JPH1131487A - Cylindrical sealed battery and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cylindrical sealed battery in an insulating ring structure for improving the permeability of an electrolyte and restraining malfunction due to stagnant liquid. SOLUTION: A cutout part is formed on the outer diameter side of an insulating ring 7 to isolate and insulate a pole plate group 3 stored in a battery case from a sealing plate 5 or a rising part is formed on a separation part to improve the permeating speed of an electrolyte into the pole plate group 3 and smoothly bleed air out of the battery case 2 for better electrolyte permeability, so that the possibility of stagnant liquid is eliminated and defective insulation of an insulating plate 6 due to a shift is avoided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealed cylindrical battery in which the structure of an insulator inserted into a battery case and the manufacturing procedure of the battery are improved to stabilize the battery performance and improve the production yield. The present invention relates to the manufacturing method.

[0002]

2. Description of the Related Art As shown in FIG. 12, a cylindrical sealed battery such as a lithium battery has a battery case 3 having an opening on one side.
1, an electrode plate group 32 formed by winding a positive electrode plate and a negative electrode plate with a separator interposed therebetween is housed, and an insulating ring 33 and an insulating plate 34 are disposed on the upper part thereof. After injecting a liquid to infiltrate the electrode group 32 with the electrolytic solution, the opening is hermetically sealed with a sealing plate 35 to complete the process. These manufacturing steps are performed by an automatic assembly device.

[0003] The electrolyte is injected from a liquid injection hole provided in the insulating plate 34, and a predetermined amount of the electrolyte is permeated into the electrode plate group 32 by repeating pressure reduction and opening to the atmosphere. Also, the lead wire 3 drawn out from one of the electrode plates 32
6 is connected to the sealing plate 35, so that the sealing plate 35 and the battery case 31 can be both positive and negative electrodes of the battery.
Further, the insulating ring 33 insulates the electrode plate group 32 and the sealing plate 35 with a predetermined space therebetween, and insulates the insulating plate so that the lead wire 36 does not contact the electrode plate group 32.

[0004]

However, in the above-described conventional structure, the electrolyte is injected from the injection hole provided in the insulating plate 34. Therefore, the displacement of the injection hole with respect to the electrolyte injection nozzle due to the displacement of the insulating plate 34. If the position shifts, the electrolytic solution scatters on the insulating plate 34 where it does not have a liquid injection hole, so that the injection amount of the electrolytic solution is reduced and there is a problem that the battery characteristics are varied.

In order to solve this problem, an insulating plate 34
Is inserted after the electrolyte is injected, a displacement of the inserted insulating plate 34 from a predetermined position occurs due to pooling of the electrolyte until the electrolyte permeates the electrode group 32, and the lead wire and the electrode group In some cases, internal short-circuit may occur due to contact with the P.32, and the battery performance may not be stable or the production yield may be reduced by any of the manufacturing procedures.

SUMMARY OF THE INVENTION An object of the present invention is to provide a sealed cylindrical battery having improved structures and manufacturing procedures of an insulating ring and an insulating plate for increasing the permeation rate of an electrolytic solution to suppress generation of a liquid pool, and a method of manufacturing the same. It is in.

[0007]

According to a first aspect of the present invention, there is provided a positive and negative electrode plate group housed in a cylindrical battery case having an opening on one side. A sealing plate that is connected to a lead wire drawn from any one of the plate groups to hermetically seal the opening, and an insulating ring that separates and insulates the sealing plate and the electrode plate group; ,
An insulating plate that insulates between the lead wire and the electrode group; a cylindrical sealed battery formed by infiltrating an electrolyte solution into the electrode group; A ring-shaped flat portion formed at an outer diameter in contact with the surface, and a rising portion rising from the inner diameter side of the flat portion toward the opening; And / or a notch portion forming a gap and / or a dividing portion for dividing the rising portion into a plurality of portions.

[0010] According to the above configuration, the notch portion and / or the split portion at the rising portion are provided on the outer diameter side of the flat portion of the insulating ring, so that the electrolyte flows from the insulating ring to the electrode plate group. Since the flow path is formed and the flow path for air escape from the inside of the battery case is formed,
The permeation speed of the electrolyte into the electrode group is increased, the occurrence of liquid pool can be suppressed, and the displacement of the insulating plate from the predetermined position due to the liquid pool can be prevented.

By forming the notch portion and the divided portion in the above configuration so that their positions are in the same radial direction, the flow of the electrolytic solution into the battery case is reduced on the inner diameter side and the outer diameter side of the insulating ring. Therefore, the permeability of the electrolytic solution is increased, and the liquid pool is reduced.

[0010] The insulating plate may be formed of a circular plate or a polygonal plate having a size capable of being inserted into the electrode plate group from the inner diameter side of the insulating ring, and the insulating plate may be formed in a mesh structure. .

Since the insulating ring structure improves the permeability of the electrolyte so that there is no liquid pool and the insulating plate can be inserted after the injection, the insulating plate does not need to be provided with a liquid injection hole, and is circular or polygonal. Can be formed into a simple plate structure. In addition, since the insulating plate has a mesh structure, even if it is inserted before the injection of the electrolytic solution, it is possible to inject the liquid and it is not affected by the liquid pool.

Further, the second invention of the present application is directed to a positive / negative electrode group housed in a cylindrical battery case having an opening on one side, and the electrode group pulled out from one of the electrode groups. A sealing plate that is connected to the lead wire and hermetically seals the opening, an insulating ring that separates and insulates the sealing plate and the electrode group, and a gap between the lead wire and the electrode group. An insulating plate that insulates the electrode group, and in a method of manufacturing a cylindrical sealed battery formed by infiltrating an electrolyte solution into the electrode group, a manufacturing process procedure includes a step of inserting the electrode group into the battery case, A step of inserting an insulating ring onto the electrode group, a step of injecting an electrolyte into the battery case, a step of inserting an insulating plate onto the electrode group from the inner diameter side of the insulating ring, and connecting a lead wire and a sealing plate. Is performed in the order of the steps of hermetically sealing the opening of the battery case with the sealing plate. And wherein the door.

According to the above manufacturing method, since the insulating plate is inserted after the electrolyte is injected, no displacement of the insulating plate occurs due to the accumulation of the liquid, and the insulating plate is inserted after the injection of the electrolyte.
Since it is not necessary to provide a liquid injection hole, it can be formed into a simple structure, and the positioning at the time of insertion can be set roughly, so that the positioning mechanism for automatic assembly can be simplified and the assembly speed can be increased. The yield can also be improved.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings to provide an understanding of the present invention.
The embodiment described below is an example embodying the present invention, and does not limit the technical scope of the present invention.

FIG. 1 is a sectional view showing an embodiment in which the present invention is applied to a cylindrical lithium ion secondary battery which is an example of a sealed cylindrical battery. This cylindrical lithium ion secondary battery is formed using LiCoO ₂ as a positive electrode active material and carbon as a negative electrode active material.

In FIG. 1, a sealed cylindrical battery 1 contains an electrode group 3 in which a positive electrode plate and a negative electrode plate are wound in a cylindrical battery case 2 with a separator interposed therebetween, and an electrolytic solution is supplied. The positive electrode lead 4 which is impregnated and pulled out from the positive electrode plate is connected to a sealing plate 5, and the opening of the battery case 2 is sealed with the sealing plate 5. An insulating plate 6 and an insulating ring 7 are provided between the electrode plate group 3 and the sealing plate 5 to separate and insulate the electrode plate group 3 and the sealing plate 5 and to improve the insulation between the positive and negative electrodes. I keep it.

The insulating plate 6 includes a positive electrode lead 4 and an electrode plate group 3.
It ensures insulation so that it does not touch the negative electrode plate of
A circular or polygonal plate or a plate formed with a mesh is used.

Further, the insulating ring 7 is formed so as to secure an appropriate interval between the electrode plate group 3 and the sealing plate 5 and to prevent the liquid pool from being generated when the electrolytic solution is injected into the electrode plate group 3. Have been. The configuration of the insulating ring 7 will be described with reference to FIGS.

As shown in FIG. 2, the insulating ring 7 has a ring-shaped flat portion 1 whose outer diameter is in contact with the inner peripheral surface of the battery case 2.
1 and a rising portion 12 rising from the inner diameter side, and as shown in FIG. 2A, an insulating ring 7 a having a shape in which a plurality of notches 13 are provided on the outer diameter side of the flat portion 11,
As shown in FIG. 2B, the insulating ring 7b has a shape in which the rising portion 12 is divided by a plurality of dividing portions 14, and FIG.
As shown in FIG. 7, the insulating ring 7c can be configured such that the notch portion 13 provided on the flat portion 11 and the dividing portion 14 provided on the rising portion 12 have the same radial position.

By providing the notch 13 in the flat portion 11 as described above, a passage for air in the battery case 2 according to the permeation of the electrolyte when the electrolyte is injected is formed, and at the same time, the notch 13 is formed. Since the electrolyte also flows into the electrode plate group 3 from the portion 13, the penetration of the electrolytic solution is accelerated. Further, since the electrolytic solution cannot accumulate on the insulating ring 7, the permeability of the electrolytic solution can be improved. Also, in the case of the divided portion 14 provided in the rising portion 12, a flow path in which the electrolytic solution flows from the inner diameter side of the insulating ring 7 into the battery case 2 is formed, so that accumulation of the electrolytic solution can be prevented. Further, the notch 13
By providing both the and the dividing portion 14 and keeping the positions in the radial direction coincident with each other, the electrolytic solution flows down to both the outer diameter side and the inner diameter side, so that the permeability of the electrolytic solution can be further improved. .

The insulating ring 7a in which the notch 13 is provided in the plane portion 11 shown in FIG. 2A can be configured as shown in the specific examples shown in FIGS. As shown
The shape of the cutout portion 13 can be formed in an arbitrary shape as long as the cutout portion 13 can be arranged at a plurality of locations on the outer diameter side of the insulating ring 7a so as to be in contact with the inner peripheral surface of the battery case 2. Further, the insulating ring 7c in which the notch 13 is provided in the flat portion 11 and the dividing portion 14 is provided in the rising portion 12 is shown in FIGS.
It can be configured as in the specific example shown in FIG. 10, and similarly, the shape of the cutout portion 13 and the division portion 14 can be formed in any shape.

A method of manufacturing the cylindrical sealed battery 1 provided with the insulating ring 7 including the functions of the insulating rings 7a to 7c and the insulating plate 6 provided with the cutout portion 13 and / or the split portion 14 or both. Will be described below. FIG. 11 shows a method of manufacturing the sealed cylindrical battery 1 in steps (a) to (d).
These steps are shown in order of (f), and each of these steps is executed by an automatic manufacturing step. The procedure will be described below in the order of the drawings.

(A) Insert the electrode plate group 3 into the battery case 2.

(B) Insert the insulating ring 7 on the electrode plate group 3.

(C) A groove 2a is formed by making a full circumference in the body circumferential direction of the battery case 2.

(D) A predetermined amount of the electrolyte is permeated into the electrode plate group 3 by repeatedly injecting the electrolyte, reducing the pressure, and opening to the atmosphere. Specifically, when a battery case 2 having an inner diameter of 17.4 mm and a height of 63.5 mm from the groove 2a to the bottom accommodates a group of electrode plates having an outer diameter of 16.5 mm and a height of 59.5 mm, firstly, 1.
After injecting 3 cc of the electrolytic solution, the pressure is reduced to 450 mmHg for 10 seconds, and then the atmosphere is released. The steps of pouring, depressurizing, and opening to the atmosphere are repeated four times, and the electrode group 3 is impregnated with 4.6 cc of the electrolytic solution.

If the insulating ring 7 does not have the cut-out portion 13 or the split portion 14 as in the conventional configuration when the electrolyte is injected, the electrolyte that does not immediately penetrate is in contact with the battery case 2 on the outer diameter side. Although a liquid pool is formed on the insulating ring 7, when the insulating ring 7 a has the notch 13 or the insulating ring 7 b has the dividing part 14, the electrolytic solution flows from the notching part 13 or the dividing part 14 into the battery case 2.
No liquid pool occurs because it flows down quickly into the inside. Also,
Since the notch 13 forms an air circulating portion between the notch 13 and the battery case 2, the air in the battery case 2 can be smoothly evacuated according to the inflow of the electrolyte, and the permeation of the electrolyte can be accelerated. . In the case of the insulating ring 7c in which both the cutout portion 13 and the divided portion 14 are formed, the electrolyte flows down to both the inner diameter side and the outer diameter side of the insulating ring 7c. Since air is also evacuated from the notch 13, the permeability of the electrolyte can be further improved.

(E) Insert the insulating plate 6 from the opening on the inner diameter side of the insulating ring 7. Since the insertion of the insulating plate 6 is performed after the injection of the electrolytic solution, the insulating plate 6 can be formed in a simple structure without the necessity of providing a liquid inlet, and the insulating ring 7 has a structure that does not cause liquid pool. No displacement occurs. Further, if the insulating plate 6 is formed in a mesh structure, the permeability of the electrolytic solution is increased. Therefore, even if the insulating plate 6 is inserted before the electrolytic solution is injected, the insulating plate 6 may hinder the injection or move from a predetermined position due to the liquid pool. No.

(F) The positive electrode lead 4 pulled out from the electrode plate group 3 is connected to the sealing plate 5, and the sealing plate 5 and the battery case 2 are connected.
The sealing plate 5 is fixed to the battery case 2 with a rubber-like member for ensuring insulation and sealing properties interposed therebetween. This sealing plate 5
At the time of mounting, the positive electrode lead 4 bends in a folded state, but since the insulating plate 6 is provided, the positive electrode lead 4 does not come into contact with the negative electrode plate to cause insulation failure.

The results of comparative verification of the structure of the insulating ring 7 and the electrolyte permeability and battery performance of the sealed cylindrical battery 1 manufactured by the manufacturing method using the same are shown below. Regarding the permeability of the electrolyte, the injection of a predetermined amount of the electrolyte into the electrode group 3, the pressure reduction, and the opening to the atmosphere are repeated, and after leaving for 5 minutes, the electrolyte remaining on the electrode group 3 is left. The amount and the degree of penetration into the electrode plate group 3 were determined. Regarding the battery performance, the battery was sealed immediately after the completion of the injection, the internal resistance was measured, and charging at a constant voltage and constant current of 0.9 A and 4.2 V was performed for 2 hours and 30 minutes. 0
The battery was discharged until the voltage dropped to V, and the battery capacity was measured. The results are as shown in Table 1. Example 1
When the insulating ring 7c shown in FIG.
When the insulating ring 7a shown in FIG. 3 is used, the conventional example is based on the configuration shown in FIG.

[0031]

[Table 1]

As is clear from the verification results, when the insulating ring 7c is used, the electrolyte has the highest permeability,
In the conventional example, there was residual electrolyte. There is a great difference in the battery performance between the embodiment and the conventional example in correspondence with the permeability of the electrolytic solution, and it has been found that the battery performance is effective not only in the production yield but also in the battery performance.

[0033]

As described above, according to the first aspect of the present invention, a flow path through which the electrolyte flows from above the insulating ring to the electrode plate group is formed by the notch or the division formed in the insulating ring. At the same time, a flow path for air escape from the inside of the battery case is formed, so that the permeability of the electrolyte to the electrode plate group is increased, and the displacement of the insulating plate due to the liquid pool can be prevented, and the occurrence of defects is suppressed. As a result, the production yield can be improved.

According to the second aspect of the present invention, since the liquid pool of the electrolytic solution is eliminated by the cut-out portion and the divided portion formed in the insulating ring, the displacement of the insulating plate due to the liquid pool does not occur. Since it is inserted after the injection of the electrolyte, it can be formed in a simple structure without the need to provide a liquid injection hole, and the positioning at the time of insertion can be set roughly, so that the positioning mechanism for automatic assembly is simplified and the assembly speed is high. And the yield of battery manufacturing can be improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a configuration of a sealed cylindrical battery according to an embodiment of the present invention.

FIG. 2A illustrates a configuration of an insulating ring according to an embodiment.
(B) The perspective view shown in each basic form of (c).

3A is a plan view and FIG. 3B is a cross-sectional view showing a specific example of the insulating ring 7a.

4A is a plan view and FIG. 4B is a sectional view showing a specific example of the insulating ring 7a.

5A is a plan view and FIG. 5B is a sectional view showing a specific example of the insulating ring 7a.

6A is a plan view and FIG. 6B is a cross-sectional view showing a specific example of the insulating ring 7a.

7A is a plan view and FIG. 7B is a cross-sectional view showing a specific example of the insulating ring 7a.

8A is a plan view and FIG. 8B is a cross-sectional view showing a specific example of the insulating ring 7c.

9A is a plan view and FIG. 9B is a cross-sectional view showing a specific example of the insulating ring 7c.

10A is a plan view and FIG. 10B is a cross-sectional view showing a specific example of the insulating ring 7c.

FIGS. 11A to 11F are process drawings showing the manufacturing process of the cylindrical sealed battery according to the embodiment in the order of (a) to (f).

FIG. 12 is a cross-sectional view illustrating a configuration of a cylindrical sealed battery according to a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cylindrical sealed type battery 2 Battery case 3 Electrode group 4 Positive electrode lead 5 Sealing plate 6 Insulating plate 7, 7a, 7b, 7c Insulating ring 11 Flat part 12 Rise part 13 Notch part 14 Division part

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Rinkichi Yonehara 1006 Kadoma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Inventor Kunio Tsuruta 1006 Kadoma, Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd.

Claims (5)

[Claims] A positive electrode and a negative electrode group housed in a cylindrical battery case having an opening on one side, and a lead wire drawn out of one of the electrode groups. A sealing plate that hermetically seals the opening, an insulating ring that separates and insulates the sealing plate and the electrode group, and an insulating plate that insulates between the lead wire and the electrode group. A cylindrical sealed battery formed by impregnating an electrolyte solution into the electrode plate group, wherein the insulating ring has a ring-shaped flat portion formed at an outer diameter in contact with an inner peripheral surface of the battery case; A rising portion that rises in the opening direction from the inner diameter side of the flat portion, and a cutout portion and / or the rising portion that form a plurality of gaps between the flat portion and the battery case on the outer diameter side of the flat portion. That it is formed by providing a dividing part Cylindrical sealed battery according to symptoms. 2. The sealed cylindrical battery according to claim 1, wherein the notch portion and the division portion are formed so that their positions are in the same radial direction. 3. The sealed cylindrical battery according to claim 1, wherein the insulating plate is formed of a circular plate or a polygonal plate having a size that can be inserted into the electrode group from the inner diameter side of the insulating ring. 4. The sealed cylindrical battery according to claim 1, wherein the insulating plate has a mesh structure. 5. A positive electrode and a negative electrode group housed in a cylindrical battery case having an opening on one side, and a lead wire drawn out of one of the electrode groups. A sealing plate that hermetically seals the opening, an insulating ring that separates and insulates the sealing plate and the electrode group, and an insulating plate that insulates between the lead wire and the electrode group. A method for manufacturing a sealed cylindrical battery formed by infiltrating an electrolyte into the electrode group, comprising: a step of inserting the electrode group into the battery case; and an insulating ring on the electrode group. Inserting the electrolyte into the battery case, inserting the insulating plate from the inner side of the insulating ring onto the electrode plate group, connecting the lead wire and the sealing plate to the battery case with the sealing plate. The step of sealing and sealing the opening is carried out in the order of Method of manufacturing a type battery.