JPS6040145B2 - Method for manufacturing electrode plates for batteries with spiral electrode bodies - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in the method of forming an exposed core portion in a method of manufacturing an electrode plate for a battery having an overwound electrode body. Another object of the present invention is to provide a strip-shaped electrode plate with stable battery characteristics.

In a sealed nickel-cadmium storage battery, which is a typical example of a battery equipped with an overwound electrode body, the conventional current collector structure with positive and negative electrodes has a lead piece attached to any point on the electrode plate 1, as shown in Figure 1. 2 was attached by spot welding or the like, and such positive and negative electrode plates were wound in an overwound manner with a separator interposed between them to form an electrode plate group.

However, with this type of current collector structure, when charging and discharging with a large current, the current concentrates on the electrode plate closer to the lead piece 2, and the polarization becomes larger. It had the disadvantage that it took less time. In order to eliminate such a drawback, as shown in FIG. The electrode plate group is slightly offset vertically so as to protrude from both the upper and lower ends of the electrode plate group, and is wound in an overwound shape with a separator interposed between the mutual polar slopes to form the exposed core material at both the upper and lower ends of the electrode plate group. It was proposed to weld the current collector. A battery with this structure can compensate for the drawbacks when discharging a large current. Conventionally, with paste-type electrode plates used in such batteries, when applying a paste-like active material to a porous core material such as punched metal at a predetermined thickness, the portion corresponding to the edge of the electrode plate is The active material was scraped off with a piece of rubber or the like, dried, pressed, and chemically formed, and then further pressed to form an electrode plate of a predetermined thickness.

However, in this manufacturing method, in the pressing process,
There is a difference in the elongation of the core material between the part where the active material has been applied and the part where it has been scraped off, causing the electrode plate to bend or the active material to bulge out in the scraped off area ( exposed core material)
There was a problem that the accuracy was not achieved. Also, instead of scraping off the paste when it is applied, it is possible to scrape off part of the green part of the electrode plate after the final pressing.
Another method is to apply a metal or plastic guide to the green edge of the electrode plate, make a line along the guide with a sharp metal blade, and then scrape it off with another piece of metal. However, this process requires three steps: scoring the active material on the edge of the electrode plate to a certain width, then scraping off the active material, and brushing the exposed part, so there is no need to peel off the active material or remove the core metal. This has the disadvantage that it takes a lot of time and effort to expose the surface. The present invention eliminates these drawbacks and will be explained below with reference to the drawings. As is clear from FIG. 3, a metal guide 5 is placed along the edge of one side of the electrode plate, and a rotatable disk-shaped metal cutting blade is rotated while maintaining a constant cutting angle 8 with respect to the guide 5. The blade 6 is moved along the guide 5 to simultaneously create grooves in the active material layer and scrape off the active material layer, thereby removing the active material layer 4'.

At this time, the disc-shaped rotary cutting blade creates grooves in the active material layer, and at the same time, by giving a cutting angle of 50 to 700 to the guide 5, the guide 5 is cut in a direction perpendicular to the guide (arrow A).
A component force acts in a direction parallel to the (arrow 8), this component force overcomes the adhesive force between the core material and the active material, and the active material 4 is easily peeled off and the core material surface is exposed in one step. obtain. Disc-shaped cutting blade 6
is in a state where it is supported by the support column 7 and is free to rotate as shown in FIG.

Normally, when the holding part (not shown) of this support is moved, the cutting blade also moves while rotating. In FIG. 3, when the supporting portion of the support column moves in the direction B, the cutting blade 6 is also guided by the guide and moves in the direction B, and the active material layer 4' is removed.

Furthermore, since the cutting blade is disc-shaped and can rotate freely, smooth movement is possible even if the cutting angle is set.

Furthermore, after removing the active material, by brushing this part, even if the metal surface is completely exposed, the core material exposed part 4
can be formed. If the cutting angle of the free-rotating disc-shaped cutting blade 6 to the guide 5 is 8', or more than 50, there will be no problem in removing the active material layer, but if it is less than 50, it will have the effect of creating grooves in the active material. There is only one.

As the angle 8 increases, the rotation of the freely rotatable disc-shaped cutting blade becomes difficult to rotate smoothly due to the increase in contact resistance with the active material 4', and when the angle 8 exceeds 700, there is no rotation at all, and at the same time the cutting edge stops rotating. The blade gets caught in the active material layer and cannot move along the guide. Therefore, the cutting angle of the cutting blade should be between 5 and 700 degrees. As described above, the present invention is a method for manufacturing a paste-type electrode plate in which the green host material at the edge of the plate is scraped off to expose the core material. By moving the active material while maintaining a predetermined cutting angle in between, it is possible to easily scrape off the active material and expose the end of the core material in a few steps.

[Brief explanation of the drawing]

FIGS. 1 and 2 are perspective views of the electrode plates constituting the conventional overwound electrode body, FIG. 3 is a diagram showing the active material removal process in an embodiment of the present invention, and FIG. FIG. 3... Electrode plate, 4... Core village exposed portion, 4'... Active material, 5... Guide, 6... Disc-shaped cutting edge. Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] 1. After cutting an electrode plate obtained by applying a paste-like active material onto a porous metal core material into strips of predetermined dimensions, a metal or plastic guide is attached to the edge of one side of the electrode plate. The active material is removed by moving the rotatable disc-shaped cutting blade along the guide while keeping the cutting angle within a certain range with respect to the guide, and then brushing this part to remove the exposed core material. A method for manufacturing an electrode plate for a battery having an overwound electrode body characterized by forming an overwound electrode body. 2. A method for manufacturing a battery electrode plate comprising an overwound electrode body according to claim 1, wherein the cutting blade has a cutting angle of 5 to 70 degrees.