JPH0917410A - Manufacture of battery electrode - Google Patents

Abstract

PURPOSE: To improve the quality of a battery and reduce its cost by integrally machining an electrode portion and a lead portion, and bending the lead portion so as to form a straightly extending lead making right angles against the long side of the electrode plate in the electrode plate machining the battery. CONSTITUTION: In a method for making an electrode by forming an electrode layer on a porous board, an electrode plate of a required dimension having an integrated L-shaped lead portion is cut out from the holes portion and the plain portion of the board of the electrode, reshaping work such as bending of the L-shaped lead portion is conducted so as to form a straightly extending lead portion 4 making right angles against the long side of the electrode plate. It is desirable to conduct pressure reshaping or spot welding on a lead overlap portion 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention forms an electrode layer on a porous substrate used for batteries, particularly nickel-cadmium batteries, nickel-hydrogen batteries, lithium batteries, etc., and extends straight perpendicularly to the long side of the electrode plate. The present invention relates to a method for manufacturing a battery electrode that forms a lead portion.

[0002]

2. Description of the Related Art Alkaline storage batteries such as nickel-cadmium batteries and nickel-hydrogen batteries, which are used as power sources for various devices, can be expected to have high reliability and can be made compact and lightweight. For equipment, large ones have been widely used for industrial and various mobile equipment.

Recently, a high energy density lithium battery has been added to this. As a method of manufacturing the electrodes of these batteries, there is a paste method which is widely adopted for lead-acid batteries. Recently, this paste type is often used for the negative electrode for alkaline storage batteries, the hydrogen storage alloy electrode, and the electrode for lithium batteries.

This paste type is an expanded metal,
A porous conductive support such as punching metal is coated with a paste containing an active material and a binder as main components, and an active material layer is formed by a process such as pressure shaping, and a lead plate is spot-welded. It is common to install in. In a cylindrical battery using this electrode, the positive and negative electrodes are spirally wound through a separator and inserted into the case, the lead plate is attached to the case and the lid, and then the electrolyte is injected and the lid is caulked for sealing. ing. In a prismatic battery, after cutting the electrodes into a predetermined size, a lead plate is also attached by spot welding, and an electrode group is formed by stacking the lead plate and a counter electrode via a separator. Then, this is inserted into a battery case, and then the electrolytic solution is injected and the lid is closed.

[0005]

The method of attaching or forming the lead plate of the electrode as described above is such that in the electrode using the expanded metal grid of the lead storage battery, the uncoated portion (the portion left as the material that is not expanded) is left untouched. Although it is adopted as a lead system, in other batteries, the lead plate is usually attached to a predetermined position of the electrode by spot welding.

However, in this spot welding, if the voltage is low, the welding becomes insufficient, and conversely, if it is too high, the lead plate or the electrode portion is damaged, oxidized, or deformed. Such a tendency becomes more remarkable because various kinds of contamination are likely to occur in the actual electrode manufacturing process, such as the welded portion of the electrode being oxidized or the active material being attached. As a result, resistance is increased, lead parts are damaged, and internal short circuit occurs in the battery, which causes defects in the manufacturing process and the market. Further, the cost burden such as the material cost of the lead member and the equipment depreciation cost of the spot welding machine is large.

[0007]

SUMMARY OF THE INVENTION The present invention relates to a method of forming an electrode by forming an electrode layer on a porous substrate to form an electrode, and the electrode portion and the L-shaped lead portion are respectively formed from the perforated portion and the uncoated portion adjacent thereto. Is integrally cut, and thereafter, the L-shaped lead portion is subjected to bending, shaping, or the like to manufacture a lead portion that extends straight in the vertical direction with respect to the long side of the electrode portion. In addition, pressure shaping or spot welding is further performed on the overlapping portion of the lead portion. The electrode part and the lead part were originally integrated from the material stage,
Compared to the conventional lead plate connected by spot welding, quality reliability can be kept high.

[0008]

In general, welding of a metal having a clean surface does not cause much trouble. Therefore, even in the battery electrode, if the substrate is not filled with the active material, there are few problems regarding welding. However, in practice, in order to ensure mass productivity, the lead plate is spot-welded after the substrate is filled with the active material, so that the lead plate and the electrode portion are easily damaged, oxidized, or deformed.

In the present invention, since the L-shaped lead portion formed on the plain portion overlapping the porous portion is bent to form the lead portion,
There is no need to spot weld the lead plate and the electrode substrate. Therefore, the occurrence of damage, oxidation, deformation or the like in the lead portion or the electrode portion, increase in resistance, short circuit, and defect in the manufacturing process or the market are eliminated. That is, the L-shaped lead portion is cut from the plain portion as an integrated body with the electrode portion. Although it functions as a lead plate even in this state, it is difficult to position and is not suitable for continuous battery production. However, as in the present invention, when the L-shaped lead portion is shaped by bending or the like so that the lead portion extends straight at a right angle to the long side of the electrode portion, the lead is formed on the conventional electrode substrate. It has almost the same structure as the spot-welded part, and there is no need to give special consideration to positioning. Further, it is advisable to press-shape or overlap spots of the lead portion or to perform spot welding. Especially, if spot welding is adopted, this spot can be fixed sufficiently by spot welding at one point.

[0010]

EXAMPLES Examples of the present invention will be described below in the case of a sintered nickel electrode. A schematic drawing of the substrate material
Perforated part 1 made of steel having a thickness of about 0.18 mm and having a hole diameter of about 2 mm and made of nickel and having a shape as shown in FIG.
Then, the one having the plain portion 2 in the center was used. The central uncoated portion 2 had a width of 7 mm, and the punching metal portions 1 on both sides thereof had a width of 33 mm, and the punching metal sheet had a total width of 73 mm. In FIG. 3, the electrode substrate portion is a perforated portion 1 in which holes are processed, and a paste containing carbonyl nickel and a binder as a main component is applied to the portion except for the plain portion 2 to form slits and The nickel electrode is manufactured through processing such as passing through a drying furnace.

Next, a method of processing the lead portion will be described. As shown in FIG. 2, an L-shaped lead portion 4 is cut out from the uncoated portion 2 at the center of the punching metal, and a substantially rectangular electrode portion 3 is cut out from the left and right perforated portions 1 to have predetermined dimensions. The part 4 and the part 4 are integrated. Plain area 2
In order to effectively utilize the lead portion 2, when the electrode portion 3 is cut out from either the left or right side, the lead portion 2 is commonly cut out so as to be continuous with the center portion of the punching metal. Figure 1 shows the external appearance of this lead-integrated electrode.
It shows in (A). Here, the width of the lead portion 4 was 6 mm. The electrode part 3 has a thickness of 0.65 mm, a width of 33 mm, and a length of 2
00 mm.

The portion which will be the lead portion of this electrode is subjected to the following processing. First, when the lead portion 4 is bent along an alternate long and short dash line 5 shown in FIG. 1A, which passes through the inner corner 6 of the L-shaped lead 4 and is inclined at 45 degrees with respect to the long side 7 of the electrode plate 3, The lead becomes a bent lead as shown in FIG. When this is again bent through the corner 6 of the lead portion of FIG. 1B and along the alternate long and short dash line 8 perpendicular to the long side 7 of the electrode plate 3, a straight line is obtained as shown in FIG. 1C. The lead portion 4 extending straight in a straight line is shaped. Then, in order to maintain the strength, pressure shaping or spot welding is applied to the overlapping portion 9 of the lead portion 4.

As another embodiment of the present invention, even if the width of the uncoated portion 2 used for the lead portion 4 is reduced, the width of the lead portion 4 is not substantially narrowed and the resistance of the lead portion 4 is reduced. An example in which the value does not increase is shown in FIG. In FIG. 4, a T-shaped lead 4 in which a pair of left and right L-shaped leads are united is cut together with the electrode portion 3, and this is bent along a dashed-dotted line 5 inclined at 45 degrees. Next, the lead 4 bent along the line 8 is further bent inward, and two leads 4 are abutted at their end faces. In the case of this example, the width of the lead 4 at the time of cutting may be half the width of the desired lead portion, and the width of the lead portion at the base of the electrode portion 3 may have the desired width.

[0014]

EFFECTS OF THE INVENTION Since the electrode plate and the lead portion are integrated as described above, there is no welding failure at the time of spot welding the lead portion and no damage caused by welding at the electrode portion, and electrode processing suitable for mass production. This is a method, and it has become possible to improve the mass productivity and quality of batteries using this electrode.

[Brief description of the drawings]

FIG. 1A is a plan view of an electrode plate integrated with a lead portion according to an embodiment of the present invention. FIG. 1B is a plan view showing a state in which the lead portion is bent along a bending line. Plan view showing the state after bending the lead part again for

FIG. 2 is a plan view showing a state in which a lead portion integrated type electrode plate is cut from punching metal.

FIG. 3 is a plan view of a punching metal having a plain portion in a center portion.

FIG. 4 is a diagram showing another embodiment of the present invention.

[Explanation of symbols]

 1 Hole with punching metal 2 Plain part of punching metal 3 Cutting shape of electrode part 4 Lead part 5 Bending line passing through the inner corner 6 of L-shaped lead part 6 Inner corner of L-shaped lead 7 Long side of electrode plate 8 L Dash-dotted line passing through the inner corner 6 of the lead

Claims (2)

[Claims] 1. A method for producing an electrode for a battery by forming an electrode layer on a porous substrate having a solid portion having no holes, wherein an L-shaped lead portion is formed by cutting the porous portion and the solid portion of the substrate. And then the inner corner of the L-shaped lead portion is passed through but the outer corner is not passed, and the L-shaped lead portion is formed on a line having an inclination angle of 45 degrees with respect to the long side of the electrode plate. In order to correct the bent portion of the newly formed lead portion by bending, the lead portion is bent again on a line that passes through the inside corner of the L-shaped lead portion and is perpendicular to the long side of the electrode plate. A method of manufacturing an electrode for a battery, which comprises forming a lead portion that extends straight in a direction perpendicular to the long side of the electrode. 2. The production of a battery electrode according to claim 1, wherein the overlapped portion due to the bending of the lead portion extending straight perpendicularly to the long side of the electrode plate is subjected to shaping by applying a pressing force or spot welding. Law.