Sanyo Electric Co., Ltd.

Other

Takeo Hamamatsu

Yoshitaka Baba

Akifumi Yamawaki

Masao Inoue

Shinsuke Nakahori

Takashi Nagase

Hideyuki Asanuma

Motoo Tadokoro

Satoru Kometani

Masao Takee

Tadashi Ise

Yasushi Kuroda

Kensuke Nakatani

Hiroshi Sato

Teruhito Nagae

Etsuya Fujisaka

Taishi Maeda

Kenji Arisawa

Hirofumi Sako

Makoto Kambayashi

Kazuaki Ozaki

Naoyoshi Hinotsu

Hiroki Ochi

Naoyoshi Hinotu

Nobuyoshi Oi

Masahito Tomida

Hiroshi Haraguchi

A rectangular alkaline storage battery includes an electrode plate which can be easily prepared and has a high packing density of active material and volumetric energy density. A connected negative electrode plate with hydrogen-absorbing alloy negative electrode plates is bent into a U-shaped form at a central portion (connecting portion). A composite positive electrode plate is then sandwiched by the hydrogen-absorbing alloy negative electrode plates with a separator made of an unwoven polypropylene fabric provided interposed therebetween to prepare an electrode plate unit. Two such electrode plate units are then laminated to form a group of electrode plates.

Rectangular battery

A alkali storage cell includes a non-sintered type nickel electrode which includes a highly efficient nickel hydroxide active material and which causes no capacity decrease during an over-discharge operation. The nickel electrode contains an active material composed of nickel hydroxide, a solid solution of at least one of zinc, cadmium, magnesium, and calcium which are added to the nickel hydroxide, and cobalt compound layers which are formed over the surfaces of particles of the nickel hydroxide. The cobalt compound layers have an oxidation number of larger than 2 and a disordered crystal structure. Such an active material can be manufactured by mixing nickel hydroxide powder containing a solid solution of at least one of zinc, cadmium, magnesium, and calcium with either metallic cobalt or a cobalt compound, and subjecting the mixture to heat treatment in the presence of oxygen and alkali. Another production method is to precipitate a cobalt compound over the surfaces of the nickel hydroxide powder containing a solid solution of at least one of zinc, cadmium, magnesium, and calcium so as to form cobalt compound layers, before subjecting it to the heat treatment in the same conditions.

NON-SINTERED NICKEL ELECTRODE WITH EXCELLENT OVER-DISCHARGE CHARACTERISTICS, AN ALKALINE STORAGE CELL HAVING THE NON-SINTERED NICKEL ELECTRODE, AND A MANUFACTURING METHOD OF THE NON-SINTERED NICKEL ELECTRODE

A sealed rectangular battery has a conductive battery case including an external casing and a sealing cap. The external casing encloses a generator element and is sealed by attaching the sealing cap using heat. The battery includes an electrode terminal with an opposite polarity to the battery case, and a safety valve. The safety valve includes a cap that is charged with the same polarity as the battery case and a valving element that covers a vent hole. The electrode terminal and safety valve are provided separately at different positions on the battery case. This construction is simpler than conventional batteries where the safety valve is integrally formed with an electrode terminal, which means that the electrode terminal can be miniaturized. This battery also has improved internal resistance.

Sealed rectangular battery and manufacturing method for the same

An alkaline storage battery has a group of spiral electrodes composed of positive and negative electrode plates spirally wound with first and second separators respectively located at the outside of the positive electrode plate and at the inside of the positive electrode plate. The weight per unit area of the first separator is greater than that of the second separator.

Alkaline storage battery with reinforced separators

An object of the invention is to provide a hermetically sealed rectangular battery which is not liable to melting of gasket during laser welding causing the deterioration of the battery airtightness as well as to occurrence of electrolyte leakage and accomplish further reduction of the thickness of the hermetically sealed rectangular battery. A hermetically sealed rectangular battery comprising a group of electrode plates received in a metallic can having a pair of opposing wide sides and a pair of opposing narrow sides, the group of electrode plates having a positive electrode plate and a negative electrode plate laminated on each other with a separator provided interposed therebetween, characterized in that the metallic can is provided with a terminal which also acts as an electrode of one of the two polarities on the wide side thereof.

Hermetically sealed rectangular battery

A battery structure is arranged such that an elastic valve body or the like cannot easily come off from the cover body during the production of the battery, which thereby enhances the production yield. A cover body of the invention includes a flange portion airtightly fixed to an injection port and a bulge portion protruding from the flange portion and provided with a space in which an elastic valve body is fitted (mounted). The bulge portion has an opening for ventilation provided on the side wall thereof and a protrusion at the lower end of the side wall thereof protruding inwardly of the side wall, whereby the elastic valve body can be held by the protrusion and the annular rim of the elastic valve body so that it can be prevented from coming off from the cover body. Accordingly, the elastic valve body can be prevented from coming off from the cover body due to vibration developed during the transportation of the cover body or like occasions, making it possible to enhance the production yield.

Hermetically sealed storage battery

A rectangular battery having an electrode group which is inserted in a battery case having an airtight structure. The electrode group is formed by alternately stacking positive electrodes and negative electrodes via separators. The battery case is rectangular had has a closed bottom and an open part that is airtightly sealed by a cover. The outermost electrodes, which are located on both faces of the electrode group, are coated with an active material on a surface of a core. Furthermore, the outermost electrodes have the same polarity and the cores thereof directly contact an inside surface of the outer battery case. In one embodiment, the capacity of the outermost electrodes is smaller than the capacity of the inwardly disposed electrodes of the same polarity.

A nickel active material for an alkali storage cell whose surface is covered with a cobalt compound, wherein the diffusion and permeation into the nickel hydroxide mother particles of cobalt compound during excessive discharging, which act to reduce the active material efficiency and the excessive discharging characteristics, are prevented. This is achieved by having a covering layer, including one or more of the following metal compounds; an aluminum compound, a magnesium compound, an indium compound and a zinc compound, in addition to a cobalt compound, formed on the surface of a mother particle of nickel hydroxide, and by heat treating the covered mother particles in the presence of alkali and oxygen so as to convert the cobalt compound into a compound of cobalt where an oxidization number of cobalt is greater than 2.

Nickel active material for use in alkali storage cells and its

Non-sintered nickel electrode with excellent over-discharge

Fine-grained nickel electrode active material, each of which contributing to electrode reaction; production method of the fine-grained nickel electrode active material; and a nickel alkali storage cell of high capacity which is excellent in over discharge characteristics. In order to produce the fine-grained nickel electrode active material, fine-grained nickel hydroxide is precipitated by adding a given amount of alkali to solution in which at least a nickel compound is dissolved while the solution is stirred. Each of the fine-grained nickel hydroxide has pores with 20 vol % or more of a combined volume of the pores being composed of pores of diameter 60 .ANG. or greater. Next, a given amount of alkali is gradually added to suspension including the fine-grained nickel hydroxide and dissolved cobalt compound so that cobalt hydroxide is precipitated on the external surface of the fine-grained nickel hydroxide. The fine-grained nickel electrode active material is produced in the above mentioned way. Each of the fine-grained nickel electrode active material comprises a nickel hydroxide and cobalt oxide having distorted crystal structure and oxidation number higher than +2. The nickel hydroxide has pores whose diameters are 60 .ANG. or greater. And the volume of such pores amounts to 20 vol % or more of the combined volume of all of the pores.

Nickel electrode active material; a nickel electrode and a nickel alkali

A method of manufacturing an electrode for a battery comprises steps of preparing a substrate formed by a metal porous body having three-dimensionally continuous pores, a slurry mainly composed of active material powder to be filled into the pores of the substrate, a vessel for containing the slurry and a filling roller located to be at least partially dipped but not completely submerged in the slurry contained in the vessel, continuously supplying the substrate onto the filling roller so that the substrate is in contact with the filling roller in at least a point not being submerged in the slurry and rotating the filling roller in such a manner that the speed of outer peripheral surface of the filling roller facing the substrate is higher than the travel speed of the substrate thereby to fill the slurry into the pores of the substrate.

Growing community of inventors

Tokushima, Japan

Takeo Hamamatsu