JPH10134789A - Pressure valve for battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make constant operation pressure with a simple structure, enhance safety and reliability as for the inner pressure of a battery, and facilitate the accommodation into the battery by fixing a sheet-like closing member so that it covers a through hole in a base. SOLUTION: A pressure valve 1 is structured such that a circular sheet-like closing member 13 is fixed by means of adhesion member 14 whose fixing strength is larger than the rupture strength of the closing member 13 so that the member 13 may cover one side of a circular through hole 12 formed at a base 11 serving also as another element of disc shape. The pressure valve 1 is housed in a battery by being integrated with a PTC element 16 and a positive terminal 17. The member 13 can be controlled constant in its rupture strength as the thickness is easily made constant owing to its sheet form. Accordingly, with a simple structure the operation pressure of the pressure valve 1 can be controlled constantly, and the safety and reliability can be enhanced, and further through change of the thickness of the member 13 and the size of the through hole 12 the operation pressure can be set arbitrally.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure valve for a battery. More particularly, the present invention relates to a pressure valve that is housed in a battery, opens when the pressure in the battery increases, and releases internal pressure.

[0002]

2. Description of the Related Art A battery has an overcurrent, heat generated due to an abnormal reaction,
A pressure valve is provided to prevent rupture due to an increase in internal pressure or the like. The pressure valve is housed in the battery, and is configured to open as the pressure in the battery increases and release the internal pressure.

FIG. 3 is a plan view showing a conventional battery pressure valve. In the figure, reference numeral 1 denotes a pressure valve, and a groove-shaped recess 4 having a substantially cross shape is formed in the center of a disk-shaped metal plate 3 having a flange 2. The disc 3 has a substantially uniform thickness as a whole, and the recess 4 is configured to have a uniform thickness smaller than the thickness.

The above-described pressure valve 1 is manufactured by forming a groove-shaped concave portion 4 by press molding at the same time as forming a flange 2 by punching a metal plate 3 in a circular shape. Such a pressure valve is integrated with a PTC element, a positive electrode terminal and the like and is housed in a battery for use.

When the internal pressure of the battery rises due to the occurrence of an abnormal state such as an overcurrent or an abnormal reaction in use, cracks enter the thin and low-strength recess 4 to release gas and release the internal pressure. This prevents accidents due to battery rupture.

[0006]

However, in the conventional battery pressure valve as described above, it is easy to form the metal plate 3 itself to have a constant thickness with a uniform material so that the strength is constant. Since the groove-shaped concave portion 4 is formed by press working, a constant thickness (depth of the groove) due to variations in processing conditions.
It is difficult to do. For this reason, the operating pressure of the pressure valve 1 is greatly different due to the variation of the thickness of the recess 4 formed, and there is a problem that safety and reliability cannot be maintained.

An object of the present invention is to provide a battery having a simple structure and a constant operating pressure, thereby improving safety and reliability, and being able to be formed integrally with other elements. An object of the present invention is to provide a battery pressure valve which can be easily housed in a battery.

[0008]

The present invention relates to the following battery pressure valve. (1) A substrate provided in the battery, a through hole provided in the substrate, and a sheet-like closing member provided to cover the through hole and fixed to the substrate around the through hole. Pressure valve for batteries. (2) The battery pressure valve according to the above (1), wherein the substrate is a single-layer substrate or a laminated substrate. (3) The battery pressure valve according to the above (1) or (2), wherein the through hole is a through hole formed in the substrate. (4) The pressure valve for a battery according to any one of the above (1) to (3), wherein the closing member is made of a metal foil, and is fixed to the base material by the fixing member.

The substrate constituting the battery pressure valve of the present invention may be a single-layer substrate or a laminated substrate, and may be a substrate dedicated to the pressure valve or a substrate shared with other elements. The material of the substrate is not particularly limited, but in the case of a single layer substrate, it is formed of a metal plate such as copper, aluminum or other conductor so that connection can be made from the positive electrode or the negative electrode to the terminal, and in the case of a laminated substrate, on both sides of the insulating substrate. It is preferable to form a conductor layer of copper, aluminum or the like. These substrates can have any shape such as a circle or a quadrilateral according to the shape of the battery.

The shape of the through-hole formed in the substrate is not limited as long as the pressure inside the battery can be detected and the internal pressure can be released after the operation of the pressure valve by releasing the gas. Thus, it is preferable to make it circular.
The size of the through-hole varies depending on the material, thickness, set pressure and the like of the closing member.
mm, preferably about 1 to 4 mm. The through-hole may be a through-hole dedicated to the pressure valve, but may be used also as a through-hole in the case of a multilayer substrate.

[0011] The closing member is a sheet-like member that can be formed into a uniform thickness, and includes those called plates, foils, films, sheets and the like. The material is not limited as long as it can provide a uniform breaking strength, but a metal material having a small change in strength over time is preferable. Specifically, a copper plate that can be easily soldered is preferable. The thickness of the closing member varies depending on the material, dimensions, set pressure, and the like.
μm, preferably 10 to 50 μm, and 5 to 200 μm when using an aluminum plate, preferably 15 to 80 μm.
Use about

Although the shape of the closing member is arbitrary, it is preferable that the closing member be circular in accordance with the through hole. The closing member has an outer shape larger than the through hole, and is fixed to the substrate around the through hole. As a fixing material, soldering, adhesive, welding, etc.
Although it can be arbitrarily selected, when metal is used for the substrate and the closing member, soldering is preferable. The fixing is performed such that the periphery of the through hole is completely closed and the passage of the gas liquid is blocked, so that the fixing strength is higher than the breaking strength of the closing member. The fixing is performed so that the portion surrounded by the fixing portion is preferably circular and has a fixed area.

The above pressure valve can be used alone or
The C element and other elements and the positive electrode terminal are integrated and housed in the battery to form a battery. In use, when the internal pressure of the battery rises due to the occurrence of overcurrent or abnormal condition,
When the pressure reaches a certain pressure, the closing member is broken, whereby the gas inside leaks and the internal pressure is released, thereby preventing an accident due to the rupture of the battery.

Since the closing member is formed in a sheet shape, unlike the concave portion formed by the conventional press working, it is easy to make the thickness of the closing member constant, and therefore, it is necessary to control the breaking strength to be constant. Can be. Therefore, by keeping the size of the through hole constant and the area receiving the internal pressure of the closing member constant, the operating pressure of the valve can be controlled to a constant value, thereby increasing safety and reliability. The operating pressure can be set arbitrarily by changing the thickness of the closing member or the size of the through hole.

The above-mentioned pressure valve can be easily housed inside the battery because it has a simple structure and can be miniaturized even if it is a structure exclusively for the pressure valve. Further, the effects of miniaturization and multifunctionalization can be obtained. For example, when a substrate such as a multilayer substrate is used for another element, a pressure valve can be configured using the substrate. In this case, if a through-hole is formed in the substrate for another element, the through-hole can be used as a through-hole to easily form a pressure valve to reduce the size of the entire element. It can also be accommodated in batteries.

The pressure valve of the present invention can be used for all batteries, regardless of whether it is a primary battery or a secondary battery. The shape of the battery can also be used for batteries having an arbitrary shape such as a cylindrical shape, a square shape, and a button shape. As the primary battery, a non-aqueous battery and an aqueous battery can be used. Examples of the non-aqueous battery include a lithium graphite fluoride battery, a lithium thionyl chloride battery, a lithium silver chromate battery, a vanadium pentoxide battery, a lithium copper oxide battery, a lithium iron sulfide battery, a lithium bismuth oxide battery, and the like. In addition, as an aqueous battery, an alkaline battery, a manganese battery, a Lucranche battery, a silver oxide battery, a mercury battery, an air zinc battery, and the like can be used.

As the secondary battery, a non-aqueous battery and an aqueous battery can be used. Examples of the non-aqueous battery include a manganese dioxide / lithium battery, a vanadium pentoxide battery, a lithium molybdenum oxide battery, a lithium lithium sulfide battery, a lithium molybdenum sulfide battery, a lithium niobium selenide battery, a carbon lithium battery, and a polymer lithium battery. Aqueous batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries,
It can be used for lead storage batteries.

The required operating pressure of the pressure valve differs depending on the type, shape, size, etc. of these various batteries, but is generally 0.5 to 4 MPa, preferably 1.times.
The operating pressure is set to be 5 to 3 MPa. When the operating pressure is set in the above range, for example, when it is set to 1.5 MPa, the operating pressure can be adjusted to 1.5 ± 0.08 MPa.

[0019]

According to the present invention, since the sheet-like closing member is fixed so as to cover the through hole provided in the substrate, the operating pressure can be made simple and the operating pressure can be kept constant. In addition to increasing the reliability, it is also possible to integrally form with other elements, and a battery pressure valve which can be easily housed in a battery is obtained.

[0020]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an exploded sectional view showing the battery pressure valve of the embodiment together with other elements, and FIG. 2 is a plan view of the battery pressure valve.

In FIGS. 1 and 2, a circular sheet-like closing member 13 is attached to a fixing member 14 so that the pressure valve 1 covers one side of a circular through hole 12 formed in a disk-shaped substrate 11.
Has been fixed by. The substrate 11 is a substrate also used as another element, and includes a copper layer 11a, an insulating layer (adhesive layer) from above.
11b and a laminated substrate of an aluminum layer 11c. The through-hole 12 also serves as a through-hole, and a cylindrical conductive layer 11d is fixed around the through-hole, and makes the copper layer 11a and the aluminum layer 11c conductive.

A copper plate is used as the closing member 13, and solder is used as the fixing member 14.
The fixing strength is higher than the breaking strength of No. 3. 1
Reference numeral 5 denotes a positive electrode lead wire connected to the aluminum layer 11c. 16 is a PTC element and 17 is a positive terminal.

The above-described pressure valve is integrated with the PTC element 16 and the positive electrode terminal 17 and housed in a battery to form a battery. In the use state, when the internal pressure of the battery rises due to the occurrence of an overcurrent or an abnormal state, the closing member 13 is broken at the time when the internal pressure of the battery reaches a certain pressure, whereby the gas inside the through hole 12 is released.
The internal pressure is released by leaking through and the accident due to the rupture of the battery is prevented.

Since the closing member 13 is formed in a sheet shape, unlike the concave portion 4 formed by the conventional press working, it is easy to make the thickness of the closing member 13 a constant value. can do. Therefore, the through hole 12
By keeping the size of the pressure member constant and the area receiving the internal pressure of the closing member 13 constant, the operating pressure of the pressure valve 1 can be controlled to a constant value, thereby increasing the safety and reliability. In addition, the thickness of the closing member 13 is changed,
By changing the size of 2, the operating pressure can be set arbitrarily.

The above-described pressure valve 1 can be easily housed in a battery because it has a simple structure and can be miniaturized even if it is a structure exclusively for the pressure valve. The effect of further miniaturization can be obtained. In the embodiment, since a multilayer substrate for another element is used as the substrate 11, the substrate 11 also serves as a pressure valve. In this case, the through-hole of the other substrate 11 can be used as the through-hole 12, whereby the pressure valve 1 can be easily formed to reduce the size of the entire device and accommodate a small battery. become.

In the above embodiment, the substrate 11 may be a single-layer substrate. Through hole 1 drilled in substrate 11
There is no particular limitation on the drilling method of No. 2, and it can be performed by NC drilling, die cutting, or the like. The diameter of the through hole 12 is
It is sufficient that the gas accompanying the increase in the internal pressure of the battery can flow out promptly, and it is sufficient that a space in which the pressure valve breaks can be secured within the range of the convex portion of the positive electrode terminal 17. The position of the through hole 12 may not be at the center of the substrate 11 and may be decentered depending on the connection state of the battery lead wire or the like.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to FIG. 1, but the present invention is not limited to these embodiments. In the embodiment, a cylindrical lithium ion secondary battery was used as the battery, and the battery could be incorporated in the battery. The external dimensions of this battery are 17.8 mmφ × 65.0 mm.
It is.

In FIG. 1, the substrate 11 has a thickness of 35 μm.
A through-hole was used as a through-hole 12 using a three-layer substrate in which an m-th copper layer 11a and a 1.0-mm aluminum layer 11c were laminated with an insulating layer 11b made of an adhesive. The substrate 11 has a diameter of 16 mm so that it has the same shape as the positive electrode terminal 17.
To form a through hole 12 having a diameter of 2 mm.
The hole position at this time was within the range of the convex portion of the positive electrode terminal 17 to secure a space where the pressure valve was broken.

Next, a soft copper foil having a thickness of 18 μm
2, the outer shape is processed to a diameter of 3 mm larger than the through hole 12 and smaller than the substrate 11, and is fixed to the substrate 11 by using solder as the fixing member 14 so as to close the through hole 12. It was integrated with the terminal 17 and incorporated into the battery body. The above pressure valve is 1.5 ± 0.1M
It was operated at a pressure of Pa.

As a comparative example, the operating pressure when the cylindrical lithium ion secondary battery 12 used in the above embodiment and the conventional pressure valve shown in FIG. 3 were used was 1.5 ± 0.3 MPa.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing a battery pressure valve of an embodiment together with other elements.

FIG. 2 is a plan view of the battery pressure valve of FIG. 1;

FIG. 3 is a plan view of a conventional battery pressure valve.

[Explanation of symbols]

 Reference Signs List 1 pressure valve 2 flange 3 metal plate 4 recess 11 substrate 11a copper layer 11b insulating layer 11c aluminum layer 11d conductive layer 12 through hole 13 closing member 14 fixing member 15 positive lead wire 16 PTC element 17 positive terminal

Claims (4)

[Claims] 1. A substrate provided in a battery, a through hole provided in the substrate, a sheet-like closing member provided so as to cover the through hole and fixed to the substrate around the through hole. Pressure valve for a battery. 2. The battery pressure valve according to claim 1, wherein the substrate is a single-layer substrate or a laminated substrate. 3. The battery pressure valve according to claim 1, wherein the through hole is a through hole formed in the substrate. 4. The pressure valve for a battery according to claim 1, wherein the closing member is made of a metal foil, and is fixed to the substrate by a fixing member.