JPH06251799A - Sealed alkaline storage battery manufacturing method and electrode group winding device used in same method - Google Patents

Abstract

PURPOSE:To arrange an electrolyte holding body in space in the center of a spiral electrode group. CONSTITUTION:A superposed electrode body 5 is formed by superposing a separator 2, a positive electrode 3 and a negative electrode 4 upon each other while using a bar shape core body 1 composed of hydrophilic porous solids as a winding core. The supoerposed electrode body 5 is loaded on a bed 10, and a part where the core body 1 of the superposed electrode body 5 is situated is rolled along a surface of the bed in a condition of being pressurized toward the bed 10 by a pressurizing jig 11, and a spiral electrode group is formed. The spiral electrode group is housed in a battery can while leaving the core body 1 in the spiral electrode group, and the core body 1 is impregnated with electrolyte, and an electrolyte holding body is formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a sealed alkaline storage battery having a spiral electrode group and an electrode group winding device.

[0002]

2. Description of the Related Art In a conventional method for manufacturing a sealed alkaline storage battery having a spiral electrode group, positive and negative electrodes arranged with a separator folded in half around a winding shaft core are used. The spirally wound electrode group is formed by spirally winding around the core, the spirally wound electrode group is removed from the winding shaft core, the spirally wound electrode group is inserted into the battery can, and the electrolytic solution is put into the battery can. A storage battery was manufactured by sealing the container with a lid. In the central part of the spiral electrode group manufactured by the conventional method, as shown in FIG.
As shown in, a wasteful space S corresponding to the size of the winding axis is provided.
Existed. On the other hand, in a sealed alkaline storage battery using a nickel electrode as a positive electrode, there is a problem that the nickel electrode expands and absorbs the electrolytic solution from the separator during repeated charging / discharging, and the separator drips.
The simplest way to solve this problem is to increase the amount of electrolyte, but in this case, if the internal pressure rises during overcharge and the safety valve is activated, liquid leakage will occur. Occurs. Therefore, a method has been proposed in which excess electrolyte is absorbed by the holder to prevent liquid leakage. Specifically, a method has been proposed in which an electrolytic solution holder is inserted into a space S existing in the central portion of the spiral electrode group.

[0003]

However, as shown in FIG. 3, the winding start portion 100 of the separator protrudes so as to surround the space S existing in the central portion of the spiral electrode group. If the electrolytic solution holder is inserted into this space later, the winding start portion 100 of the separator may be damaged to cause a short circuit between the electrodes, or the spiral electrode group itself may be broken. There are many.

An object of the present invention is to provide a method capable of producing a sealed alkaline storage battery having an electrolytic solution holder at the center of a spiral electrode group without damaging the separator. Another object of the present invention is to provide an electrode group winding device capable of easily forming a spiral electrode group having an electrolytic solution holder at the center thereof.

[0005]

According to the invention of claims 1 and 2, one of a positive electrode and a negative electrode is sandwiched between a pair of opposing separator halves of a separator folded in two around a winding core, A polymerization step of forming an electrode polymer by stacking the other of the positive and negative electrodes on the outer surface of one of the pair of separator halves, and the electrode polymer is wound around the winding core and swirled. A sealed alkaline storage battery is manufactured by a winding process for forming a group of electrode groups, a storing process for storing a spiral electrode group in a battery can, an impregnation process for impregnating an electrolyte with a separator, and a sealing process for sealing the battery can. How to do it.

According to the first aspect of the present invention, a rod-shaped core body made of a hydrophilic porous solid is used as the winding core. Then, the spiral electrode group is housed in the battery can while leaving the core body in the spiral electrode group, and the core body is impregnated with the electrolytic solution to form an electrolytic solution holder.

When a rod-shaped core body made of a hydrophilic porous solid is used as the winding core, it is optional how to wind the electrode polymer around the core body. For example, if the strength of the core is increased to some extent and the length thereof is increased to some extent, the spiral electrode group may be formed with the core as the central axis, that is, with both ends of the core rotatably supported. It is possible. In this case, it is necessary to use a special core, and a step of cutting both ends of the core after winding is required.

The invention of claim 2 specifies one aspect of winding of the electrode polymer, and first, a core having a length that can be stored in a battery can is used. Then, in the winding step, the electrode polymer is placed on a flat bed, and the portion of the electrode polymer in which the core is located is pressed toward the bed and rolled along the surface of the bed to roll the core of the core. The electrode polymer is wound around to form a spiral electrode group.

The invention of claim 3 is directed to an electrode group winding device used in a winding step. This electrode group winding device includes a bed on which an electrode polymer is placed, a first pressing jig having a contact surface facing the surface of the bed and extending along the surface, A first means for urging the pressure jig toward the surface of the bed and movably holding it in a vertical direction orthogonal to the surface.
Vertical moving mechanism, a second pressing jig for pressing the overlapping portion of the electrode polymer electrode and the separator half portion toward the bed, and a second pressing jig attached to the surface of the bed. A second member for energizing and movably holding in a vertical direction perpendicular to the surface
And a horizontal moving mechanism that supports the first and second vertical moving mechanisms and moves them in the horizontal direction along the surface of the bed.

[0010]

When the rod-shaped core body made of the hydrophilic porous solid is used as the winding core as in the first aspect of the invention, the electrolytic solution holder is used as the electrode after the spiral electrode group is formed as in the conventional case. No need to insert into the group. As a result, it is possible to dispose the electrolyte holder at the center of the spiral electrode group without causing a short circuit due to damage to the separator or damaging the spiral electrode group itself, and it is possible to extend the life of the battery. It will be.

According to the second aspect of the present invention, the spiral electrode group is formed without rotatably supporting the core body and winding the electrode polymer around the central axis. Place the electrode polymer on the bed, and roll the electrode polymer around the core by rolling along the surface of the bed while pressing the part of the electrode polymer where the core is located toward the bed. it can. This makes it possible to easily wind the electrode group without increasing the strength of the core, lengthening the length of the core, or cutting both ends of the core after winding.

According to the electrode group winding device of the third aspect, the electrode polymer can be easily wound.

[0013]

Embodiments of the method of the present invention will now be described in detail with reference to the drawings.

FIG. 1 shows an electrode polymer 5 produced in the polymerization process.
It is a side view of an example. In this electrode polymer 5, a rod-shaped core body 1 made of a hydrophilic porous solid is used as a winding core. The core body 1 was formed by winding a polyamide nonwoven fabric having a thickness of 0.15 mm around a core having a diameter of 0.5 mm to form a cylinder having a diameter of 3 mm, and removing the core from the cylinder. The ends were glued with a cellulosic water-soluble polymer. The core 1 has a length that can be stored in a battery can. The separator 2 is folded in two with the core 1 as the center, the positive electrode is sandwiched between a pair of opposing separator halves 2a and 2b, and the negative electrode 4 is polymerized on the outer surface of one separator half 2a to form an electrode assembly. Body 5 was formed. In this embodiment, as the positive electrode 3, a sintering type N is used.
An i electrode was used, and a paste type Cd electrode was used as the negative electrode 4.

Next, the electrode polymer 5 is wound around the winding core to form a spiral electrode group. In this example, the electrode polymer 5 was placed on a flat bed, and the portion of the electrode polymer 5 where the core was located was pressed toward the bed and rolled along the surface of the bed to roll the core. A spiral electrode group is formed by winding an electrode polymer around 1.

FIG. 2 shows the construction of the essential parts of an electrode group winding device that can be used when forming a spiral electrode group. In FIG. 2, 10 is the electrode polymer 5 on the surface 10a.
Is the bed on which is placed. 11 is a contact surface 1 that faces the surface 10a of the bed 10 and extends along the surface 10a.
It is the 1st pressurizing jig which has 1a. This contact surface 11a
Has a rubber lining to prevent slipping.
The first pressure jig 11 urges the first pressure jig toward the surface 10a of the bed 10 and holds the first pressure jig movably in a vertical direction orthogonal to the surface 10a. It is attached to a backing plate 12 as a horizontal moving mechanism via a pressure / stroke adjuster 13 as a vertical moving mechanism. Specifically, the pressurization / stroke adjuster 13 has a structure with a built-in spring. As the pad plate 12 is moved from the right side to the left side in the drawing, the winding progresses and the diameter of the wound body increases, so that the pressurization / stroke adjuster 13 causes the first pressurizing jig 11 to gradually move from the bed 10. The position of the first pressurizing jig 10 is displaced so as to be separated from the position.

On the backing plate 12, a second pressing jig 14 which presses the overlapping portion of the electrode of the electrode polymer 5 and the separator half portion toward the bed 10 constitutes a second vertical moving mechanism. It is attached to the backing plate 12 via a pressure / stroke adjuster 15. This pressurization / stroke adjuster 15
Presses the second pressure jig 14 toward the surface 10a of the bed 10, and also holds the second pressure jig 14 movably in the vertical direction. The second pressing jig 14 moves in the horizontal direction in synchronization with the movement of the first pressing jig 11 in the horizontal direction. An end portion of the pressure / stroke adjuster 15 is fitted in a guide groove 16 provided on a side surface of the contact plate 12 so that the position thereof can be adjusted. The second pressure mechanism 14 is
It is preferable to dispose it as close to the core body 1 as possible.
In the second pressing jig 14, a free roller 17 is rotatably arranged at a portion of the electrode polymer 5 that contacts the negative electrode 4. Due to this free roller 17, even if the second pressing jig 14 is moved in the horizontal direction, it is possible to press the electrode polymer 5 in the vertical direction without applying horizontal tension to the negative electrode 4. it can.

When a spiral electrode group is formed using this apparatus, after the electrode polymer is set on the bed 10, the core 1 of the electrode polymer 1 is removed by the first pressing jig 11. When the contact plate 12 is moved in the horizontal direction while applying a pressing force to the positioned portion, the portion where the core body 1 is positioned rolls to form a spiral electrode group.

The spiral electrode group thus obtained is inserted into a battery can, and an excessive amount of electrolytic solution (31% KOH aqueous solution) is injected into the can, so that the core body 1 and the separator 2 are sufficiently filled with the electrolytic solution. After soaking in, it penetrates in an inverted state,
Excess electrolytic solution not retained in the spiral electrode group was discharged. At this time, the amount of electrolytic solution held in the spiral electrode group is
It was about 1.3 times the amount retained in the conventional spiral electrode group having a space in the center. An upper lid was attached to this to form a sealed battery.

The battery thus manufactured was compared with the battery of the following comparative example.

Comparative Example 1: A conventional sealed battery in which an amount of electrolyte normally held in the spiral electrode group is injected into a conventional spiral electrode group having a space in the center.

COMPARATIVE EXAMPLE 2 A conventional spiral electrode group having a space in the center has a volume of 1.3 which is held in the spiral electrode group.
A sealed battery with double the electrolyte.

Comparative Example 3: A conventional spirally wound electrode group having a space in the center, and a diameter of 3 mm made of the above polyamide nonwoven fabric.
The sealed battery in which the cylindrical core body of 1 is inserted and the same amount of the electrolytic solution as in Comparative Example 1 is injected.

Comparative Example 4 A conventional spirally wound electrode group having a space in the center is formed by using the above polyamide nonwoven fabric and having a diameter of 3 mm.
The sealed battery in which the cylindrical core body of 1 is inserted and the same amount of the electrolytic solution as in Comparative Example 2 is injected.

These batteries were subjected to a short circuit test, a liquid leakage test and a charge / discharge life test, and the results were compared. The results are shown in Table 1. From the results shown in Table 1, Comparative Example 1 has a short life, Comparative Example 2 causes liquid leakage, and Comparative Examples 3 and 4 cause short circuit. In contrast, in the examples of the present invention, short circuit and liquid leakage occurred. It can be seen that a long life is obtained without any generation.

[0026]

[Table 1] As shown in Table 1, according to the production by the method of the present invention,
A sealed battery having a long life can be obtained without causing a short circuit or liquid leakage.

[0027]

According to the first aspect of the invention, since the rod-shaped core body made of the hydrophilic porous solid is used as the winding core, the electrolytic solution holder is formed after the spiral electrode group is formed as in the conventional case. Need not be inserted into the electrode group. Therefore, the electrolytic solution holder can be arranged in the central portion of the spiral electrode group without causing a short circuit due to damage to the separator and without damaging the spiral electrode group itself, and a long-life storage battery can be manufactured. it can.

According to the invention of claim 2, it is not necessary to increase the strength of the core body, to increase the length of the core body, or to cut both ends of the core body after winding, and the electrode group can be easily assembled. There is an advantage that can be wound.

According to the electrode group winding device of the third aspect, the electrode polymer can be easily wound.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of an electrode polymer used in Examples of the present invention.

FIG. 2 is a diagram showing a schematic configuration of an electrode group winding device used in an example of the present invention.

FIG. 3 is a view showing a cross section of a conventional spiral electrode group.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Core 2 Separator 3 Positive electrode 4 Negative electrode 5 Electrode polymer 10 Bed 11 First pressing jig A 12 Abutment plate (horizontal moving mechanism) 13 Pressurizing / stroke adjuster with built-in spring (first vertical moving mechanism) ) 14 2nd pressurizing jig 15 Pressurizing / stroke adjuster with a built-in spring (2nd vertical movement mechanism) 16 Guide groove 17 Free roller

Claims (3)

[Claims] 1. One of positive and negative electrodes is sandwiched between a pair of opposing separator halves of a separator that is folded in two around a winding core, and one of the pair of separator halves is separated from the other of the separator halves. A polymerization step of forming the electrode polymer by stacking the other of the positive and negative electrodes on the outer surface, and a winding step of winding the electrode polymer around the winding core to form a spiral electrode group, A method for producing a sealed alkaline storage battery from a housing step of housing the spiral electrode group in a battery can, an impregnation step of impregnating the separator with an electrolytic solution, and a sealing step of sealing the battery can, wherein: A rod-shaped core body made of a hydrophilic porous solid is used as a winding core, and the spiral electrode group is housed in the battery can while leaving the core body in the spiral electrode group, and the core body is electrolyzed. It should be impregnated with electrolyte to form an electrolyte holder. Method of manufacturing a sealed alkaline storage battery according to claim. 2. A core having a length that can be stored in the battery can is used as the core, and the electrode polymer is placed on a flat bed in the winding step. Forming the spiral electrode group by rolling along the surface of the bed while pressing the portion where the core is located toward the bed to wind the electrode polymer around the core. The method for manufacturing a sealed alkaline storage battery according to claim 1, wherein the sealed alkaline storage battery is manufactured. 3. An electrode group winding device used in the winding step according to claim 2, wherein a bed on the surface of which the electrode polymer is placed, and a surface of the bed facing the surface of the bed. A first pressing jig having an abutting surface extending along it, and urging the first pressing jig toward the surface of the bed and movably holding it in a vertical direction orthogonal to the surface. A first vertical movement mechanism, a second pressure jig that presses the overlapping portion of the electrode polymer of the electrode polymer and the separator half portion toward the bed, and the second pressure jig. A second vertical movement mechanism for urging the first vertical movement mechanism toward the surface of the bed and movably holding the bed in a vertical direction orthogonal to the surface, and supporting the first and second vertical movement mechanisms. A horizontal movement mechanism for horizontally moving along the surface of the bed; An electrode group winding device, comprising: