JPS6093755A - Manufacture of organic electrolyte battery - Google Patents

Abstract

PURPOSE:To obtain an organic electrolyte battery of a stabilized electric characteristic by forming a wavy area either on the surface of a positive current collector touching a positive mixture or on the inner bottom surface of a positive case before a conductive carbon paint is applied to the wavy area. CONSTITUTION:A current collector 5 is welded to the inner bottom surface of a positive case 4. Next, a negative electrode 2 made of lithium metal, a separator 6 made of a nonwoven polypropylene fabric, an electrolyte-holding member 7 made of the same material as the separator 6 and impregnated with organic electrolyte and a positive mixture 8 are installed in the positive case 4. After that, a stainless steel sealing plate 1 is attached to the opening of the positive case 4 with a gasket 3 interposed to seal the battery. The surface of the above current collector 5 has a wavy area which is formed by sandblasting and coated with a conductive carbon paint. By the means mentioned above, it is possible to manufacture an organic electrolyte battery of stabilized electric characteristics by improving the close contact between the paint film (P) and the metal (M).

Description

[Detailed Description of the Invention] Industrial Field of Application The present invention is directed to an organic type M? The present invention relates to a method for manufacturing an FFL battery, particularly a flat type organic electrolyte battery.

Conventional configuration and its problems In response to recent rapid advances in electronics technology,
Higher capacity, smaller size, and
There is a strong emphasis on improving leakage resistance and reducing deterioration due to self-discharge during storage.

In response to these requirements, organic electrolyte batteries must have high energy density, leakage resistance, and storage deterioration.

Various battery systems have been proposed due to their excellent low-temperature characteristics, and some have already been put into practical use. Among these organic electrolyte batteries, metal lithium is particularly used as the negative electrode active material, and metal oxides such as manganese dioxide and copper oxide, nonmetal halides such as carbon fluoride, thionyl chloride, sulfur dioxide, etc. are used as the positive electrode active material. The batteries used are electronic watches and cameras.

It is used in calculators, water meters, banokanog power supplies for semiconductor memory, etc.

These organic electrolyte batteries have the above-mentioned excellent advantages, but on the other hand, the internal resistance of the batteries is considerably higher than that of batteries using a water-based calcination solution system, so it is difficult to handle during heavy load discharge. Particularly in flat batteries, which are characterized by measures to suppress a drop in battery voltage, a conductive carbon pigment may be applied to prevent contact between the 1st charge agent and the pressure-detecting current collector or the positive electrode case. This is intended to reduce the internal resistance of the battery. However, the conductive carbon paint applied to the metal surface of these J'L et al. is more likely to peel off from the metal surface due to I', i7 smoke, making the silicon 11 surface unstable and reducing the internal resistance when used as a battery. Problems such as rising occurred. 'Also, during storage, an increase in the internal resistance of the battery was observed due to the electrolyte penetrating the interface between the paint layer and the metal surface.

In order to solve the above problem, it was proposed that the positive electrode current collector be made of metal M with a roughened surface of 6 to 20μ as shown in Figure 1, and that a conductive carbon paint be applied to this. However, it is difficult to regulate the surface roughness of the metal itself, and attempting to maintain the roughness within a certain range results in a very poor material yield. ? J. Since the irregularities of the metal itself are usually very small,
The phenomenon in which the conductive carbon paint did not fully enter the concave HB, resulting in insufficient adhesion and easy peeling, could not be completely resolved.

In addition, in batteries where conductive carbon paint is applied directly to the inner bottom of the case, the material with a rough surface also makes the rising part of the case rough, and the electrolyte creeps onto this rough surface. This caused capillarity to occur easily, causing battery leakage.

OBJECTS OF THE INVENTION It is an object of the present invention to solve all of the above-mentioned conventional problems and to provide a method for manufacturing a battery that has good adhesion between the current collector or the inner bottom surface of the positive electrode case and the conductive carbon paint.

Structure of the Invention] 1.1.
+! After forming a wavy uneven portion on the inner bottom surface of the positive electrode current collector or positive electrode case that is in contact with the I+ material by electrical discharge machining, Sand Plus F method, surface treatment using a file or abrasive powder, etc., conductive It is characterized by applying a carbonaceous paint. According to such a method VC, the contact layer between the conductive carbon paint and the metal surface is improved, the peeling of the conductive carbon paint is prevented, and 'l''Ii, It is also possible to prevent penetration of dissolution, and it is possible to provide an organic 7L main battery with a high quality.

Description of examples Examples of the present invention are shown below with reference to the drawings! I will explain.

FIG. 2 is a schematic cross-sectional view of an A1 flat battery according to the invention. In the figure, 1 is a sealing plate made of stainless steel, 2 is a negative electrode made of metallic lithium, 3 is a separator made of polypropylene,
7 is an impregnating material made of the same material and impregnated with an organic electrolyte. 8 is a positive electrode mixture.

The positive electrode current collector 5 has two types: one in which the surface is completely formed with wavy irregularities by sandblasting and then coated with conductive carbon paint, and the other in which the conductive carbon paint is coated without roughening the surface. After drying the material in E by a conventional method, a battery cell was assembled. The following table shows the results of examining the peeling state of the conductive paint on the dried case.

(Left below) It can be seen that in cases where the conductive carbon paint was applied after the metal surface was roughened in this way, no peeling occurred after drying.

Furthermore, the results of investigations into the electrical characteristics of these batteries are also shown in the table. In the table, the average 1st shift of 1000 pieces is shown as i, and the standard deviation total σ is shown. Further, FIG. 3 shows changes in internal resistance when these batteries were stored in an atmosphere at 60°C.

In Fig. 3, a shows no roughening.

b is a roughened surface. In this way, the battery using the uninvented case has good contact between the paint surface and the metal surface, so it has excellent internal resistance and 7Tj discharge characteristics. Since it is difficult for the electrolyte to penetrate into the interface with M, it has excellent features such as a small increase in internal resistance after high temperature storage.

This is done by surface processing such as sandblasting on the current collector or the inner bottom of the case to form gentle unevenness with a pitch of 40 to 100μ as shown in Figure 4 on the surface of the current collector or the inner bottom of the case. This improves the adhesion of the paint and improves battery characteristics.

By roughening the surface of the current collector or positive electrode case to a degree exceeding the effects of the invention, and then applying a conductive carbon paint, a battery with stable electrical characteristics can be manufactured.

[Brief explanation of drawings]

FIG. 1 is an enlarged sectional view showing a positive electrode current collector of a conventional battery, FIG. 2 is a schematic cross-sectional view of an organic electrolyte battery according to an embodiment of the present invention, and FIG. 3 is an organic electrolyte battery according to the present invention. FIG. 4 is an enlarged cross-sectional view of the positive electrode current collector in the present invention. 4... Positive electrode case, 6... Positive electrode current collector. Name of agent: Patent attorney Toshio Nakao (1st person)
m 3rd cause Q 20 47) 60 8θ lo0 Otsu07shii Ryojii 4 days “number C days” 4th figure

Claims (1)

[Claims] An organic electrolytic solution characterized in that a wavy uneven portion is formed on the surface of a positive electrode current collector in contact with a positive electrode mixture or on the inner bottom surface of a positive electrode case by surface treatment, and then a conductive carbon paint is applied to the wavy uneven portion. Battery manufacturing method.