JP3229673B2 - Explosion-proof sealed battery - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealed battery which releases an internal gas when the pressure in the battery reaches a set value to prevent explosion.

[0002]

2. Description of the Related Art An internal pressure of a sealed type secondary battery sometimes rises abnormally depending on operating conditions. For example, in a lithium ion secondary battery, the internal pressure rises abnormally when overcharged. If the internal pressure rises abnormally, the battery can will burst. The rupture of the outer can damages the electric equipment containing the battery. In addition, if a corrosive gas or electrolyte leaks from the ruptured outer can, the corrosive gas or electrolyte may corrode the electric equipment. To avoid this drawback, explosion-proof sealed secondary batteries have been developed. This battery includes a mechanism for preventing an abnormal increase in internal pressure. An abnormal increase in internal pressure when overcharging is prevented by interrupting the current inside the battery. When the current is cut off, the chemical reaction inside the battery is stopped. However, even when the current is interrupted, the internal pressure may further increase. In order to prevent the outer can from being destroyed in this state, a sealed secondary battery having a built-in safety valve that breaks due to the internal pressure of the battery in a sealing body has been developed (Japanese Patent Laid-Open Publication No. Heisei 2-
112151, and JP-A-2-288063). The cross-sectional structure of the battery described in this publication is shown in FIG.
3 to FIG. In this battery, a flexible valve body 2 that is deformed by internal pressure and breaks is built in a sealing body 1 as a safety valve. The flexible valve body 2 is provided with a thin portion 2A so as to be easily broken by internal pressure. When the internal pressure of the battery rises to the set pressure, the valve element 2 is deformed and broken by the pressure. Since the flexible valve element 2 is stretched on the inner surface of the cap 6 which is a terminal plate, when it is broken, the safety valve is opened and the gas in the battery is discharged to the outside of the battery. Therefore, when the safety valve is opened, the battery pressure is prevented from rising.

The sealed battery described in this publication operates as follows to prevent an abnormal increase in internal pressure. Normal state in which the internal pressure of the battery is lower than the set pressure In this state, the valve body 2 is connected to the lead wire 4 as shown in FIG. This is because the valve body 2 is not deformed. Therefore, the battery cap 6 is connected to the power generation element 7 via the valve body 2 and the lead wire 4 and is in a state where electricity can be supplied. State in which the internal pressure of the battery rises higher than the set pressure When the internal pressure of the battery rises, as shown in FIG. 2, the valve body 2 is pushed up by the pressure. At this time, the rise of the lead wire 4 is prevented by the stopper 3. Therefore, the lead wire 4 is at a fixed position, only the valve body 2 rises, and the valve body 2 is separated from the lead wire 4. When the valve body 2 is disconnected from the lead wire 4, the battery shuts off the current internally. In this state, no current flows through the battery, and the chemical reaction inside the battery stops. Therefore, the rise of the internal pressure is limited. When the internal pressure further increases even when the current is interrupted Even when the current is interrupted, the internal pressure of the battery may further increase. At this time, as shown in FIG. 3, the amount of deformation of the valve body 2 further increases. The greatly deformed valve body 2 is broken at the thin portion 2A. The broken valve body 2 exhausts gas in the battery. The gas that has passed through the valve body 2 is exhausted to the outside of the battery from the gas vent hole 8 of the cap 6.

[0004]

The explosion-proof sealed battery having the above structure can prevent the internal pressure from abnormally increasing by opening the safety valve when the internal pressure increases. However, in order to reliably prevent the outer can from being damaged when the battery is overcharged, the sealed battery having this structure needs to be designed to have the operating pressure at which the safety valve opens as low as possible. that is,
If the operating pressure is high, there is a high risk that the outer can will break before the safety valve is opened. However, when the operating pressure of the safety valve is set low, the safety valve opens at a pressure that does not require the safety valve to be opened, and there is a disadvantage that the battery cannot be reused thereafter. In other words, improving the safety of the battery by reliably opening the safety valve at the time of overcharging to prevent the outer can from being destroyed, and preventing malfunction of the safety valve in normal use are mutually exclusive. It is extremely difficult to satisfy both of these characteristics.

The present invention has been developed to solve this problem. An important object of the present invention is to ensure that the safety valve can be opened at the time of overcharging, and in a state where it is not necessary to open the safety valve, to prevent malfunction of the safety valve and increase the safety of the battery, An object of the present invention is to provide an explosion-proof sealed battery that can prevent a malfunction of a safety valve.

[0006]

Means for Solving the Problems A sealed battery of the present invention has the following configuration in order to achieve the above object. That is, the explosion-proof sealed battery of the present invention is an improved version of the sealed battery having a built-in safety valve that opens when the pressure reaches a predetermined pressure and releases gas in the battery. The safety valve 3 has a built-in flexible thin plate 3A that is broken and opened when a predetermined pressure is reached.
The flexible thin plate 3A breaks when it cannot withstand deformation,
Or, it is broken by being pierced by a protrusion. Flexible thin plate 3
When A is broken, the safety valve is opened, and the gas inside the battery is released to the outside. Therefore, when the internal pressure of the battery becomes equal to or higher than the set pressure, the safety valve is opened to prevent the internal pressure from rising.

Further, in the sealed battery of the present invention, a laminated plate of a metal thin film 3a and a plastic film 3b is used for the flexible thin plate 3A of the safety valve 3. In the laminate having this structure, the breaking strength decreases as the temperature increases. For this reason, when the internal temperature of the battery is increased due to overcharging, the flexible thin plate 3A is easily broken, and the valve opening pressure of the safety valve is reduced.

[0008]

With the explosion-proof sealed battery of the present invention, as the internal temperature of the battery increases, the safety valve can be easily opened. That is,
The internal pressure of the battery at which the safety valve is opened is a function of the temperature. When the temperature is low, the operating pressure is high, and when the temperature is high, the operating pressure is low. This state is shown in FIG. When the battery temperature is as low as 20 ° C., the safety valve shown in FIG.
The valve opening pressure of kg / cm ² is too high to easily open the valve. However, when the battery temperature rises to 80 ° C., the valve opening pressure of the safety valve becomes extremely low at about 12 kg / cm ^2, and the valve is easily opened.

As described above, the valve opening pressure of the safety valve decreases with the temperature because the flexible thin plate 3A is a laminate of the metal thin film 3a and the plastic film 3b. This is because the metal thin film 3a is easily stretched, the reinforcing effect is reduced, and the metal thin film 3a is easily broken. The breaking strength of the flexible thin plate 3A is
Can be adjusted by changing the thickness and material of the metal thin film 3a and the thickness and material of the metal thin film 3a. For example, when a synthetic resin having heat resistance is used for the plastic film 3b, a decrease in the breaking strength of the flexible thin plate 3A due to an increase in temperature is reduced.

[0010] Advantageously, secondary batteries have the property of increasing the battery temperature when overcharged. This is because, when the battery is overcharged, the ratio of the input power to the battery used for charging decreases, and the battery is consumed as heat energy. With sealed batteries of the present invention utilizes this property,
As a unique thing to the flexible thin plate 3A, the safety valve is reliably opened at the time of overcharging. When the battery temperature rises due to overcharging,
The flexible thin plate 3A, which is a laminated plate of the metal thin film 3a and the plastic film 3b used for the safety valve 3, has a reduced breaking strength. Therefore, when the battery is overcharged, the valve opening pressure of the safety valve 3 decreases, and the valve is reliably opened. In a state where the battery temperature does not rise, the valve opening pressure of the safety valve is high, so that it is prevented that the valve is opened by mistake and the secondary battery becomes unusable.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. However, the following examples illustrate a sealed secondary battery for embodying the technical idea of the present invention, and the sealed secondary battery of the present invention includes the types, types, materials, The shape, structure and arrangement are not specified below. Various changes can be added to the sealed secondary battery of the present invention within the scope of the claims.

Further, in this specification, in order to facilitate understanding of the claims, the numbers corresponding to the members shown in the embodiments will be referred to as "claims", "actions", and "actions". In the column of "Means for solving the problem". However, the members shown in the claims are
It is by no means specific to the members of the embodiment.

The explosion-proof type sealed secondary battery shown in FIG. 5 has an outer can 10, a power generating element 7 composed of a +/− electrode plate housed in the outer can 10, and a closure for closing an opening of the outer can 10. And a body 1. The outer can 10 has a cylindrical shape with its bottom closed, and the sealing body 1 is caulked and fixed to the opening at the upper end.

The sealing body 1 is fixed by caulking to the outer can 10 via an insulating packing 11 to hermetically close the outer can 10. The sealing body 1 cuts off the current when the internal pressure of the battery increases. After the current is cut off, the internal gas is discharged when the internal pressure further increases.

In order to realize this, the sealing body 1 is
A cap 6, a flexible thin plate 3A constituting the safety valve 3,
A valve body 2 and a valve holder 9 are provided. Cap 6 and valve 2
The valve holder 9 is required to have conductivity. For this reason, these members are manufactured by press-forming a metal plate. The sealing body 1 having this structure uses the cap 6 as a positive electrode. The cap 6 is connected to a positive electrode plate, which is a power generating element 7, via the valve body 2, the valve holder 9, and the lead wire 4. Cap 6
, Valve body 2 and valve holding body 9 are cut into a disk shape. The peripheral edge of the valve holding body 9 which is a metal plate is bent upward and caulked so as to sandwich the valve body 2 and the cap 6 to connect the three metal plates. Although the cap 6 and the valve body 2 are in direct contact with each other, an insulating packing 12 is sandwiched between the valve body 2 and the valve holder 9.

The cap 6 is pressed into a convex shape at the center,
The gas vent hole 8 is opened. The valve element 2 has a central portion projecting downward, and the projecting portion is welded to the valve holder 9. The valve body 2 and the valve holder 9 can be connected by spot welding or ultrasonic welding.

When the internal pressure of the battery reaches a set pressure, the valve body 2
It deforms as shown in FIG. 6 and is separated from the valve holder 9. The strength at which the valve body 2 is separated from the valve holder 9 can be adjusted by the strength at which the valve body 2 is welded to the valve holder 9 and the deformation strength of the valve body 2. When the valve body 2 is strongly welded to the valve holding body 9 and the valve body 2 is made of a thick metal plate to increase the deformation strength,
It becomes difficult for the valve body 2 to separate from the valve holding body 9. That is, the set pressure of the battery that interrupts the current increases. Conversely, if the strength of welding the valve body 2 to the valve holding body 9 is reduced and the valve body 2 is made of a thin metal plate, the set pressure for interrupting the current can be reduced.

The flexible thin plate 3A is hermetically welded to the upper surface of the valve body 2. The flexible thin plate 3A hermetically closes the gas hole 13 opened in the valve body 2. When the flexible thin plate 3A is broken, gas in the battery passes through the gas holes 13 of the valve body 2 and is exhausted to the outside of the battery. The flexible thin plate 3A is designed to have a strength to break when the pressure exceeds a set value. Further, the breaking strength of the flexible thin plate 3A decreases as the temperature increases. This is because when the battery temperature rises due to overcharging, the battery is surely broken.

As the flexible thin plate 3A having this characteristic, a laminated plate in which a plastic film 3b is laminated on a metal thin film 3a is used. As the metal thin film 3a, a corrosion-resistant metal thin film such as titanium, stainless steel, or aluminum can be used. Aluminum is optimal for these metal thin films. This is because it is inexpensive, easy to make into a thin film, and can have optimum strength. When aluminum is used for the metal thin film 3a, the thickness of the metal thin film 3a is usually designed to be in a range of 10 μm to 300 μm, preferably 15 μm to 50 μm. For the plastic film 3b, a thermoplastic synthetic resin such as polyethylene or polypropylene can be used. The film pressure of the plastic film 3b is
Usually 10 μm to 500 μm, preferably 20 μm to 10
It is designed in the range of 0. The flexible thin plate 3A of this structure is
It can be manufactured by coating the surface of the metal thin film 3a with plastic. Further, the metal thin film 3a and the plastic film 3b
Can also be manufactured by bonding them with an adhesive. The simplest flexible thin plate 3A is a two-layer laminated plate in which a plastic film 3b is laminated on one surface of a metal thin film 3a. However, a plastic film laminated on both sides of a metal thin film, or
A laminate in which a metal thin film is laminated on both surfaces of a plastic film, or a laminate in which a plurality of metal thin films and a plastic film are laminated can also be used.

The flexible thin plate 3A shown in FIGS.
The lower surface is hermetically welded to the upper surface of the valve body 2 as a plastic film 3b. Further, the flexible thin plate 3A is
And smaller than the laminated portion of the valve body 2. In other words, there is a flexible thin plate 3A between the cap 6 and the valve body 2.
Is not pinched. It is the cap 6 and the valve 2
This is because if the flexible thin plate 3A is sandwiched between the cap 6 and the valve body 2, the cap 6 and the valve body 2 cannot be laminated in an energized state.

However, although not shown, a flexible thin plate having a plastic film laminated thereon may be sandwiched between the cap and the valve body. However, in this case, it is necessary to spot weld the cap and the valve body through the flexible thin plate, or to electrically connect the outer periphery with the cap.

In the sealing body 1 shown in FIGS. 5 to 7, the outer periphery of the disc-shaped flexible thin plate 3A is welded to the upper surface of the valve body 2. As shown in FIGS. 8 to 10, the flexible thin plate 3A can be welded to the outer periphery and the central portion on the upper surface of the valve body 2. The central portion of the flexible thin plate 3A is welded to the outer periphery of the protrusion provided at the center of the valve body 2. In this way, the flexible thin plate 3A whose center is welded can be reliably connected to the valve body 2 to prevent the flexible thin plate 3A from being damaged in the manufacturing process.

Further, the sealing member 1 shown in FIGS.
Has a flexible thin plate 3A stretched over the top surface of the valve body. As shown in FIG. 11, the flexible thin plate 3A can be stretched on the lower surface of the valve body 2. Flexible thin plate 3A stretched on the lower surface
Has a plastic film 3b on the upper surface. It is preferable that the flexible thin plate 3A be airtightly adhered to the lower surface of the valve body 2 via the plastic film 3b on the upper surface.

Further, when the flexible thin plate 3A is stretched and broken by the internal pressure of the battery as shown in FIGS. 5 to 7, and when it is protruded and broken by the protrusion 20 as shown in FIG. There is. The safety valve 3 which breaks the flexible thin plate 3A by protruding with the protrusion 20 is provided at a position where the flexible thin plate 3A protrudes when the flexible thin plate 3A is deformed and swells due to internal pressure. .

In FIGS. 5 to 7, the valve holder 9 disposed below the valve body 2 penetrates through the gas
4 is open. The gas permeable hole 14 allows a plate-shaped gas to pass through the valve holder 9 and deforms the valve body 2 and the flexible thin plate 3A by the internal pressure of the battery. The lead wire 4 is connected to the lower surface of the valve holder 9. The lead wire 4 connects the valve holder 9 to the power generating element 7.
Connect to That is, in the sealing body 1 shown in FIG. 5, the cap 6 is connected to the power generation element 7 via the valve body 2, the valve holder 9, and the lead wire 4.

The sealing body 1 shown in FIGS. 5 to 7 is configured so that when the internal pressure of the battery rises, the valve body 2 is separated from the valve holding body 9 to cut off the current. However, the present invention does not specify the structure of the sealing body to this structure, for example,
Although not shown, it is also possible to connect the valve body directly to the lead wire without passing through the valve holder, and to separate the valve body from the lead wire when the internal pressure of the battery increases.

The sealing body 1 of the sealed battery shown in FIGS.
Are connected by welding the valve body 2 to the valve holding body 9. However, the valve body 2 may be elastically pressed against the valve holding body 9 to be electrically connected. The sealing body that elastically presses and connects the valve body to the valve holding body is provided with a through hole in the valve holding body to more reliably connect the valve body to the valve holding body. Insert a ridge.

In order to adjust the pressure when the valve body 2 separates from the valve holder 9, an elastic ring 17 can be provided between the valve body 2 and the cap 6, as shown in FIG. In the sealing body having this structure, the flexible thin plate 3A can be sandwiched between the elastic ring 17 and the valve body. The elastic ring 17 elastically presses the upper surface of the valve body 2 to press the valve body 2 against the valve holder 9. When the inner diameter of the elastic ring 17 is reduced and the pressing force of the valve body 2 is increased, the valve body 2 becomes difficult to separate from the valve holding body 9 and the set pressure for interrupting the current increases, and at the same time, the flexible thin plate 3A By adjusting the pressure area, the pressure release pressure can be adjusted at the same time. As the elastic ring 17, a cylinder or a coil spring that elastically deforms can be used.

A sealing body in which a cap, a flexible thin plate, a valve body and a valve holder are laminated can be assembled in the following steps. The ring-shaped insulating packing 12 is fitted into the valve holding body 9 whose peripheral edge is bent upward, and the disc-shaped valve body 2 is laminated on the insulating packing 12. As shown in FIG. 14, after the center of the valve body 2 is welded to the upper surface of the valve holder 9, the valve body 2 is laminated on the upper surface of the valve body 2, and the flexible thin plate 3A is hermetically welded. The flexible thin plate 3 </ b> A is heated and melted and welded to the valve body 2 with the plastic film 3 b facing downward. The cap 6 is laminated on the valve body 2, and thereafter, the periphery of the valve holder 9 is bent, and the valve holder 2 and the periphery of the cap 6 are caulked with the valve holder 9 via the insulating packing 12 and fixed. I do.

As shown in FIG. 11, the sealing body 1 in which the flexible thin plate 3A is welded to the lower surface of the valve body 2 has the flexible thin plate 3A welded to the lower surface of the valve body 2. Is welded to the valve holder to assemble. Also, as shown in FIG.
A polyswitch (PTC) 21 may be laminated on the upper surface of the valve body, and the valve body 2 and the cap 6 may be electrically connected via the polyswitch (PTC) 21. Poly switch (P
The TC) 21 rapidly increases the resistance as the temperature increases, and decreases the battery current.

The sealed secondary battery having the structure shown in FIGS. 5 to 7 operates as follows to prevent an increase in internal pressure.
Normal state in which the internal pressure of the battery does not rise abnormally In this state, the valve body 2 is connected to the valve holder 9. Valve holder 9
Is connected to the lead wire 4, the valve body 2 is connected to the lead wire 4 via the valve holder 9. Therefore, the battery cap 6 is connected to the power generation element 7 via the valve body 2 and the lead wire 4 and is in a state where electricity can be supplied. State in which the battery is overcharged and the internal pressure rises higher than the set pressure When the battery is overcharged and the internal pressure rises, as shown in FIG. 6, the valve body 2 is pushed up by the pressure. The pushed up valve body 2 is separated from the upper surface of the valve holding body 9. Therefore,
The valve body 2 and the lead wire 4 are disconnected, and the current is cut off. When the internal pressure further rises even after the current is cut off When the internal pressure of the battery further increases, as shown in FIG. 7, the flexible thin plate 3A cannot withstand the internal pressure of the battery and breaks. In this state, since the battery is overcharged and the temperature is high, the flexible thin plate 3A is easily broken.
The broken flexible thin plate 3A exhausts gas in the battery.
The gas that has passed through the flexible thin plate 3A is exhausted to the outside of the battery from the gas vent hole 8 of the cap 6. As described above, when the pressure further increases even after the battery is overcharged and the current is cut off, the flexible thin plate 3A is broken, thereby preventing the outer can 10 from being ruptured.

[0032]

According to the explosion-proof sealed battery of the present invention, when the internal pressure of the battery rises abnormally due to overcharging, the safety valve can be reliably opened. Has the feature that it can be minimized from becoming unusable. That is, when the sealed battery of the present invention uses a laminated plate of a metal thin film and a plastic film on a flexible thin plate, and when the battery temperature rises due to overcharging, the breaking strength of the flexible thin plate is reduced. This is because, in a normal use state in which the battery is easily broken and the battery temperature does not rise, the flexible thin plate has a high breaking strength and cannot be easily broken. That is, the density of the present invention
Closed batteries make effective use of the unique properties of rechargeable batteries, in which the battery temperature rises when overcharged, and the unique properties of the laminate of a metal thin film and plastic film, in which the breaking strength decreases with increasing temperature. In order to prevent the safety valve from opening due to malfunction and opening the safety valve due to malfunction, it is necessary to open the safety valve when the temperature is low. By preventing the thin plate from being easily broken, the safety is high and the safety valve is prevented from malfunctioning and cannot be reused.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an example of a conventional explosion-proof sealed secondary battery.

FIG. 2 is a sectional view showing a state where the internal pressure of the sealed secondary battery shown in FIG.

FIG. 3 is a sectional view showing a state in which the internal pressure of the sealed secondary battery shown in FIG. 1 is further increased and a safety valve is opened.

FIG. 4 is a graph showing the breaking pressure against the battery temperature of a flexible thin plate.

FIG. 5 is a sectional view showing a sealing body of the sealed secondary battery according to the embodiment of the present invention;

FIG. 6 is a cross-sectional view showing a sealing body portion in a state in which the internal pressure of the battery shown in FIG.

FIG. 7 is a cross-sectional view showing a sealing body in a state where the internal pressure of the battery shown in FIG. 5 is increased and the flexible thin plate is broken.

FIG. 8 is a cross-sectional view showing a sealing body of the sealed secondary battery according to the embodiment of the present invention.

FIG. 9 is a cross-sectional view showing the sealing member in a state where the internal pressure of the battery shown in FIG.

FIG. 10 is a cross-sectional view showing a sealing body portion in a state where the internal pressure of the battery shown in FIG. 8 is increased and the flexible thin plate is broken.

FIG. 11 is a sectional view showing a sealing body of a sealed secondary battery according to another embodiment of the present invention.

FIG. 12 is a sectional view showing a sealing body of a sealed secondary battery according to another embodiment of the present invention.

FIG. 13 is a sectional view showing a manufacturing process of the sealing body shown in FIG. 5;

FIG. 14 is a sectional view showing a manufacturing process of the sealing body shown in FIG. 5;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Sealing body 2 ... Valve element 2A ... Thin part 3 ... Safety valve 3A ... Flexible thin plate 3a ... Metal thin film 3b ... Plastic film 4 ... Lead wire 5 ... Through-hole 6 ... Cap 7 ... Power generation element 8 ... Gas vent hole 9 ... Valve holder plate 10 ... Outer can 11 ... Insulating packing 12 ... Insulating packing 13 ... Gas hole 14 ... Gas permeation hole 15 ... Through hole 16 ... Protrusion 17 ... Elastic ring 18 ... Insulation resin 19 ... Bending part 20 ... Protrusion 21 ... Poly switch (PTC)

──────────────────────────────────────────────────の Continued on the front page (72) Inventor Kazuo Moriwaki 2-18-18 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (72) Keiichi Ito 2--18 Keihanhondori, Moriguchi-shi, Osaka JP-A-1-151152 (JP, A) JP-A-2-12757 (JP, A) JP-A-2-284349 (JP, A) JP-A-1-220368 (JP, A) JP-A-1-31558 (JP, A) JP-A-2-112151 (JP, A) JP-A-2-288063 (JP, A) JP-A-4-2499073 (JP, A) Kaihei 4-46358 (JP, U) Real Kaihei 4-24262 (JP, U) (58) Fields surveyed (Int. Cl. ⁷ , DB name) H01M 2/12 101

Claims (4)

(57) [Claims] 1. A safety valve (3) for opening a valve when a predetermined pressure is reached to release gas in a battery.
But, when the pressure reaches a certain value, it deforms and shuts off the current.
(2) , an explosion-proof sealed battery having a flexible thin plate (3A) that is broken and opened at a predetermined pressure , wherein the flexible thin plate (3A) is a metal thin film (3a) Plastic membrane (3b)
With the laminated plate , and with a configuration in which the breaking strength of the laminated plate is reduced as the temperature rises , this flexible thin plate (3A),
A valve element that deforms and shuts off current when the internal pressure of the battery increases
(2) is provided so as to hermetically close the gas hole (13),
When the internal pressure of the battery rises, the valve (2) deforms and interrupts the current
When the current is cut off and the internal pressure rises further, the internal gas
Sealed battery explosion-proof characterized by comprising in the so that to discharge the. 2. When a predetermined pressure is reached, the valve opens to open the gas in the battery.
With a built-in safety valve (3)
But, when the pressure reaches a certain value, it deforms and shuts off the current.
(2) and flexibility that breaks and opens the valve when the specified pressure is reached
Explosion-proof sealed battery having a thin plate (3A), A flexible thin plate (3A) in which the sealing body (1) constitutes the safety valve (3) and a valve
A valve (2) and a valve holder (9) are provided.
The body (9) has conductivity, and the valve body (2) and the valve holder (9)
Between the insulation packing (12) and the valve holder (9)
Is connected to the power generating element (7) via the lead wire (4), The valve element (2) deforms when the internal pressure of the battery reaches the set pressure,
Hold the valve so that it is disconnected from the holder (9) and interrupts the current.
The valve (2) is connected to the holding body (9) and is made of a flexible thin plate (3A).
The gas hole (13) that opens to the
Flexible thin plate (3A) consists of metal thin film (3a) and plastic film (3b)
The breaking strength of the laminate decreases with increasing temperature.
When the pressure rises above the set value,
When the plate (3A) is broken, the gas in the battery is released from the gas in the valve (2).
Pass through the hole (13) and exhaust to the outside of the battery.
And When the internal pressure of the battery rises, the current is cut off,
When the internal pressure rises further, the internal gas is exhausted.
An explosion-proof sealed battery characterized by the following. 3. The sealing body (1) includes a cap (6) and a safety valve.
Flexibility that constitutes (3) Thin plate (3A), valve body (2), valve holder
(9), the periphery of the valve holder (9) is bent,
(2) and the cap (6)
The tip (6) and the valve (2) are in direct contact, and the valve (2) and the valve
Claims wherein an insulating packing (12) is sandwiched between the body (9).
2. The explosion-proof sealed battery described in 2. 4. A position where a flexible thin plate (3A) deformed by internal pressure is struck.
The projection (20) is disposed on the
The plate (3A) is pierced and broken.
2. The explosion-proof sealed battery described in 2.