JP2908896B2 - Electrodes for spiral-wound batteries - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrode plate for a spiral type battery such as an alkaline storage battery or a non-aqueous solvent battery.

[0002]

2. Description of the Related Art Conventionally, a spiral-wound battery electrode plate used as an electrode plate of an alkaline storage battery is prepared by impregnating and filling a sintered substrate of nickel powder with a solution-type active material, a wire mesh, a punched metal plate, or the like. And a method of directly filling a two-dimensional structure substrate such as a lath metal with an active material. The former is superior in terms of heavy load performance and life due to charge and discharge, and the latter is superior in terms of cost and volume efficiency, and each has advantages and disadvantages.

In recent years, a method of filling a substrate having a three-dimensional network structure such as a foamed metal or a sintered substrate with an active material has been developed and partially put into practical use. As a current collecting method in an electrode plate using such a porous metal body having a three-dimensional network structure as a substrate, a part of the three-dimensional network structure substrate is formed into a high-density portion by pressing or the like, and then connected to a + terminal. There has been proposed a method of directly connecting lead tabs by welding or the like, and a method of forming a high-density upper end portion of a substrate, welding a strip-shaped metal piece, and connecting the lead tab and a current collector plate thereto. Conventionally,
The metal plate is often formed by a punching die or the like. In order to improve the strength of the corner portion of the electrode plate and the durability of the mold, the corner portion of the electrode plate is provided with an R.

[0004]

However, in the method of filling the three-dimensional network structure substrate with a substance, if the flexibility of the strip-shaped metal piece is low or the shape of both ends is not proper, the winding is performed. It is difficult to bend along the spiral of the electrode plate at the time, and the metal piece may be peeled from the substrate, causing the winding to slip, and the peeled metal piece end may damage the separator and come into contact with the counter electrode plate and metal case This caused a short circuit in the battery.

The present invention has been made to solve the above-mentioned drawbacks, and an object of the present invention is to provide an electrode plate for a spiral-wound battery in which the occurrence of defects at the time of winding the electrode plate is reduced. .

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a thin strip-shaped mounting portion at the upper end of a strip-shaped electrode plate filled with an active material for a battery, in which a previously provided substrate is exposed. In a spiral-wound battery electrode plate in which a metal piece is welded to form a current collector, the metal piece is made of an annealed 0.1 mm or less metal plate, and the upper corner of the electrode plate to which the metal piece is welded is a metal plate. It is characterized in that it is a quarter circle having a radius equal to or less than the metal piece width.

[0007]

According to the present invention, the winding of the metal piece can be easily started without projecting or peeling of the metal piece at the time of winding, so that the separator is prevented from being damaged and the occurrence rate of defects due to internal short circuit can be remarkably reduced.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. As shown in FIG. 2, the end of the nickel substrate 1 having a three-dimensional network structure is pressed in the longitudinal direction of the substrate,
After forming the current collecting terminal mounting portion 2, portions other than the mounting portion 2 are filled with an active material mainly composed of nickel hydroxide, and dried and rolled.

Next, the current collecting terminal mounting portion 2 where the substrate to which the active material is scarcely adhered is exposed, and has a width of 2 mm and a thickness of 0.1 mm.
The 08 mm-annealed metal plate 3 is attached by seam welding. Thereafter, as shown in FIGS. 3 (a) and 4, when forming the electrode plate of a predetermined shape, the upper corner portion of the electrode plate is formed into a corner R corresponding to the metal piece 3 by using a punching die.
Is set to a size that is ／ of the width of the metal piece 3 to form the positive electrode plate 5. 9 is a current collecting terminal. Also, as shown in FIG. 3B, a negative electrode plate 6 mainly composed of cadmium and a punched metal substrate is formed, and the negative electrode plate 6 is wound between the positive electrode plate 5 and the negative electrode plate 6 with a separator 7 interposed therebetween. Is formed, this electrode group is inserted into the case 8 as shown in FIG.

Here, as shown in Table 1, the material, the plate thickness and the corner R of the upper end portion of the metal piece 3 were similarly formed into an electrode plate group using a positive electrode plate which was changed stepwise. The number of internal short-circuit defects was investigated for each 50 pieces.

[0011]

[Table 1]

As a result, all the non-defective products were annealed metal plates of 0.1 mm or less, and the corners R were １ ／, ２ ，, 2/3, 1/1 of the width of the metal pieces. Was satisfied. On the other hand, the defective one is a metal plate that is the material of the metal piece 3 and the one that has not been annealed, and the one that has a thickness of 0.15 mm has poor flexibility of the metal piece. This is caused by peeling off and causing winding deviation, or lead pieces contacting the metal case, causing an internal short circuit. As a comparative example, in the case where the corner R shown in FIG. 5 is larger than 1/1 of the width of the metal piece, the lower end 10 of the metal piece 3 has an acute angle, so that the separator may be slightly peeled off. In some cases, it may come into contact with the negative electrode plate or the metal case, causing an internal short circuit at a low rate.

In the present embodiment, the metal piece 3 having a width of 2 mm is used. However, the present invention is not limited to this as long as the electrode capacity is not significantly reduced. Is desirable. Furthermore, if it is a spiral type battery,
For example, similar effects can be obtained in other batteries such as a non-aqueous solvent battery.

[0014]

As described above, according to the present invention,
Since there is no protrusion and peeling of the metal piece during winding, it can be easily wound, preventing damage to the separator,
An excellent effect that the rate of occurrence of defects due to internal short circuits can be significantly reduced is exhibited.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a case accommodating a spiral electrode group according to an embodiment of the present invention.

FIG. 2 is a plan view of a main part of an electrode plate during mounting of a metal piece according to an embodiment of the present invention.

FIGS. 3A and 3B are plan views of a positive electrode plate and a negative electrode plate according to one embodiment of the present invention, respectively.

FIG. 4 is an enlarged view of a main part of a corner R portion cut after attaching a metal piece in the embodiment of the present invention.

FIG. 5 is an enlarged view of a main part of a corner R portion cut after attaching a metal piece in a comparative example of the present invention.

[Description of Signs] 1 ... substrate, 2 ... current collecting terminal mounting part, 3 ... metal piece, 4 ... connecting part, 5 ... positive electrode plate, 6 ... negative electrode plate, 7 ... separator, 8 ... battery case, 9 ... current collecting Terminal.

Continuation of front page (72) Inventor Osamu Takahashi 3-4-10 Minamishinagawa, Shinagawa-ku, Tokyo Toshiba Battery Corporation (56) References JP-A-62-219462 (JP, A) JP-A-1- 251563 (JP, A) Actually open 1979-138125 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) H01M 2/20-2/34

Claims (1)

(57) [Claims] 1. A spiral-type battery for use as a current collector in which a metal piece is welded to a narrow strip-shaped mounting portion at the upper end of a strip-shaped electrode plate filled with a battery active material, from which a previously provided substrate is exposed. In the electrode plate, the metal piece is made of an annealed 0.1 mm or less metal plate, and the upper corner of the electrode plate to which the metal piece is welded is a quarter circle having a radius equal to or less than the width of the metal piece. An electrode plate for a spiral-wound battery characterized by the following.