JPH11195426A - Cylindrical alkaline storage battery - Google Patents

Abstract

(57) [Problem] To provide a good cylindrical alkaline storage battery which prevents the electrode from being displaced when a spiral electrode group is formed and has no internal short circuit. SOLUTION: A group of electrode plates formed by spirally winding a sintered positive electrode plate 1, a separator 5, and a negative electrode plate 6 is inserted into a battery case 7, and a core formed on the upper end edge of the positive electrode plate 1 in the longitudinal direction. The other end of the lead piece 4 having one end welded to the material exposed portion 3 is connected to the case 7
The alkaline storage battery is welded to the lower surface of the sealing plate 8 for closing the opening of the positive electrode plate 1, and the core material exposed portion 3 of the positive electrode plate 1
And the length from the winding start end to about 2/5 of the total length of the positive electrode plate, and one end of the lead piece 4 was welded to the winding outer surface of the final end of the exposed core material 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylindrical alkaline storage battery having a band-shaped sintered positive electrode plate, a separator, and a spirally wound electrode plate group in which a negative electrode plate is spirally wound.

[0002]

2. Description of the Related Art In recent years, with the spread of various portable devices, alkaline storage batteries such as rechargeable nickel-cadmium storage batteries and nickel-hydrogen storage batteries have been used as power sources. In particular, cylindrical alkaline storage batteries are widely used because of their simple structure.

[0003] In a conventional cylindrical alkaline storage battery, for example, a band-shaped positive electrode plate and a negative electrode plate, and a group of electrode plates spirally wound with a separator interposed therebetween are housed in a metal battery case. A configuration in which a predetermined amount of an alkaline electrolyte is injected into the electrode plate group, and the tip of a lead piece drawn from the positive electrode plate is spot-welded to the lower surface of a sealing plate also serving as a positive electrode terminal, and the upper part of the battery case is sealed with the sealing plate. Has become.

However, if a large current, for example, 10 A or more, is taken out instantaneously from the battery, the current concentrates on the mounting portion where the lead piece is welded, and the lead piece generates heat mainly at the welded portion. Also, the large current output characteristics of the battery were not sufficient.

[0005] For this reason, the positive electrode plate is provided with a core exposed portion which is not filled with an active material on the entire upper end surface in the longitudinal direction, where one end of a lead piece is spot-welded to concentrate current at a lead welding point. Was eliminated.

[0006]

In the configuration of the cylindrical alkaline storage battery as described above, it is possible to increase the current collecting portion, eliminate the current concentration, and take out a large current.
However, when forming a spiral electrode group by winding a strip-shaped positive electrode plate, a negative electrode plate and a separator, the upper end face along the longitudinal direction of the positive electrode plate is a core material exposed portion not filled with an active material. However, since the thickness of this portion and the portion filled with the active material are different over the entire length of the electrode plate, winding deviation is likely to occur. Therefore, the width of the exposed portion of the core may be reduced to eliminate the winding deviation. However, in this case, the width of the mounting portion for welding the lead piece is insufficient, and spot welding failure of the lead piece increases.

Furthermore, since the lead pieces are spot-welded to the inner surface of the exposed portion of the core material on the upper portion of the positive electrode plate when it is spirally wound, the spot-welded lead pieces fall down inside, and the adjacent negative electrode plate , Causing an internal short circuit.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention is to insert a group of electrode plates obtained by spirally winding a strip-shaped sintered positive electrode plate, a separator and a negative electrode plate into a battery case, A battery in which the other end of the strip-shaped lead piece whose one end is welded to the exposed core material formed on the longitudinal edge of the positive electrode plate is welded to the lower surface of a sealing plate also serving as a positive electrode terminal for sealing the opening of the battery case. The exposed portion of the core of the positive electrode plate has a length from the winding start end of the positive electrode plate to 1/3 to 1/2 of the entire length of the positive electrode plate, and one end of the lead piece is the final end of the exposed portion of the core material. It is welded to the winding outer surface of the part.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is directed to a battery in which a spiral electrode group is inserted into a battery case as described above, wherein a core material exposed portion of the positive electrode plate is The length from the winding start end to the length of 1/3 to 1/2 of the entire length of the positive electrode plate is set, and one end of the positive electrode side lead piece is welded to the winding outer surface of the final end of the exposed core material. .

[0010] This is because the length of the exposed portion of the core of the positive electrode plate is set to a length from one end (starting end of winding) of the positive electrode plate to 1/3 to 1/2 of the entire length. When the negative electrode plate and the separator are spirally wound, the positive electrode plate is less likely to be displaced in winding, so that a group of wound electrode plates close to a perfect circle can be formed. In addition, a sufficient current can be collected from the electrode plate at the exposed portion of the core material, so that the current does not concentrate at one place, and a large current can be taken out from the configured battery.

[0011] Further, since the lead piece is spot-welded to the final end of the winding outer surface of the exposed core material of the positive electrode plate, the exposed core material inside supports the lead piece, so that when the lead piece is bent, As a result, the lead piece falls down sharply inside the spiral electrode group, so that the lead piece does not come into contact with the upper end of the negative electrode plate, and an internal short circuit can be prevented.

[0012]

Embodiments of the present invention will be described below.

A sintered substrate having a porosity of about 80%, obtained by sintering nickel powder in a reducing atmosphere, is placed in a nickel nitrate aqueous solution having a liquid temperature of 80 ° C., a specific gravity of 1.75 and a pH of 1.5 for 30 minutes. After immersing and drying sufficiently at a liquid temperature of 80 ° C.,
% Of sodium hydroxide solution, the nickel salt is converted into nickel hydroxide as an active material, and then a series of operations for filling the active material is repeated three times. A nickel positive electrode was manufactured. Then, this is cut to obtain a positive electrode plate 1 as shown in FIG.
I got The positive electrode plate 1 includes a portion 2 filled with an active material and a core exposed portion 3 not filled with an active material. The size of the portion 2 filled with the active material is 0.65 mm in thickness and 3 mm in width.
9 mm and 63 mm in length.
Is formed on the upper end edge in the longitudinal direction with a length of about 約 of the entire length of the positive electrode plate from its winding start end (left end), and has dimensions of 0.17 mm in thickness, 5 mm in width, and 25 mm in length.

Further, as shown in FIG. 4 for comparison, a positive electrode plate 10 was manufactured by using the same active material filling method as described above.
In the positive electrode plate 10, the portion 11 filled with the active material has a thickness of 0.65 mm, a width of 39 mm, and a length of 30 mm, and the core material exposed portion 12 is formed on the entire upper edge in the longitudinal direction of the positive electrode plate 10. Dimensions are thickness 0.17mm, width 5mm, length 30
mm.

[0015] Next, as shown in FIG. 2, a 13 m length is added to the final end of the core material exposed portion 3 which becomes the outer surface when the positive electrode plate 1 is wound.
One end of a lead piece 4 was prepared by spot-welding a nickel-plated lead piece 4 having a width of 3 mm. Further, as shown in FIG. 5, one end of the lead piece 4 was spot-welded to the center of the exposed core material 11 on the inner surface of the winding of the comparative positive electrode plate 10.

The positive electrode plate 1 to which the lead pieces 4 are spot-welded, the separator 5 made of polypropylene nonwoven fabric, and the cadmium negative electrode plate 6 are spirally wound to form an electrode group, which is inserted into an iron battery case 7. A predetermined amount of an alkaline electrolyte is injected into the electrode plate group, then the lead piece 4 is pulled out, and the other end of the lead piece 4 is spot-welded to the lower surface of a sealing plate 8 also serving as a positive electrode terminal. The battery A according to the embodiment of the present invention having a size AA was sealed by closing the insulating gasket 9. FIG. 3 shows an upper sectional view of the battery A. Next, a battery B of AA size comparative example having the same configuration as the battery A except that the positive electrode plate 10 of FIG. FIG. 6 is a top sectional view of the battery B.
Shown in

A comparison was made between the winding misalignment failure in the electrode group when 50 batteries A and B were configured, respectively, and the failure (internal short circuit failure) of the terminal voltage of 0 V of the configured batteries. The results are shown in (Table 1). In addition, the electrode group winding misalignment failure at this time means that the positive electrode plate is shifted in the width direction and protrudes from the electrode group,
The exposed part of the core material of the positive electrode plate is over the separator and comes into contact with the negative electrode plate.

[0018]

[Table 1]

As shown in (Table 1), in the battery A of the embodiment,
There was no winding deviation failure when the electrode group was formed, and the terminal voltage of the formed battery was good with no 0V failure. On the other hand, in the battery B, when the electrode group is formed, 2/50 defective winding deviations of the electrode plates occur, and 2/50 terminal voltage 0V defects of the battery configured above occur. I have.

This is because, in the battery B, the exposed portion of the core located at the upper end edge of the positive electrode plate 10 has the same length as the entire length of the positive electrode plate. The thickness of the exposed portion of the core material 12 is different from the thickness of the positive electrode plate 10 over the entire length, and the winding force is not uniform from the start to the end of the winding, resulting in a winding deviation. Furthermore, since the lead piece 4 is spot-welded to the inner surface of the wound portion of the exposed core material 11 of the positive electrode plate 10, the lead piece 4 falls down sharply inward when the lead piece 4 is attached to the sealing plate. Since the lead piece 4 and the nearby negative electrode plate 6 contacted each other and caused an internal short circuit, 2/50 of the batteries had a terminal voltage 0V failure.

On the other hand, in the battery A, when the electrode plate is spirally wound, about 2% of the total length of the positive electrode plate from the winding start end forming the core exposed portion 3 of the positive electrode plate 1 is formed. Although the winding tends to be slightly deviated when the length is / 5, since there is no exposed core material, the winding position of the positive electrode plate 1 is well controlled, and the electrode group as a whole is close to a perfect circle. Can be rolled. For this reason, in the battery A, no winding misalignment failure occurred in 50 pieces. Furthermore, since the lead piece 4 is spot-welded to the positive electrode plate 1 on the winding outer surface of the exposed core member 3,
Since the lead piece 4 is supported by the core exposed portion 3 located inside, the lead piece 4 does not fall inward at an acute angle, and the lead piece 4 does not come into contact with the upper end of the adjacent negative electrode plate 6. There was no battery terminal voltage 0V failure.

In the embodiment of the present invention, the length of the exposed portion of the core of the positive electrode plate is set to 2/5 of the entire length of the positive electrode plate from the winding start end of the upper edge of the positive electrode plate. The length of the exposed portion of the core of the positive electrode plate is 1/1 of the entire length of the positive electrode plate from the winding start end of the positive electrode plate.
When the length was from 3 to 1/2, it was confirmed that the winding displacement as the electrode plate group did not occur.

[0023]

As described above, according to the present invention, a strip-shaped sintered positive electrode plate, a separator and a negative electrode plate are spirally wound and inserted into a battery case. A cylindrical alkaline storage battery in which the other end of a lead piece whose one end is welded to a core material exposed portion formed on an edge is welded to the lower surface of a sealing plate also serving as a positive electrode terminal for sealing an opening of a battery case,
The exposed part of the core of the positive electrode plate has a length from the winding start end of the positive electrode plate to 1/3 to 1/2 of the entire length of the positive electrode plate, and one end of the lead piece is wound at the last end of the exposed part of the core material. A good cylindrical alkaline storage battery that is welded to the outer surface, so there is no winding misalignment during the construction of the spiral electrode group, and there is no internal short circuit failure due to contact between the lead piece of the positive electrode plate and the negative electrode plate. Can be configured.

[Brief description of the drawings]

FIG. 1 is a plan view of a positive electrode plate according to an embodiment of the present invention.

FIG. 2 is a plan view of a positive electrode plate in which the lead piece is spot-welded to a final end of a core exposed portion.

FIG. 3 is a top sectional view of the nickel-cadmium storage battery.

FIG. 4 is a plan view of a positive electrode plate of a comparative example.

FIG. 5 is a plan view of a positive electrode plate in which the lead piece is spot-welded to the center of the exposed core material.

FIG. 6 is a top sectional view of the nickel-cadmium storage battery.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Positive electrode plate 2 Active material filling part 3 Core material exposed part 4 Lead piece 5 Separator 6 Negative plate 7 Case 8 Sealing plate 9 Insulating gasket

Claims (1)

[Claims] An electrode group formed by spirally winding a strip-shaped sintered positive electrode plate, a separator, and a negative electrode plate into a battery case, and forming a core exposed portion formed at a longitudinal edge of the positive electrode plate. A battery in which the other end of a lead piece whose one end is welded to the lower surface of a sealing plate also serving as a positive electrode terminal for sealing an opening of the battery case, wherein the core material exposed portion of the positive electrode plate is the positive electrode. A cylinder having a length from the winding start end of the plate to 1/3 to 1/2 of the total length of the positive electrode plate, and one end of the lead piece being welded to a winding outer surface of a final end of the core exposed portion; Type alkaline storage battery.