy plating solution as a photo-plating solution contains at least one of copper, nickel, cobalt or tin, and a sacrificial reagent which supplies electrons as a result of irreversible oxidative decomposition. A semiconductor is supported on a substrate, and dipped in the photo-plating solution, and the surface of the semiconductor is irradiated with light having a higher level of energy than the exciting energy of the semiconductor. A thick coating containing at least one of copper, nickel, cobalt or tin can be formed on that portion of the semiconductor which has been irradiated with light.

Photo-plating solution and process

A process for photo-plating only a light-irradiated portion of a dye layer formed on a substrate comprises: forming a dye layer on the surface of a substrate; immersing the substrate with the dye layer into an electroless plating solution comprising a sacrificial reagent for supplying electrons by irreversible oxidative decomposition, and at least one of copper ions, nickel ions, cobalt ions, and tin ions; and irradiating the surface of the dye layer with light having an energy higher than the excitation energy of the dye in the dye layer. A thick coating containing at least one of copper, nickel, cobalt, and tin can be formed with excellent adhesion strength only on the light-irradiated portion of the dye layer formed on the substrate.

Photo-plating process

A reference electrode is formed of lead, zinc, tin, indium, cadmium, magnesium, or any alloy thereof. A pair of electrodes comprising the reference electrode and a responding electrode made of a conductive solid, when placed in oil, develop a potential difference varying with the acidity or basicity of the oil and thus enable the efficient determination of the acidity or basicity.

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Nagoya, Japan

Shinya Morishita