JPH03241666A - Manufacture of plate for battery - Google Patents

Abstract

PURPOSE:To obtain a plate with no core material burr and high reliability by pressing a granular positive electrode mix to a core material with a current collector to form the sheet-shaped plate, cutting it off at a fixed width, then pressurizing its both end sections with recessed rollers. CONSTITUTION:A plate 1 is constituted of a core material 4 serving as a current collector and a positive electrode mix 3 pressed on it and mainly made of manganese dioxide. The plate 1 is cut off with slit edges 2 divided into six and having no excess lug section. Core material burrs are generated on one side of both ends at this time. Sheet shaped plates 10 divided into six are inserted between a recessed roller 5 and a roller 6 below it, and pressure is applied to the roller 5 to press downward. Tips of the plates 10 are continuously pulled to the left. The core burrs can surely be pressed to the side sections of the mix.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method for producing a sheet-like battery electrode plate comprising a powdery positive electrode mixture and a current collector.

BACKGROUND OF THE INVENTION Conventionally, the manufacturing process for this type of battery plate has been carried out in the following steps as shown in FIG.

(1) A granular positive electrode mixture 3 made of manganese dioxide or carbon fluoride and a binder is formed into a sheet, crimped onto the upper surface of a core material 4 made of a current collector, dried, rolled, and then wound into a hoop shape. Width: 180+nm, length: 35
Manufacture sheet-like battery electrode plates with a diameter of 0.0 cm.

1 shown in FIG. 3(a) is a sectional view of the sheet-shaped battery electrode plate manufactured in this manner.

(2) Next, the electrode plate 1 with the mixture 3 on the top is sandwiched between slit blades with the cross section shown in Figure 3(b), and the upper and lower blades are interlocked to cut it into six parts into a hoop shape. Wind it up.

As shown in FIG. 3(b), each of the blades 2 for cutting the electrode plate 1 at five locations excluding both ends has two upper blades and one lower blade. Therefore, the electrode plate after cutting is shown in Figure 3 (C
As shown in the plan view in ), an extra ear portion 8 of about 3 mm remains.

Although the ear part 8 cannot be used as an electrode plate, the reason why such a cutting method was adopted was to prevent core material burrs 41 generated during cutting as shown in FIG. 3(d). be.

That is, if the blade with the configuration shown in FIG. 3(b) is used, the core material burr 4
1 is pushed up by the lower blade and can be made to bite into the side surface 31 of the mixture 3 as shown in FIG. 3(e). Therefore, even if the corner portion 21 of the slit blade is worn to some extent, the core material burr 41 is less likely to occur.

However, when this cutting method is used, the surplus ear portion 8 cannot be used as described above, resulting in a manufacturing method with a poor yield, leading to an increase in costs. In addition, the surplus ears 8 become entangled in the process of winding up a good electrode plate, making continuous production difficult.

Furthermore, as the wear of the slit blade corner portion 21 progresses,
Even if the configuration of the slit blade 2 is used, the average lifespan of the blade is 50
0,000 times (a manufacturing method with low reliability).

Note that the core material burr 41 has an effect on battery characteristics such that it pierces the separator interposed between the positive electrode and the negative electrode, making it easy to cause an internal short circuit.

Problems to be Solved by the Invention In this conventional electrode plate cutting method, the yield of electrode plates is poor because the production method leaves surplus edges generated during slitting (leading to increased costs, and the remaining edges are There were problems such as scum getting tangled during continuous manufacturing.

The present invention solves these problems and aims to continuously manufacture highly reliable electrode plates.

Means for Solving the Problems In order to solve the problems described above, the present invention provides cutting methods that do not require excess ears, and then use a roller having a concave shape to cut both end surfaces of the cut electrode plate. It is manufactured by crimping the core material and forcing the core material burrs inward.

Function: As a matter of course, when cutting is performed that does not require a surplus ear, core material burrs are generated on one side of the electrode plate. This burr is pressed into the mixture side by winding up the sheet-like electrode plate while applying a constant force to both cut end faces using a concave roller and pressing them together. As a result, highly reliable electrode plates without core burrs can be continuously manufactured.

Embodiment An embodiment of the present invention will be described with reference to FIGS. 1 and 2.

Figure 1 (a) shows a sheet with a width of 180 mm and a length of 35 mm.
A battery electrode plate 1 having a length of 0 m is wound up into a hoop shape. This electrode plate 1 is composed of a core material 4 used as a current collector and a positive electrode mixture 3 containing manganese dioxide as a main component and pressed onto the upper surface of the core material 4.

In the next cutting process, this electrode plate 1 was cut without any surplus ears 5 using a slit blade 2 divided into six parts as shown in FIG. 1(b). As a result, as a matter of course, the yield of the electrode plate 1 has improved and highly reliable manufacturing has become possible. However, in the configuration of the slit blade 2, core material burrs 41 are generated on one side of both end surfaces, as shown in FIG. 1(e).

FIG. 2 shows the process of pressing the core material burrs inward and the shape of the rollers.

10 is a sheet-like electrode plate divided into six parts in the above process.

This electrode plate 10 is interposed between a roller 5 having a concave shape and a roller 6 located below the roller 5. The front and rear portions are set via a regulation guide 7 which is provided with a margin of 0.1 to 0.2 mm relative to the width of the electrode plate 10. In this case, the electrode plate 10 was installed with the core material 4 facing upward, and then pressure was applied to the roller 5 to press it downward. Next, manufacturing was performed by continuously pulling the tip of the electrode plate 10 to the left.

The relationship between the groove depth 51 of the roller 5 having a concave shape used here and the electrode plate thickness 11 was set so that electrode plate thickness>roller groove depth. This is because the experimental results revealed that in the case of the electrode plate thickness and the cape roller groove depth, core material burrs were not suppressed to the mixture side and remained locally.

Next, after cutting, the relationship between the electrode plate width 12 and the roller groove width 52 was set so that the electrode plate width was equal to the roller groove width, or the electrode plate width was equal to the roller groove width.

This is because, in the case where the electrode plate width>the roller groove, the core material burr 4 is not pressed against the mixture side and remains locally as described above.

The following table shows the state of electrode plates manufactured by changing the roller shape and roller pressure. ◯ indicates no problem, Δ indicates a slight problem, and × indicates a problem.

Here, the dimensions and shapes of the groove corner portions 53 of the roller 5 were set to four types: R0.1, 0.2, 0.3, 0.4+n+n, and the roller pressures were set to five types: 1, 2, 3, and 4.5 kg. . Further, the electrode plate width 12 and the roller groove width 52 were set to the electrode plate width ζ roller groove width.

The above experiment revealed the following.

(1) When the R dimension is 0.3 mm or more, core material burrs remain locally even if the roller pressure is increased.

c2) R dimension: 0.211II11 or less If the pressure of the nitride roller exceeds 4 kg, core material burrs will not remain locally, but will affect the mixture and cause the problem of falling off.

(3) R dimension is 0.2 mm or less and roller pressure is 1 to 3
It was found that in the region where kg was used, the above problems (1) and (2) did not occur, and the core material burr 4 existed in a form that reliably bit into the side surface 31 of the mixture 3.

In addition, in the relationship between the electrode plate width and the roller groove width, it has been confirmed that core material burrs remain in experiments using the electrode plate width>the roller groove.

Effects of the Invention As described above, according to the present invention, after cutting using the configuration of the slit blade having no surplus ears, the electrode plate is cut by pressing both end surfaces of the electrode plate using a roller having a concave shape. In addition to improving the yield, it is possible to reliably suppress core material burrs to the side surfaces of the mixture, making it possible to manufacture highly reliable battery plates. Furthermore, even if the core material burr grows due to wear of the slit blade, it is possible to manufacture the blade approximately 10 times longer than the conventional blade configuration.

[Brief explanation of drawings]

Figure 1 shows the cutting method of the present invention; (a) is a side view of the electrode plate wound into a hoop shape, (b) is a cross-sectional view of the upper and lower slit blades, and (C) is the core material burr. A cross-sectional view of the produced electrode plate, and FIG. 2 show the method of applying pressure using the roller of the present invention, (a) is a diagram showing the process of pressing the core material burr inward, and (b) is a diagram showing the process of pressing the core material burr inward. Diagram showing the groove width, (C) is a diagram showing the electrode plate width, (d) is a diagram showing the roller groove R, (e) is a diagram showing the electrode plate thickness, and Figure 3 shows the conventional manufacturing method. (a) is a cross-sectional view of the sheet-like electrode plate, (b) is a cross-sectional view of the slit blade, (C) is a plan view of the electrode plate after cutting, and (d) is the electrode plate with core material burrs. (e) is a cross-sectional view of the electrode plate in which the core material burr has bitten into the side surface of the mixture, and (Cf) is a view showing the worn corner of the slit blade. 1...Battery plate, 2...Slit blade, 3...Mixture containing manganese dioxide as the main component,
4...core material, 5...concave roller,
6... Roller, 10... Cut battery plate, 11... Thickness of the electrode plate, 12...
・Electrode plate width, 51...Groove depth, 52...
Groove width, 53...Groove corner part.

Claims (4)

[Claims] (1) A step of press-bonding a powdery positive electrode mixture 3 to a core material 4 having a current collector to make a sheet-shaped battery plate 1; and a step of cutting the electrode plate 1 into a certain width. A roller 5 having a concave shape at both ends of the cut electrode plate 10
A method for manufacturing a battery electrode plate, which comprises a step of pressurizing using. (2) The method for manufacturing a battery electrode plate according to claim 1, wherein the groove depth 51 of the roller 5 having a concave shape is larger than the electrode plate thickness 11. (3) The groove width 52 of the roller 5 having a concave shape is the electrode plate width 1
2. A method for manufacturing a battery electrode plate according to claim 1 or 2, wherein the electrode plate is approximately equal to or larger than 2. (4) The method for manufacturing a battery electrode plate according to any one of claims 1 to 3, wherein the groove corner portion 53 of the roller having a concave shape has a radius of 0.2 mm or less.