JP2000260418A - Current collector for cylindrical storage battery and cylindrical storage battery - Google Patents

Abstract

(57) [Problem] To provide a current collector for a cylindrical storage battery in which the welding strength of a spiral electrode group to a spiral positive electrode plate or a negative electrode plate is increased. SOLUTION: A ridge 2 having a flat bottom surface 2a intersecting with a protruding edge P1 of a spiral positive electrode plate P of a spiral electrode plate group G is disposed on a current collecting metal plate 1a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a current collector for a cylindrical storage battery and a cylindrical storage battery.

[0002]

2. Description of the Related Art A current collector used in a conventional cylindrical storage battery is disclosed in JP-B-53-3052 and JP-A-60-105.
As disclosed in Japanese Patent Publication No. 166/166 and the like, a linear projection corresponding to the thickness of the current collecting metal plate is formed by bending a part of the current collecting metal plate at a right angle and projecting from the plate surface. When using the spiral electrode, the projecting ridge is brought into contact with the projecting end edge of the spiral electrode plate having a predetermined polarity in the spiral electrode plate group by intersecting with the projecting edge, and the point-like intersection is electrically welded by a welding electrode. It is known to collect electricity from the polar plates of the same polarity in a plate group and to take out the electricity to the polar terminals of the cylindrical storage battery.

[0003]

However, in the above-mentioned current collector, the linear ridge corresponding to the thickness of the metal plate is welded at a point intersection with the projecting edge of the spiral electrode plate. Therefore, since the welding area is small, the welding strength is low. Therefore, the current collector welded to the spiral electrode plate group easily peels off due to impact, vibration, etc., and the welding fixation to the spiral electrode plate group lacks reliability. The internal resistance of the spirally-wound electrode plate increased, and the electric energy of the spirally-wound electrode plate could not be sufficiently extracted to the outside via the current collector. Therefore, it is desired to develop a current collector for a cylindrical storage battery which has a small internal resistance, can increase the welding strength to the spiral electrode plate, and can reduce the internal resistance.

[0004]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional problems and provides a current collector for a cylindrical storage battery which satisfies the above-mentioned demands. The present invention is characterized in that a protruding ridge having a flat bottom surface intersecting with and abutting on a protruding end edge of a spiral electrode plate having a predetermined polarity of a plate group is provided. Furthermore, the present invention provides a current collector for a cylindrical storage battery that reduces current shunt during current welding and provides a stronger current welding fixation.
An opening interposed between the ridges having the flat bottom surface is provided. Further, the present invention provides a cylindrical storage battery having good stability, and comprises a spirally wound electrode plate group to which the above-mentioned current collector of the present invention is welded.

[0005]

The current collector is mounted on the current collector with a projection having a flat bottom face crossing the projecting edge of the spiral electrode plate having a predetermined polarity in the spiral electrode plate group, and a welding electrode is placed on the upper surface thereof. When the contact welding current is applied, the welding current is concentrated on the ridge, and the intersection between the flat bottom surface of the ridge and the protruding edge of the spiral electrode plate with respect to the protruding edge of the spiral electrode plate. Since linear welding with the protruding edge having a length corresponding to the width of the flat bottom is performed,
The welding area is increased as compared with spot welding, and stronger welding is performed.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the accompanying drawings. In the drawing, reference numeral 1 denotes a current collector for a cylindrical storage battery according to an embodiment of the present invention, which is used for current welding to a spiral positive electrode plate of a spiral electrode plate group. The current collector 1
Is punched and formed from a large nickel-plated steel plate having a thickness of about 0.3 mm into, for example, a disk having a size suitable for being accommodated in the upper opening of the bottomed cylindrical can of a predetermined cylindrical storage battery. In the example shown in the figure, a circular hole 1b for injecting an electrolytic solution is formed at the center of the current collecting metal plate 1a. An ear 1c to be welded is provided on the back surface of the punched cylindrical storage battery lid.

According to the present invention, as shown in FIGS. 1 and 2, the current collector 1 is provided on a current collecting metal plate 1a with a projecting edge of a spiral positive electrode plate of a predetermined spiral electrode plate group. A ridge 2 having a flat bottom surface 2a that crosses and abuts (hereinafter, abbreviated as a flat ridge 2) is provided. In FIG. 1, the spiral positive electrode plate P and its protruding edge P1 are represented by imaginary lines, and the positional relationship between the current collecting metal plate 1a and the flat ridge 2 is shown. In addition, as shown in the figure, it is preferable that the flat ridge 2 has a length that crosses and abuts the entire circumference from the innermost circumference to the outermost circumference of the spiral positive electrode plate P. As a result, it is possible to obtain extremely strong fixation by current welding to the entire spiral positive plate P. In the example shown in the figure, the flat ridge 2 is formed by bending a metal plate 1a for circular current collection with a mold, and is bent downward from the surface of the plate into a U-shaped cross section. The end is located in the vicinity of the center circular hole 1b, the outer end of which has a length reaching the periphery of the circular current collecting metal plate 1a, and has a rectangular ridge 2 having a flat bottom surface 2a. The flat ridges 2 were formed on the current collector 1 which was disposed on the circular current collecting metal plate 1a at 90-degree angle intervals in the front, rear, left, and right directions. The number of the flat ridges 2 and the rotation angle interval are not limited to these and are arbitrary. As an example, the diameter of the current collecting metal plate is 2
3.0 mm, the length of the flat ridge 2, in other words, the length of the flat bottom surface 2 a is a dimension close to the radius of the circular current collecting metal plate, and the degree of protrusion is 0 mm from the metal plate surface. .
5 mm, and the width of the flat bottom surface 2a was about 1-2 mm. Of course, it is not limited to this dimension.

[0008] Since there are various types of diameters of the spiral electrode plate group, the size of the current collecting metal plate having a different size is selected and manufactured in accordance with the diameter, and a long flat ridge is formed in accordance with the selected size. Formed to produce various current collectors.

FIGS. 3 and 4 show another embodiment of the current collector 1 of the present invention. In this embodiment, the circular current collecting metal plate 1 is used.
The elongated rectangular flat ridge 2 formed on the metal plate 1a is formed up to the vicinity of the periphery of the circular metal plate 1a.
A pair of parallel flat ridges 2 and 2 are disposed at four locations at an angular interval of 90 degrees, and a slit-shaped opening 3 is interposed between the pair of parallel flat ridges 2 and 2. Is formed.

FIGS. 5 and 6 show still another embodiment of the present invention. In this embodiment, a square current collecting metal plate 1a is used.
On both sides of the central hole 1b, flat ridges 2 reaching the left and right ends of the current collecting metal plate 1a are disposed in parallel, and the current collecting metal plate 1a is interposed between the flat ridges 2 and 2. A slit-shaped opening 3 extending from the left and right ends to the vicinity of the center hole 1b is disposed on the left and right.

The spiral electrode group for current welding the current collector plate 1 of the present invention is composed of a spiral positive electrode plate P and a spiral negative electrode plate N laminated via a separator S and spirally wound. As shown in FIG. 7, the outer edge P1 of the positive electrode plate P protrudes toward one side by shifting the positive electrode plate P and the negative electrode plate N by a small allowable position in the width direction as shown in FIG. When the spirally wound electrode plate group G is erected as shown in FIG. 8 with the outer edge projecting to the other side, the upper edge P1 of the spirally wound positive electrode plate P projects on the upper surface, while the spirally wound electrode plate G On the lower surface of the group G, a lower edge N1 of the spiral negative electrode plate N is configured to protrude. In FIG. 8, T indicates an adhesive tape for preventing the spirally wound electrode group G from being unwound.

In this case, the protruding edge P1 of the positive electrode plate P and the protruding edge N1 of the negative electrode plate N are, as shown in FIG. Preferably, at least one side of the porous metal substrate filled with is formed of a metal band-shaped plate portion such as non-porous nickel-plated iron not filled with an active material.

In the illustrated embodiment, a Ni positive electrode plate P is used as the positive electrode plate P, and an MH negative electrode plate mainly composed of MmNi-based hydrogen storage alloy powder is used as the negative electrode plate N, and these are made of nylon as described above. Spirally wound through a microporous separator S, such as a non-porous end portion P of the spirally wound positive electrode plate P on the upper surface thereof.
1 was protruded, and a spiral electrode plate group G having a non-porous end portion N1 of the spiral negative electrode plate N protruding from the lower surface thereof was produced. For example, the current collector 1 of the present invention shown in FIGS.
Of the spiral positive electrode plate P projecting from the upper surface of the spiral electrode plate group G.
And a pair of welding electrodes 4 and 5 having a diameter larger than the width of the U-shaped cross section of the upper surface of the flat ridge 2.
Is pressed onto the upper surfaces of the pair of flat ridges 2 and 2 in a state of straddling the concave groove having a U-shaped cross section, and when a welding current is applied, the welding current is concentrated on the ridges 2 and 2 at the same time. 9, the flat bottoms 2a, 2 of the flat ridges 2, 2 are clearly shown in FIG.
As for a, each linear crossing portion 5, 5 having a length corresponding to the width of the rectangular bottom surface 2a, 2a is formed with respect to the protruding edge P1 of the spiral positive electrode plate P intersecting therewith. Flat ridges 2 that contact the upper end surface of each protruding edge P1 in the portions 5 and 5
Of each flat surface 2a is obtained.
In the example shown in the figure, the shape of the welding electrode is cylindrical, but the shape is not limited to this. The upper surface of the U-shaped groove on the upper surface of the flat ridge 2 is not limited thereto. Can be used in a desired shape such as a rectangular parallelepiped shape that covers the entire length of the object.

As described above, according to the present invention, the flat ridges 2 provided on the current collecting metal plate 1a of the current collector 1 are fixed to the spiral positive electrode plate by the long rectangular wide flat surface 2a of the bottom wall thereof. 1 is a linear intersection having a larger area than the conventional point-like intersection, so that it is significantly stronger than the conventional point-like welding. Welding is obtained, and each linear weld fixing portion 5 having increased peel resistance is obtained. Thus,
An assembly in which the current collector 1 is stably and securely welded to the spiral electrode plate group G is obtained. Further, since the linear crossing portion 5 has an extremely large area as compared with the point crossing portion, the internal resistance of the welding fixing portion 5 is significantly reduced as compared with the conventional point fixing welding portion. The spirally wound electrode plate group G to which the current collector 1 of the present invention is welded.
Is manufactured in a cylindrical can and is stable and robust, and the current collecting characteristic from the spiral electrode plate P via the current collector 1 is remarkably improved as compared with the related art. For comparison, the same configuration as that shown in FIG. 3 was used, except that a linear ridge having the same length as the flat ridge of the present application but having a V-shaped cross section was disposed on the current collecting metal plate. When the current collector plate was placed with the ridges crossed over the protruding end of the positive electrode plate of the spiral electrode plate group, and the internal resistance of the point weld fixing portion when welding was performed at the point cross portion, the current resistance was found to be 7
〜１０10 mΩ. On the other hand, when the internal resistance of the linear welded portion of the present invention was measured, it was remarkably reduced to 3 to 4 mΩ. In addition, when the opening 3 shown in FIGS. 3 and 5 is provided between the flat ridges 2 and 2 provided on the current collecting metal plate 1a, the shunt at the time of current welding can be reduced. ,
Highly efficient current welding is possible.

The protruding edge N1 of the spiral negative electrode plate N projecting from the lower surface of the spiral electrode plate group G has the same diameter as the above-mentioned current collecting metal plate 1a, but lacks the peripheral edge 1c. A flat current collector cut into a central portion of a circular metal plate in an arc shape or a U-shape, and a free piece formed by the cut and capable of bending downward and projecting downward is used as an ear; The current collector formed with the flat ridges 2 is welded by energization. Thus, after the current collector has the spirally-wound electrode group G accommodated in the cylindrical metal container, its ear is spot-welded to the inner bottom surface of the bottom wall of the container.

[0016]

As described above, the current collector for a cylindrical storage battery of the present invention is formed by arranging flat ridges on the current collecting metal plate. A significantly larger welding area is formed at the intersection of the spiral electrode plate of a predetermined polarity with the protruding edge of the group, compared with the conventional point-like intersection, so that extremely strong welding fixation by electric current welding is easily and quickly performed. In addition, the internal resistance of the weld-fixed portion can be significantly reduced as compared with the point-welded portion, resulting in an excellent cylindrical storage battery and a weld-fix having a higher welding strength than conventional spot welding. In this case, when the opening is provided by being interposed between the flat ridges provided on the current collecting metal plate, the shunt at the time of energization can be reduced, and highly efficient current welding can be obtained. Thus, the cylindrical storage battery including the spirally wound electrode plate group in which the current collector of the present invention is welded as described above can satisfactorily extract electric energy of a specific electrode plate polarity.

[Brief description of the drawings]

FIG. 1 is a top view of a current collector for a cylindrical storage battery according to an embodiment of the present invention.

FIG. 2 is a side view of the current collector of FIG.

FIG. 3 is a top view of a current collector for a cylindrical storage battery according to another embodiment of the present invention.

FIG. 4 is a sectional view taken along line AA of FIG. 3;

FIG. 5 is a top view of a current collector for a cylindrical storage battery according to still another embodiment of the present invention.

FIG. 6 is a sectional view taken along line BB of FIG. 5;

FIG. 7 is a front view showing a part of a development view of the spiral electrode group.

FIG. 8 is a perspective view of an assembly in which a current collector for a positive electrode terminal is electrically welded to a spiral electrode plate group.

FIG. 9 is an enlarged view of a part of the line CC shown in FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Current collector for cylindrical storage batteries 1a Metal plate for current collection 2 Flat ridge 2a Flat bottom of flat ridge 3 Opening 5 Welding fixing part P Positive plate P1 Protruding edge of positive plate N Negative plate N1 Negative plate Protruding edge S Separator G Spiral electrode group

Claims (3)

[Claims] The present invention is characterized in that a ridge having a flat bottom surface which crosses and abuts on a protruding end edge of a spiral electrode plate having a predetermined polarity of a spiral electrode plate group is provided on a current collecting metal plate. Characteristic current collector for cylindrical storage batteries. 2. The current collector for a cylindrical storage battery according to claim 1, wherein the metal plate for current collection has an opening interposed between the ridges having the flat bottom surface. 3. A cylindrical storage battery comprising a spirally wound electrode plate group to which the current collector according to claim 1 is welded.