JPH09245763A - Pole plate for alkaline storage battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a pole plate for an alkali accumulator with its improved rigidity of a boundary area and the reduced generation of failures due to breakage by forming the boundary between a coining part formed on one side of an electrode and a non-coining part linearly. SOLUTION: A pole plate 1 for alkali accumulator coins the marginal part of the upper side of a porous board by means of a pressure jig, a coining part from which an adhered active substance is reduced and is made of a non-coining part 1a filled with a positive pole or a negative active substance and extended with a specified thickness. A boundary 2 between this non-coining part 1a and a coining part 3 is formed in the non-linear shape of an upward or downward arc-shape over its full width. A current take-up terminal 4 made of a bonding part 4a of the same size as that of the coining part 3 polymerized on the full face of the coining part 3 and an ear part 4b protruded at the center of an upper edge b thereof is superimposed on the coining part 3 with the arc-shaped lower edge an into contact with a nonlinear margin 1a1 of a non-coining part 1a and spot-welded.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an electrode plate for an alkaline storage battery.

[0002]

2. Description of the Related Art In recent years, CMC has been used as a high capacity alkaline storage battery electrode plate on a three-dimensional porous substrate such as metal foam nickel.
A paste-type electrode plate is used which is obtained by adding and kneading an aqueous solution of a viscous agent such as the above to highly densely fill a paste-like active material, drying and pressing.

In this case, in order to attach a current extraction terminal to this paste type electrode plate, generally, before filling the electrode plate with an active material, the peripheral portion of the porous substrate is pressed (hereinafter coined). Then, the coining portion is filled with the active material after being prevented from being filled with the active material.
Next, a method is used in which the active material adhering to the surface of the coining portion is removed and then the current output terminal is attached to the coining portion by spot welding or the like.

The purpose of the coining is to press a portion of the current take-out terminal where the current take-out terminal is to be welded in order to prevent welding failure caused by adhesion of an active material to the welded place of the current take-out terminal in the electrode plate. To increase the mechanical strength, to make it difficult to fill the active material, and to easily remove the active material filled / adhered to the welded portion after the filling step.

In the same coining, a porous electrode substrate made of metal such as an iron or Ni net or a punched porous sheet is used as a core material, Ni powder is applied to the core material, and the core material is dried.
This is also applied to a sintered electrode plate in which a sintered substrate obtained by sintering in a reducing atmosphere is filled with an active material by a chemical impregnation method or the like.

Also in the case of attaching a current extraction terminal to this sintered electrode plate, a method of coining the edge portion of the electrode plate and welding the current extraction terminal by spot welding or the like, similarly to the above-mentioned paste type electrode plate. Is used.

12 and 13 show a state in which a current extraction terminal is attached to a conventional paste type electrode plate. FIG.
Indicates a pole plate, a coining portion a1 is formed in a predetermined constant width over the entire width of the upper edge portion, and the current extracting terminal B is connected to the joining portion b1 at the coining portion a1.
It was attached by spot welding at. a2 indicates a non-coining portion filled with the paste active material. Thus, the current take-out terminal B is formed on the electrode plate A having the ear portion b2 protruding upward from the upper edge portion of the electrode plate from the joint portion b1 which is overlapped and welded with the coining portion a1. . The conventional paste type electrode plate A shown in FIG. 13 has a rectangular coining portion a1 of a facet area surrounded by three sides formed in the center of the edge portion of the upper side thereof, and is composed of an elongated rectangular piece. The current output terminal B is attached by spot welding at its joint b1, and the electrode plate A has an ear b1 protruding upward from the upper edge of the electrode plate A.

[0008]

By the way, the above-mentioned conventional electrode plate for an alkaline storage battery, as shown in FIGS. 12 and 13, has the above-mentioned porous plate with a pressing jig during the manufacturing process of the electrode plate. As shown in FIG. 12, the boundary line C between the coining part a1 and the non-coining part a2 is formed in a straight line shape across the width direction of the electrode plate A. The one shown in FIG. 13 is formed in a straight line having three sides. Particularly, in the case of a large electrode plate used for a storage battery for an electric vehicle, stress is likely to be concentrated on the boundary line and cracks or breakage easily occur at the boundary line during the manufacturing process, or during handling such as incorporation into the battery after manufacturing. However, there is a problem in that production loss of electrodes and batteries and deterioration of quality occur.

[0009]

DISCLOSURE OF THE INVENTION The present invention provides an electrode plate for an alkaline storage battery in which the above-mentioned conventional inconvenience is solved, and a coining for attaching a current extraction terminal formed on at least one side of the electrode plate. The boundary line between the portion and the non-coining portion filled with the active material is formed in a non-linear shape. Further, according to the present invention, an electrode capable of taking out a battery is provided by attaching a current taking-out terminal to the coining portion. The current extraction terminal of the electrode plate for an alkaline storage battery provided with the current extraction terminal is composed of a joint portion having a non-linear edge having the same shape as the boundary line, and an ear portion. The electrode plate is welded to the coining portion and the ear portion is projected outward from the electrode plate, or the ear portion integrally protruding from the coining portion of the electrode plate.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. 1 to 3 show a first embodiment of the present invention.
An example is shown, and 1 shows an electrode plate for an alkaline storage battery, and the electrode plate 1
Is 70 mm in width, 150 mm in length, 1.6 mm in thickness, and the upper edge of the porous substrate made of a metal foam nickel sheet having a porosity of 96% is coined and attached by a pressing jig. It comprises a coining portion 3 from which the active material has been removed and a non-coining portion 1a which is filled with a positive electrode or negative electrode active material and rolled to a predetermined thickness. Thus, according to the present invention, the non-coining portion 1a and the coining portion 3 are
The boundary line 2 between and is formed in a non-linear shape over the entire width, for example, in an upward or downward arc shape, in this example, an upward arc shape as shown in FIG. 3, for example, the maximum width is 20 mm and the minimum width is 20 mm. Was formed on the non-linear boundary line 2 having a thickness of 10 mm. The coining portion 3 had a thickness of 0.1 mm. 1 and 2
The joining portion 4a has a shape in which the lower edge a matches the arcuate boundary line 2 and has the same size as the coining portion 3 overlapping the entire surface of the coining portion 3 in the coining portion 3. And a current take-out terminal 4 consisting of an ear 4b projecting from the center of the upper edge b thereof, a joining portion 4a thereof, an arcuate lower edge a thereof and a non-linear side edge 1a of the non-coining portion 1a.
1. In the case shown in the figure, there are shown a plan view and a side view of an electrode plate which is abutted against the arc-shaped upper edge 1a1 and is superposed on the coining portion 3 and attached by spot welding or the like. In FIG. 2, reference numeral 5 denotes a recess space formed on the outer surface of the coining portion 3 for accommodating the joint portion 4a of the current output terminal 4. The recess spaces 5 and 5 are formed on the outer surface and the back surface of the coining portion 3, and one of the recess spaces 5 is formed.
Is selected and the current output terminal 4 is housed therein, and the joint portion 4a is attached to the coining portion 3, but the coining portion 3 is biased to one side and only one concave space is provided on the opposite side. It may be formed. In the above, preferably, the thickness of the joint 4a is accommodated in the recess space 5, that is, the thickness of the joint 4a is equal to the coining portion 3.
It is preferable that the joint portion 4a is flush with the surface of the non-coining portion 1a so that the joint portion 4a does not protrude from the surface of the non-coining portion 1a. This electrode plate is referred to as an electrode plate of Example A.

In FIG. 4, the coining portion 3 is formed on the upper edge of the electrode plate 1 so that the boundary line 2 has a wavy shape, for example, a maximum width of 20 mm and a minimum width of 10 mm, and
The electrode plate 1 of another embodiment of the present invention when the joint portion 4a of the current extraction terminal 4 is welded to the coining portion 3 is shown. This electrode plate is referred to as an electrode plate of Example B.

In FIG. 5, the coining portion 3 is formed on the upper edge of the electrode plate 1 so that the boundary line 2 has a sawtooth shape with a maximum width of 20 mm and a minimum width of 10 mm, and , The joint portion 4a of the current output terminal 4 to the coining portion 3
Fig. 7 shows an electrode plate 1 according to still another embodiment of the present invention when welded together. This electrode plate is referred to as an electrode plate of Example C.

In FIG. 6, the boundary line 2 is arranged along the upper edge of the electrode plate 1 such that the maximum width is 20 mm and the minimum width is 10 mm, and the concave portions and the convex portions are arranged vertically continuously. The electrode plate 1 according to still another embodiment of the present invention is shown in which the coining portion 3 is formed on the coining portion 3 and the joint portion 4a of the current extraction terminal 4 is welded to the coining portion 3. This electrode plate was used as Example D.
And the electrode plate.

In FIG. 7, the boundary line 2 is arranged at the upper edge of the electrode plate 1 such that arcs and straight lines are alternately and continuously arranged within a range in which the maximum width is 20 mm and the minimum width is 10 mm. The electrode plate 1 of still another embodiment of the present invention in which the coining portion 3 is formed and the joint portion 4a of the current extraction terminal 4 is welded to the coining portion 3 is shown. This electrode plate was used in Example E.
And the electrode plate.

As described above, when the current take-out terminal 4 is attached with the joining portion 4a of the non-linear lower edge a thereof meshed with the non-linear upper edge 1a1 of the non-coining portion 1a, This facilitates the work of correctly attaching the current output terminal 4 to a predetermined position, and improves the mechanical strength and current output performance of the joint portion 4. In addition, it is common to use the current extraction terminal 4 having the same thickness as the height of the recessed space 5, so that when the coin extraction portion 3 is stacked, the entire outer surface of the electrode plate 1 is flat. It is possible to stably form a laminate with a separator at the time of assembling a battery.

It is preferable that the shape and size of the joint portion 4a of the current output terminal 4 be the same shape and size as the coining portion 3 as described above in order to prevent stress concentration, but it is not limited to this. It is possible to fabricate it in a desired size and shape, not just one.

FIG. 8 shows a case where the current extracting terminal 4 whose size and shape of the joint portion 4a does not match the coining portion 3 is attached to the coining portion 3 as described above. That is, for example, a strip-shaped current output terminal 4 is attached to the coining portion 3 of the electrode plate 1 by spot-welding the joint portion 4a, and the ear portion 4b is projected upward from the upper side of the electrode plate 1. 7 shows an electrode plate according to still another embodiment of the present invention.

In FIG. 9, when a porous substrate is punched out from its porous blank, it is punched out so that the portion corresponding to the ear 4b has a protruding plate portion protruding from the porous substrate.
When the edge portion of the upper side is pressed to form the coining portion 3, the ear portion 4b is simultaneously formed integrally with the coining portion 3 formed by pressing the protruding plate portion. 2 shows an electrode plate having a current extraction terminal 4 composed of only the ear portion 4a. According to this, the work of attaching the separately prepared current extraction terminal 4 to the coining portion 3 by welding can be omitted, and the electrode plate 1 having the robust current extraction terminal 4 integrated with the electrode plate can be obtained.

In FIG. 10, pressure is applied locally to a part of the upper side of the electrode plate 1 in a part of the width direction of the electrode plate, for example, to the central part thereof by a pressure jig having three non-linear sides. Forming a rectangular coining portion 3 having a length of 20 mm and a width of 20 mm, the three sides of which are non-linear, and the coining portion 3 and its surrounding non-coining portion 1a.
Fig. 6 shows a plate of yet another embodiment of the present invention in which the boundary line 2 of the electrode plate and the non-linear boundary line 2 is formed, and a strip shape is formed in the center of the coining portion 3 of the plate plate 1. The electrode plate 1 is formed by superimposing and welding the joint portion 4a of the current output terminal 4 and attaching the ear portion 3b beyond the upper side of the electrode plate 1.

FIG. 11 shows an integral structure with the coining portion 3 of the electrode plate 1 having the three-sided non-linear boundary line 2 shown in FIG. 10, in the same manner as the embodiment shown in FIG. At the same time as forming the coining portion 3, the current extracting terminal 4 which is integrally protruded from the electrode plate substrate is pressed at the same time, and the current extracting terminal 4 is formed by the ear portion 4b which is coined to the same thickness.
It is formed integrally with.

In the above, the case of the paste type electrode plate made of metal foam nickel as the electrode plate 1 has been described.
Even in the case of a sintered electrode plate made of a Ni powder sintered body,
The boundary line over the entire width of the electrode plate 1 or the boundary line consisting of three sides,
Similar to the above, the boundary line can be formed into a non-linear boundary line composed of a curved line such as an arc shape, a wavy shape, or a sawtooth shape, or a combination of a curved line and a straight line, as in the case of the above-described embodiment.

Table 1 below shows the electrodes A to D of Examples A to E shown in FIGS. 1, 4, 5, 6 and 7, and the electrode of Comparative Example F consisting of the conventional electrodes shown in FIG. The result of the tensile strength test of is shown. In addition, Table 2 below shows the results of these bending strength tests. The tensile strength test is performed by using the J
As a test sample prepared according to IS-B-7771 and having a size such that the electrode plate can be attached to the tensile tester, a length of 120 m with a coining part in the center is used.
An electrode plate having a size of m and a width of 25 mm was prepared. The pulling speed was 0.1 mm / min. In the bending strength test, a bending strength tester compliant with JIS-Z-2248 is used, and the coin plate is used as a test sample prepared to have a size such that the electrode plate can be attached to the bending tester. An electrode plate having a length of 120 mm and a width of 25 mm centered at was prepared. The moving speed was 0.1 mm / min.

[0023]

[Table 1]

[0024]

[Table 2]

As is clear from Tables 1 and 2, the tensile strength and the bending strength of the electrode plates of Examples A to E of the present invention are remarkably improved as compared with the conventional example F, whereby the manufacturing yield and It is understood that the performance quality of the plates is improved.

[0026]

As described above, according to the present invention, the boundary line between the coining portion for attaching the current extracting terminal and the non-coining portion formed on the edge portion of at least one side of the electrode plate for alkaline storage battery is made non-linear. With such a shape, the low-strength boundary line is two-dimensionally dispersed, and the rigidity of the boundary line region is improved,
This has the advantages that the production yield can be improved by reducing the occurrence of defects such as breakage, and that the performance quality of the electrode plate can be significantly improved. Thus, by using an electrode plate having a current extraction terminal attached to the coining portion, a stable and good quality electrode plate without cracks or breaks can be obtained.
When the periphery of the joint of the current take-out terminal is made non-linear and has the same shape as the non-linear boundary line and the joint is made to coincide with the coining portion and polymerized and welded, Installation work to the coining part becomes easy,
Mechanical and electrical properties can be improved. Further, when the current output terminal is formed in the ear portion integrated with the coining portion of the electrode plate, welding can be omitted, and a stable and robust electrode plate having the current output terminal can be obtained.

[Brief description of drawings]

FIG. 1 is a plan view of an electrode plate for an alkaline storage battery including an ear portion according to an embodiment of the present invention.

FIG. 2 is a side view of the electrode plate shown in FIG.

FIG. 3 is a plan view of the electrode plate and the current output terminal separated from each other.

FIG. 4 is a plan view similar to FIG. 1 with a part removed in another embodiment of the present invention.

FIG. 5 is a plan view similar to FIG. 1 with a part removed in still another embodiment of the present invention.

FIG. 6 is a plan view similar to FIG. 1 but with a part removed in still another embodiment of the present invention.

FIG. 7 is a plan view similar to FIG. 1 with a part cut away in still another embodiment of the present invention.

FIG. 8 is a plan view of an electrode plate similar to that shown in FIG. 1 according to still another embodiment of the present invention.

FIG. 9 is a plan view of an electrode plate according to still another embodiment of the present invention.

FIG. 10 is a plan view of an electrode plate according to still another embodiment of the present invention.

FIG. 11 is a plan view of an electrode plate according to still another embodiment of the present invention.

FIG. 12 is a plan view in which a part of a conventional electrode plate is cut away.

FIG. 13 is a plan view of another conventional electrode plate.

[Explanation of symbols]

1 Electrode 1a Non-coining part 2
Boundary line 3 Coining section 4 Current extraction terminal 4
a Joint 4b Ear, current output terminal

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Mitsuru Nagano 7-2-1, Nakayama, Aoba-ku, Sendai City, Miyagi Prefecture Inside the R & D Center of Tohoku Electric Power Co., Inc. (72) Fumio Sato 7 Nakayama, Aoba-ku, Sendai City, Miyagi Prefecture (2-1) Inventor Ken Koyama 7-2-1, Nakayama, Aoba-ku, Aoba-ku, Sendai-shi, Miyagi Pref.

Claims (4)

[Claims] 1. An electrode for an alkaline storage battery, wherein a boundary line between a coining portion formed on at least one side edge portion of an electrode plate and a non-coining portion filled with an active material is formed in a non-linear shape. Board. 2. The electrode plate for an alkaline storage battery according to claim 1, wherein a current extraction terminal is attached to the coining portion. 3. The current extracting terminal is composed of a joint portion having a non-linear edge having the same shape as the boundary line and an ear portion, and at the joint portion, at the coining portion of the electrode plate. The electrode plate for an alkaline storage battery according to claim 2, wherein the electrode plate is attached and the ears are projected outward from the electrode plate. 4. The electrode plate for an alkaline storage battery according to claim 2, wherein the current output terminal comprises an ear portion integrally protruding from a coining portion of the electrode plate.