JPH0631643Y2 - Explosion-proof sealed battery - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial application field> The present invention relates to an explosion-proof sealed battery having an explosion-proof structure.

<Outline of the Invention> The present invention provides a lid of a sealed battery, a first lid made of aluminum or aluminum metal and having a thin portion having a thickness of 50 μm to 300 μm, and a vent hole made of hard metal. By having a double structure with the second lid,
It is an object of the present invention to provide an explosion-proof sealed battery capable of ensuring explosion-proof and strength of the battery with a simple structure.

<Prior Art> Conventionally, for example, secondary batteries such as lithium batteries and carbon lithium batteries have been widely used in video tape recorders, watches and the like.

By the way, in the battery as described above, the power generation element housed in the battery may undergo a chemical change to increase the internal pressure and cause an explosion. For example, when a non-aqueous electrolyte battery such as a normal lithium secondary battery is supplied with a current higher than normal to bring it into a so-called overcharged state, or when the polarity is reversely connected during charging, the gas in which the electrolyte is decomposed is These gases may be generated, and these gases may gradually fill up, increasing the pressure in the battery and finally exploding.

Conventionally, in order to prevent the explosion of the battery as described above, for example, Japanese Utility Model Laid-Open No. 58-5328 and Japanese Utility Model Laid-Open No. 61-13396.
A technique as described in Japanese Patent No. 5 has been proposed.

The batteries described in the above publications, as shown in FIG.
An outer can that houses the power generation element and also serves as the negative electrode terminal (1
(00) is equipped with explosion-proof melting safety valve device. This explosion-proof melting safety valve device is attached to the upper surface of the gasket (102), and has a lid (104) in which a valve hole (103) is formed in the center and a bottom surface in which a recess (105a) is formed. Is a thin (105b) cylindrical elastic valve body (105) and a gas vent hole (10) attached so as to cover the upper part of the elastic valve body (105).
6a) is formed with a dish-shaped terminal plate (106), and the recess (105a) of the elastic valve body (105) is provided with a cutting blade (107a) protruding in the direction of the thin portion (105). A cutting member (107) is provided.

According to the conventional battery, the power generating element housed in the outer can (100) undergoes a chemical change, and when the inner pressure of the outer can (100) becomes high, the thin portion of the elastic valve body (105) ( 105b)
Extend in the direction of the cutting blade (107a) provided on the cutting member (107). Then, the thin portion (105b) is the cutting blade (107
When the inner pressure is further increased by contacting a), the thin portion (105b) is broken by the cutting blade (107a), and is released into the atmosphere through the gas vent hole (106a) formed in the modified terminal plate (106). The gas is exhausted to.

<Problems to be Solved by the Invention> However, in the above battery, as described above, the cutting member (1
Since the thin blade (105b) of the elastic valve body (105) is destroyed by the cutting blade (107a) provided in 07), the structure becomes complicated and the manufacturing is time-consuming.

Therefore, the present invention has been proposed in view of the problems of the above-mentioned conventional technology, and provides an explosion-proof sealed battery that has a simple structure, can be easily manufactured, and can surely prevent an explosion. The purpose is to do.

<Means for Solving the Problems> In order to achieve the above object, the present invention has an outer case having a power generating element housed therein, a gasket having a through hole in the center, and a thickness of 0.2 mm to 0 mm. It has a concave portion that is made of aluminum or aluminum alloy of 6 mm and faces the through hole in the center, and a substantially radial thin portion having a thickness of 50 μm to 300 μm is formed on the bottom surface of the concave portion and rises to the outer peripheral portion. A first lid body having a portion and a second lid body made of hard metal and provided with a gas vent hole,
The outer can and the first lid body and the second lid body are caulked via the gasket, and the rising edge of the first lid body is in contact with the peripheral edge of the second lid body. It is characterized by that.

<Operation> In the present invention, when the power generating element housed in the outer can is chemically changed and gas is generated, the internal pressure increased by the gas causes the thin wall provided on the first lid, which is a component of the present invention. There is a crack in the part.

Therefore, the gas in the can escapes to the outside through the crack to the first lid body, and further escapes to the atmosphere through the gas vent hole provided in the second lid body.

Since the thin portion is formed on the bottom surface of the concave portion of the first lid body, it does not inadvertently split when caulking the first lid body, and the pressure required for the splitting is stable. It will be

<Example> Hereinafter, an example of the present invention will be described with reference to the drawings.

The explosion-proof sealed battery according to the present invention, as shown in FIG.
A cylindrical outer can (1) in which the power generation element is housed, a gasket (2) provided on the inner circumference of the upper end of the outer can (1), and an intermediate lid fitted and supported by the gasket (2). (3) and a closing lid (4) for closing the outer can (1), and the gasket (2), the intermediate lid (3), and the closing lid (4) are the outer casing. It is caulked and attached to the can (1).

In the outer can (1), a negative electrode material (for example, a metal lithium foil) and a positive electrode material (for example, a positive electrode substrate coated with molybdenum sulfide) are spirally wound with a separator impregnated with an electrolytic solution interposed therebetween. The power generator (20) configured as described above is housed as a power generating element, and a sheet-like insulating plate (5) is formed on the upper part of the power generator (20). An insertion hole (7) for inserting the lead terminal (6) is formed in the center of the insulating plate (5). The lead terminal (6) has one end attached to the spirally wound positive electrode material, and the other end through the insertion hole (7) from the lower surface of the insulating plate (5) to be described later. It is attached to the lower surface of the intermediate lid body (3) by a technique such as spot welding.

On the other hand, a large diameter portion (8) is provided on the upper end side of the outer can (1) accommodating the power generating element, and the gasket (2) is fitted into the large diameter portion (8). The gasket (2) is provided on the inner circumference of the outer can (1) to prevent the electrolyte solution that has penetrated into the separator (not shown) contained in the outer can (1) from leaking to the outside of the battery. And is made of a synthetic resin material in order to prevent a short circuit between the positive electrode and the negative electrode. And the above gasket (2) is
As shown in FIG. 2, the lead terminal (6) and a through hole (9) through which gas generated from the power generating element described below is inserted are formed in the central portion of the disk, and the peripheral portion is formed. Is provided with an annular rising portion (10).

An intermediate lid (3) is provided on the upper surface of the gasket (2). The intermediate lid (3) is shown in FIGS.
As shown in the figure, while forming a disc shape with a diameter slightly shorter than the diameter of the gasket (2), it is fitted on the inner peripheral side of the annular rising portion (10) provided on the gasket (2). ,
In this embodiment, the aluminum plate is formed to have a wall thickness of about 0.4 mm. The material of the intermediate lid (3) is not limited to this, and a relatively soft aluminum alloy or the like can be used, and the thickness thereof may be about 0.2 to 0.6 mm. And, in the center of this intermediate lid (3) is provided a concave portion (11) that fits into the through hole (9) provided in the gasket, and on the bottom surface of this concave portion (11). , 130
The thin portion (12) having a thickness of μm is radial (in this example, X
Character shape). The thickness of the thin portion (12) may be appropriately set in consideration of the allowable internal pressure of the can and the thickness of the intermediate lid (3) itself, and is preferably about 50 to 300 μm. If the thin portion (12) is too thick, the pressure inside the can increases too much and there is a risk of rupture. On the contrary, if the thin portion (12) is too thin, the mechanical strength is insufficient and even a slight impact may cause rupture. Further, a flange portion (13) is provided on the outer peripheral portion of the intermediate lid body (3). On the back surface of the concave portion (11),
Lead terminal with one end attached to the lithium foil
The other end of (6) is attached. Also, the concave portion (11)
The peripheral portion of the flat surface is formed as a flat surface portion (3a), and the surface of the flat surface portion (3a) and the flat surface portion (4a) of the closing lid body (4) described later are in sliding contact with each other to establish electrical connection.

The intermediate lid (3) has a stepped flat portion (3a) between the concave portion (11) and the collar portion (13).
This is because (3) is deformed downward when the battery is crimped, and the deformation is absorbed by the flat portion (3a) and does not affect the thin portion (12). Further, when the concave portion (11) swells due to an increase in battery internal pressure, it dazzles with the boundary with the flat portion (3a) as a fulcrum, so that the thin portion irrespective of the size of the intermediate lid (3).
(12) can be provided.

Further, a closing lid body (4) is provided above the intermediate lid body (3) so as to face the intermediate lid body (3). This closing lid (4) is to serve as a positive electrode terminal and has a disc shape with a diameter slightly shorter than the diameter of the intermediate lid (3), and is provided on the peripheral portion of the intermediate lid (3). Further, it is formed in a disk shape so as to be housed in the neck portion (13), and a bulging portion (14) bulging and provided above the battery is formed in the central portion. The closing lid (4) is made of a hard metal material, in this example, a stainless plate,
In this example, it is formed of a stainless plate to enhance the strength of this battery. Furthermore, the bulging portion of the closing lid (4)
In this embodiment, two gas vent holes (15) and (1) are provided in (14).
6) is drilled.

And, the gasket (2), the intermediate lid (3) and the closing lid.
As shown in FIG. 1, (4) is caulked from the outer peripheral portion of the outer can (1) toward the axis of the battery. As described above, the caulking-attached intermediate lid body (3) and closing lid body (4) and the outer can (1) are the gasket (2).
The battery is integrated with the battery, and the battery is insulated. That is, the gasket (2) is provided with a rising portion (10) in the peripheral portion, and the intermediate lid body (3) and the closing lid body (4) are arranged in the rising portion (10). The outer wall of the rising can (10) is provided with the peripheral wall (1a) of the outer can (1).
Is located, the outer can (1) and the intermediate lid (3) can be caulked from the outer periphery of the outer can (1) in the axial direction of the battery.
The gasket (2) is interposed between the battery and the closing lid (4) to seal the battery.

Therefore, the intermediate lid (3) and the closing lid which are connected to the lithium terminal of the positive electrode by the gasket (2).
Insulation is achieved between (4) and the outer can (1).

On the other hand, the flange portion (13) of the intermediate lid body (3) is formed by the above-mentioned caulking.
Is pressed against the peripheral edge of the closing lid body (9) and comes into contact therewith, so even if the intermediate lid body (3) is deformed and the flat surface portion (3a) and the flat surface portion (4) are separated from each other, Electrical continuity between them is secured.

According to the battery according to this example configured as described above,
Gas is generated by the chemical change of the power generating element housed in the battery, and when the internal pressure of the outer can (1) rises due to this gas, the intermediate lid (3) is gradually changed as shown in FIG. As shown in FIG. 5, when the bulge in the direction of the closing lid (4) further increases the internal pressure, as shown in FIG. 5, the bulges gradually in the direction of the closing lid (4) and further increases in the internal pressure. As described above, the X-shaped thin portion (12) formed on the intermediate lid (3)
Break from position. In this embodiment, the internal pressure of the battery increases and
When the pressure became 5 to ²⁰ kg / cm ² , the concave portion (11) swelled toward the closing lid (4) side, a crack was generated in the thin portion (12), and the internal pressure escaped. The operating pressure of the explosion-proof part can be controlled by the size and thickness of the thin part (12). Due to the breaking of the thin portion (12), the gas filled in the outer can (1) escapes from the breaking position toward the closing lid (4) arranged above the intermediate lid (3). And, since the two gas vent holes (15, (16) are formed in the closing lid body (4), the gas released from the breaking position of the intermediate lid body (3) is
The gas is released from the vent holes (15) and (16) into the atmosphere.

Therefore, according to the battery according to the present embodiment, it is possible to reliably prevent the battery from exploding due to the pressure of the gas generated by the chemical change of the power generating element housed in the outer can (1) of the battery. it can. Also, the intermediate lid (3)
Is disposed between the closing lid (4) and the power generating element, so that even if the intermediate lid (3) is broken by the pressure of gas, the electrolytic solution constituting the power generating element is It can be prevented from flowing out of the.

In the embodiment described above, the intermediate lid body (4), which is a component of the present invention, has the X-shaped thin portion (12). However, the present invention is not limited to the embodiment. Without being limited thereto, for example, as shown in FIG. 6, the main surface of the intermediate lid body (4) is provided with a thin portion in the radial direction and two thin portions from both ends of this thin portion. May be.

<Effects of the Invention> According to the present invention, since each component such as the outer can, the intermediate lid, and the closing lid can be manufactured by pressing a flat plate, it is difficult to process the conventional technology. It can be easily manufactured without involving, and is also advantageous in terms of cost.

Further, in the present invention, since the closing lid body made of stainless steel is provided so as to face the intermediate lid body made of aluminum or aluminum alloy, the strength of the battery can be sufficiently ensured.

Further, since the intermediate lid, which is a component of the present invention, is arranged between the closing lid and the power generating element, the intermediate lid is broken by the pressure of the gas generated by the chemical change of the power generating element. Even in this case, the electrolytic solution can be prevented from flowing out.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention, and FIG.
FIG. 3 is an exploded perspective view of the figure, FIG. 3 is a plan view of the intermediate lid, FIG. 4 is a sectional view of the intermediate lid, and FIG. 5 is a sectional view showing a state where the intermediate lid is bulged, and FIG. FIG. 6 is a perspective view showing another example of the intermediate lid body. FIG. 7 is a schematic sectional view of a main part showing a conventional example. (1) …… Outer can (2) …… Gasket (3) …… Intermediate lid (4) …… Closed lid (12) …… Thin portion

Claims (1)

[Scope of utility model registration request] 1. An outer can containing an electric power generating element inside, a gasket having a through hole in the center, and a thickness of 0.2 mm to 0.6.
mm aluminum or aluminum alloy and has a concave portion facing the through hole in the center and 50 μ on the bottom surface of the concave portion.
A first lid having a substantially radial thin portion having a thickness of m to 300 μm and a rising portion on the outer peripheral portion, and a second lid made of hard metal and having a vent hole formed therein. A body, and the outer can, the first lid and the second lid are caulked via the gasket, and the second lid is provided on the rising portion of the first lid. An explosion-proof sealed battery, characterized in that the peripheral edges of the body are in contact with each other.