Kabushiki Kaisha Toyoda Jidoshokki Seisakusho

Toyota Jidosha Kabushiki Kaisha

Kabushiki Kaisha Toyota Chuo Kenkyusho

Shin-ichi Towata

Masakazu Aoki

Shinya Morishita

Hiroshi Kawase

Tatsumi Hioki

Yasuhito Kondo

Katsushi Saito

Akio Itoh

Kazuhiko Itoh

Katsushi Abe

Tatsuo Noritake

Akihiko Koiwai

Toshihiro Mouri

Nobuko Oba

Shunsuke Yamakawa

Yutaka Ohya

A hydrogen storage material is expressed by a composition formula, (CaA)(SiB), wherein 'A' is at least one member selected from the group consisting of alkali metal elements, alkaline-earth metal elements, rare-earth elements, the elements of groups 3 through 6, Ni, Au, In, Tl, Sn, Fe, Co, Cu and Ag; 'B' is at least one member selected from the group consisting of the elements of groups 7 through 17, rare-earth elements, Hf and Be; 0&#x2266;x&#x3c;1 by atomic ratio; 0&#x2266;y&#x3c;1 by atomic ratio; and 0.38&#x2266;z&#x2266;0.58 by atomic ratio. It is lightweight as well as less expensive. In principle, neither high-temperature nor high-pressure activation is required, because it exhibits a high initial activity. The operation temperature can be lowered and the hydrogen absorption content can be enlarged by controlling the kind and substitution proportion of the substituent elements appropriately.

Hydrogen storage material

A multilayered hydrogen absorbing body is provided which is formed by laminating at least two types of hydrogen absorbing materials. The degrees of strains cause due to absorption/desorption of hydrogen are different between the hydrogen absorbing materials adjacent to each other.

Multilayered hydrogen absorbing body

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

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

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Nagoya, Japan

Shin-ichi Towata