JPH10172522A - Alkaline battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an alkaline battery which has a large capacity and a good super heavy load characteristic and storage characteristic. SOLUTION: In an alkaline battery, as a terminal and container filled with generating elements, a cold-rolled steel sheet 11 has one side on which a nickel cobalt alloy plating layer 12 is applied, and the other side on which a nickel plating layer 10 is applied. Using a can drawn to make the former side become inside prevents the depression of short-circuit current, thus improving battery performance. When an additional conductive film mainly made of graphite is formed on the nickel cobalt alloy plating layer 12 after the drawing, effectiveness is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an alkaline battery.

[0002]

2. Description of the Related Art In recent years, alkaline batteries have attracted attention as ultra-heavy or heavy-load power supplies for portable AV devices such as notebook personal computers, CD players, MD players, and liquid crystal televisions, and mobile phones. The positive electrode container of such an alkaline battery is prepared by press-drawing a steel plate that has been nickel-plated on both sides in advance, or by drawing only with a steel plate and then nickel-plating, each containing graphite as a main component on the inner surface. The conductive film to be formed is formed.

[0003]

When a steel plate is preliminarily plated with nickel, if the container is subjected to press drawing, cracks occur on the surface of the nickel plating and the surface of iron is exposed, so that the surface area of the nickel plating is reduced. , The contact resistance increases accordingly. Further, when nickel plating is performed after drawing only with a steel plate, nickel plating is performed on the outer surface side, but plating around the inner surface side deteriorates. For example, when nickel plating is applied to the outer surface side with a thickness of 3 μm, the inner surface side has a thickness of about 0.5 μm. For this reason, the contact with the positive electrode mixture deteriorates, the contact resistance increases, the short-circuit current decreases, the performance deteriorates during long-term storage, and the amount of generated hydrogen gas increases. The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an alkaline battery having high capacity, excellent super heavy load characteristics, and excellent storage characteristics.

[0004]

In order to achieve the above object, an alkaline battery of the present invention is provided with a nickel-cobalt alloy plating layer on one surface and a terminal / container containing a power generation element, The present invention is characterized in that a can is formed by press-drawing a cold-rolled steel sheet having a nickel-plated layer on its surface so that the former surface becomes an inner surface.

According to the present invention, nickel
By performing the cobalt alloy plating, a very hard plating layer can be obtained. This causes very fine cracks on the surface during the press drawing, so that very fine irregularities are formed, and the contact with the positive electrode mixture is improved. Therefore, the contact resistance does not increase and the short-circuit current can be improved.

Further, the effect can be further improved by forming a conductive film mainly composed of graphite on the nickel-cobalt alloy plating layer on the inner surface of the can after press-drawing.

[0007]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view of a first embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a bottomed cylindrical metal can also serving as a positive electrode terminal. The metal can 1 is filled with a positive electrode mixture 2 formed into a cylindrical pressure. Positive electrode mixture 2
Is obtained by mixing a manganese dioxide powder and a graphite powder, storing the mixture in a metal can 1, and press-molding the mixture into a hollow cylinder at a predetermined pressure. The hollow portion of the positive electrode mixture 2 is filled with a gelled negative electrode 4 via a bottomed cylindrical separator 3 made of a nonwoven fabric of acetalized polyvinyl alcohol fiber. In the gelled negative electrode 4, a negative electrode current collector rod 5 made of brass is provided.
The upper end is inserted so as to protrude from the gelled negative electrode 4. An insulating gasket 6 made of a double annular polyamide resin is disposed on the outer peripheral surface of the protruding portion of the negative electrode current collector rod 5 and the inner peripheral surface of the upper portion of the metal can 1. A ring-shaped metal plate 7 is disposed on the double annular portion of the gasket 6, and a cap-shaped metal sealing plate 8 also serving as a negative electrode terminal is provided on the metal plate 7 so as to contact the head of the current collecting rod 5. It is arranged in. And
The inside edge of the metal can 1 is sealed by the gasket 6 and the metal sealing plate 8 by bending the opening edge of the metal can 1 inward.

Thus, the JIS standard LR6 type (AA)
Shape) Alkaline battery was assembled. In the above, metal can 1
Is the nickel or nickel
It is formed by applying a cobalt alloy plating by 2 to 3 μm, applying a nickel plating to the outer surface by 2 to 3 μm, and press-drawing into a bottomed cylindrical shape. FIG. 2 shows a cross section of the plating configuration of the metal can 1. In FIG. 2, 11 is a steel plate, 10 is a nickel plating layer, and 12 is a nickel-cobalt alloy plating layer.

(Embodiment 2) After a metal can was formed in the same manner as in Embodiment 1, a conductive film mainly composed of graphite was formed in a portion of the opening on the inner surface side except a portion in contact with the gasket. . FIG. 3 shows a cross-sectional view of the metal can 1 of the present embodiment.
In FIG. 3, reference numerals 10 to 12 are the same as those in FIG. 2, and reference numeral 13 is a conductive film layer mainly containing graphite.

In the method of applying the conductive film, a conductive paint containing graphite as a main component is diluted with a low boiling organic solvent such as methyl ethyl ketone (MEK) and applied to the inner surface of the metal can in a mist by a spray gun. At this time, the portion of the metal can opening that is in contact with the gasket is not coated. After applying the conductive paint with a spray gun, the solvent is evaporated by a dryer. The thickness of the remaining conductive film is desirably about 1 to 10 μm. Except for this conductive film, a JIS standard LR6 type (AA) alkaline battery was assembled in the same manner as in Example 1.

(Comparative Example 1) As a terminal / container in which a power generating element is to be filled, a can obtained by subjecting a cold-rolled steel sheet to nickel plating on both sides and press-drawing the same is used. Except for this, a JIS standard LR6 type (AA) alkaline battery was assembled in the same manner as in Example 1.

(Comparative Example 2) As a terminal / container in which a power generating element was to be filled, a can which had been subjected to press drawing of a cold-rolled steel sheet and then plated with nickel was used. Otherwise, Example 1
A LR6 (AA) alkaline battery according to JIS was assembled in the same manner as described above.

With respect to each of the alkaline batteries assembled as described above, the open-circuit voltage (average value of n = 100) and short-circuit current (n = 10) after storage at 60 ° C. for 10 days and 60 days.
Average value of 0), hydrogen gas amount (average value of n = 100)
Was examined. The amount of hydrogen gas was measured by disassembling the battery in water and collecting gas inside the battery. Table 1 shows the results.

[0015]

[Table 1]

In Table 1, when Example 1 and Comparative Example 1 are compared, there is a difference in short-circuit current deterioration after storage at 60 ° C. for 60 days, and a difference in hydrogen gas amount after storage at 60 ° C. for 60 days. Was. Also, from the result of Example 2, it can be confirmed that the effect is further enhanced by forming the conductive film on the inner surface of the can.

In Comparative Example 2 in which a cold-rolled steel sheet was subjected to press-drawing and then subjected to nickel plating, the deterioration of short-circuit current was large, the amount of hydrogen gas generated was large, and the storage deterioration was large as compared with the embodiment.

[0018]

As described above, according to the present invention,
By forming a nickel-cobalt alloy plating layer on a steel sheet, a very hard plating layer is obtained, very fine cracks are generated on the surface during press drawing, and very fine irregularities are formed. Contact is improved. Therefore, the contact resistance does not increase and the short-circuit current can be improved. Therefore, the alkaline battery of the present invention has excellent high capacity, super heavy load characteristics, and excellent storage characteristics.

[Brief description of the drawings]

FIG. 1 is a sectional view of an alkaline battery according to one embodiment of the present invention.

FIG. 2 is a cross-sectional view of the metal can 1 of FIG.

FIG. 3 is a view showing a cross section of a metal can of another embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Metal can, 2 ... Positive electrode mixture, 3 ... Separator, 4 ... Gelled negative electrode, 5 ... Negative electrode current collecting rod, 6 ... Insulating gasket, 7 ... Ring-shaped metal plate, 8 ... Metal sealing plate, 9 ... Label jacket, 10: nickel plating layer, 11: steel plate, 12: nickel-cobalt alloy plating layer, 13: conductive film layer mainly composed of graphite.

Claims (2)

[Claims] 1. A terminal / container in which a power generating element is filled,
A cold-rolled steel sheet with a nickel-cobalt alloy plating layer on one side and a nickel plating layer on the other side,
An alkaline battery using a can formed by press-drawing so that the former surface is the inner surface. 2. The alkaline battery according to claim 1, wherein a conductive film containing graphite as a main component is formed on the inner surface of the can after press drawing.