JP2000106166A - Storage battery and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a storage battery appropriate for use with charge and discharge which have, low internal resistance and heavy current. SOLUTION: An electrode group 10 is formed by winding a positive plate 11 and a negative plate 12 through a separator 13 interposed between them, and a positive electrode collector 14 is welded to the end of a conductive core 11a exposed at the upper end, and a negative electrode collector 15 is welded to an end of a conductive core 12a which is exposed at the lower end so as to form an electrode body 10a. This electrode body 10a is inserted into a battery can 16, and the tip of a collector lead plate 14a extended from the collector 14 is welded to the bottom surface of a sealing body 17, and the electrolyte is filled. The sealing body 17 is placed on an opening part of the battery can 16 via an insulating gasket 18, and an end of the opening part of the battery can 16 is caulked for sealing, and thereafter the battery can 16 is passed through the inside a tubular jig so as to contract the diameter of the battery can 16. At this stage, the negative electrode collector 15 having a diameter smaller than the inside diameter of the battery can 16 before the diameter contraction and larger than the inside diameter of the battery can 16 after the diameter contraction is used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery can having an opening which also serves as a terminal of one electrode, a sealing body which seals this opening and also serves as a terminal of the other electrode, and a battery can and a sealing body. The present invention relates to a storage battery including a positive / negative electrode plate housed in a battery container and a power generation element made of an electrolytic solution, and a method for manufacturing the same. And a current collector structure of a current collector connected to the bottom of the battery can.

[0002]

2. Description of the Related Art Generally, nickel-cadmium storage batteries,
In a storage battery such as an alkaline storage battery such as a nickel-hydride storage battery or a lithium ion storage battery, a separator is interposed between a positive electrode plate and a negative electrode plate, and these are spirally wound or laminated to form an electrode group. After forming an electrode body by connecting a current collector to the upper and lower ends, the electrode body is housed in a cylindrical or square metal battery can, and a current collector lead plate extending from the positive electrode current collector is sealed. After being welded to the lower surface and injecting the electrolyte, the battery can is hermetically sealed by attaching a sealing body to the opening of the battery can with an insulating gasket interposed therebetween.

For example, in a nickel-cadmium storage battery, as shown in FIG. 3, a nickel positive electrode plate 21 in which a nickel sintered substrate is filled with a predetermined amount of a nickel active material by a chemical impregnation method, and a nickel sintered substrate similarly A cadmium negative electrode plate 22 filled with a predetermined amount of a cadmium active material was produced by a chemical impregnation method.
And a cadmium negative electrode plate 22 and a separator 23 interposed therebetween to form an electrode group 20.

Then, a disk-shaped or square-shaped positive electrode current collector 24 having a large number of openings is welded to the end of the conductive core 21a exposed at the upper end of the electrode group 20, thereby forming an electrode group 2
And a disk-shaped or square-shaped negative electrode current collector 25 is welded to the end of the conductive core 22a exposed at the lower end of the electrode body 2
After forming 0a, the electrode body 20a is inserted into a bottomed cylindrical battery can 26 in which nickel is plated on nickel. Thereafter, a welding rod (not shown) is connected to the central through hole 20 of the electrode body 20a.
After the battery current is inserted into the battery can 26, a current is applied between the battery can 26 and another welding rod disposed on the surface facing the welding rod outside, and the negative electrode current collector 25 and the inner bottom of the battery can 26 are welded. .

Then, the tip of the positive electrode current collector lead plate 24a extending from the positive electrode current collector 24 welded to the end of the conductive core 21a of the nickel positive electrode plate 21 is connected to the lid 2 of the sealing body 27.
7a, the sealing body 27 is placed on the opening of the battery can 26 via an insulating gasket 28,
The battery is sealed by crimping the end of the opening inward to produce a nickel-cadmium storage battery.

[0006]

In recent years, storage batteries of this kind, such as alkaline storage batteries or lithium ion storage batteries, have been used as power sources for various portable electronic and communication devices, electric tools, electric bicycles, electric motorcycles, and the like. As a result, it has been required to be able to discharge with a large current. In order to discharge this type of storage battery with a large current, it is necessary to reduce the internal resistance of the battery as much as possible. However, the electrical connection between the negative electrode current collector and the battery can cannot be reduced to a sufficiently low resistance required by a large current discharge only by the electrical connection by welding as described above. .

On the other hand, in a battery using a spirally wound electrode group, a welding rod is inserted into a central through hole of the spirally wound electrode group to insert the welding rod into the battery can. It is necessary to apply a current between the disposed welding rod and another welding rod disposed at a position facing the welding rod via the battery can to weld the negative electrode current collector and the inner bottom of the battery can. In addition, this welding operation is complicated, has the disadvantages of poor production efficiency and poor workability. Furthermore, if the central through-hole of the spiral electrode group is made as thin as possible to increase the capacity of the battery to eliminate useless space from the battery can, the welding rod cannot be inserted into the battery can. This causes a problem that welding of the negative electrode current collector and the battery can becomes difficult.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has been made in view of the above-mentioned problems. It is an object of the present invention to improve the contact and obtain a storage battery capable of charging and discharging with a large current.

For this reason, the storage battery of the present invention is arranged such that the maximum length of the current collector contacting the bottom of the battery can is smaller than the inner diameter of the battery can and larger than the inner diameter of the reduced battery can. At least a part of the electric body is in close contact with the inner wall of the battery can. As described above, when at least a part of the current collector is in close contact with the inner wall of the battery can, the current collector and the battery can can be connected without welding the current collector to the bottom of the can of the battery can. Current collection. When the current collector is welded to the inner bottom of the battery can, the number of current collecting points between the current collector and the battery can is increased, so that the internal resistance of the battery is further reduced and the battery is charged with a large current. A storage battery that can be discharged can be obtained.

Further, the method of manufacturing a storage battery according to the present invention
A current collector is welded to the electrode group forming step of forming an electrode group by winding or laminating a separator between the negative electrode plates and a conductive edge protruding from the positive and negative electrode plates on the upper and lower end surfaces of the electrode group. Electrode body forming step of forming an electrode body by doing
The method includes a sealing step of inserting the electrode body together with the electrolytic solution into the battery can and sealing with the sealing body, and a reducing step of reducing the diameter of the entire battery can sealed with the sealing body, and contacting the can bottom of the battery can. The maximum length of the current collector is less than the inner diameter of the battery can,
At least a part of the current collector is in close contact with the inner wall of the battery can so as to be equal to or larger than the inner diameter of the reduced battery can.

As described above, a current collector whose maximum length is less than the inner diameter of the battery can and whose inner length is equal to or more than the inner diameter of the reduced battery can is used.
After inserting the electrode body to which the current collector is welded into the battery can and bringing the electrode body into contact with the bottom of the battery can, the sealing body is sealed in a sealing step, and the diameter of the entire battery can is reduced in a reducing step. Then, at least a part of the current collector comes into close contact with the inner wall of the battery can. Therefore, current collection between the current collector and the battery can becomes possible without welding the current collector to the bottom of the battery can. When the current collector is welded to the inner bottom of the battery can, the number of current collecting points between the current collector and the battery can is increased, so that the internal resistance of the battery is further reduced and the battery is charged with a large current. A storage battery that can be discharged can be obtained.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows the present invention using nickel-
It is sectional drawing which shows the principal part of the alkaline storage battery of this embodiment applied to the cadmium storage battery.

1. Preparation of Nickel Sintered Substrate First, a slurry is prepared by kneading a thickener such as carboxymethylcellulose and water into nickel powder, and this slurry is applied to conductive cores 11a and 12a made of nickel punched metal. Thereafter, the conductive cores 11a and 12a to which the slurry has been applied are sintered in a reducing atmosphere to produce a nickel sintered substrate having a porosity of 80%.

2. Preparation of Nickel Positive Electrode A predetermined amount of nickel active material is filled in the nickel sintered substrate prepared as described above by a chemical impregnation method. That is, the nickel sintered substrate is immersed in an aqueous solution mainly composed of nickel nitrate, and nickel nitrate is precipitated in the pores of the nickel sintered substrate. An active material conversion treatment for replacing the precipitated nickel nitrate with nickel hydroxide is performed. The same processing step is repeated a predetermined number of times (for example, 6 to 8 times) to produce a nickel positive electrode plate 11 in which a nickel sintered substrate is filled with a predetermined amount of a nickel active material mainly composed of nickel hydroxide.

3. Preparation of Cadmium Anode Plate A predetermined amount of a cadmium active material is filled into the nickel sintered substrate prepared as described above by a chemical impregnation method. That is, a nickel sintered substrate is immersed in an aqueous solution mainly composed of cadmium nitrate to precipitate cadmium nitrate in pores of the nickel sintered substrate, and then immersed in an alkaline aqueous solution (for example, sodium hydroxide aqueous solution). Then, an active material conversion treatment for replacing cadmium nitrate precipitated in the pores with cadmium hydroxide is performed. The same process is repeated a predetermined number of times (for example, 6 to 8 times) to produce a cadmium negative electrode plate 12 in which a nickel sintered substrate is filled with a predetermined amount of a cadmium active material mainly composed of cadmium hydroxide.

4. Preparation of Electrode Assembly The electrode group 10 is wound by winding a separator 13 between the nickel positive electrode plate 11 and the cadmium negative electrode plate 12.
To form At the upper end of the nickel positive electrode plate 12 of the electrode group 10, the end of the conductive core 11a of the nickel sintered substrate is exposed, and at the lower end of the electrode group 10, the conductive core 11a of the nickel sintered substrate is exposed. The end of the core 12a is exposed. The conductive core 11 exposed at the upper end of the electrode group 10
A disk-shaped or square-shaped positive electrode current collector 14 having a large number of openings is welded to an end of the conductive core 12a exposed at the lower end of the electrode group 10, and a disc-shaped or The rectangular negative electrode current collector 15 is welded to form the electrode body 10a.

Here, as the negative electrode current collector 15, FIG.
A disk shape as shown in FIG. 2A or a square shape as shown in FIG. 2B is used, and its maximum length (diameter for a disk shape, diagonal of a square for a square shape) (Length) is smaller than the inner diameter of the battery can 16 described later, and is larger than the inner diameter of the battery can 16 when the battery can 16 is reduced in the diameter reducing step described later.

5. Production of Nickel-Cadmium Storage Battery As described above, the positive electrode current collector 14 and the negative electrode current collector 15 are welded to the upper and lower surfaces of the electrode group 10 to form the electrode body 10a, and the nickel-plated iron bottom is formed. Cylindrical battery can (with an inner diameter of 22.0 mm and an outer diameter of 22.3 mm) 16
Insert inside. Then, the distal end of the positive electrode current collector lead plate 14a extending from the positive electrode current collector 14 welded to the end of the conductive core 11a of the nickel positive electrode plate 11 is resistance-welded to the bottom surface of the lid 17a of the sealing body 17. Then, an electrolytic solution is injected into the battery can 16. Thereafter, the sealing body 17 is placed on the opening of the battery can 16 via the insulating gasket 18 and the end of the opening of the battery can 16 is crimped inward to seal the battery.

Next, the outer diameter of the battery can 16 (22.3 m
m), the battery can 16 sealed as described above is placed at the entrance of a tubular jig (not shown) having a slightly smaller diameter (22.0 mm) at the outlet than using the pressing jig (not shown). hand,
The outer diameter of the battery can 16 is reduced from 22.3 mm to 22.0 mm by pressing the battery can 16 and passing the battery can 16 through the tubular jig.
mm (diameter reduction) to 22.0 mm
mm to 21.7 mm, with a nominal capacity of 1.7 Ah
To produce a nickel-cadmium storage battery of SC size.

The sealing body 17 has a lid 17a having a circular downward protruding part formed on the bottom surface, a positive electrode cap (positive electrode external terminal) 17b, and interposed between the lid 17a and the positive electrode cap 17b. Spring 17c and valve plate 1
A gas vent hole 17e is formed in the center of the lid 17a. Further, the positive electrode current collector 14 has a through hole (not shown) formed in a portion of the sealing body 17 facing the gas vent hole 17e.
The positive electrode current collector 14 does not block the gas vent 17 e, and the gas inside the battery passes through the through hole of the positive electrode current collector 14 to close the sealing body 1.
7 can be smoothly discharged out of the battery through the gas vent hole 17e.

Here, a disk-shaped disk having a diameter of 21.7 m is used.
The nickel-cadmium storage battery (battery A) using the negative electrode current collector 15 of Example 1 was a disk-shaped nickel-cadmium storage battery having a diameter of 2 m.
A battery using the 1.8 mm negative electrode current collector 15 is referred to as a nickel-cadmium storage battery (battery B) of Example 2, and a disk-shaped negative electrode current collector 15 having a diameter of 21.9 mm is used in Example. No. 3 nickel-cadmium storage battery (battery C).

On the other hand, a disc-shaped nickel-cadmium storage battery (battery D) using the negative electrode current collector 15 having a diameter of 21.5 mm is referred to as a disc-shaped nickel-cadmium storage battery (battery D) having a diameter of 21.6 m.
The battery using the m negative electrode current collector 15 is referred to as a nickel-cadmium storage battery (battery E) of Comparative Example 2. Further, a disc-shaped negative electrode current collector 15 having a diameter of 21.5 mm, which was welded to the bottom of the battery can 16 was used as a nickel-cadmium storage battery (battery F) of Comparative Example 3. I do.

6. Battery Performance Test Each of the batteries A, B, C, D, E,
Using F, the internal resistance of each of the batteries A, B, C, D, E, and F was measured by the alternating current method (AC method; 1000 Hz), and the results shown in Table 1 below were obtained. Also, after charging each of these batteries A, B, C, D, E, and F with a current of 5 A to 120% of the nominal capacity, the battery A is discharged at a current of 20 A so that the battery voltage becomes 0.8 V. When the operating voltage was measured, the results were as shown in Table 1 below.

[0024]

[Table 1]

In Table 1, the internal resistance was measured for the battery F (the nickel-cadmium storage battery of Comparative Example 3 having a disk-like shape and a diameter of 21.5 mm (the inner diameter of the battery can after reducing the diameter was 21.7).
mm smaller than 0.2 mm).
The internal resistance of the negative electrode current collector 15 (welded to the bottom of the battery can 16) is set to 100, and the value corresponding thereto is shown.

As apparent from Table 1, the nickel-cadmium storage battery of Example 1 has a disk shape and a diameter of 21.20 mm.
The battery A using the negative electrode current collector 15 of 7 mm (same as the inner diameter of the battery can after reducing the diameter of 21.7 mm), the nickel of Example 2 was used.
Battery B using a negative electrode current collector 15 of a cadmium storage battery having a disk shape and a diameter of 21.8 mm (0.1 mm larger than the inner diameter of the reduced battery can of 21.7 mm), and Example 3
Nickel-cadmium storage battery with a disk shape and a diameter of 2
Battery C using negative electrode current collector 15 of 1.9 mm (0.2 mm larger than inner diameter 21.7 mm of battery can after reduced diameter)
Is a nickel-cadmium storage battery of Comparative Example 3 having a disk shape and a diameter of 21.5 mm (the inner diameter of the battery can after reducing the diameter is 21.7 mm).
mm smaller than 0.2 mm).
Even when the negative electrode current collector 15 is compared with the battery F in which the negative electrode current collector 15 is welded to the bottom of the battery can 16, it can be seen that the internal resistance and the operating voltage are almost equal.

On the other hand, in the nickel-cadmium storage battery of Comparative Example 1, a disc-shaped negative electrode current collector 15 having a diameter of 21.5 mm (0.2 mm smaller than the inner diameter of the battery can after reduction of 21.7 mm) was used. Battery D, a nickel-cadmium storage battery of Comparative Example 2, using a disk-shaped negative electrode current collector 15 having a diameter of 21.6 mm (0.1 mm smaller than the inner diameter of the battery can after reduction of 21.7 mm). It can be seen that the battery E is inferior in internal resistance and operating voltage as compared with the nickel-cadmium storage battery of Comparative Example 3 (battery F).

From the above, the inner diameter of the battery can after the diameter reduction is the same as the inner diameter of the battery can, or 0.1 mm to
In the case of using the negative electrode current collector 15 having a diameter of 0.2 mm larger and reducing the diameter of the battery can 16 after assembling the battery, even if the current collector 15 and the inner bottom of the battery can 16 are not welded, A storage battery having excellent internal resistance and operating voltage can be obtained, and using such a storage battery makes it possible to charge and discharge with a large current. Therefore, by applying the present invention, a storage battery having a low internal resistance and an improved operating voltage can be easily obtained.

In each example of the above-described embodiment, an example was described in which the negative electrode current collector and the battery can were not welded. However, when the negative electrode current collector and the battery can were welded,
A nickel-cadmium storage battery having further reduced internal resistance and improved operating voltage was obtained. In the above-described embodiment, the positive electrode current collector is disposed above the electrode group, the negative electrode current collector is disposed below the electrode group, and the positive electrode current collector is connected to the lower surface of the sealing body. Although the description has been made, substantially the same applies when the negative electrode current collector is arranged at the upper part of the electrode group, the positive electrode current collector is arranged at the lower part of the electrode group, and the negative electrode current collector is connected to the lower surface of the sealing body. The result was obtained.

Further, in the nickel-cadmium storage battery of the above-described embodiment, both the positive electrode plate and the negative electrode plate use sintered electrode plates, but an experiment was conducted using a battery using a non-sintered electrode plate such as a paste type. The same result was obtained in the case of the above. Further, in the nickel-cadmium storage battery of the above-described embodiment, an example in which the positive / negative electrode plate is spirally wound via a separator to form an electrode group has been described. However, the present invention is not limited to this. The positive and negative electrodes may be stacked to form an electrode group.

In the above-described embodiment, an example in which the present invention is applied to a nickel-cadmium storage battery has been described. However, the present invention is not limited to this, and various types of alkaline storage batteries such as nickel-hydride storage batteries and lithium-ion storage batteries can be used. It is needless to say that the present invention can be applied to the above storage battery. Further, in the above-described embodiment, an example has been described in which the present invention is applied to a cylindrical storage battery. However, the present invention is not limited to this, and it goes without saying that the present invention can be applied to various shapes of storage batteries such as a rectangular shape.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a main part of an alkaline storage battery according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a state where a negative electrode current collector is welded to the electrode group of the alkaline storage battery of FIG. 1;

FIG. 3 is a sectional view showing a main part of a conventional alkaline storage battery.

[Explanation of symbols]

10 electrode group, 10a electrode body, 11 positive electrode plate, 11a
... conductive core, 12 ... negative electrode plate, 12a ... conductive core, 1
DESCRIPTION OF SYMBOLS 3 ... Separator, 14 ... Positive electrode collector, 14a ... Collector lead plate, 15 ... Negative electrode collector, 16 ... Battery can (negative electrode external terminal), 17 ... Sealing body, 17a ... Lid, 17b ... Positive electrode cap ( Positive electrode external terminal), 18 ... insulating gasket

Continued on the front page F term (reference) 5H022 AA04 AA09 AA18 BB01 BB11 CC12 CC16 CC22 5H028 BB04 BB05 BB07 CC05 CC12 CC21 HH05 HH06

Claims (2)

[Claims] 1. A bottomed cylindrical battery can having an opening also serving as one terminal, a sealing body sealing the opening, also serving as the other terminal, and a battery comprising the battery can and the sealing body. A storage battery comprising: a positive / negative electrode plate housed in a container; and a power generation element made of an electrolytic solution, wherein the storage battery is formed by reducing the diameter of the battery can, wherein the current collector contacts a bottom of the battery can. The maximum length of the body is less than the inner diameter of the battery can, and is equal to or greater than the inner diameter of the reduced battery can, so that at least a portion of the current collector closely contacts the inner wall of the battery can. A storage battery characterized in that: 2. A bottomed cylindrical battery can provided with an opening also serving as one terminal, a sealing body sealing the opening, also serving as the other terminal, and a battery comprising the battery can and the sealing body. A method for manufacturing a storage battery including a positive / negative electrode plate housed in a container and a power generating element made of an electrolytic solution, comprising forming an electrode group by winding or laminating the positive / negative electrode plate with a separator interposed therebetween. An electrode assembly forming step of forming an electrode assembly by welding current collectors to conductive edges protruding from the positive / negative electrode plates on the upper and lower end surfaces of the electrode assembly, respectively. A sealing step of inserting together with the electrolytic solution into the battery can and sealing with the sealing body; and a reducing step of reducing the diameter of the whole battery can sealed with the sealing body, and contacting the can bottom of the battery can. The maximum length of the current collector is Wherein the current collector is in close contact with the inner wall of the battery can so as to be smaller than the inner diameter of the battery can or more than the inner diameter of the reduced battery can. Method.