JPH0864479A - Electrochemical element and method of manufacture - Google Patents

Abstract

PURPOSE: To avoid generation of dislocation of an electrode sheet or a separator by using two sets of an anode compound material or a cathode compound material, that are symmetrically positioned, as anode sheets or cathode sheets that are formed to be a U shape. CONSTITUTION: Two positions of compound material coated parts 6a and 6b are formed, and a compound material uncoated part 6c is formed on an area between them, on a current collector 6. An anode sheet 8A, that is formed to be that an anode compound material 7 is applied on each of the compound material coated parts 6a and 6b, the current collector 6 is formed so that the compound material uncoated part 6c is positioned at the base of the U shape and each of the compound material coated parts 6a and 6b is positioned at the rising parts of the U shape and facing each other, is used. A cathode sheet 8B, that is formed to be the U shape, in which a cathode compound material 9 is applied on each of the compound material coated parts 6a and 6b, the current collector 6 is formed so that the compound material uncoated part 6c is positioned at the base of the U shape and each of the compound material coated parts 6a and 6b is positioned at the rising parts of the U shape and faces each other, is used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrochemical device such as a capacitor and a battery and a method for manufacturing the same.

[0002]

2. Description of the Related Art FIG. 5 is a sectional view showing an example of a conventional rectangular electric double layer capacitor, and FIG. 6 is a front view of an electrode sheet constituting the rectangular electric double layer capacitor shown in FIG.

As shown in FIG. 6, a conventional rectangular electric double layer capacitor 1 includes an electrode sheet 8 (a positive electrode sheet 8A and a positive electrode sheet 8A and a positive electrode sheet 8A and a positive electrode sheet 8A and a negative electrode mixture 9) coated on both sides or one side of a current collector 6, respectively. Make the required number of negative electrode sheets 8B),
As shown in FIG. 5, these electrode sheet 8 and separator 1
A structure having a structure in which 0 and 1 are alternately stacked and inserted into the metal outer can 2 is widely used.

[0004]

However, in this case, when the laminated body of the electrode sheet 8 and the separator 10 is inserted into the outer can 2, the electrode sheet 8 and the separator 10 are easily displaced, and the number of laminated layers is large. In that case, it is difficult to stack the layers, and there is a drawback that productivity is low.

This is because the square electric double layer capacitor 1
The same applies to other electrochemical devices (for example, batteries).

In view of the above circumstances, it is an object of the present invention to provide an electrochemical device having excellent productivity and high reliability, and a method for producing the same.

[0007]

That is, the invention of the electrochemical device of the present invention has an outer can (2) and a current collector (6).
A predetermined number of positive electrode sheets (8A) coated with the positive electrode mixture (7) on both sides or one side and negative electrode sheets (8B) coated with the negative electrode mixture (9) on both sides or one side of the current collector The sheets are alternately laminated and inserted into the outer can, and a separator (10) is provided between each of the positive electrode sheets and each of the negative electrode sheets to form a positive electrode mixture of the positive electrode sheet and a negative electrode mixture of the negative electrode sheet. It is inserted so as to be isolated, and the sealing plate (1
1) The electrochemical device (1) fitted with the above-mentioned material, wherein the positive electrode sheet has two mixture application parts (6a, 6a) on a current collector.
b) is provided in such a manner that a mixture-uncoated portion (6c) is formed between them, and a positive electrode mixture is applied to each of these mixture-coated portions, and the current collector is U-shaped in the mixture-uncoated portion. A positive electrode sheet formed in a U shape is used so that each mixture application portion is located at the bottom side and faces each other at each rising side of the U shape, and the negative electrode sheet is used as a negative electrode sheet.
The mixed material application portions (6a, 6b) are provided so as to form an unmixed material mixture applied portion (6c) therebetween, and the negative electrode material mixture is applied to each of the mixed material application portions, and the current collector is A negative electrode sheet formed in a U-shape is formed so that the mixture-uncoated portion is located at the bottom of the U-shape and at the same time that each mixture-coated portion is located at each rising edge of the U-shape and faces each other. . In addition, the positive electrode sheet (8A) and the negative electrode sheet (8B)
An insulating core material (16) is inserted in the central portion of an electrode group (3) including the separator (10) and the separator (10). Further, the invention of the method for producing an electrochemical element of the present invention is a mixture of a predetermined width (W2) at the center of a flat plate-shaped current collector (6) when producing the electrochemical element (1). Uncoated part (6
c) and forming a mixture coating portion (6a, 6b) on each of the collector portions on both sides of the mixture uncoated portion, and then forming a positive electrode on each mixture coating portion of the current collector. The mixture (7) or the negative electrode mixture (9) is applied in a predetermined width (W1), and then the current collector is sequentially cut together with the positive electrode mixture or the negative electrode mixture in a predetermined length (L1). To prepare the required number of positive electrode sheets (8A) and negative electrode sheets (8B),
Next, these positive electrode sheets and negative electrode sheets are alternately laminated, and a separator (10) is provided between each positive electrode sheet and each negative electrode sheet as a positive electrode mixture of the positive electrode sheet and a negative electrode mixture of the negative electrode sheet. Are laminated so as to be separated from each other, and in this state, the entire positive electrode sheet, negative electrode sheet and separator are bent into a U shape to form an electrode group (3), and then the electrode group is inserted into the outer can, Further, an electrolytic solution is injected into the outer can, and finally, a sealing plate (1) is inserted into the opening of the outer can via a gasket (12).
1) is fitted and sealed.

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]

With the above structure, in the present invention, two sets of positive electrode mixture (7) or negative electrode mixture (9) located symmetrically are
The U-shaped positive electrode sheet (8A) or the negative electrode sheet (8B) serves as an integral unit. In addition, the positive electrode sheet and the negative electrode sheet are separated by the separator (10) and act so as to be completely independent. Further, the core material (16) inserted into the outer can (2) together with the electrode group (3) acts so as to prevent the electrode group from being bent during insertion.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. 1 is a front view showing an embodiment of a rectangular electric double layer capacitor according to the present invention, FIG. 2 is an enlarged sectional view of a bottom portion of the rectangular electric double layer capacitor shown in FIG. 1, and FIG. FIG. 4 is an enlarged cross-sectional view of the bottom of another embodiment of the double-layer capacitor, and FIG. 4 is a process diagram showing a method for producing a positive electrode sheet and a negative electrode sheet that constitute the rectangular electric double-layer capacitor shown in FIG. 2 or 3.

Rectangular electric double layer capacitor 1 according to the present invention
As shown in FIG. 1, it has a metallic outer can 2 that also serves as a negative electrode terminal, and a sealing plate 11 that also serves as a positive electrode terminal is fitted in the opening of the outer can 2 via a gasket 12. ing. An insulating plate 13 is placed on the upper side of the sealing plate 11 so as to cover the opening of the outer can 2, and an insulating tube 15 presses the insulating plate 13 toward the outer can 2 on the outer periphery of the outer can 2. It is provided in the form of.

By the way, an electrode group 3 is inserted in the outer can 2, and an insulating core material 16 is inserted in the center of the electrode group 3. In addition, the electrode group 3 includes a positive electrode sheet 8A, a negative electrode sheet 8B, and a separator 1 as shown in FIG.
0, and the positive electrode sheet 8A includes a current collector 6 and a positive electrode mixture 7. That is, the positive electrode sheet 8A
The current collector 6 of is formed in a U shape,
The positive electrode mixture 7 is applied to one surface of each of the mixture application parts 6a and 6b. Similarly, the negative electrode sheet 8B
Is composed of a current collector 6 and a negative electrode mixture 9. That is,
Although the current collector 6 of the negative electrode sheet 8B is formed in a U shape, the negative electrode mixture 9 is applied to one surface of each of the two mixture application portions 6a and 6b of the current collector 6. Furthermore,
The separator 10 is formed in a U shape, and is inserted between the positive electrode sheet 8A and the negative electrode sheet 8B to separate the positive electrode mixture 7 of the positive electrode sheet 8A and the negative electrode mixture 9 of the negative electrode sheet 8B adjacent thereto. Isolated from each other.

Rectangular electric double layer capacitor 1 according to the present invention
Has a configuration as described above, and therefore, when manufacturing the rectangular electric double layer capacitor 1, the following procedure is performed.

First, a slurry-like positive electrode mixture 7 and negative electrode mixture 9 are prepared. For example, it can be prepared by using N-methylpyrrolidone as a solvent and mixing activated carbon, acetylene black, and polyvinylidene fluoride in a weight ratio of 7: 1: 2.

Next, as shown in FIG. 4, the positive electrode mixture 7 is applied to the two mixture application portions 6a and 6b of the flat plate-shaped current collector 6 made of aluminum or the like having a predetermined thickness (for example, 20 μm). Is applied with a predetermined width W1. At this time, a predetermined width W is provided between the mixture application portions 6a and 6b and on both the left and right sides.
2, mixture-uncoated portions 6c, 6d, and 6e of W3 and W4 are formed. Alternatively, the positive electrode mixture 7 may be applied to the entire surface of the flat plate-shaped current collector 6, and then the positive electrode mixture 7 on the mixture-unapplied portions 6c, 6d, and 6e may be scraped off.

Similarly, a predetermined thickness (for example, 20 μm)
2 of the plate-shaped current collector 6 made of aluminum or copper
The negative electrode mixture 9 is applied to the mixture application portions 6a and 6b at the locations with a predetermined width W1. At this time, these mixture application parts 6a, 6
Predetermined widths W2, W3, W4 between b and on the left and right sides respectively
Mixing agent uncoated portions 6c, 6d, and 6e are formed. Alternatively, after the negative electrode mixture 9 is applied to the entire surface of the flat plate-shaped current collector 6, the negative electrode mixture 9 on the mixture-uncoated portions 6c, 6d, and 6e may be scraped off.

Here, the width W2 of the central mixture-uncoated portion 6c of the current collector 6 coated with the positive electrode mixture 7 is equal to the width W2 of the central mixture-uncoated portion of the current collector 6 coated with the negative electrode mixture 9. It is made narrower than the width W2 of 6c. For example, the former is 5 mm and the latter is 7 mm.

Next, the current collector 6 coated with the positive electrode mixture 7 or the negative electrode mixture 9 has a predetermined length L1 (for example, 13 mm).
And the positive and negative electrode sheets 8A and 8B having the connection terminals 8a by cutting off the left and right ends partially.
Are produced in the required number. Furthermore, these positive electrode sheets 8
A and the negative electrode sheet 8B are alternately laminated, and the separator 10 is laminated between the positive electrode sheet 8A and the negative electrode sheet 8B to separate the positive electrode mixture 7 of the positive electrode sheet 8A and the negative electrode mixture 9 of the negative electrode sheet 8B from each other. After that, thickness 1 in the center
A plate (not shown) having a size of about mm is applied, and in that state, the whole is bent into a U shape to form the electrode group 3. At this time, the positive electrode sheet 8
The width W2 of the mixture-uncoated portion 6c at the center of the current collector 6 of A is the width W of the mixture-uncoated portion 6c at the center of the current collector 6 of the negative electrode sheet 8B.
Since it is narrower than 2, the positive electrode sheet 8A is positioned inside the negative electrode sheet 8B. Then, as shown in FIG. 2, all the positive electrode mixture 7 and the negative electrode mixture 9 are aligned at substantially the same height.

Thus, when the electrode group 3 including the U-shaped positive electrode sheet 8A, the negative electrode sheet 8B and the separator 10 is manufactured, the electrode group 3 is inserted into the outer can 2 together with the insulating core material 16. At this time, the two sets of positive electrode mixture 7 in the symmetrical positions are integrated through one U-shaped positive electrode sheet 8A, and the two sets of negative electrodes in the symmetrical position are formed. The mixture 9 is integrated through one U-shaped negative electrode sheet 8B, so that the positive electrode sheet 8A, the negative electrode sheet 8B, and the separator 10 will not be displaced during insertion. Further, the bending of the electrode group 3 at the time of insertion is prevented by the core material 16 inserted into the outer can 2 at the same time as the electrode group 3. As a result, the positive electrode sheet 8A,
Since the electrode group 3 can be easily inserted into the outer can 2 even if the number of laminated negative electrode sheets 8B is large, the productivity of the rectangular electric double layer capacitor 1 can be improved.

In this way, when the electrode group 3 and the insulating core material 16 are inserted into the outer can 2, the electrolytic solution is injected into the outer can 2. At this time, the positive electrode sheet 8A and the negative electrode sheet 8
Since it is separated from B by the separator 10 and is completely independent (that is, including the vicinity of the bottom of the outer can 2), even if the electrolytic solution is excessively injected, a short circuit occurs due to it. There is no risk of a situation occurring.

Finally, the gasket 1 is attached to the opening of the outer can 2.
After the sealing plate 11 is fitted and sealed via 2 and the insulating plate 13 is placed thereon, the insulating tube 1 is attached to the outer periphery of the outer can 2.
Wind 5. Here, the manufacture of the rectangular electric double layer capacitor 1 is completed.

In the above embodiment, the current collector 6
The electrode group 3 including the positive electrode sheet 8A, the negative electrode sheet 8B, and the like, in which the positive electrode mixture 7 or the negative electrode mixture 9 is applied to one surface of the mixture application portions 6a and 6b, is placed in the outer can 2 together with the insulating core material 16. Although the case of insertion is explained, in the present invention,
As shown in FIG. 3, the positive electrode mixture 7 or the negative electrode mixture 9 may be applied to both surfaces of the mixture application portions 6a and 6b of the current collector 6, and the insulating core material 16 may be omitted. I can. Further, it is needless to say that the number of the positive electrode sheets 8A, the negative electrode sheets 8B, and the separators 10 constituting the electrode group 3 is not limited to one each, and two or more of these may be used. In this example, since the number of stacked electrodes was one for the positive electrode and one for the negative electrode, the width W2 of the mixture-uncoated portion 6c happened to be narrower for the positive electrode on the inner side and wider for the negative electrode on the outer side. When the number of stacked layers is large, the electrode inside the group is the width W2 of the mixture-uncoated portion 6c regardless of whether it is positive or negative.
Must be narrow and the outer electrode must be wide.

Further, although the rectangular electric double layer capacitor 1 has been described in the above embodiments, the present invention may be applied to an electrochemical element (for example, a battery) other than the rectangular electric double layer capacitor 1. It is possible.

[0024]

As described above, according to the invention of the electrochemical element of the present invention, the positive electrode sheet 8 having the outer can 2 and having the positive electrode mixture 7 applied to both sides or one side of the current collector 6 is provided.
A and a negative electrode sheet 8B in which the negative electrode mixture 9 is applied to both sides or one side of the current collector 6 are alternately laminated in a predetermined number and inserted into the outer can 2 to insert each of the positive electrode sheets 8
A separator 10 is inserted between A and each of the negative electrode sheets 8B so as to separate the positive electrode mixture 7 of the positive electrode sheet 8A and the negative electrode mixture 9 of the negative electrode sheet 8B from each other, and the opening of the outer can 2 An electrochemical element such as a rectangular electric double layer capacitor 1 in which a sealing plate 11 is fitted to a portion via a gasket 12, and the positive electrode sheet 8A has a mixture coating portion 6a at two locations on a current collector 6. 6b is provided so as to form a mixture-uncoated portion 6c between them, and the positive electrode mixture 7 is applied to each of the mixture-coated portions 6a and 6b, and the current collector 6 is attached to the mixture-uncoated portion 6c. The positive electrode sheet 8A is formed in a U shape so that it is located at the bottom of the U shape, and at the same time, the mixture application portions 6a and 6b are located at the respective rising sides of the U shape and face each other, and the negative electrode sheet 8B is used. As a mixture coating on the current collector 6 at two locations 6a, 6b and provided in the form of forming a material mixture uncoated portion 6c therebetween, these mixture application portion 6a, 6b
The negative electrode mixture 9 is applied to each of the above, and the current collector 6 is placed at the bottom of the U shape with the mixture non-application portion 6c, and at the same time, the mixture application portions 6a and 6b are provided on the respective rising sides of the U shape. Since the negative electrode sheet 8B formed in a U shape so as to be positioned and opposed to each other is used, two sets of the positive electrode mixture 7 or the negative electrode mixture 9 in symmetrical positions are formed in a U shape. Since the positive electrode sheet 8A or the negative electrode sheet 8B is integrated with each other, when the positive electrode sheet 8A, the negative electrode sheet 8B and the separator 10 are inserted into the outer can 2, the positive electrode sheet 8A, the negative electrode sheet 8B and the separator 10 are It is possible to avoid the occurrence of the situation of slipping. In addition, an insulating core material 16 is provided at the center of the electrode group 3 including the positive electrode sheet 8A, the negative electrode sheet 8B, and the separator 10.
In addition to the above effects, the electrode group 3
At the same time, the core material 16 inserted into the outer can 2 prevents the electrode group 3 from being bent when it is inserted.
Even if the number of laminated sheets A and the negative electrode sheet 8B is large, the electrode group 3 can be easily inserted into the outer can 2 and the productivity of the electrochemical device can be improved. Further, according to the invention of the method for producing an electrochemical element of the present invention, when an electrochemical element such as the rectangular electric double layer capacitor 1 is produced, a predetermined width is provided in the central portion of the flat plate-shaped current collector 6. The mixture-uncoated portion 6c of W2 is formed, and the mixture-coated portions 6a and 6b are formed on the current collector 6 portions on both sides of the mixture-uncoated portion 6c, respectively. The positive electrode mixture 7 or the negative electrode mixture 9 is applied to the mixture application portions 6a and 6b respectively with a predetermined width W1, and then,
The current collector 6 is sequentially cut together with the positive electrode mixture 7 or the negative electrode mixture 9 at a predetermined length L1 to produce the required number of positive electrode sheets 8A and negative electrode sheets 8B, and then these positive electrode sheets 8A. And the negative electrode sheets 8B are alternately laminated,
A separator 10 is laminated between each of the positive electrode sheets 8A and each of the negative electrode sheets 8B so as to separate the positive electrode mixture 7 of the positive electrode sheet 8A and the negative electrode mixture 9 of the negative electrode sheet 8B from each other. Then, the positive electrode sheet 8A, the negative electrode sheet 8B and the entire separator 10 are bent into a U shape to form an electrode group 3, and then the electrode group 3 is attached to the outer can 2
And then inject the electrolyte into the outer can 2,
Finally, since the sealing plate 11 is fitted into the opening of the outer can 2 via the gasket 12 to seal the casing, a method for manufacturing an electrochemical device having excellent productivity and high reliability is provided. It becomes possible to provide.

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of a rectangular electric double layer capacitor according to the present invention.

FIG. 2 is an enlarged sectional view of a bottom portion of the rectangular electric double layer capacitor shown in FIG.

FIG. 3 is an enlarged cross-sectional view of the bottom of another embodiment of the rectangular electric double layer capacitor according to the present invention.

4A to 4D are process diagrams showing a method for producing a positive electrode sheet and a negative electrode sheet that form the rectangular electric double layer capacitor shown in FIG. 2 or FIG.

FIG. 5 is a cross-sectional view showing an example of a conventional rectangular electric double layer capacitor.

FIG. 6 is a front view of an electrode sheet constituting the rectangular electric double layer capacitor shown in FIG.

[Explanation of symbols]

 1 ... Electrochemical element (square electric double layer capacitor) 2 ... Outer can 3 ... Electrode group 6 ... Current collectors 6a, 6b ... Mixing agent application part 6c ... Mixing agent unapplication part 7 ... Positive electrode mixture 8A ... Positive electrode sheet 8B ... Negative electrode sheet 9 ... Negative electrode mixture 10 ... Separator 11 ... Sealing plate 12 ... Gasket 16 ... Insulating core material

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical indication location H01M 10/04 Z 10/38 (72) Inventor Mitsuhiro Nakamura 5-36-11 Shinbashi, Minato-ku, Tokyo No. Fuji Electric Kagaku Co., Ltd. (72) Inventor Kazuo Takada 5 36-11 Shimbashi, Minato-ku, Tokyo Fuji Electric Kagaku Co., Ltd.

Claims (3)

[Claims] 1. A positive electrode sheet (8A) having an outer can (2), wherein a positive electrode mixture (7) is applied to both sides or one side of a current collector (6), and a negative electrode on both sides or one side of the current collector. A predetermined number of the negative electrode sheets (8B) coated with the mixture (9) are alternately laminated and inserted into the outer can, and separators (10) are provided between the positive electrode sheets and the negative electrode sheets. ) Is inserted so as to separate the positive electrode mixture of the positive electrode sheet and the negative electrode mixture of the negative electrode sheet from each other, and a sealing plate (11) is fitted to the opening of the outer can via a gasket (12). The above-mentioned electrochemical element (1), wherein the positive electrode sheet is provided with two mixture application portions (6a, 6b) on the current collector in the form of forming the mixture non-application portion (6c) therebetween. , The positive electrode mixture is applied to each of the mixture application parts, and the current collector is not applied with the mixture. Is formed on the bottom side of the U-shape, and at the same time, the mixture application portions are formed on the rising sides of the U-shape so as to face each other, and a positive electrode sheet formed in a U shape is used. The body is provided with two mixture-applied parts (6a, 6b) so as to form a mixture-unapplied part (6c) therebetween, and the negative electrode mixture is applied to each of the mixture-applied parts to collect the current. A negative electrode sheet was used in which the body was formed in a U-shape so that the mixture-uncoated portion was located on the bottom side of the U-shape and at the same time the mixture-coated portions were located on the rising sides of the U-shape and face each other. An electrochemical device characterized by the above. 2. A positive electrode sheet (8A) and a negative electrode sheet (8)
The electrochemical element according to claim 1, wherein an insulating core material (16) is inserted in a central portion of an electrode group (3) composed of B) and a separator (10). 3. When manufacturing the electrochemical device (1), a mixture-uncoated portion (6c) having a predetermined width (W2) is formed at the center of the flat plate-shaped current collector (6), and Mixture applying portions (6a, 6b) are formed on the current collector portions on both sides of the mixture unapplied portion, and then, the positive electrode mixture (7) or the negative electrode is applied to each mixture applying portion of the current collector. The mixture (9) is applied in a predetermined width (W1), and then the current collector is sequentially cut together with the positive electrode mixture or the negative electrode mixture in a predetermined length (L1) to obtain a required number of positive electrodes. A sheet (8A) and a negative electrode sheet (8B) are produced, and then the positive electrode sheet and the negative electrode sheet are alternately laminated, and a separator (10) is provided between the positive electrode sheet and the negative electrode sheet. The positive electrode mixture of the sheet and the negative electrode mixture of the negative electrode sheet are laminated so as to be separated from each other, In this state, the positive electrode sheet, the negative electrode sheet, and the separator as a whole are bent in a U shape to form an electrode group (3), and then the electrode group is inserted into the outer can, and further, an electrolyte solution is placed in the outer can. And finally, a sealing plate (11) is fitted into the opening of the outer can via a gasket (12) to seal the same.