Kabushiki Kaisha Toshiba

Toshiba Battery Co., Ltd.

Tokyo Shibaura Denki Kabushiki Kaisha

Kiyoshi Mitsuyasu

Yuji Sato

Motoya Kanda

Kazuta Takeno

Hiroyuki Takahashi

Hiroyuki Hasebe

Hirotaka Hayashida

Ichirou Sawatari

Yuichi Sato

Kazuhiro Yoshida

Kazuya Hiratsuka

Shuji Yamada

Takahisa Ohsaki

Kunihiko Sasaki

Katuyuki Hata

Yoshiyasu Aoki

Eriko Yagasaki

Kenichi Kochiwa

Koji Ishiwa

Eriko Shincho

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.

Disclosed is a hydrogen storage alloy electrode prepared by integrating a mixture of a hydrogen storage alloy powder, an electrical conducting powder and a polymer binder with a current collector, characterized in that the polymer binder is composed of a polyacrylic acid salt and polytetrafluoroethylene as essential components, and that the hydrogen storage alloy powder is coated with polyacrylic acid salt, wherein the three-dimensional reticulate molecular chain of the polyacrylic acid salt itself is partially severed. Disclosed also is a method of preparing a hydrogen storage alloy electrode which comprises the steps of preparing a paste of a mixture containing hydrogen storage alloy powder, electrical conducting powder and a polymer binder, coating a current collector with the paste, drying it and pressure molding the current collector coated with the paste, the method being characterized in that at least a polyacrylic acid salt and polytetrafluoroethylene are used as the polymer binder, and after the paste is stirred at a high speed, the current collector is coated with the paste.

Hydrogen storage alloy electrode and method for preparing the same

A non-aqueous electrochemical cell has an anode consisting of an element selected from the group consisting of lithium, sodium and aluminum; a cathode consisting of a porous carbon body and a current collector; and an electrolyte containing an oxyhalide, wherein the porous carbon body contains a carbon black having a structure wherein a thin layer of graphite crystals is formed on a surface of each of chain-like carbon black particles. The cell has a high discharge capacity and an excellent discharge efficiency in high rate discharge.

Non-aqueous electrochemical cell

A rechargeable electrochemical cell a positive electrode, an alkaline electrolyte and a negative electrode made mainly of a hydrogen absorbing alloy containing a mixture of at least two rare earth elements including Ce whose content relative to the total amount of rare earth elements is less than 40 wt % and is preferably 0.1 wt % to 12 wt % or in the range 0.1-8 wt %, which gives still better capacity and life characteristics. Moreover, larger capacity characteristics can be obtained if the negative electrode contains a conductive powder preferably with an average particle diameter of 10 .mu.m or less as a subsidiary material.

Rechargeable electrochemical cell with a negative electrode comprising a

Disclosed is a method of producing a sealed metal oxide-hydrogen storage cell, comprising the step of housing in a container a cathode containing a metal oxide as an active material, an anode containing a hydrogen storage alloy as the main component, a separator for separating the cathode and the anode, a pre-charging member, and an electrolyte solution consisting of an alkaline aqueous solution. The pre-charging member is electrically combined with the anode and consists of a metal having a less noble potential than the hydrogen electrode potential within the alkaline solution. A material containing said metal as the main component may also be used as the pre-charging member. The storage cell has a desired anode-cathode capacity balance and exhibits a long life.

Sealed metal oxide-hydrogen storage cell

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Yokohama, Japan

Kiyoshi Mitsuyasu