JPS5833666B2 - Manufacturing method of electrode plates for alkaline storage batteries - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing electrode plates for alkaline storage batteries, particularly cadmium cathode plates for nickel-cadmium storage batteries.

The general method for constructing a nickel-cadmium cylindrical storage battery is to place an insulating disk at the inner bottom of a battery case A, which also serves as a cathode terminal, as shown in Figure 1, and insert a strip-shaped nickel anode plate through a separator C. d and a cadmium cathode plate e that are spirally wound.

After this, the anode lead f is connected to the anode terminal fixed to the sealing plate g, an alkaline electrolyte is injected into the case, and the open end of the case is bent inward around the periphery of the sealing plate g. It is sealed by tightening it.

The cadmium cathode plate used here has excellent workability and plate properties, so instead of the conventional nickel sintered substrate impregnated and filled with cadmium active material, a paste-like cadmium-based cathode plate is used directly on the core material. Apply the active material,
We are now transitioning to chemical products.

The general manufacturing process for a cathode plate obtained by applying such a paste-like cathode active material to a core material is as shown in Figure 2, in which a central portion 1 is made porous by punching a large number of holes.
and non-porous side edges 3, 31 that are in contact with each other with the elongated hole 2 as the boundary, a core material 4 is prepared, and a paste-like cathode active material 5 is continuously applied to both sides of the porous central portion. -Next, after adjusting the thickness of the active material, it is subjected to a chemical conversion treatment, and then simply pressurized with a pair of rolls 6 or the like in order to adjust the porosity and thickness of the active material.

However, in the pressurizing process after this chemical conversion treatment, the active material is pressurized and becomes porous in the central part 1 of the core material, which is the part where the active material is applied, and the non-porous side edges 3, 31. The central part 0, which is easier to stretch, is easier to stretch along the length direction of the core material than the side edges 3, 31, and there is a difference in the stretching ratio of the image parts, so as shown in FIG. There was a problem in that the electrode plate in the conventional method was bent like a tire or wavy.

Therefore, in order to prevent this curvature and waving phenomenon, as shown in FIG. Next, the thickness of the electrode plate is adjusted using a pair of pressure rolls, and after being introduced into the chemical conversion equipment 10 and subjected to chemical conversion treatment, the electrode plate is used with a cutter 8 to prevent bending or waving even during the pressure process described later. It is long enough to pass through a pair of pressure rolls 6 with the cut surface facing at right angles.

The active material layer was cut into pieces 9 and pressed with a pair of pressure rolls 6 to adjust the porosity and thickness of the active material layer.

Then, the electrode plate 9 that had undergone this pressurizing step was turned again by 90° and cut into a predetermined width with a cutter 11 to form a strip-shaped electrode plate 12 suitable for being spirally wound.

However, this manufacturing method involves a step of cutting and reorienting the strip-shaped electrode plate, which divides the work and makes it impossible to efficiently manufacture the electrode plate with good workability.

The present invention solves the drawbacks of conventional manufacturing methods in manufacturing such cadmium cathode plates, and provides a manufacturing method that can continuously manufacture electrode plates with good workability.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 5 shows the manufacturing process in the method for manufacturing a cadmium cathode plate of the present invention. While the strip-shaped core material 4 is being sent out one after another, a paste-like material mainly composed of cadmium is applied to the porous central portion of the core material 4 using a blade 7. The cathode active material 5 is continuously applied, and after drying, the thickness is temporarily adjusted using a pair of pressure rolls 13, and the material is introduced into a chemical conversion device 10 for chemical conversion treatment.

Then, the non-porous side edges 3, 31 of the band-shaped electrode plate were subjected to chemical conversion treatment.
is stretched by a predetermined amount by a pair of stretching devices 14 before the pressing process by the pressure roll 6.

In this distraction device 14, as described above, the center portion 1 to which the active material is coated and the side edges 3, 31 have a difference in the amount of distraction during the pressurization process using the pressure roll 6, and may be curved. Therefore, in order to solve this problem, the both side edges 3, 31 of the core material 4, which have a small elongation ratio, are stretched by a certain amount in advance, and the center portion of the core material and the both side edges are stretched by a certain amount in the pressurization process that will be performed later. Both side edges 3, 31 are extended in the length direction of the core material by an amount commensurate with the difference in amount.

The core material side edges 3, 31 may be stretched continuously in the length direction over the entire core material, but it may be an intermittent distraction method that is easy to work with and can reliably prevent curvature. There may be.

The distraction device 14 shown in FIG. 5 is an intermittent distraction device.

6 and 7 show this distraction device 14, with both side edges 3
, 31, and a punch 1 having a knife-shaped tip that fits therein.
6 and a pair of pressers 17 that press down and fix the side edges.
The width α and depth β of the V-shaped groove 18 of the die 15 are the center part 1 of the core material and the side edge parts 3 generated in the pressing process.
, 3' is converted into the difference Aδ in the amount of distraction corresponding to the pitch P between the long holes 2 of the core material, and this Jδ is set so that it extends between the pitches P. .

Therefore, if the chemical conversion-treated band-shaped electrode plate is sequentially moved according to the pitch P of the long holes 2, the center line of the long holes 2 will be at the die 15.
It is located on the ■-shaped groove 18 of.

In this state, the presser 17 is lowered to prevent the side edges 3, 3/ from moving, and the punch 16 is lowered to prevent the side edges from moving between the V-shaped groove 18 and the knife-shaped portion at the tip of the punch 16. 3
, 3' are extended in a V-shape.

By applying this to each portion between the elongated holes 2, a shallow V-shaped liquid 19 is formed intermittently as shown in FIG.

Therefore, both side edges 3 and 31 are stretched in advance by the length of this V-shaped groove 19, and then passed between a pair of pressure rolls 6 to adjust the porosity and thickness of the active material layer. Even if the central portion of the core material 4 is stretched significantly in the length direction of the core material, since both side edges 3 and 31 have been stretched in advance, the extent of the distraction will ultimately be the same between the central portion and both side edge portions. matches,
There is no bending or waving of the electrode plate due to the difference in elongation ratio, and a continuous flat electrode plate can be obtained.

After this pressurizing step, if the electrode plate is cut to a predetermined width with a cutter 11 as in the conventional case, a strip-shaped electrode plate 12 corresponding to the battery size is produced.
is obtained.

As described above, in the manufacturing method of the present invention, before the pressing step, the both side edge portions of the core material of the strip-shaped electrode plate are stretched by an amount equal to the difference in the amount of elongation between the center portion of the core material and the both side edge portions that occurs during the pressing step. Since it is stretched in advance, it is possible to prevent bending and waving of the electrode plate, and the steps of supplying the strip core material, applying the paste active material, forming, and cutting can be performed in a continuous series of operations. I can do it,
It has the advantage of being easy to work with and producing high quality cathode plates.

[Brief explanation of drawings]

Fig. 1 is a longitudinal cross-sectional view showing a nickel-cadmium cylindrical storage battery using a strip-shaped cadmium cathode plate, Fig. 2 is a diagram showing the relationship between the strip-shaped core material and the application of paste-like cathode active material, and Fig. 3 4 is a diagram showing the curvature of the electrode plate that occurs when a strip-shaped electrode plate is simply pressurized after chemical conversion treatment. FIG. 4 is a diagram showing the manufacturing process of a conventional cadmium cathode plate. FIG. FIG. 6 is a diagram showing the manufacturing process, FIG. 6 is a diagram showing the relationship between the distraction device and the strip-shaped electrode plate, and FIG. 7 is an enlarged view showing the distraction device. 1...Porous central part, 2...Long hole, 3,3'...Non-porous side edge part, 4...
Core material, 5...Paste active material, 10...
...Chemical conversion device, 14...Distraction device.

Claims (1)

[Scope of Claims] 1. A step of continuously applying a paste-like cathode active material to the center portion of a strip-shaped core material whose center portion is porous and whose side edges are non-porous, and this cathode active material. There is a process of continuously chemically converting the core material coated with active material, a stretching process of stretching both edges of the core material by a certain amount in the length direction of the core material, and a process of applying pressure to the entire core material to separate the parts coated with the active material. A method for producing electrode plates for alkaline storage batteries, characterized by comprising a pressurizing process for adjusting porosity and thickness to a constant value. 2. Claim No. 2, wherein the amount of elongation of both side edges of the core material applied in the elongation process is equivalent to the difference in the elongation amount between the center portion to which the active material is applied and the both side edges, which occurs during the pressurizing process. A method for producing an electrode plate for an alkaline storage battery according to item 1. 3. The method for manufacturing an electrode plate for an alkaline storage battery according to claim 1 or 2, wherein the stretching of both side edges of the core material is performed intermittently or continuously.