Katsunori Komori

ALKALINE STORAGE BATTERY

An alkaline storage battery includes, as main constituent elements, a positive electrode having nickel hydroxide as an active material, a negative electrode, a separator, and an electrolyte made of an aqueous alkali solution, and a foamed three-dimensional porous substrate composed of nickel as a main component is used as a core substrate of the positive electrode, and the weight ratio of this core substrate in the positive electrode is set to 30% to 50%, thereby allowing both electron conductivity and ion conductivity of the positive electrode, with long life and high output even under severe conditions.

Effect of alkali-treatment of hydrogen storage alloy on the degradation of Ni/MH batteries

Alkali-treatment at high temperature of the hydrogen storage alloy which was used as the negative electrode of nickel/metal-hydride batteries could enhance the cycle life. Al dissolves from the alloy surface, rare earth metal hydroxides form on the alloy surface, while Ni and Co exist as metals near the surface. Mn dissolves first and then deposits again as an oxide on the alloy surface. The corrosion reaction caused by alkali-treatment of the alloy stops at a certain stage. The above three points can be considered as the main factors for the long cycle life for the alkali-treated alloys.

Method for producing hydrogen storage alloy particles and sealed-type nickel-metal hydride storage battery using the same

A method for manufacturing hydrogen storage alloy particles comprises steps of obtaining a melt of the hydrogen storage alloy and pulverizing the hydrogen storage alloy by water atomizing process, whereby the melt is pulverized by contacting or colliding with high-speed jetting thereto to be dispersed in the form of solidified fine particles. By employing an aqueous solution of hypophosphorous acid or an alkali aqueous solution in place of water during the water atomizing process, or by etching the oxide films once formed on the surface of the hydrogen storage alloy particles with an aqueous solution of a strong acid, the thickness of the oxide film can be made thinner, and thus a high discharge capacity of a battery configured with a negative electrode comprising the alloy particles can be realized.