JPH08287891A - Flat battery - Google Patents

Abstract

PURPOSE: To avoid troubles in a process due to the leak of a sealing compound applied between an insulating gasket and a negative electrode terminal. CONSTITUTION: A cylindrical partitioning wall 9d is erected on the bottom part 9a of an insulating gasket 9 over the whole periphery of the bottom part 9a. On the bottom part 9a between the wall 9d and an inner cylinder part 9c, an air vent hole 9e is formed with which a liquid injection space 10 on the outer periphery of the cylinder part 9c and a space in the lower part of the bottom part 9a and the inner side of the cylinder part 9c are communicated. The movement of a sealing compound to the hole 9e of the gasket 9 is prevented by the wall 9d, thereby inhibiting the sealing compound from passing the hole 9e to be leaked to the outside of the gasket 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention contains a power generating element between a positive electrode can and a negative electrode terminal, and an insulating gasket is fitted between the peripheral portion of the positive electrode can and the peripheral portion of the negative electrode terminal. The present invention relates to a flat type battery such as a coin type lithium battery which is crimped and sealed.

[0002]

2. Description of the Related Art FIG. 6 is a sectional view showing a step of fitting an insulating gasket to a negative electrode terminal, (a) showing a step of applying a sealant, and (b) showing a step of taking out a negative electrode terminal and an insulating gasket. FIG. 7 is a sectional view showing an example of an insulating gasket of a conventional flat battery.

Conventionally, when assembling a flat battery of this type, shortening the time for injecting the electrolytic solution has been an important factor for improving productivity, and as shown in FIG. , A proposal has been made that the air vent hole 9e is formed in the bottom portion 9a of the insulating gasket 9 having a U-shaped cross section so that the air is discharged at the time of injecting the electrolyte solution to realize smooth fluid injection. (See JP-A-6-111796).

[0004]

However, this causes the following problems. That is, as a method of fitting the insulating gasket 9 to the negative electrode terminal 7, first, as shown in FIG. 6A, the insulating gasket 9 is fixed on the holder 12, and a sealant having an appropriate viscosity is discharged from the nozzle 13. 6 is poured onto the inner surface of the insulating gasket 9 (a surface contacting with the negative electrode terminal 7) and applied, and then the negative electrode terminal 7 is placed on the insulating gasket 9 as shown in FIG. A method of taking out the negative electrode terminal 7 together with the insulating gasket 9 is widely used. However, since the insulating gasket 9 has the air vent hole 9e, the sealing agent passes through the air vent hole 9e and the insulating gasket 9 and the holder 12 are connected to each other. Will wrap around in the gap. As a result, not only is it difficult to separate the insulating gasket 9 from the holder 12 in the process of taking out the negative electrode terminal 7 and the insulating gasket 9, but also in the subsequent process, since the sealing agent adheres to the outer peripheral surface of the insulating gasket 9. There is a high risk that various troubles will occur. For example, the insulating gasket 9 fitted to the negative electrode terminal 7
Is put into the parts feeder and supplied to the assembly line. At this time, the sealant is transferred to the terminal portion of the negative electrode terminal 7, which causes poor contact with the device when the battery is used. An additional cleaning step is required to remove the sealant), which eventually leads to an increase in cost.

In view of the above-mentioned circumstances, the present invention has a flat surface which can prevent the sealing agent from adhering to the outer peripheral surface of the insulating gasket by devising the shape of the insulating gasket to avoid the above-mentioned inconvenience. The purpose is to provide a shaped battery.

[0006]

That is, according to the present invention, a positive electrode mixture (3), a separator (5), and a negative electrode (6) are laminated in this order to form a space between a positive electrode can (2) and a negative electrode terminal (7). Stow,
Between the peripheral portion of the positive electrode can and the peripheral portion of the negative electrode terminal,
A ring-shaped insulating gasket (9) having a U-shaped cross section, in which an outer tubular portion (9b) and an inner tubular portion (9c) are formed on an annular bottom portion (9a), the inner tubular portion being the outer periphery of the positive electrode mixture. In the flat battery (1), which is fitted in a form of being located at, and the positive electrode can is crimped and sealed, a cylindrical partition wall (9d) is erected all around the bottom of the insulating gasket. In addition, at the bottom between the partition wall of the insulating gasket and the inner cylinder, an air vent hole (9e) is formed in which the liquid injection space (10) on the outer circumference of the inner cylinder communicates with the space below the bottom. It is constructed by forming.

In the present invention, the positive electrode mixture (3), the separator (5) and the negative electrode (6) are laminated in this order and housed between the positive electrode can (2) and the negative electrode terminal (7). An annular bottom portion (9a) between the peripheral portion of the negative electrode terminal and the peripheral portion of the negative electrode terminal.
U on which the outer tubular portion (9b) and the inner tubular portion (9c) are formed
A flat battery (1) in which a ring-shaped insulating gasket (9) having a letter-shaped cross section is fitted in such a manner that the inner cylindrical portion is located on the outer periphery of the positive electrode mixture, and the positive electrode can is crimped and sealed.
A cylindrical partition wall (9d) is erected all over the bottom of the insulating gasket, and the outer circumference of the inner cylinder is provided at the bottom between the partition wall of the insulating gasket and the inner cylinder. Is formed by forming an air vent hole (9e) communicating with the liquid injection space (10) and the space below the bottom and inside the inner cylinder.

It should be noted that the numbers in parentheses are for convenience of showing the corresponding elements in the drawings, and the present invention is not limited to the description in the drawings. This also applies to the "Claims" and "Action" columns.

[0009]

In the present invention, the partition wall (9d) prevents the sealant from moving to the air vent hole (9e) of the insulating gasket (9) when the insulating gasket is fitted to the negative electrode terminal (7). ) Acts to be blocked by.

Further, the air vent hole (9e) of the insulating gasket (9) serves as an escape route for the air when the electrolyte solution is injected, and also serves as a movement path for the electrolyte solution after the flat battery (1) is assembled. Acts to become.

Further, the inner cylindrical portion (9) of the insulating gasket (9) is
c) acts to suppress the expansion of the positive electrode mixture (3) that accompanies the discharge of the flat battery (1).

[0012]

Embodiments of the present invention will be described below with reference to the drawings. 1 is a cross-sectional view showing an embodiment of the flat battery according to the present invention, FIG. 2 is a view showing an insulating gasket of the flat battery shown in FIG. 1, (a) is a plan view thereof, and (b) is ( a)
3 is a cross-sectional view taken along line AA of FIG. 3, FIG. 3 is a cross-sectional view showing a liquid injection process of the flat-shaped battery shown in FIG. 1, FIG. 4 is a graph showing results of discharge performance test of the flat-shaped battery, and FIG. It is sectional drawing which shows the insulating gasket of another Example of a flat type battery.

As shown in FIG. 1, a coin type lithium battery 1 which is a flat type battery according to the present invention has a positive electrode can 2, and a positive electrode mixture 3 is placed on the positive electrode can 2. . A lithium negative electrode 6 is placed on the upper side of the positive electrode mixture 3 via a separator 5, and a negative electrode terminal 7 is placed on the upper side of the lithium negative electrode 6. The peripheral edge of the negative electrode terminal 7 is crimp-sealed to the peripheral edge of the positive electrode can 2 via a ring-shaped insulating gasket 9.

By the way, the insulating gasket 9 has an annular bottom portion 9a as shown in FIG.
An outer cylinder portion 9b and an inner cylinder portion 9c are integrally formed on the top. A cylindrical partition wall 9d is integrally formed between the outer tubular portion 9b and the inner tubular portion 9c so as to be erected over the entire circumference of the bottom portion 9a. As shown in FIG. 2A, three air vent holes 9e are arranged at equal angular intervals (that is, 120 ° intervals) in the bottom portion 9a between them and 9c. Here, as shown in FIG. 2B, each air vent hole 9e is provided with a liquid injection space 10 on the outer periphery of the inner cylinder portion 9c and a bottom portion 9a.
Is formed so as to communicate with the space below (on the positive electrode can 2 side) and on the inside of the inner cylindrical portion 9c (on the positive electrode mixture 3 side).

Since the coin type lithium battery 1 has the above-mentioned structure, when assembling the coin type lithium battery 1, first, the insulating gasket 9 is fitted to the negative electrode terminal 7. To this end, as shown in FIG. 6A, the insulating gasket 9 is fixed on the holder 12, and a sealant having an appropriate viscosity is discharged from the nozzle 13 so that the inner surface of the insulating gasket 9 (contact with the negative electrode terminal 7) can be obtained. Surface and apply. At this time, since the partition wall 9d is erected between the inner surface of the insulating gasket 9 and the air vent hole 9e, the sealant flows around the gap between the insulating gasket 9 and the holder 12 through the air vent hole 9e. There is no such a case, and the sealant can be applied smoothly without any trouble. Next, as shown in FIG. 6B, after the negative electrode terminal 7 is placed and fitted on the insulating gasket 9, the negative electrode terminal 7 is taken out together with the insulating gasket 9 using the suction tool 15.

In this way, when the insulating gasket 9 is fitted to the negative electrode terminal 7, the negative electrode terminal 7 is turned upside down.
Is positioned on the lower side, the lithium negative electrode 6, the separator 5, and the positive electrode mixture 3 are sequentially placed on the negative electrode terminal 7, and the electrolytic solution is injected, as shown in FIG. At this time, since the air bleed hole 9e is formed in the insulating gasket 9,
The electrolytic solution is injected in a short time.

Then, the positive electrode can 2 is covered from above the insulating gasket 9, and the positive electrode can 2 is crimped and sealed. At this point, the assembly of the coin type lithium battery 1 is completed.

In the coin-type lithium battery 1 thus assembled, as shown in FIG. 1, the bottom 9a of the insulating gasket 9 is in contact with the positive electrode can 2, but the inner tubular portion 9c of the insulating gasket 9 is in contact. Since the space inside (on the side of the positive electrode mixture 3) communicates with the liquid injection space 10 through the air vent hole 9e, the air vent hole 9e serves as a movement path for the electrolyte solution to permeate the electrolyte solution. Be done. Further, since the inner cylinder portion 9c of the insulating gasket 9 exists on the outer periphery of the positive electrode mixture 3, even if the positive electrode mixture 3 expands in the radial direction as the coin-shaped lithium battery 1 discharges, The expansion of the agent 3 is suppressed by the inner cylindrical portion 9c of the insulating gasket 9. As a result, the discharge performance of the coin type lithium battery 1 is improved.

In order to confirm the presence or absence of the above effects, a coin-type lithium battery (CR2032) was used as a prototype of the product of the present invention and a conventional product, and a 2.7 kΩ continuous discharge performance test (20 ° C.) was carried out. FIG. 4 shows the results. As is clear from FIG. 4, the product of the present invention is superior in discharge performance to the conventional product,
It has been experimentally proved that the above-mentioned effects are certainly obtained.

[0020]

As described above, according to the present invention, the positive electrode mixture 3, the separator 5 and the negative electrode 6 are laminated in this order and housed between the positive electrode can 2 and the negative electrode terminal 7, An annular bottom portion 9 is provided between the peripheral portion and the peripheral portion of the negative electrode terminal 7.
A ring-shaped insulating gasket 9 having a U-shaped cross section, in which an outer tubular portion 9b and an inner tubular portion 9c are formed on a, is fitted such that the inner tubular portion 9c is located on the outer periphery of the positive electrode mixture 3, and Positive electrode can 2
In a flat type battery such as a coin type lithium battery 1 in which the above is crimped and sealed, a cylindrical partition wall 9d is provided upright over the entire circumference of the bottom portion 9a of the insulating gasket 9, and Partition wall 9d and inner cylinder portion 9c
Since an air vent hole 9e is formed in the bottom portion 9a between the inner cylinder portion 9c and the space below the bottom portion 9a to communicate with the liquid injection space 10 on the outer periphery of the inner tubular portion 9c, the negative electrode terminal 7 is insulated. When the gasket 9 is fitted, the sealing agent is applied to the insulating gasket 9
Since the partition wall 9d can prevent the sealing agent from moving to the air bleeding hole 9e, it is possible to prevent the sealing agent from leaking to the outside of the insulating gasket 9 through the air bleeding hole 9e. It is possible to avoid various process troubles due to the leakage of the agent.
Further, since the air vent hole 9e of the insulating gasket 9 serves as an escape route for the air when injecting the electrolytic solution, the time for injecting the electrolytic solution can be shortened. Furthermore, since the inner cylinder portion 9c of the insulating gasket 9 suppresses the expansion of the positive electrode mixture 3 that accompanies the discharge of the flat battery, the discharge performance of the flat battery can be improved.

Further, according to the present invention, the positive electrode mixture 3, the separator 5 and the negative electrode 6 are sequentially laminated to form a positive electrode can 2 and a negative electrode terminal 7.
And the outer cylindrical portion 9b on the annular bottom portion 9a between the peripheral portion of the positive electrode can 2 and the peripheral portion of the negative electrode terminal 7.
And a ring-shaped insulating gasket 9 having a U-shaped cross section in which the inner tubular portion 9c is formed, and the inner tubular portion 9c is located on the outer periphery of the positive electrode mixture 3, and the positive electrode can 2 is crimped. In a flat battery such as a sealed coin-type lithium battery 1, a cylindrical partition wall 9d is provided upright on the bottom 9a of the insulating gasket 9 over the entire circumference thereof, and the partition wall 9d of the insulating gasket 9 is Bottom 9 between inner cylinder 9c
Since the liquid injection space 10 on the outer periphery of the inner cylindrical portion 9c and the space below the bottom portion 9a and the space inside the inner cylindrical portion 9c communicate with each other in a, the negative electrode terminal is formed. Since the partition wall 9d can prevent the sealing agent from moving to the air bleeding hole 9e of the insulating gasket 9 when the insulating gasket 9 is fitted on the insulating gasket 9, the sealing agent passes through the air bleeding hole 9e and It is possible to prevent the occurrence of the situation of leaking to the outside, and it is possible to avoid various troubles in the process due to the leak of the sealant. In addition, the air vent hole 9e of the insulating gasket 9
Becomes an escape route for air when injecting electrolyte,
It is possible to shorten the injection time of the electrolytic solution. Furthermore,
In addition to the inner cylinder portion 9c of the insulating gasket 9 suppressing the expansion of the positive electrode mixture 3 due to the discharge of the flat battery, the air vent hole 9e of the insulating gasket 9 has an electrolyte solution after the flat battery is assembled. Therefore, the discharge performance of the flat battery can be further improved.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a flat battery according to the present invention.

2 is a view showing an insulating gasket of the flat battery shown in FIG. 1, in which (a) is a plan view thereof and (b) is A- of (a).
It is sectional drawing in the A line.

FIG. 3 is a cross-sectional view showing a liquid injection process of the flat battery shown in FIG.

FIG. 4 is a graph showing the results of discharge performance tests of flat type batteries.

FIG. 5 is a sectional view showing an insulating gasket of another embodiment of the flat battery according to the present invention.

6A and 6B are cross-sectional views showing a process of fitting an insulating gasket to a negative electrode terminal, wherein FIG. 6A is a diagram showing a sealing agent applying process, and FIG. 6B is a diagram showing a negative electrode terminal and insulating gasket removing process. is there.

FIG. 7 is a sectional view showing an example of an insulating gasket of a conventional flat battery.

[Explanation of symbols]

 1 flat battery (coin type lithium battery) 2 positive electrode can 3 positive electrode mixture 5 separator 6 negative electrode 7 negative electrode terminal 9 insulation gasket 9a bottom 9b outer cylinder Part 9c ...... Inner cylinder part 9d ...... Partition wall 9e …… Air vent hole 10 …… Liquid injection space

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masaaki Suzuki 5-3-11 Shimbashi, Minato-ku, Tokyo Fuji Electric Chemical Co., Ltd. (72) Yoshihiro Onoda 5-36-11 Shinbashi, Minato-ku, Tokyo Fuji Electric Chemical Co., Ltd.

Claims (2)

[Claims] 1. A positive electrode mixture (3), a separator (5) and a negative electrode (6) are laminated in this order and housed between a positive electrode can (2) and a negative electrode terminal (7), and a peripheral portion of the positive electrode can. And a peripheral portion of the negative electrode terminal, a ring-shaped insulating gasket (9) having a U-shaped cross section, in which an outer tubular portion (9b) and an inner tubular portion (9c) are formed on an annular bottom portion (9a). In a flat battery (1) in which the inner cylindrical portion is fitted so as to be located on the outer periphery of the positive electrode mixture, and the positive electrode can is crimped and sealed, in the bottom portion of the insulating gasket, the entire periphery is provided. And a cylindrical partition wall (9d) is erected, and at the bottom between the partition wall of the insulating gasket and the inner cylinder part, the liquid injection space (10) on the outer periphery of the inner cylinder part and below the bottom part. The flat type battery is characterized in that an air vent hole (9e) communicating with the space is formed. 2. A positive electrode mixture (3), a separator (5) and a negative electrode (6) are laminated in this order and housed between a positive electrode can (2) and a negative electrode terminal (7), and a peripheral portion of the positive electrode can. And a peripheral portion of the negative electrode terminal, a ring-shaped insulating gasket (9) having a U-shaped cross section, in which an outer tubular portion (9b) and an inner tubular portion (9c) are formed on an annular bottom portion (9a). In a flat battery (1) in which the inner cylindrical portion is fitted so as to be located on the outer periphery of the positive electrode mixture, and the positive electrode can is crimped and sealed, in the bottom portion of the insulating gasket, the entire periphery is provided. And a cylindrical partition wall (9d) is erected, and at the bottom between the partition wall of the insulating gasket and the inner cylinder part, the liquid injection space (10) on the outer periphery of the inner cylinder part and below the bottom part. And an air vent hole (9e) communicating with the inner space of the inner cylindrical portion. .