Kabushiki Kaisha Toshiba

Toshiba Battery Co., Ltd.

Ichirou Sawatari

Yuji Sato

Hiroyuki Takahashi

Hiroyuki Hasebe

Hirotaka Hayashida

Kazuta Takeno

Kiyoshi Mitsuyasu

Kazuhiro Yoshida

Kunihiko Sasaki

Katuyuki Hata

Koji Ishiwa

A nickel-metal hydride secondary cell comprising an enclosure, a non-sinter type nickel positive electrode accommodated in said enclosure and formed of a conductive core and a layer formed on the core and made mainly of a binding medium, nickel hydroxide powder, and cobalt monoxide powder, a hydrogen absorbing alloy negative electrode accommodated in said enclosure and formed of punched metal and a layer formed on the punched metal by applying a paste thereto, said punched metal having a plurality of apertures having a diameter of 1 to 5 mm at an aperture rate of 45 to 70% and having a thickness equal to 10 to 35% of the overall thickness of the negative electrode, and said paste made of 100 parts by weight of hydrogen absorbing alloy powder, 0.005 to 1 part by weight of polyacrylate, 0.01 to 1 part by weight of carboxymethylcellulose, 0.5 to 7 parts by weight of fluoro-resin, and 0.1 to 4 parts by weight of conductive material powder, a separator made of synthetic resin unwoven fabric and located between said positive and negative electrodes, and an alkali electrolyte contained in said enclosure.

Nickel-metal hydride secondary cell

A nickel-metal hydride secondary cell comprising a non-sinter type nickel positive electrode accommodated in an enclosure and comprised of a conductive core and a layer formed on the conductive core, the layer made of a mixture of nickel hydroxide power and cobalt monoxide powder covered with a layer of high-valence cobalt oxide, a hydrogen absorbing alloy negative electrode accommodated in the enclosure and comprised of a conductive core and a layer formed on the conductive core and made of a mixture hydrogen absorbing alloy powder and carbon black having a specific surface area of 700 m.sup.2 /g or more, and having a capacity 1.0 to 2.5 times the sum of the capacity of the nickel hydroxide contained in the positive electrode and the electricity required to oxidize the cobalt monoxide powder, a separator made of synthetic resin unwoven fabric having a texture size of 50 to 100 g/m.sup.2 and a thickness of 0.1 to 0.25 mm, and located between the positive electrode and the negative electrode, and alkali electrolyte contained in the enclosure.

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Oomiya, Japan

Ichirou Sawatari