JPH0132676Y2 - - Google Patents

Description

[Detailed description of the invention] (a) Field of industrial application The present invention relates to a sealed battery formed by sealing an outer case with a sealing lid body provided with a safety valve by welding.

(b) Prior Art Figures 1 and 2 are sectional views of essential parts of a conventional sealed battery. A conventional sealed battery will be explained below using these drawings.

Conventional sealed batteries generally have the following characteristics, as shown in Figure 1:
After inserting the power generation element body 1, which is formed by winding an anode plate and a cathode plate with a separator in between, into a cylindrical metal exterior case 2, and injecting electrolyte, etc., the opening of the exterior case 2 is seamed. By machining and caulking this opening, a seal is created between the safety valve-equipped electrode terminal portion 3 and the exterior case 2 via the resin insulating packing 4. This sealing method is usually called a mechanical resin seal, and has the effect of electrically insulating and sealing the outer case and the electrode terminals, and this method is used for most cylindrical batteries.

However, the insulation packing used in the sealed battery shown in Figure 1 is made of resin such as nylon or polypropylene, and due to deterioration of this resin, it has poor sealing performance when used for long periods of time and at high temperatures, and is resistant to electrolyte leakage. It cannot be said that the quality is good. Furthermore, since the power generating element is located below the seam-processed portion of the exterior case, there is a large surplus space inside the battery, making it impossible to obtain a high-capacity battery. Furthermore, this sealing method can be used for batteries with non-true cylinder shapes, such as long cylinders, elliptical cylinders,
Sealing of a battery shaped like a rectangular cylinder cannot be used because it is plastically difficult to seam the outer case.

A sealed battery as shown in FIG. 2 has been proposed to solve the above problems. This sealed battery is used for primary batteries, especially lithium batteries, and the edge of the central hole of the metal ring 5 of the sealing lid and the electrode terminal 6 are sealed with a glass seal (or ceramic seal) 7. Insulated and fixed by
The end portions of the sealing lid body and the outer lid case 2 thus manufactured are welded together in a ring shape using laser seam welding or gas arc welding to seal the lid.Since no seam processing is required, there is a large space for housing the power generation elements. A high-capacity battery can be obtained, excellent sealing performance, and it can also be applied to batteries with a non-true cylindrical shape.

However, since lithium batteries generate almost no gas inside the battery, they generally do not have a safety valve and there is no problem. When charging, etc., there was a risk that the battery would explode due to an increase in gas pressure inside the battery.

(c) Purpose of the invention In view of the above points, the present invention improves leakage resistance, allows a sealing lid body equipped with a safety valve to be used as an electrode terminal, and is applicable to batteries with a non-true cylindrical shape. The purpose is to provide a sealed battery.

(d) Structure of the invention The present invention is a sealed battery in which the outer periphery of a sealing lid is welded and fixed to the opening of an exterior case in which a power generating element is housed, and the sealing lid has a small hole in the center. A top cover is integrated onto the bottom plate via a safety valve body, and a metal ring body is fixed to the outer periphery of the bottom plate via an insulating member such as a glass seal or ceramic. be.

(e) Embodiment An embodiment of the present invention will be described below with reference to the drawings. FIG. 3 is a cross-sectional view of a main part showing an embodiment of the present invention, and FIG. 4 is a diagram showing a method of manufacturing a sealing lid according to the present invention.

In the drawing, 5' is a metal ring body having a through hole in the center, the outer peripheral edge of which is bent upward, and the edge of the through hole is bent downward, and the sealing lid body is connected to the metal ring. a hole edge bent downwards of the body 5';
The downwardly bent outer peripheral edge of the bottom plate 8 having a small hole in the center is fixed via an insulating member such as a glass seal or a ceramic seal 9, and then the bottom plate 8 and the top cover 10 are connected to a safety valve made of a rubber body. It is manufactured by fixing through the body 11 by resistance welding, laser welding, or the like. Normally, glass seal processing or ceramic seal processing involves high temperatures of 900 to 1100°C, so the safety valve body is made of a material that is sensitive to heat, such as a rubber body alone or a combination of a spring and a rubber plate made of steel or stainless steel. If the sealing process is performed after the bottom plate and the top cover have been integrated through the safety valve body, heat will adversely affect the process.
When producing a sealing lid by the method described above, the safety valve body 11 is not in contact with the bottom plate 8 during glass seal processing or ceramic seal processing, so there is no adverse effect due to heat, and the glass seal or ceramic seal 9 is not in contact with the bottom plate 8. The sealing performance is also good. Next, a power generation element body 1 is formed by spirally winding the anode plate 12 and the cathode plate 13 with a separator 14 in between.
The completed battery is sealed by welding the opening of the metal exterior case 2 containing the battery inside and the outer circumferential edge bent upward of the outer circumferential member 5' of the sealing lid using arc welding or laser welding. is produced.

(F) Effects of the invention The invention consists of a bottom plate, a top cover integrated onto the bottom plate via a safety valve body, and a top cover fixed to the outer periphery of the bottom plate via an insulating member such as a glass seal or a ceramic seal. Since it has a sealing lid made up of a metal ring, gas can escape through the safety valve even if the internal pressure of the battery increases, and the glass seal or ceramic seal prevents electrolysis from occurring between the bottom plate and the metal ring. No liquid leaks. Furthermore, since the sealing lid and the outer case are welded together, leakage of electrolyte from between the sealing lid and the outer case is also prevented, and a sealed battery with almost perfect sealing performance is obtained. It can also be used for non-true cylindrical batteries to which mechanical resin seals cannot be applied.

[Brief explanation of drawings]

Figures 1 and 2 are sectional views of the main parts of a conventional sealed battery, Figure 3 is a sectional view of the main parts of the sealed battery of the present invention, and Figure 4 shows the manufacturing method of the sealing lid of the present invention. It is an explanatory diagram. 2...Metallic exterior case, 8...Bottom plate, 10...
...Top lid, 11...Safety valve body, 5'...Metal ring body, 9...Glass seal or ceramic seal.

Claims (1)

[Scope of utility model registration request] A sealed battery in which the outer periphery of a sealing lid is welded and fixed to the opening of an exterior case that houses a power generating element, the sealing lid having a bottom plate having a small hole in the center, and a bottom plate on the bottom plate. A sealed battery comprising a top lid integrated through a safety valve body, and a metal ring body fixed to the outer periphery of the bottom plate through an insulating member such as a glass seal or a ceramic seal. .