JPH06140029A - Manufacture of electrode - Google Patents

Abstract

PURPOSE:To reduce a cost, enhance productivity, and keep cleanness of a coated surface. CONSTITUTION:A battery element comprising a positive electrode active material 5, an electrolyte or a negative electrode active material is disposed on a current collector 3, thus obtaining an electrode. Holes 7 formed in a predetermined pattern on a resin film 1 are coated with the battery element while pressurizing the surface of the resin film 1 bonded to the current collector 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an electrode of a thin battery used in the fields of electronic equipment, toys, accessories, electric vehicles and the like.

[0002]

2. Description of the Related Art In a conventional battery, for example, in the case of a positive electrode current collector, a plurality of layers of resin film such as an adhesive and a peeling film are arranged on the periphery of the positive electrode current collector, and the exposed surface area of the positive electrode current collector (holes in the resin film The positive electrode active material was placed (applied) in a region), dried and cured, and then the uppermost contaminated resin film was peeled off. Further, an electrolyte was placed on the surface of the positive electrode active material in the same manner, dried and cured, and then the uppermost contaminated resin film was peeled off to manufacture a positive electrode plate.

In such a structure, after the adhesive is arranged and processed (only the outer frame is formed by half cut, etc.), different kinds of battery elements such as the positive electrode active material and the electrolyte are arranged (coated) in the hole of the resin film. (By engineering, printing, etc.),
It is necessary to form the resin film in multiple layers. Also, if there is no difference in the adhesive force between the layers of the resin film of multiple layers, it is not possible to peel well when peeling the upper resin film after the first battery element is placed, and bubbles enter between the resin films It changed locally, and the current collector was sometimes caught in the coating portion when the next battery element was coated. Further, after coating a battery element on a series of current collectors, if the feed roll surface comes into contact with the coating surface when moving to the next step, the coated surface becomes dirty or the battery element falls off. If the thickness of the resin film made into multiple layers is thick, after adhering to the current collector,
When rolled into a roll, a gap occurs between the layers of the resin film,
When the film was unwound, it could not be sent to the next step at all because the resin film had wrinkles and the holes were misaligned.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to reduce costs, improve productivity and maintain cleanliness of a coated surface. It is to provide a manufacturing method of.

[0005]

Means for Solving the Problems The present invention achieves the above object, and in a manufacturing method for producing an electrode by disposing a battery element such as a positive electrode active material, an electrolyte or a negative electrode active material on a current collector surface, The battery element is coated in the hole while applying pressure to the resin film surface of the current collector to which the resin film having the holes is formed by a pattern, and a layer having a thickness h that expands and contracts in the thickness direction or Adhering a plurality of layers of resin films to the current collector surface, coating the battery element to a thickness h1 (the shortest distance between the resin film pressure surface and the current collector surface; h1 <h) when pressure is applied, After pressurization, the thickness of the resin film is restored so that the thickness of the coated battery element is smaller than the thickness of the resin film, and after coating the battery element, cleaning the resin film surface. After drying or cleaning the resin film surface, Applying another battery element into the hole while applying pressure to the resin film surface, and then applying a thickness h2 (the shortest distance between the resin film pressure surface and the current collector surface; h2 <h) at the time of applying the pressure. The battery element is characterized by being coated, and the above-mentioned problems are solved by this.

[0006]

According to the first to fourth aspects, the battery element can be coated with high productivity in the resin film holes having a constant pattern on the continuous current collector. The resin film is only one layer, and the cost of consumable parts can be reduced. Further, in the case of a plurality of layers, by combining the adhesive film and the resin film, there is no adhesive arrangement after coating, and the number of steps can be reduced. In addition, the battery element can be coated to an arbitrary thickness by adjusting the pressure applied to the resin film, and there is no need to adjust the resin film thickness in advance and bond it to the current collector, which reduces material cost and versatility. Increase. Furthermore, since the thickness of the resin film is restored, when changing the moving direction of the current collector after coating (for example, when sending it to a drying oven), it makes contact even if the feed roll surface contacts the coating surface. Since there is no battery element on the surface, the coated surface is not contaminated or missing. By cleaning the resin film surface contaminated by the coating according to any one of claims 5 to 7, the active material cured in the subsequent coating of the active material is not mixed, and a coated surface having excellent smoothness is obtained. be able to.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. A strip-shaped resin film (for example, PET having both sides coated with modified PP to a thickness of about 200 μ or aluminum foil having both sides coated with modified PP) may be provided with sprocket 2 for film feeding at both ends. The holes were provided in parallel and series with a constant pattern. Next, the resin film 1 was adhered to the stainless foil surface as the current collector 3. FIG. 1 shows a plan view in this case, and FIG. 2 shows a sectional view (portion AA ′ in FIG. 1). FIG. 3 shows a state in which the positive electrode active material 5 is applied while pressing the surface of the resin film 1 on the current collector 3 with a pressure roll 4. Before the positive electrode active material 5 is applied, the surface of the current collector 3 is under-coated (however, it is not shown in the drawing because it is thin). Reference numeral 6 is a coating blade, and the pressure roll 4 may also serve as the coating blade. In this state, the positive electrode active material 5 is applied to the surface of the current collector 3 (inside the holes 7 of the resin film 1), and then the resin film 1 (thickness h) is pressed by the pressure roll 4. The thickness is set to h1 and the hole 7
The positive electrode active material 5 therein is crushed and removed to a thickness h1. The thickness of the resin film 1 of the current collector with the resin film 1 that has passed the pressure roll 4 is restored to h. At this time, the positive electrode active material 5 is coated in the hole 7 to have a thickness h1, and the upper h-h1 has no positive electrode active material 5. Next, one surface of the resin film is cleaned by cleaning the one surface of the resin film with a cleaning roll 8.

Next, the current collector 2 with the resin film 1 coated with the positive electrode active material 5 in the holes 7 is dried and cured by electron beam irradiation, and then the electrolyte 9 is similarly processed. FIG. 4 shows the method. Hole 7 in resin film 1
(Depth>h-h1; the thickness becomes smaller than h1 due to drying and curing of the positive electrode active material 5. For example, the thickness is about 50% of h1.
~ About 80%. The electrolyte 9 is applied in the above. At this time, the positive electrode active material 5 is coated in the hole 7 to have a thickness h1, and the upper h-h1 has no positive electrode active material 5. When the resin film 1 (thickness h) is pressed by the pressure roll 4'to make the thickness h2, the electrolyte 9 in the hole 7 is squeezed and removed so as to have the thickness h2. The thickness h2 at this time is the total thickness of the dried and cured positive electrode active material 5 and the coated electrolyte 9. The thickness of the resin film 1 of the current collector with the resin film 1 that has passed through the pressure roll 4 ′ is restored to h. Next, one surface of the resin film is cleaned by cleaning the one surface of the resin film with a cleaning roll 8. Further, the electrolyte 9 is dried and cured.

The thickness of the resin film is about 400μ and the coating thickness of the electrolyte is about 40μ (about 25μ after drying and curing).
The coating thickness of the positive electrode active material is about 300μ (about 200μ after drying and curing), h is 400μ and h1 is 300μ.
μ and h2 are 240 μ (total of positive electrode active material thickness 200 μ and electrolyte coating thickness 40 μ). The relationship between h1 and h2 cannot be limited because it changes depending on the coating thickness of the battery element and the thickness after drying / curing (depending on the volatile content).

Such a manufacturing method can be used for coating all battery elements with a single-layer resin film, and the processing and adhesion of the resin film to the current collector are easy and highly accurate. In addition, the effect of multiple layers is that if the resin film 1 side cannot be cleaned by smoothing the resin film 1 side with the cleaning roll 8, and if a contaminated part occurs, the upper film is peeled off to clean it. When the thickness of the battery element is changed on the same production line, the upper film is peeled off and the thickness is adjusted, so that the coating can be performed without making a large change. Conventionally, positioning accuracy when bonding a plurality of resin films is poor, for example, there is a positional deviation of about 0.5 mm between the positive electrode active material and the end of the electrolyte, and when assembled in a battery, a battery internal short circuit of about 7% occurs. However, in the present invention, there was no positional deviation between the positive electrode active material and the end of the electrolyte, and the internal short circuit of the battery did not occur.

[0011]

As described above, the present invention has the following effects. (1) Consumable materials are small and production cost is reduced. (2) Each process can be processed continuously, resulting in high production. (3) There is no positional deviation between the battery elements, and the coating accuracy is high. (4) When used as a battery, there is no risk of short circuit inside the battery. It should be noted that the present invention is not limited to those shown in the examples, but the resin film material / thickness / configuration, current collector metal material / thickness / configuration (the resin film may be coated with metal), and the activity. Details such as the material thickness, the electrolyte thickness, the size and shape, and the number of patterns are not particularly limited, and various kinds may be changed according to the application.

[Brief description of drawings]

FIG. 1 is a plan view of a resin film bonded onto a current collector according to the present invention.

FIG. 2 is a sectional view taken along the length A-A ′ of FIG.

FIG. 3 is a cross-sectional view showing a state during coating of the battery element according to the present invention.

FIG. 4 is a cross-sectional view showing a state when another battery element according to the present invention is further coated.

[Explanation of symbols]

 1 Resin Film 3 Current Collector 4, 4'Pressure Roll 5, 5'Positive Active Material 7 Hole 8 Clean Roll 9 Electrolyte

Claims (7)

[Claims] 1. A method for producing an electrode by disposing a battery element made of a positive electrode active material, an electrolyte or a negative electrode active material on the surface of a current collector, wherein a resin film having holes formed at a certain pattern is adhered. A method for producing an electrode, characterized in that a battery element is coated in the hole while pressing the resin film surface of an electric body. 2. The method for producing an electrode according to claim 1, wherein the resin film comprises one layer or a plurality of layers having a thickness h that expands and contracts in the thickness direction. 3. The battery element is applied to a thickness h1 under pressure (shortest distance between the resin film pressure surface and the current collector surface; h1 <h), wherein the battery element is coated. Manufacturing method of electrode. 4. The thickness of the resin film is restored after the pressure is applied so that the thickness of the coated battery element is smaller than the thickness of the resin film. Electrode manufacturing method. 5. The method of manufacturing an electrode according to claim 1, wherein the resin film surface is cleaned after coating the battery element. 6. The battery element is coated with another battery element while pressing the resin film surface again after the battery element is dried or after the resin film surface is cleaned. The method for producing an electrode according to 2, 3, 4 or 5. 7. The following battery element is applied to a thickness h2 (the shortest distance between the resin film pressing surface and the current collector surface; h2 <h) at the time of pressurization. Manufacturing method of electrode.