Sanyo Electric Co., Ltd.

Tadashi Ise

Teruhiko Imoto

Masao Takee

Tetsuyuki Murata

Yohei Hirota

Yasushi Kuroda

Hiroshi Fukuda

Nobuyasu Ishimaru

Koji Miki

Shin Fujitani

Koji Nishio

Ikuo Yonezu

Mamoru Kimoto

Masao Inoue

Nobuhiro Furukawa

Nobuyuki Higashiyama

Yoshinori Matsuura

Motoo Tadokoro

Kikuko Kato

Mitsuzou Nogami

Takeo Hamamatsu

Akifumi Yamawaki

Hiroshi Sato

Takashi Nagase

Yasuhiko Ikeda

Hirofumi Sako

Satoru Kometani

Hideo Kasuga

Takayuki Murakami

Nobuyoshi Oi

An electrode for the alkaline storage battery includes a binding agent containing thermoplastic xylene-formaldehyde resin. Since the thermoplastic xylene-formaldehyde resin is non-aqueous, it is not dissolved into moisture in the air or the alkaline electrolyte within the battery. The electrode is prepared by immersing an active-material-applied or -filled electrode substrate in a solution in which the thermoplastic xylene-formaldehyde resin is dissolved; immersing it in an emulsion of the thermoplastic xylene-formaldehyde resin with an emulsifier; or applying or filling a slurry of the active material with an emulsion of the thermoplastic xylene-formaldehyde resin to or in the electrode substrate. The electrode retains the active material using a binding agent which has excellent adhesion to the active material and imparts high binding capacity of the active materials with one another.

Electrode for alkaline storage battery and method of manufacturing the same

A nickel-hydrogen storage battery having improved charge and discharge cycle characteristics even in high temperature, which has a negative electrode comprising a hydrogen absorbing alloy capable of electrochemically storing and releasing hydrogen, a positive electrode comprising nickel hydroxide as a main active material, and an alkaline electrolytic solution mainly comprising an aqueous potassium hydroxide solution, wherein the positive electrode contains a cobalt compound, a yttrium compound, and 100 ppm or more of lithium based on the total weight of the nickel hydroxide, the cobalt compound, and the yttrium compound.

Nickel-hydrogen storage battery and method of producing the same

An alkaline storage battery including a group of spiral electrodes composed of positive and negative electrode plates spirally wound with a separator interposed therebetween and contained in a metallic cell casing used as an external terminal, wherein the group of spiral electrodes is formed at its central portion with a space defined by a winding core during the winding process of the electrode plates and is provided with a first current-collector welded to an upper end of one of the electrode plates and a second current-collector welded to a lower end of the other electrode plate, wherein the second current-collector is welded to an internal surface of the bottom of the cell casing without being welded to an end portion of the other plate located at the outermost periphery of the group of spiral electrodes, and wherein the other electrode plate at the outermost periphery of the group of spiral electrodes is pressed into contact with an internal peripheral wall of the cell casing.

Alkaline storage battery with group of spiral electrodes

The method of manufacturing a hydrogen-absorbing alloy electrode according to this invention comprises the steps of: dissolving a particle surface of said hydrogen-absorbing alloy by a surface-treatment solution; and washing the hydrogen-absorbing alloy with the particle surface dissolved using an alkaline solution at a temperature of 30&deg; C.&tilde;40&deg; C. The metal ions dissolved by the surface-treatment solution can be completely washed away by the alkaline solution so that they will not be precipitated onto the surface of the hydrogen-absorbing alloy again as the hydroxide.

Method of manufacturing hydrogen-absorbing alloy electrode

A hydrogen-absorbing alloy electrode is prepared by reducing an oxide or hydroxide residing on the surface of a hydrogen-absorbing alloy particle while the alloy particle is held in an atmosphere of a hydrogen gas maintained at a temperature where absorbing of a hydrogen gas does not substantially occur; cooling the atmosphere from a temperature where absorbing of the hydrogen gas does not substantially occur to a temperature where the equilibrium hydrogen pressure of the hyrogen-absorbing alloy is equal to the hydrogen pressure in the atmosphere of the hydrogen gas and thereafter vacuum-evacuating and removing the hydrogen gas so that the hydrogen-absorbing alloy particle is cooled to room temperature while the hydrogen gas is exhausted; and thereafter introducing argon, nitrogen or carbon dioxide gas into the atmosphere, thereby returning the atmosphere to normal atmospheric pressure; and immersing the hydrogen-absorbing alloy particle so prepared in a solution containing an oxidation inhibiting agent.

The invention provides a method of producing hydrogen-absorbing alloy that can remarkably improve a high-rate discharge characteristic of a nickel-hydrogen alkaline storage cell at low temperature. This is achieved by a method of producing hydrogen-absorbing alloy for use in a nickel-hydrogen alkaline storage cell including the following steps of (a) immersing a hydrogen-absorbing alloy in an alkali treatment solution having a temperature of 60&deg; C. or higher to subject a surface of the hydrogen-absorbing alloy to an alkali treatment; (b) after the step (a), adding a pH-adjusting agent and a reducing agent to the alkali treatment solution to treat the surface of the hydrogen-absorbing alloy using the alkali treatment solution; and (c) washing the hydrogen-absorbing alloy treated by the step (b).

Method of producing hydrogen-absorbing alloy for nickel-hydrogen alkaline storage cell

The present invention certainly provides a metal hydride storage cell having excellent cycle characteristic and a method of producing such a cell. In order to realize the objectives, the cell is produced under a condition which makes the particle size distribution y/x of the activated hydrogen absorbing alloy electrode below 0.90.

Metal hydride storage cell having excellent charge and discharge cycle characteristic

Nickel-metal hydride storage cell having a high capacity and an excellent cycle characteristic and manufacturing

An object of the present invention is to provide an effective hydrogen-absorbing alloy activation process which can enhance the electrochemical activity of a hydrogen-absorbing alloy and to provide a hydrogen-absorbing alloy electrode which, when used in a battery, ensures an excellent initial inner pressure characteristic, low-temperature discharge characteristic, high-rate discharge characteristic and cycle characteristic. In accordance with the present invention, a hydrogen-absorbing alloy electrode production process is provided which comprises an alloy activation treatment step of immersing a hydrogen-absorbing alloy in a strong acid treatment solution containing metal ions and, in the course of the pH rise of the acid treatment solution, adding an alkali to the acid treatment solution to promote the pH rise of the acid treatment solution.

Hydrogen storing alloy electrode and process for producing hydrogen storage alloy electrode

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.

Rectangular battery

Process for producing hydrogen-occlusion alloy electrode of alkaline

The object of the present invention is to provide an acid treatment for enhancing the high-rate discharge characteristic, cycle characteristic, and other characteristics of a hydrogen-absorbing alloy electrode to a large extent. The object can be achieved by subjecting a hydrogen-absorbing alloy as a negative electrode active material to an acid treatment comprising the steps of acid-treating the surface of the hydrogen-absorbing alloy by using a metallic ion-containing treatment solution which contains metallic ions and whose initial pH is in the range of 0.5 to 3.0; and heat-treating the hydrogen-absorbing alloy in an atmosphere with the presence of hydrogen.

Method of manufacturing a hydrogen-absorbing alloy for use in an alkali

A metal-hydrogen alkaline storage cell comprising a rare earth hydrogen absorbing alloy and positive and negative electrodes, wherein the rare earth hydrogen absorbing alloy contains praseodymium in a weight ratio of no more than about 3 weight percent based on the total weight of rare earth elements.

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Itano-gun, Japan

Tadashi Ise