JPS60216446A - Flat enclosed type battery - Google Patents

Abstract

PURPOSE:To prevent leakage of an electrolyte by using a reinforced ring having a concave part, in which the height of its inner peripheral part is lowered than the outer peripheral part, on its upper part for assembling a battery while placing a separator periphery on said concave part. CONSTITUTION:When housing a positive pole active material 2 inside a positive pole can 1 while mounting an L-shaped reinforced ring 7 on the peripheral part of said active material, the reinforced ring 7 is formed so that its upper part may have a concave part, where its inner peripheral side part is lower in height than the outer peripheral side part, while placing the periphery of the separator 3 on its concave part so as to become one level. Then, the positive pole active material 2, the separator 3 and the negative pole active material 4 are laminated while being sealed up through a gasket 6 with a negative pole terminal plate 5 for forming a flat type enclosed system battery. Accordingly, even when an electrolyte is squeezed from the separator 3 when sealing, it does not travel to the inside wall of the positive pole can 1 thus enabling to effectively prevent the leakage of the electrolyte.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to non-torpedo vR liquid batteries and alkaline batteries 4I: flat sealed battery type batteries that are commonly found in
Regarding improvement of its internal structure.

FIG. 1 shows a typical conventional structure of a flat sealed battery called a button type or coin type battery. this is,
A power generation element in which a positive electrode active material 2, a separator 3, and a negative electrode active material 4 are laminated is housed in a flat positive electrode can 1, and the positive electrode can 1
The inside of the battery is sealed by fitting the dish-shaped zero-electrode terminal plate 5 inside the opening of the battery via a synthetic resin annular sealing gasket 6, and by curling the open edge of the positive electrode can 1 inward. It is closed.

The positive electrode active material 2 is press-molded in advance into a disk shape, and at the same time, a reinforcing ring 7 is attached to its peripheral edge. The reinforcing ring 7 is made of stainless steel or the like, has an L-shaped cross section, and is in close contact with the positive electrode active material 2 from its circumferential surface to its upper surface. This reinforcing ring 7 uniformly receives the sealing force when the opening edge of the positive electrode can 1 is molded inward and sealed, thereby preventing the positive electrode active material 2 from collapsing due to the sealing force. The main purpose was to prevent this. Separator number 3 is also impregnated with an electrolytic solution, for example, from polypropylene non-woven fabric 4f.

As shown in FIG.
The inside diameter of the positive electrode can 1 is approximately equal to the inner diameter of the positive electrode can 1, and the power generation elements are filled in the positive electrode can 1 with almost no gaps. Conventionally, this has caused the following problems.

As described above, in the step of sealing the battery by curling the positive electrode can 1, there is not enough space inside the battery, so the inside of the battery is compressed as a whole. 1 then? Parator 3 is also compressed. Especially the reinforcement ring 7.
Two-sided part 14 El gasket 1 to 6 sandwiched between the bottom part [? The area around the palator 30 is strongly compressed. Lee
The electrolyte impregnated in the lever lever 3 may be squeezed out and leak to the outside through the space between the outer periphery of the gasket 1 and the positive electrode can 1. lJ
In the past, defects such as electrolyte leakage during the battery sealing process occurred relatively frequently, at about 2-3%.

This invention was made in view of the above-mentioned conventional problems, and its purpose is to reliably prevent leakage of electrolyte during the battery sealing process by a simple improvement means. The object of the present invention is to provide a flat sealed battery.

In order to achieve the above object, the present invention provides a flat sealed battery having the basic structure described above, in which a recess is provided on the upper surface of the reinforcing ring, the inner circumferential side of which is one step lower in height than the outer circumferential side. The outer diameter of the pallet is slightly smaller than the outer diameter of the recess, and the peripheral edge of the pallet is disposed on the recess.

Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

The structure of a button-type non-aqueous electrolyte battery as an embodiment of the flat sealed battery of the present invention is shown in FIG. A power generation element in which a positive electrode active material 2, a separator 3, and a negative electrode active material 4 are laminated is housed, and a negative electrode terminal plate 5 is fitted inside the opening of the positive electrode can 1 via a sealing gasket 1-0, and the positive electrode The inside of the battery is sealed by curling the mouth edge inward.Furthermore, as the negative electrode active material 4, a light metal such as lithium snow is used. The separator 3 is made of a non-woven fabric of Volip 11 pyrene, which is impregnated with a non-aqueous frosting solution.The positive electrode active material 2 is made of a mixture mainly composed of manganese dioxide, etc., which is pressure-molded into a disc shape in advance. .knee b
Therefore, a reinforcing ring 7, which is one of the essential parts of the present invention, is attached to the peripheral edge of the press-formed material 11.1.

FIG. 3 shows the elongation of the reinforcing ring 70 in FIG. 2. The reinforcing ring 7 is made of stainless steel or the like, and has a circumferential surface portion 71 and a top surface portion 72 that closely contact the circumferential surface and the top surface of the positive electrode active material 2, and has an L-shaped cross section. However, the upper surface portion 72 is not flat. A recessed portion 73 is formed in the face portion 72 of the reinforcing ring 7, with the height of the inner peripheral portion being lower than that of the outer peripheral portion. This depression 73
The step difference is approximately equal to the thickness of the separator 3 in a compressed state.

As shown in FIG. 2, the upper surface of the positive electrode active material 2, which has been pressure-formed together with the reinforcing ring 7, has the above-mentioned depression 7.
The top surface of 3 is flush. Further, the outer diameter of the positive electrode active material 2 with the reinforcing ring 7 is approximately equal to the inner diameter of the positive electrode can 1;
It is loaded into the positive electrode can with almost no gaps.

Further, in the battery of the present invention, the outer diameter of the separator 3 is considerably smaller than the inner diameter of the positive electrode can 1. Specifically, the outer diameter of the separator 3 is larger than the inner diameter of the recess 73 of the reinforcing ring 7 shown in FIG. 3, but slightly smaller than the outer diameter a of the recess 73. Then, as shown in Fig. 2, the separator 3
is superimposed on the upper surface of the positive electrode active material 2, and its peripheral portion is placed on the recessed portion 73 of the reinforcing ring 7, and is housed inside the stepped portion of the recessed portion 73.

In the above configuration, when the battery is sealed, the - side of the separator 3 is substantially flush with the upper surface of the upper surface portion 72 of the reinforcing ring 7. Particularly noteworthy here is that the peripheral edge of the separator 3 fits into the recess 73 and does not reach close to the inner surface of the positive electrode can 1, and that near the inner surface of the positive electrode can 1, the upper surface 72 of the reinforcing ring 7 and the sealing 1. The bottom surfaces of the gaskets 6 are in 0"I contact, and the peripheral edge of the separator 30 is not sandwiched between them.

For this purpose, J3 was involved in the battery sealing process of curling the edges of iT'41tri 1, and lever 3
Even if the electrolytic solution impregnated in it is compressed and squeezed out, the close contact between the top surface 72 of the reinforcing ring 7 and the bottom surface of the J.Roe I gasket 6 is an obstacle and prevents the squeezing out. Electrolyte solution t, t if C is not transmitted to the inner surface of electrode 1. However, ζ, I] pole ζ1, 1 and I:! I [11
Failures such as leakage of the electrolyte through the gap between the gas holes 1-6 rarely occur.

FIG. 4 shows another example of the structure of the reinforcing ring 7. In this example, by reducing the thickness of the upper surface portion 72 of the reinforcing ring 7, the recessed portion 73 described in - is formed. Of course, this example also provides the same effects as described above.

As explained in detail above, according to the flat sealed battery according to the present invention, defects such as leakage of electrolyte to the outside during the battery sealing process can be completely avoided, and the product can be improved. Yield is improved.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a conventional flat sealed battery, Fig. 2 is a sectional view of a flat sealed battery according to an embodiment of the present invention, and Fig. 3 is a partial detail of the reinforcing ring in the battery of Fig. 2. figure,
FIG. 4 is a partially detailed view of a reinforcing ring showing another embodiment of the invention. 1... Positive electrode can 1 2... Positive electrode active material 23... [Parator 3 4... Negative electrode active material 45... Negative electrode terminal plate 5
6... Sealing gasket 7... Reinforcement ring 71.
...Surrounding surface portion 72...Top surface portion 73...Concave portion Patent applicant Fuji Electrochemical Co., Ltd. Agent Patent attorney - Kensuke Iro

Claims (1)

[Claims] (1) A reinforcing ring is attached to the periphery (the disk-shaped positive electrode active material is housed in a flat positive electrode can, and
Layer 1 electrode material on top of the above-mentioned positive electrode can, and include 1 negative electrode gasket inside the positive electrode can through a 1.10 gasket 1~. In a flat sealed battery in which the opening edge of the positive electrode can is curled inward to seal the inside of the battery, the height of the inner peripheral portion is set inside the L of the reinforcing ring. From the outer periphery side - form a paper (1, /: ) '1' recessed part, and make the outer diameter of the valet slightly smaller than the outer diameter of the above-mentioned living part, and make the outer diameter of the valet slightly smaller than the outer diameter of the above-mentioned living part, and the periphery of the separator is formed into the above-mentioned living part. A flat sealed battery that is characterized by its metering on the top.