Furukawa Denchi Kabushiki Kaisha

Takashi Mizuno

Masanori Suzuki

Yukinari Kondo

A stepped insulating ring having a large-diameter upper portion, a small-diameter foot portion, and a step portion formed on the inside is inserted from a top opening of a bottomed cylindrical can containing a plate group and electrolyte and the small-diameter foot portion is set onto the plate group, a peripheral portion of a cover in which a safety valve is incorporated is set onto the step portion of the stepped insulating ring, and the areas to be sealed where an inside wall of top opening of the bottomed cylindrical can faces an outside wall of the large-diameter upper portion of the stepped insulating ring and an inside wall of the large-diameter upper portion faces a peripheral portion of the cover is formed, and when crimping operation on said areas to be sealed is performed from the outside of the upper part of the bottomed cylindrical can to form a closed construction, a sealing compound consisting of oily bitumen, organic solvent, and paraffin base oil is applied to the areas where an inside wall of top opening of the bottomed cylindrical can faces an outside wall of the large-diameter upper portion of the stepped insulating ring and an inside wall of the large-diameter upper portion faces a peripheral portion of the cover before the areas to be sealed are formed, and drying operation of the sealing compound is performed. On the battery obtained, the leakage of electrolyte scarcely occurs even in a high-temperature, high-humidity environment.

Method for manufacturing a cylindrical nickel-hydrogen rechargeable

A hydrogen-occlusion electrode and a method of manufacturing the electrode are described. The hydrogen-occlusion electrode comprises from about 42-84 vol. % of a hydrogen-occlusion alloy, from about 3-13 vol. % of a bonding material, from about 3-15 vol. % of an electroconductive material, and has residual pores in an amount of 10-30 vol. %. The electroconductive material has an average particle size of 1.3 .mu.m or less. The bonding material is preferably polyvinylidene fluoride (PVdf). In manufacturing the foregoing hydrogen-occlusion electrode, a formed electrode plate body including PVdF as a bonding material is heat-treated in a vacuum or inert gas atmosphere at a temperature ranging from about 160.degree. C. to about 200.degree. C. An electrode is thereby obtained wherein the alloy particles are prevented from separating from the electrode resulting in an improvement of mechanical strength and electroconductivity in the electrode. When the hydrogen-occlusion electrode includes a thickener in an amount of not more than about 0.5 wt. % based on the weight of the hydrogen-occlusion alloy, improvements in the charge-discharge characteristics and the internal pressure of the battery are obtained.

Hydrogen-occlusion electrode and a method of manufacturing the electrode

A hydrogen-occlusion electrode and a method of manufacturing the electrode are described. The hydrogen-occlusion electrode comprises from about 42-84 vol. % of a hydrogen-occlusion alloy, from about 3-13 vol. % of a bonding material where the volume percent is based on 100% from about 3-15 vol. % of an electroconductive material, and has residual pores in an amount of 10-30 vol. %. The electroconductive material has an average particle size of 1.3 .mu.m or less. The bonding material is preferably polyvinylidene flouride (PVdf). In manufacturing the foregoing hydrogen-occlusion electrode, a formed electrode plate body including PVdF as a bonding material is heat-treated in a vacuum or inert gas atmosphere at a temperature ranging from about 160.degree. C. to about 200.degree. C. An electrode is thereby obtained wherein the alloy particles are prevented from separating from the electrode resulting in an improvement of mechanical strength and electroconductivity in the electrode. When the hydrogen-occlusion electrode includes a thickener in an amount of not more than about 0.5 wt. % based on the weight of the hydrogen-occlusion alloy, improvements in the charge-discharge characteristics and the internal pressure of the battery are obtained.

Growing community of inventors

Iwaki, Japan

Takashi Mizuno