JP3167667B2 - Battery current collector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a current collector for a battery, and more particularly to a current collector for an alkaline secondary battery.

[0002]

2. Description of the Related Art A current collector for electrically connecting them is provided between a current collecting strip (tab) of a winding electrode inside a battery and an external terminal of the battery. Figure 5
And FIG.

The current collector 1 comprises a rectangular flat plate portion 2, a cutout 3 formed by cutting a rectangular central portion of the flat plate portion 2 into a rectangular shape and rising, and a raised portion. And a contact portion 4 to be brought into contact with an external terminal of the battery. A bent edge portion 6 is formed at a longitudinal outer edge portion 5 of the flat plate portion 2 by bending downward at 90 ° in the figure. I have. Then, as shown in FIG. 7, the tip of the contact portion 4 is bent into a U-shape and welded to the lid 8 having the external terminal 7, and the bent edge portion 6 of the battery winding electrode 9 as shown in FIG. A current collecting strip (tab) 10 fixed to the end is fitted and engaged and welded.

[0004]

By the way, as shown in FIG. 7, the contact portion 4 is welded to the inner surface of the lid 8, and the contact portion 4 has a shorter length and a larger plate thickness. As a result, a large amount of current flows to improve the discharge characteristics of the battery. However,
The length of the contact portion 4 cannot be reduced to a certain value or less due to welding with the lid 8, and changing the shape of the contact portion 4 also causes an increase in cost. Further, if the thickness of the current collector 1 is increased, the thickness of the contact portion 4 is also increased, which is convenient. However, the bent edge portion 6 is also thicker than the bent edge portion 6. When welding with a thin current collecting strip (tab) 10, there is a problem that a welding current does not easily flow to the current collecting strip 10 and the wraparound of the welding current becomes small so that welding cannot be performed.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a battery current collector having good discharge characteristics.

[0006]

In order to solve the above-mentioned problems of the prior art, a battery current collector of the present invention has a plurality of radial cutouts formed in a disc-shaped substrate, and the cutouts of the cutouts are mutually connected. A bent edge portion for bending both opposing radial edges in one direction with respect to the plane of the substrate to be fixed to the current collecting strip of the electrode is provided. A slit having a length wider than the width is formed, and a plate-shaped rising portion extending in the other direction from the substrate plane is formed by cutting and rising at a central portion of the substrate, and a rising portion of the rising portion is formed at a tip side of the rising portion. It is characterized in that a contact plate thicker than the plate thickness is fixed. It is desirable that a portion corresponding to the leading end of the rising portion of the cut in the center of the substrate for forming the plate-like rising portion is formed in an arc shape.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a current collector of a battery according to the present invention will be described below with reference to FIGS.

The current collector 15 is, for example, a current collector for an alkaline secondary battery, and has a circular substrate 16 and an elongated tongue-shaped contact plate 17. The substrate 16 is made of a nickel plate, and has a rising portion 18 formed by cutting and raising.
, A plurality of radial notches 19, and bent edges 20 on both side edges of each notch 19.

The rising portion 18 is formed by cutting a central portion of the substrate 16 into a tongue shape and rising substantially perpendicularly upward with respect to the substrate 16. When the leading end 18a (FIG. 1) is formed in an arc shape at the time of cutting the rising portion 18, it is possible to prevent the distance S from the slit 21 shown in FIG.

Each of the notches 19 has a rectangular shape.
6 are formed radially at intervals of 60 °, for example, from the periphery of 6 toward the rising portion 18 at the center and surrounding the rising portion 18. A slit 21 having a length perpendicular to the length direction of the notch 19 and wider than the width of the notch 19 is formed at the back of the notch 19. A roundness 23 is formed.

The bent edge portion 20 is formed so that both edges 24 parallel to each other in the longitudinal direction of the notch portion 19 face downward in FIG.
° bent.

The contact plate 17 is a nickel plate which is thicker than the substrate 16 and is formed in an elongated tongue shape having a curved edge 17a as shown in FIG. Then, the contact plate 17
Is fixed at a position near the front end of the surface of the rising portion 18 of the substrate 16 by welding or the like as shown in FIGS.

The contact plate 17 of the current collector 15 is configured as described above and is thicker than the rising portion 18 of the substrate 16, so that the rising portion 18 is welded to the lower surface of the lid 8 (FIG. 7). Electric resistance is lower than that. On the other hand, since the thickness of the bent edge portion 20 is the same as the thickness of the substrate 16 and the conventional thickness, the welding between the bent edge portion 20 and the current collecting strip (tab) 10 shown in FIG. Can also be performed neatly.

The reason for providing the slit 21 is as follows. That is, assuming that there is no slit 21, when welding the bent edge portion 20 to the current collecting strip 10 (FIG. 6), a welding current to flow from the bent edge section 20 to the current collecting strip 10 is applied to the surface of the substrate 16. It flows along, and welding tends to be insufficient. However, when the slit 21 is provided,
The slit 21 prevents free current flow on the substrate 16 and facilitates current flow to the welded portion. Also, slit 2
The roundness at the end of 1 prevents stress concentration, prevents cracking and cracking during welding, and also prevents cracking and cracking due to vibration.

In the present embodiment, the substrate 16 and the contact plate 17 of the current collector 15 are nickel plates, but may be nickel-plated iron. The current collector 15
Shows a case where the present invention is applied to an alkaline secondary battery, but can be applied to other batteries.

[0016]

As described above, the current collector of the battery according to the present invention has a plurality of radial cutouts formed in a disc-shaped substrate.
A bent edge portion is provided to bend the opposite radial edges of each cutout in one direction with respect to the plane of the substrate and to fix the cutout to the current collecting strip of the electrode. Forming a slit having a length wider than the width of the notch, forming a plate-shaped rising portion extending in the other direction from the substrate plane by cutting and rising the central portion of the substrate, and forming a tip of the rising portion. Since the contact plate thicker than the plate thickness of the rising portion is fixed to the side, current flows easily through the contact plate, so that the current collector is easily welded to the lid, and the discharge characteristics of the battery are improved. In addition, since the substrate has this shape, the positive electrode of the current collector (this embodiment) has a shape similar to that of the negative electrode (not shown) of the current collector, and the welding conditions for the current collector to the lid and the like are different. Can be made the same, and productivity is improved. Furthermore, since the rising portion and the contact plate are of a split type, the position at which the contact plate is fixed to the rising portion can be selected, so that the positioning between the current collector and the lid becomes easy. Since the rising portion uses a part of the substrate, there is an effect that the material cost can be saved. In addition, the notch of the current collector substrate is set in the radial direction, and bent edges are formed at both opposite radial edges of each notch, so that the shape of the current collector conforms to the wound electrode, and further the notch is formed. By the slit in the back of
This makes it easier to supply current to the welded portion, and prevents the substrate portion near the slit from becoming too narrow. In addition, if the cut portion corresponding to the leading end portion is formed in an arc shape, the current to the welded portion can more easily flow,
The substrate portion near the slit can be further prevented from becoming too narrow.

[Brief description of the drawings]

FIG. 1 is a perspective view showing one embodiment of a current collector of a battery of the present invention.

FIG. 2 is a plan view of FIG. 1;

FIG. 3 is a vertical sectional view taken along line AA of FIG. 2;

FIG. 4 is an elevation view of a contact plate.

FIG. 5 is a perspective view of a current collector of a conventional battery.

FIG. 6 is a partial cross-sectional perspective view of a conventional battery.

FIG. 7 is a longitudinal sectional view of a conventional battery.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 15 Current collector 16 Substrate 17 Contact plate 18 Rise 19 Notch 20 Bent edge 21 Slit 23 Roundness

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01M 2/20-2/34 H01M 10/28

Claims (2)

(57) [Claims] 1. A plurality of radial cutouts are formed in a disk-shaped substrate, and both radial edges of each cutout facing each other are bent in one direction with respect to the plane of the substrate to form a current collecting strip for an electrode. A bent edge part is provided for fixing to the bottom of each radial cutout.
Forming a slit having a length wider than the width of the notch, forming a plate-shaped rising portion extending in the other direction from the substrate plane by cutting and rising at the center of the substrate, and the leading end side of the rising portion. A contact plate thicker than the plate thickness of the rising portion. 2. A current collector for a battery according to claim 1, wherein a portion corresponding to the leading end of the rising portion of the cut in the center of the substrate for forming the plate-shaped rising portion is formed in an arc shape. body.