JP2002279962A - Sealed battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sealed battery which enables enhancing current-collecting efficiency and restraining the cost. SOLUTION: This sealed battery 10 comprises a power-generating element 14 equipped with a metal foil 12 to be a negative electrode and a positive electrode interposing a separator and current-collecting plates 15, 20 of the negative and positive electrodes connected with an end edge of the foil 12 in a surface direction through electric resistance welding; plural current collecting section s16 of the negative and positive electrodes with an approximately V-shaped in section for laminatingly storing the metal foil 12 for each plural sheets are respectively formed on the plates 15, 20 of the negative and positive electrodes and the sections 16 are arranged in parallel with each other. The battery 10 has both sections 16 connected with each other via a terminal support sections 18, 21 of the negative and positive electrodes mounted on respective end part 17 in the longitudinal direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealed battery,
In particular, the present invention relates to a sealed battery having a power generation element in which a negative electrode and a positive electrode are stacked with a separator interposed therebetween, and a negative electrode current collector is connected to one side of the power generator and a positive electrode current collector is connected to the other side.

[0002]

2. Description of the Related Art A sealed battery 70 shown in FIG. 12 is composed of a wound power generating element 72 having a negative electrode and a positive electrode laminated via a separator, having a substantially elliptical shape, and an axial direction of the power generating element 72. Positive electrode part 74 and negative electrode part provided respectively at both ends
76, a positive current collector 75 and a negative current collector 77 connected to the positive electrode portion 74 and the negative electrode portion 76, respectively, and a power generating element connected to the positive current collector 75 and the negative current collector 77, respectively.
A positive electrode terminal 78 and a negative electrode terminal 79 extending substantially parallel to the axis of the power generating element 72 from the positive electrode part 74 side of the power generating element 72, and the power is generated such that an end 78 A of the positive terminal 78 and an end 79 A of the negative terminal 79 are externally exposed. A substantially box-shaped sealed battery package 80 that accommodates the element 72 is provided.

The negative electrode of the power generating element 72 is a strip-shaped copper foil, and a carbon-based organic polymer is applied as an active material on both surfaces thereof so that copper is exposed at a predetermined width from both ends in the width direction.
On the other hand, the positive electrode of the power generating element 72 is a band-shaped aluminum foil, and an oxide such as cobalt, nickel, or manganese is applied as an active material on both surfaces thereof so that aluminum is exposed at a predetermined width from both ends in the width direction. .

Incidentally, the positive electrode current collector 75 and the negative electrode current collector 77
Various improvements have been made to increase the current collection efficiency. For example, as shown in FIG. 13, the technology disclosed in Japanese Patent Application Laid-Open No. H10-26144 presses a plate 84 of a positive electrode current collector 82 corresponding to the positive electrode current collector 75 shown in FIG. A few positive electrodes 87 stacked on the bent portions 85A, 85B, 85C
(See Fig. 14). Next, as shown in FIG. 14, the positive electrode 87 exposed from the notch 86 formed in the bent portion 85A, 85B, 85C of the bellows-shaped plate 84 is welded by a laser beam so as to be filled with the welded portion 88. The positive electrode in the bent part 85
Connect 87.

[0005]

However, the positive electrode current collector 82
Has a narrow portion 92 between the bellows-like bent portions 85A, 85B, 85C and a mounting hole 91 for mounting a positive electrode terminal (not shown), and this portion 92 constitutes a current collecting path. I do. As described above, since the narrow portion 92 exists in the middle of the current collection path, the current collection resistance of the portion 92 increases during current collection,
This hinders the efficiency of current collection.

In order to weld the positive electrode 87 exposed from the notch portion 86 of the bent portion 85 so as to fill the same, the angle of the laser is set to 15 degrees as an example in order to perform welding while avoiding the exposed positive electrode 87. It is necessary to adjust with high precision. For this reason, the equipment cost increases, which hinders the cost of the sealed battery from being reduced. Further, if a portion 85A of the bent portion 85 shown in FIG. 13 is damaged, the other bent portions 85B and 85C are separated from the portion 92, so that the current is also collected from the bent portions 85B and 85C. Cannot be performed, which hinders the improvement of current collection efficiency.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a sealed battery capable of increasing current collection efficiency and reducing costs.

[0008]

In order to achieve the above-mentioned object, the present invention provides a power generating element including a metal foil serving as a negative electrode and a positive electrode via a separator, as described in claim 1; A current collector connected to the edge in the surface direction of the metal foil by electric resistance welding, and a plurality of current collectors having a substantially V-shaped cross-section for stacking and storing a plurality of the metal foils are provided on the current collector; A sealed battery in which the current collectors are arranged in parallel with each other, wherein the current collectors are connected via a terminal support provided at a longitudinal end. Features.

In the sealed battery thus configured, a plurality of metal foils are stacked and housed in a plurality of metal foils at a current collector having a substantially V-shaped cross section, and a plurality of current collectors are provided at the ends in the longitudinal direction. They were connected via a terminal support. Therefore, power can be collected from both sides of the power generating element. In addition, by connecting the plurality of current collectors via the terminal support, there is no portion that suddenly narrows in the middle of the current collection path. For this reason, at the time of current collection, the current collection resistance can be kept small. Furthermore, by connecting a plurality of current collectors via terminal supports, it is possible to collect power from each of the current collectors in parallel, so to speak, even if a specific location is damaged, power can be collected from other portions. it can.

Further, in the present invention, as set forth in claim 2, each of the current collectors and the terminal support are connected by welding. Since each current collector is connected to the terminal support by welding, it is not necessary to integrally form each current collector and the terminal support.

Further, in the present invention, as set forth in claim 3, each of the current collectors is formed by press working. By pressing each current collector, the current collector can be easily formed as compared with cutting.

[0012]

Embodiments of the present invention will be described below in detail with reference to the drawings. In each of the embodiments described below, the members and the like already described in FIG. 1 are denoted by the same reference numerals or corresponding reference numerals in the drawings to simplify or omit the description.

As shown in FIG. 1, a sealed battery 10 according to a first embodiment of the present invention includes a metal foil 12 (a metal foil of a positive electrode) serving as a positive electrode and a negative electrode via a separator (not shown). 12 with only 12)
14, a positive electrode current collector 15 connected to the planar edge of the metal foil 12 serving as the positive electrode by electric resistance welding, and a negative current collector connected to the planar edge of the metal foil serving as the negative electrode by electric resistance welding. Board
20, the positive and negative terminals 25 and 26 connected to the positive and negative current collectors 15 and 20, respectively, and the power generating element 14 so that the end 25A of the positive terminal 25 and the end 26A of the negative terminal 26 are externally exposed. And a substantially box-shaped sealed battery package 29 for housing the battery.

As shown in FIG. 2, the positive electrode current collector plate 15 is provided with a plurality of positive electrode current collectors 16 each having a substantially V-shaped cross section for accommodating a plurality of metal foils 12 each serving as a positive electrode. The current collectors 16 are arranged in parallel with each other, and the respective positive electrode current collectors 16 are connected via a positive electrode terminal support 18 provided at a longitudinal end portion 17.

Here, the respective positive electrode current collectors 16 are arranged over both sides 14A, 14B of a winding type power generating element 14 which is flattened in a substantially elliptical shape, so that both sides 14A, 14B of the power generating element 14 are provided. Since current can be collected from the power supply, the current collection efficiency can be increased. In addition, since the plurality of positive electrode current collectors 16 are individually connected to the positive electrode terminal support 18, there is no sharply narrow portion in the current collection path. For this reason, at the time of power collection, the current collection resistance of the current collection path can be reduced, and the current collection efficiency can be increased.

Further, by connecting the plurality of positive current collectors 16 individually to the positive terminal support 18, each of the plurality of positive current collectors 16 is connected to the positive terminal support 18 independently. Therefore, since the current can be collected in parallel from the respective positive electrode current collectors 16 to the positive electrode terminal supporters 18, so to speak, even if a specific location (that is, one of the plurality of positive electrode current collectors 16) is damaged, Power can be collected from the other positive electrode current collector 16. For this reason, current collection efficiency can be improved.

The positive electrode terminal supporting portion 18 is bent at the center 18A so as to be substantially L-shaped.
The respective longitudinal ends 17 of the power generating elements 16 are connected, and the upper piece 19B is disposed so as to cover the upper side 14C (see FIG. 1) of the power generating element 14, and the positive electrode 25 is erected on the upper piece 19B. Therefore, the positive electrode 25 is provided on the upper side 14C side of the power generation element 14.

The negative electrode current collector 20 shown in FIG.
Similarly to the above, a plurality of negative electrode current collectors (not shown) each having a substantially V-shaped cross-section for stacking and storing a plurality of metal foils serving as negative electrodes are provided, and the respective negative electrode current collectors are arranged in parallel with each other.
Each negative electrode current collector is connected via a negative electrode terminal support 21 provided at a longitudinal end (not shown). Therefore, the same effect as that of the positive electrode current collector plate can be obtained. Since the negative electrode current collector 20 has the same configuration as the positive electrode current collector 15, the positive electrode current collector 15 will be described below and the description of the negative electrode current collector 20 will be omitted.

In the positive electrode current collector 15 shown in FIG. 2, each positive electrode current collector 16 is connected to the positive electrode terminal support 18 by welding, as described above. Therefore, it is not necessary to integrally form each of the positive electrode current collectors 16 and the positive electrode terminal support portions 18, so that component costs and manufacturing costs can be reduced. In addition, each positive electrode current collector 16
Is formed in a substantially V-shaped cross section by press working.
By pressing each positive electrode current collector 16, each positive electrode current collector
16 can be formed at a lower cost than when cutting.

As shown in FIG. 3, the metal foil 12 serving as the positive electrode fitted into the positive electrode current collector 16 is irradiated with a laser beam 28 on the ridge 16A of the positive electrode current collector 16 so as to form a positive electrode. 16 ridges
16A and the metal foil 12 are welded. Thus, the laser light
Since it is only necessary to adjust the distance of the laser beam 28 to the ridge 16A of the positive electrode current collector 16, the metal foil 12 and the ridge 16A of the positive electrode current collector 16 need not be strictly adjusted. Can be reliably welded and connected. For this reason, equipment costs for adjusting the angle of the laser beam 28 can be reduced. In addition, since it is not necessary to strictly adjust the angle of the laser beam 28, it is possible to prevent a welding error from occurring. Therefore, the quality of the sealed battery 10 can be improved.

The positive electrode current collector 16 is formed by caulking both pieces 16B and 16C bent in a substantially V shape from both sides as shown by arrows. Thus, both pieces 16B, 16B of the positive electrode current collector 16 are
By crimping C, a plurality of metal foils 12
Can be reliably maintained in a stably inserted state, and laser light can be reliably prevented from coming off. Therefore, the quality of the sealed battery 10 can be improved.

Next, a second embodiment will be described with reference to FIGS. The positive electrode current collector 30 of the second embodiment shown in FIG.
A plurality of through-holes 32 are formed at predetermined intervals in a ridge 31A of the positive electrode current collector 31. Therefore, as shown in FIG.
It can be confirmed whether the metal foil 12 serving as the positive electrode has been inserted deep into the positive electrode current collector 31. In addition, the ridge 31A of the positive electrode current collector 31
By providing the through-holes 32, the positive electrode current collector 31 in the unfolded state shown in FIG. 6 can be easily bent at the ridges 31A as indicated by arrows. Therefore, the quality of the sealed battery 10 can be improved.

Next, a third embodiment will be described with reference to FIGS. The positive electrode current collector 40 of the third embodiment shown in FIG.
The slit (through hole) 42 provided in the ridge 41A of the positive electrode current collector 41 is formed continuously from the ridge 41A toward the skirt 41B for a predetermined length. In this manner, by providing the slit 42 at the ridge 41A of the positive electrode current collector 41, it is confirmed whether the metal foil 12 serving as the positive electrode has been inserted deep into the positive electrode current collector 41 as shown in FIG. it can.

In addition, the slit 42 is formed from the ridge 41A to the hem.
By continuing the specified length toward 41B, the positive current collector
When the two pieces bent into the V-shape 41 are caulked, the metal foil 12 can be caulked with a light caulking force.
Can be securely gripped. Therefore, the quality of the sealed battery 10 can be improved.

It is preferable that the relationship between the developed width W of the positive electrode current collector 41 shown in FIG. 9 and the length W1 of the slit 42 be W1 ≦ (1/2) × W. If W1 exceeds (1/2) × W, the positive electrode current collector 41 may be broken. However, when there is no possibility that the positive electrode current collector 41 is broken, W1 can exceed (1/2) × W.

The width W2 of the positive electrode current collector 41 is 0.1 to 0.5 mm.
It is preferable to set The width W2 of the positive electrode current collector 41 is 0.
If it is smaller than 1 mm, the slit 42 is too small and the slit 4
It is difficult to obtain the effect of forming 2, and there is a possibility that the equipment for processing the slit 42 may increase. On the other hand, if the width W2 of the positive electrode current collector 41 exceeds 0.5 mm, the width W2 of the slit 42 is too large, and the connection portion between the metal foil 12 and the positive electrode current collector 41 is reduced, thereby lowering the current collection efficiency. Also,
It is difficult to secure the rigidity of the positive electrode current collector 41.

Next, a sealed battery according to the third and fourth embodiments will be described with reference to FIGS. In a sealed battery 50 according to the third embodiment shown in FIG. 10, a positive current collector 52 and a positive terminal support 53 of a positive current collector 51 are integrally formed, and a negative current collector of a negative current collector 55 (see FIG. 10). (Not shown) and the negative electrode terminal supporting portion 57 are integrally formed. Therefore, each positive electrode current collector
The work of welding 52 to the positive terminal support 53 can be omitted, and the work of welding the negative current collector to the negative terminal support 57 can be saved.

The sealed battery 60 of the fourth embodiment shown in FIG.
Are the positive terminal support parts of the positive and negative current collectors 61 and 65, respectively.
By making the configuration that the 62 and 66 are not bent into the L shape, the positive and negative terminals 67 and 68 are provided at both ends 14D and 14E of the power generating element 14. Therefore, the positions of the positive and negative terminals can be appropriately changed according to the use of the sealed battery.

It should be noted that the sealed battery of the present invention is not limited to the above-described embodiment, but can be appropriately modified and improved. In addition, the materials, shapes, dimensions, and the like of the negative electrode, the positive electrode, the power generation element, the positive and negative electrode current collectors, the positive and negative electrode current collectors, the positive and negative electrode terminal support parts, and the like exemplified in the above-described embodiments.
The form, the number, the location, the thickness and the like are not limited as long as the present invention can be achieved.

[0030]

As described above, according to the present invention, as described in the first aspect, a plurality of metal foils are stacked and accommodated in the current collector having a substantially V-shaped cross section, and a plurality of collectors are formed. The electrical parts were connected via a terminal support provided at the longitudinal end.
For this reason, since current can be collected from both sides of the power generation element, the current collection efficiency can be increased.

In addition, by connecting a plurality of current collectors via the terminal support, there is no portion that suddenly narrows in the middle of the current collection path. For this reason, at the time of current collection, the current collection resistance can be kept small, and the current collection efficiency can be increased. Furthermore, by connecting a plurality of current collectors via terminal supports, it is possible to collect power from each of the current collectors in parallel, so to speak, even if a specific location is damaged, power can be collected from other portions. it can. For this reason, current collection efficiency can be improved. In addition, since the difference in resistance between each part of the electrode and the current collecting terminal is reduced, even at a high rate of charge / discharge, variations in the potential distribution and operation depth of the electrode can be reduced, and a decrease in cycle life can be reduced.

Further, in the present invention, since each current collector is connected to the terminal support by welding, it is not necessary to integrally form each current collector and the terminal support. . For this reason, component costs and manufacturing costs can be reduced.

Further, in the present invention, as described in claim 3, by pressing each current collector, the current collector can be formed at a lower cost than cutting.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a sealed battery according to a first embodiment of the present invention.

FIG. 2 is an enlarged view of a main part of the sealed battery according to the first embodiment of the present invention.

FIG. 3 is a cross-sectional view showing a positive electrode current collector of the sealed battery according to the first embodiment of the present invention.

FIG. 4 is a perspective view showing a positive electrode current collector plate of a sealed battery according to a second embodiment of the present invention.

FIG. 5 is a side view showing a positive electrode current collector of a sealed battery according to a second embodiment of the present invention.

FIG. 6 is a developed view showing a positive electrode current collector of a sealed battery according to a second embodiment of the present invention.

FIG. 7 is a perspective view showing a positive electrode current collector plate of a sealed battery according to a third embodiment of the present invention.

FIG. 8 is a side view showing a positive electrode current collector of a sealed battery according to a third embodiment of the present invention.

FIG. 9 is a developed view showing a positive electrode current collector of a sealed battery according to a third embodiment of the present invention.

FIG. 10 is a perspective view showing a sealed battery according to a fourth embodiment of the present invention.

FIG. 11 is a perspective view showing a sealed battery according to a fifth embodiment of the present invention.

FIG. 12 is a perspective view showing a conventional sealed battery.

FIG. 13 is a perspective view showing a positive electrode current collector plate of a conventional sealed battery.

FIG. 14 is a side view showing a positive electrode current collector plate of a conventional sealed battery.

[Explanation of Signs] 10, 50, 60 sealed battery 12 metal foil 14 power generation element 15, 30, 40, 51, 61 current collector (positive electrode current collector) 16, 31, 41, 52 current collector (positive electrode current collector) 17) Longitudinal end 18, 53, 62 Terminal support (positive terminal support) 20, 55, 65 Current collector (negative current collector) 21, 57, 66 Terminal support (positive terminal support)

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Hiroshi Yufu, 2-3-1, Furube-cho, Takatsuki-shi, Osaka F-term in Yuasa Corporation (reference) 5H022 BB01 BB17 CC12 CC16 CC22 EE01 5H029 AJ02 AJ05 AJ14 AK03 AL06 BJ02 BJ14 CJ03 CJ05 DJ05 DJ07

Claims (3)

[Claims] 1. A power generating element including a metal foil serving as a negative electrode and a positive electrode with a separator interposed therebetween, and a current collector connected to an edge in a surface direction of the metal foil by electric resistance welding, wherein the metal foil A plurality of current collectors each having a substantially V-shaped cross section for stacking and storing a plurality of the plurality of power collectors are provided on the current collector plate, and the current collectors are arranged in parallel with each other. A sealed battery, wherein a current collector is connected via a terminal support provided at a longitudinal end. 2. The sealed battery according to claim 1, wherein each of the current collectors and the terminal support are connected by welding. 3. The sealed battery according to claim 1, wherein each of the current collectors is formed by press working.