JPH03171551A - Thin type call and manufacture thereof - Google Patents

Abstract

PURPOSE:To reduce the deterioration of performance when the cell is left for a long time by providing a collector-cum-battery jars in which uneven surfaces are formed, at the upper side and the lower side of a power generating element, and sealing up the peripheral edges through an adhesive resin. CONSTITUTION:At the upper side and the lower side of a power generating element made by laminating a positive electrode active substance 3, an electrolyte layer 5, and a negative electrode active substance 4 in layers, battery jars 1 and 2 being collectors concurrently on whose surfaces unevennesses 7 are formed are provided, and the peripheral edges are sealed up through adhesive resins 6. By forming the unevennesses 7 on the surfaces of the collector-cum- battery jars 1 and 2 in such a way, the contact of the collector-cum-battery jars 1 and 2 and the active substances 3 and 4, and the adhesion of the sealing resins 6 can be maintained for long, and thereby a deterioration of performance when the cell is left for a long time can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION The present invention relates to a thin battery used in the field of small electronic devices such as smart cards and a method for manufacturing the same.

Prior art and its problems Conventionally, this type of thin battery has a structure shown in FIG. 3. In this battery, after long-term storage, the adhesive force between the sealing resin part and the battery case that also serves as a current collector decreases, causing problems such as the generation of "cm" liquid and the intrusion of gas from the outside.

In addition, if bending stress is applied during use, the adhesive strength of the sealing resin part and the current collector [1] may decrease, or the adhesive strength of the sealing resin part and the current collector may decrease. There was a problem that the contact with the dregs deteriorated and the internal resistance of the battery increased.Object of the InventionThe present invention was made in view of the above-mentioned conventional problems.
The object of the present invention is to provide a highly reliable thin battery with excellent productivity and a method for manufacturing the same.

Structure of the Invention In order to achieve the above-mentioned object, the present invention provides a power generating element in which a positive electrode active material% electrolyte layer and a negative electrode active material are stacked in layers, and a battery case that also serves as a current collector is arranged above and below the power generating element, and the peripheral part is This is a thin battery characterized in that a battery case which is sealed with an adhesive resin and which also serves as a current collector has irregularities formed on the surface thereof.

Another method for producing the above-mentioned thin battery is to spray hard particles onto the surface of a battery case that also serves as a current collector and to mold the battery under pressure.

Another method is to manufacture the above-mentioned thin battery in which the battery case is pressurized and molded using a template having many uneven parts on the surface of the battery case which also serves as a current collector.

Example The details of the present invention will be explained below with reference to Examples.

FIG. 1 is a sectional view of a thin battery showing an embodiment of the present invention;
Fig. 2 is the same figure showing another embodiment of the present invention, and Fig. 3 is the conventional one! This is the same diagram of the pond. Figure 4 is a diagram showing a performance comparison between the product of the present invention and the conventional product.

Here, 1 is a battery case that also serves as a positive electrode current collector, 2 is a battery case that also serves as a negative electrode current collector, 3 is a positive electrode active material, 4 is a negative electrode active material, 5 is an electrolyte,
6 is an adhesive resin, and 7 is an uneven portion.

Example 1 The positive electrode active material was mainly manganese dioxide, and the negative electrode active material was lithium foil. The electrolyte is a polyethylene carbonate membrane or polyglobylene nonwoven fabric impregnated with a propylene carbonate solution of lithium perchlorate, or a solid polymer electrolyte film in which lithium perchlorate is dissolved in polyethylene oxide or the like. Stainless steel current collectors are placed above and below these power generating elements. The surface of this stainless steel plate that comes into contact with the active material is coated with 0.1 to 0.5 pm.
By scattering spherical alumina particles and applying it to a rolling roll, an unevenness of 0.1 to 1 pm is formed on the surface. This method is suitable for thin batteries with a total thickness of 0.1 to 0.5 cm. The peripheral portion was sealed with a polyderopylene thermoadhesive resin to obtain a battery 1 of the present invention (FIG. 1).

Example 2 The structural elements are the same as in Example 1, and vlPfJ also serves as a current collector.
A template having a number of convex portions with a height of lc20 to 50ttm was pressed onto the surface of a stainless steel plate, and pressure molded using an oil press. Using this battery case which also serves as a current collector and is suitable for a thin battery having a total thickness of 1 to 5 mm, a battery m (FIG. 2) of the present invention was obtained.

Comparative Example The structure or elements were the same as in Example 1, and the battery shown in FIG. 5, which also served as a current collector and had no processing on the surface of the stainless steel plate of the tank, was used as a conventional product.

Using the inventive product 1, a plate, and the conventional product, the temperature was 40°C and the humidity was 9.
Comparative test results when left in 0% RH are shown in FIG. 4.Both batteries 1.1 of the present invention show little performance deterioration when left for a long period of time, and have excellent long-term reliability.゜This is because the surface of the battery case that also serves as a current collector has irregularities, which allows the contact between the current collector and the active material or the adhesion between the battery case and the sealing resin to be maintained for a long period of time.

Effects of the Invention As described above, the present invention can provide a thin battery with excellent productivity and high reliability, and a method for manufacturing the same.
Its industrial value is extremely large.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a battery showing one embodiment of the present invention, and FIG.
The figures are the same diagram of another embodiment, FIG. 3 is the same diagram of the conventional product, and FIG. 4 is a diagram comparing the characteristics of the present invention and the conventional product. 1...Positive electrode current collector double use battery case 2...Negative 3...Positive electrode active material 4...Negative l 5...Electrolyte 6...Adhesive resin 7...Irregular portion

Claims (3)

[Claims] (1) A battery is constructed by placing a battery case that also serves as a current collector above and below a power generation element in which a positive electrode active material, an electrolyte layer, and a negative electrode active material are stacked in layers, and sealing the periphery with an adhesive resin. A thin battery characterized in that a battery case that also serves as a current collector has unevenness formed on the surface thereof. (2) The method for manufacturing a thin battery according to claim 1, wherein hard particles are sprinkled on the surface of a battery case that also serves as a current collector, and then pressure molded. (3) The method of manufacturing a thin battery according to claim 1, wherein the battery case is press-molded using a template having many uneven parts on the surface of the battery case which also serves as a current collector.