JPH03127442A - Flat type organic electrolyte cell - Google Patents

Abstract

PURPOSE:To stabilize an assembling process as well as to remarkably enhance leaktightness by letting thermal weldable resin be deposited in advance onto the inner surface side section of a case, the outer circumferential section of a sealing plate and the circumference of a bottom section. CONSTITUTION:By the use of thermal weldable resin 9' in an organic resistance solvent series, parts on which the aforesaid resin is deposited, are assembled together with the inner surface side section of a case 1, the outermost circumference of a sealing plate 2 and with the circumference of a bottom section so as to be closely sealed. This thereby allows the resin 9' to be more firmly bonded with metals, and concurrently allows the resin 9' to flow into minute irregularities on the metal surfaces while being dissolved so that gaps are thereby closely filled up. Since the resin 9' is interposed between the case 1 and a gasket 6, and between the gasket 6 and the sealing plate 2, bonding is accomplished with the metals by means of thermal welding, and with the gasket 6 by means of adhesion between the resin 9' and the resin.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to improvements in flat top organic electrolyte batteries.

Conventional technology Flat batteries have high energy density and excellent reliability, so the demand for them has increased rapidly in recent years.In particular, with the development of electronic devices, coin-shaped batteries have become lighter, thinner, and smaller. There is a growing demand for such flat shapes.

Conventionally, as a countermeasure against leakage from the caulked parts of the case, gasket, and sealing plate for flat batteries, materials such as blown asphalt and polybutene are diluted with solvents and After coating, drying, removing the solvent, and sealing, the gap between the case and gasket, and the gasket and sealing plate was filled in to prevent the organic electrolyte inside from leaking to the outside.

Problems to be Solved by the Invention However, according to the conventional method, as described above): t + l:
Effective! Most of the materials with 'e' have the property of being easily soluble in organic solvents, so the sealant will gradually dissolve due to the organic electrolyte inside the battery, and if stored for a long time or due to temperature shock. There was a problem in which the leakage level deteriorated during accelerated testing.

In addition, since it is in a solution form when applied to the case or sealing plate, it may cause contamination of parts during the process, and due to variations in the amount of application or unevenness in the caulking area, the sealant may not adhere to the external surface of the battery. There were also problems such as protrusion, poor appearance, and poor contact with equipment terminals.

The present invention aims to solve the above-mentioned conventional problems, stabilize the assembly process, and significantly improve leakage resistance.

Means for Solving the Problem In order to solve this problem, the present invention uses an organic solvent-resistant heat-fusible resin to seal the inner side of the case 1 and the outermost and bottom circumferences of the sealing plate 2. The resin is welded to the parts to seal the opening.

By heat-welding the action-resistant organic solvent-based heat-welding resin to the case, sealing plate, etc., the adhesion between the resin and the metal becomes stronger, and the resin dissolves into the fine irregularities of the fully curved surface. It is possible to completely fill the flow gap. In addition, since there is heat-welding 16+ grease between the case and the gasket, and between the gasket and the sealing plate, the metal is heat-welded and the gasket is a resin, so it is impossible to completely prevent liquid leakage after the seal is crimped. can.

Examples Below, examples of the present invention will be described with a height of 5.4 mm and a diameter of 2 mm.
This will be explained using a 3 m flat organic electrolyte battery as an example.

Figure 1 is a cross section of a flat organic electrolyte battery based on lithium and manganese dioxide. In the figure, 1 is a stainless steel case, 2 is a stainless steel sealing plate, 3 is an active material of manganese dioxide, A positive electrode mixture consisting of a doryo agent and a binder, 4 is lithium as a negative electrode active material, 5 is a polypropylene nonwoven fabric separator, 6 is a polypropylene gasket, 7
Reference numeral 8 indicates a conductive carbon film, 8 indicates a positive electrode ring, and 9 indicates a P-P type welding resin according to the present invention applied in advance to the inner side of the case, the outermost periphery of the sealing plate, and the bottom circumference. The electrolyte used was lithium perchlorate dissolved in a mixed solvent of propylene carbonate and 1,2 dimethoxyethane.

As a method of welding thermofusible resin to the case and sealing plate,
As shown in Figure 2, the area of the part to be welded in advance and
The resin is processed to match the shape, and then welded by pressing metal jigs with built-in heaters. At this time, in order to prevent the heat-welding resin from welding to the metal jig, apply heat-welding 11 resin to the case and sealing plate side to be welded, and laminate heat-resistant resin to the metal jig side. Use Shitachino.

Next, in order to compare the present invention and the conventional product, the results of a temperature check test and the appearance results are shown in Table 1. The test conditions were -10 to 60'C and the hold time was L.
This is the result of leakage after 500 ncycles using H and 2H as one cycle.

Further, FIG. 3 shows the results of storing and discharging the battery at 60° C.-90% for 100 days. From these results, it is clear that the product of the present invention is superior in terms of duration and I-R stability during discharge even when stored in humid conditions for a long period of time.

Effects of the Invention As is clear from the above explanation, by welding a heat-fusible resin to the inner side of the case, the outer periphery of the sealing plate, and the bottom circumference, the characteristics under humid storage and leakage resistance are improved.
The effects of improving and stabilizing the process, stabilizing the process, and reducing appearance defects were obtained.

[Brief explanation of the drawing]

FIG. 1 is an organic electrolytic power purchase characteristic diagram in an example of the present invention. 1... Case, 2... Sealing plate, 3...
...Positive electrode, 4...Negative electrode, 5...Separator, 6...Gasket, 7...
・Conductive carbon film, 8... Positive electrode ring, 9...
... Sealant, 9' ... Heat-fusible resin.

Claims (3)

[Claims] (1) A negative electrode 4 that uses a light metal as an active material, a positive electrode 3, a separator 5 interposed between these positive and negative electrodes, a battery case 1 that includes an organic electrolyte, and that also serves as a positive terminal, and a sealing plate 2 that also serves as a negative terminal. and a battery that is sealed between the battery case and the sealing plate with a compressed gasket 6 using the bottom surface of the battery case as a seat, the circumference of the inner side of the case 1 and the outermost and bottom circumference of the sealing plate 2 in advance. A flat organic electrolyte battery characterized by having a heat-fusible resin welded thereon. (2) The flat organic electrolyte battery according to claim 1, wherein the material of the heat-fusible resin is polypropylene. (3) The flat organic electrolyte battery according to claim 1, wherein the heat-fusible resin is laminated with a heat-resistant resin.