JP2002025603A - Method for manufacturing cylindrical battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an alkaline storage battery with high electrolyte leakage resistance and high capacity by reducing the diameter of only the upper part of a battery case before an electrolyte is injected, sealing the battery case with a sealing plate smaller than the outer diameter of the battery case in a completed battery, then reducing the diameter of the whole battery case. SOLUTION: This method for manufacturing the cylindrical battery is such that an electrode group is formed by interposing a separator between a belt- shaped positive electrode plate and a belt-shaped negative electrode plate and spirally winding them, the electrode group is housed in the battery case, and when the upper part of the battery case is sealed with the sealing plate, after the electrode group is inserted into the battery case having large diameter, the diameter of the upper part of the battery case is previously reduced smaller than the outer diameter of the battery case in the completed battery.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a battery, in which a positive / negative electrode plate is spirally wound via a separator, housed in a case, and the upper part of the case is sealed with a sealing plate.

[0002]

2. Description of the Related Art In recent years, with the rapid progress of cordless devices, there is an increasing demand for small and lightweight secondary batteries having a high energy density as these power supplies.

Conventionally, such a battery is composed of a positive electrode plate, a negative electrode plate, a separator, a negative electrode plate, and an electrode plate group formed by spirally winding a positive electrode plate interposed therebetween to electrically insulate. The battery pack is housed in a battery case, and after a predetermined amount of electrolyte is injected into the electrode group, the upper part of the battery case is sealed with a sealing plate serving also as a positive or negative terminal.

[0004] The electric capacity of the battery thus produced is determined by the volume of the spirally wound electrode body, that is, the diameter and length of the electrode plate group. In particular, a difference in diameter causes a large capacity difference. Therefore, in order to obtain the maximum capacity in batteries having the same outer diameter, it is desirable to increase the diameter of the electrode group as much as possible.

On the other hand, when the electrode group is inserted into the battery case, the outer diameter of the electrode group is somewhat smaller than the inner diameter of the battery case. It is desirable in terms of sex. At present, cylindrical batteries having such a structure are manufactured with the electrode plate group having a slightly smaller diameter than the inner diameter of the battery case, inevitably in terms of productivity.

In the battery manufacturing method, for example,
Japanese Patent Application Laid-Open No. Sho 57-130368 discloses a method of inserting a group of electrodes using a case having a large diameter in advance and reducing the diameter of the entire case after assembling the battery. However, in this method, when the diameter of the case is reduced, the shrinking tubular jig rubs the sealing plate, so that the degree of caulking of the sealing plate is reduced.

[0007] Instead of this, Japanese Patent Laid-Open No. Hei 6-215792
Japanese Patent Application Publication No. JP-A-2003-115139 discloses a method of reducing the diameter after inserting the electrode plate group into the case and before closing the upper part of the case.

[0008]

However, even with this method, when the diameter of the case is reduced, rubbing with the sealing plate always occurs, so that the caulked state is insufficient and the liquid leakage resistance is reduced. The challenge remains.

It is an object of the present invention to solve the above-mentioned problems and to provide a high-capacity battery having excellent resistance to liquid leakage.

[0010]

In order to achieve the above object, a battery of the present invention uses a battery case having an outer diameter larger than the outer diameter of the battery case in the final finished battery in advance, and uses the battery case. After inserting the electrode group having an outer diameter larger than the inner diameter of the battery case in the final finished battery, only the outer diameter of the upper part of the battery case before injecting the electrolytic solution matches the final finished size in advance. Reduce the outer diameter of the case, seal it with a sealing plate having the same diameter as the outer diameter, perform initial charge and discharge after sealing, and then fit the entire outer diameter of the battery case to the final finished size of the battery The manufacturing method was to reduce the outer diameter of the case.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the first aspect of the present invention, a spirally wound electrode plate group is housed in a case with a separator interposed between a strip-shaped positive electrode plate and a negative electrode plate. In the manufacturing process of sealing the upper part of the case with a sealing plate, a battery case having an outer diameter larger than the outer diameter of the battery case in the final finished battery is used in advance, and the inner diameter of the battery case in the final finished battery is added to the battery case. After inserting the electrode group having an outer diameter larger than that, before injecting the electrolyte, only the outer diameter of the upper part of the battery case is reduced in advance to the outer diameter of the battery case that matches the final finished size of the battery. After sealing and sealing with a sealing plate having the same diameter as the outer diameter, the manufacturing method is such that the entire outer diameter of the battery case is reduced to the outer diameter of the battery case that matches the final finished size of the battery.

Thus, the diameter of the upper portion of the case is reduced in advance, and a sealing plate having an outer diameter corresponding to the diameter is used. Since the tubular jig for use does not rub against the sealing plate, the swaged shape of the sealing plate can be maintained without being distorted, so that liquid leakage resistance can be maintained.

The electrolyte in the battery after the initial charge and discharge is in a state of being sufficiently absorbed by the positive and negative electrode plates and the separator. Since the electrolyte does not leak out of the battery, the leakage resistance is also excellent.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific examples of the present invention will be described.

(Example) Carboxymethyl cellulose 0.2 as a binder was added to 100 parts by weight of nickel hydroxide.
Water was added and kneaded so as to be 25 parts by weight of the total paste and 25 parts by weight of the total paste to prepare a paste-like active material.

This paste-like active material was filled in a nickel sponge-like substrate, dried, and then pressed to increase the packing density, thereby producing a positive electrode plate 1 having a width of 61 mm, a thickness of 0.8 mm and a length of 26 mm.

A negative electrode plate 2 having a width of 61 mm, a thickness of 0.4 mm, and a length of 45 mm was prepared by coating a hydrogen absorbing alloy powder on a punching metal.

Next, a positive electrode plate 1 and a negative electrode plate 2 are spirally wound by an electrically insulating separator 3 to form an electrode plate group, which is then nickel-plated with iron into a battery case 4 having a diameter of 8.55 mm. 7. Insert only the top of battery case 4
After passing through a tubular jig 6 adjusted to a diameter of 15 mm, the outer diameter of the upper part of the battery case 4 is reduced to 8.15 mm, an alkaline electrolyte is injected, and a sealing plate 5 having a diameter of 8.15 mm also serving as a positive electrode terminal. And the battery was charged at a current value of 70 mA for 15 hours. At a current value of 700 mAh, the terminal voltage of the battery was 1.
After repeating the initial charge / discharge of discharging to 0V twice,
As shown in FIG. 1, a tubular jig 6 adjusted to a diameter of 8.40 mm is passed while being pressed by a pressing jig 7 so that the entire outer diameter of the battery is 8.40 mm, and the HR8.4 / 67 size of the present invention is used. The nickel-hydrogen storage battery A in the example was manufactured.
FIG. 2 shows a half sectional view of the battery A.

In this embodiment, the outer diameter of the upper part of the case 4 is reduced to 97% with respect to the final finished outer diameter of the case 4. When the caulking state is insufficient, the liquid leakage resistance is reduced, and when it exceeds 98%, the tubular jig 6 rubs the sealing plate 5 when passing the tubular jig 6 and reducing the outer diameter of the battery. Therefore, the caulking shape is distorted and the liquid leakage resistance is reduced, so that the content is preferably set to 90 to 98%.

Comparative Example 1 A sealing plate 8 having a diameter of 8.40 mm
And a case 9 having a diameter of 8.40 mm, and a battery is formed without reducing the outer diameter of the case 9. First, a positive electrode plate 1 and a negative electrode plate 2 are spirally wound with an electrically insulating separator 3 to form an electrode plate group, which is inserted into a nickel-plated 8.40 mm diameter battery case 9 of iron. After injecting the alkaline electrolyte into the case 9, the container was sealed with a sealing plate 8 also serving as a positive electrode terminal and having a diameter of 8.40 mm. The battery was charged at a current value of 70 mA for 15 hours. The initial charge / discharge of discharging the voltage to 1.0 V was repeated twice to produce a nickel-hydrogen storage battery B of Comparative Example 1. Since the outer diameter of the case of the battery B is smaller than that of the battery A by 0.15 mm, the internal volume of the battery B is smaller than that of the battery A by 0.25 cc. Battery B
In the example, the filling amount of the positive electrode and the negative electrode and the amount of the electrolytic solution were smaller than those of the battery A.

Comparative Example 2 A sealing plate 8 having a diameter of 8.40 mm
And a case 4 having a diameter of 8.55 mm, and the outer diameter of the case 9 is reduced to form a battery. First, a positive electrode plate 1 and a negative electrode plate 2 are spirally wound with an electrically insulating separator 3 to form an electrode plate group, which is inserted into a nickel-plated 8.55 mm diameter battery case 4 of iron. After injecting the alkaline electrolyte into the case 4, the case 4 is sealed with a sealing plate 5 also serving as a positive electrode terminal and having a diameter of 8.40 mm, and pressed by a pressing jig 7 as shown in a schematic sectional view of FIG. 8.40mm
Through a tubular jig 6 having an inner diameter of
Of Comparative Example 2 in which the entire outer diameter of was reduced to 8.40 mm
The battery C was charged at a current value of 70 mA for 15 hours, and the initial charge and discharge of discharging the terminal voltage of the battery to 1.0 V at a current value of 700 mAh was repeated twice.

Battery A, Battery B and Battery C are each 100
These batteries were manufactured individually, and these batteries were charged at a current of 20 ° C. and a current of 70 mA for 15 hours, and discharged at a current of 20 ° C. and a current of 140 mA until the terminal voltage of the battery was 1.0 V. At this time, the discharge capacity of each battery was measured. Further, the number of leaks per 100 batteries after charging and discharging of these batteries was examined. The results are shown in (Table 1).

[0023]

[Table 1]

As shown in Table 1, battery A and battery C
Has a discharge capacity about 14% higher than that of the battery B. This is because the batteries A and C have a larger amount of positive and negative electrodes than the battery B.

The batteries A and B did not leak after charging / discharging, but the battery C leaked seven out of 100 batteries.
The leaked portion of the battery C was a swaged portion of the sealing plate. This is presumably because the caulking portion of the sealing plate was rubbed against the tubular jig when the battery C was formed, and the caulking shape was deformed.

As described above, the battery A of the embodiment is a battery having a large battery capacity and good leakage resistance.

In the above embodiment, only the upper part of the battery case is contracted by passing through the tubular jig to have 97% of the outer diameter of the final finished case before shrinking, but this outer diameter is 90 to 98%. Has the same effect.

The material of the tubular jig 6 is preferably made of a ceramic material since the diameter of the battery can be reduced with a small amount of abrasion because the abrasion is small.

[0029]

As described above, according to the method for manufacturing a cylindrical battery of the present invention, the filling material such as the positive electrode and the negative electrode can be filled more in the battery, so that a high capacity cylindrical battery is provided. be able to.

Further, only the upper part of the battery case is previously contracted by passing through a tubular jig, and a sealing plate having a diameter smaller than the outer diameter of the final finished case before contraction is used. In addition, since the shrinking tubular jig does not rub against the sealing plate, there is no change in the swaged shape of the sealing plate, and a cylindrical battery excellent in liquid leakage resistance can be provided.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a diameter reduction of a battery according to an embodiment of the present invention.

FIG. 2 is a half sectional view of the nickel-hydrogen storage battery A;

FIG. 3 is a schematic diagram of a reduced diameter of a battery in Comparative Example 2.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Positive electrode plate 2 Negative electrode plate 3 Separator 4 Battery case 5 Sealing plate 6 Tubular jig 7 Pressing jig 8 Sealing plate of comparative examples 1 and 2 9 Battery case of comparative example 1

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yoshitaka Namizu 1006 Kazuma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. F term (reference) 5H011 AA03 AA17 BB03 DD05 DD15 DD26 5H028 AA01 AA07 BB01 BB04 BB10 BB17 CC12 CC17

Claims (3)

[Claims] In a method for manufacturing a cylindrical battery in which a group of electrode plates in which a strip-shaped positive electrode plate and a negative electrode plate are spirally wound via a separator is housed in a battery case, the battery case of a battery case in a final finished battery is previously prepared. A step of using a battery case having an outer diameter larger than the outer diameter, and inserting an electrode plate group having an outer diameter larger than the inner diameter of the battery case in the final finished battery into the battery case; A step of reducing the outer diameter of the battery case upper part so as to be smaller than the outer diameter dimension, and a step of sealing with a sealing plate having an outer diameter dimension that matches the outer diameter of the battery case upper part,
Reducing the entire outer diameter of the battery case to an outer diameter dimension that matches the final finished dimensions of the battery. 2. The method for manufacturing a cylindrical battery according to claim 1, wherein the step of reducing the entire outer diameter of the battery case to the outer diameter dimension of the battery case that matches the final finished size of the battery is performed after the initial charge and discharge. 3. The method for manufacturing a cylindrical battery according to claim 1, wherein the material of the tubular jig used to reduce the outer diameter of the battery case to the final finished size is ceramic.