JPH11345554A - Pressure crushing type protective device, battery using the same, and portable electronic equipment using the battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pressure crushing type protective device which can be enclosed in a rechargeable battery, is easy to assemble, and can easily cope with miniaturization of the rechargeable type. SOLUTION: A pressure crushing type protective device A is so formed that in the recess 11 of a pressure regulating container 10 roughly taking the form of a rectangular solid, each side 24 of a crushing plate 20 made of ceramics is supported at each end against a support plate 23 formed in the recess 11. A pressure-regulating cut groove 23 of an almost V-shaped cross section is provided in the upper surface of the crushing plate 20 so that the crushing plate 20 is readily broken by external pressure. A conductor part 21 made of a metal thin film is formed on the lower surface of the crushing plate 20 and is electrically connected to an electrode part 30 which is insert molded in the pressure regulating container 10. A film sheet 40 is put over the upper surface of the pressure regulating container 10. The peripheral edge of the film sheet 40 is pressed against an upper end face around an opening 13 in the pressure regulating container 10 by thermal bonding or the like to close the pressure regulating container 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a pressure crush type protection device, a battery using the same, and a portable electronic device using the battery. Specifically, a pressure crush type protection device suitable for a safety mechanism of a rechargeable battery such as a lithium ion battery, a rechargeable battery such as a lithium ion battery using the pressure crush type protection device, and a rechargeable battery using the rechargeable battery. Portable electronic devices such as mobile phones.

[0002]

2. Description of the Related Art Conventionally, many rechargeable batteries such as lead-acid batteries and nickel-cadmium batteries have been used in electronic devices such as mobile phones and video cameras. When these various rechargeable batteries are overcharged or short-circuited due to failure or misuse of electronic devices, for example, the inside of the battery is heated,
The electrolyte is decomposed to generate gas, and the internal pressure of the battery increases,
Sometimes exploded. For this reason, these rechargeable batteries are provided with various protection devices.

For example, Japanese Unexamined Utility Model Publication No. 64-64864 discloses a flat metal current collector lead for electrically connecting a negative electrode or positive electrode metal current collector to an output terminal. There is disclosed a protective device in which a perforated shape is provided and the vicinity of the perforated portion is covered with a fluororesin.

[0004] In the protection device, the current collecting lead has a narrow lead width at the perforated portion and is easily cut by the increased battery internal pressure. In addition, since the vicinity of the perforated portion is covered with a fluorine-based resin, corrosion due to the electrolyte can be prevented, and malfunction of the protection device is prevented.

[0005] Also, Japanese Patent Application Laid-Open No. 6-36752 discloses that
A protective device is disclosed in which a pressure-release hole is provided in a sealing body that closes the upper part of a battery, and a thin film having a valve membrane formed corresponding to the hole is provided on the outer surface of the sealing body. In the protective device, a valve film or a thin film having a constant thickness can be obtained, so that a stable operating pressure can be obtained.

[0006]

However, in the protective device disclosed in Japanese Utility Model Laid-Open Publication No. 64-64864, since the vicinity of the perforated portion to be cut is covered with a fluororesin, a predetermined operation is not possible. It is difficult to adjust the pressure, and as the size of the rechargeable battery is reduced, there is a problem that it becomes difficult to form a hole of a predetermined size in a narrow lead width. Furthermore, since the current collecting lead operates due to mechanical breakage, the operating pressure must be relatively high, and it has been difficult to operate safely.

Further, in the protection device disclosed in Japanese Patent Application Laid-Open No. 6-36752, it is necessary to provide two membranes, a valve membrane and a thin film, in a hole opened in a sealing body, which results in a complicated structure. ing. For this reason, as the size of the rechargeable battery has been reduced, it has been extremely difficult to produce a protective device. Furthermore, since the valve membrane is exposed to the outside, malfunction may occur due to external factors, and the internal electrolyte may be released during operation.

The present invention has been made in view of the above-mentioned drawbacks of the conventional example, and is a protection device that can be housed inside a rechargeable battery, is easy to assemble, and can easily cope with miniaturization of the rechargeable battery. And a battery using the battery and a portable electronic device using the battery.

[0009]

Means for Solving the Problems Claim 1 according to the present invention.
The pressure crushing type protection device according to the aspect of the invention includes a pressure adjusting container having a concave portion, a crushing plate having a conductor portion, which is supported in the concave portion of the pressure adjusting container in a double-ended manner and covers the concave portion, and the pressure adjustment. It is characterized by comprising a pair of electrode portions electrically connected to a conductor portion of a crushing plate covering a concave portion of the container, and a film sheet for sealing the pressure adjusting container.

[0010] The pressure crushing type protection device according to claim 2 is characterized in that an opening is provided in a region of the film sheet corresponding to the center of the crushing plate.

Further, the pressure crushing type protection device according to claim 3 is characterized in that a notch groove for adjusting pressure is provided in the crushing plate substantially in parallel with a side portion supported by the crushing plate. .

According to a fourth aspect of the present invention, there is provided a pressure crushing type protection device according to the third aspect, wherein the conductor is provided so as to cross the notch groove. .

According to a fifth aspect of the present invention, there is provided a pressure crushing type protection device according to the fourth aspect, wherein the pair of electrodes are provided on one side end surface of the pressure regulating container. It is characterized by.

Further, the pressure crushing type protection device according to claim 6 is characterized in that in the pressure crushing type protection device, the electrode portion is insert-molded in the pressure adjusting container.

According to a seventh aspect of the present invention, there is provided a battery including a positive or negative electrode current collector and an output electrode, wherein the current collector and the output electrode are connected to each other.
It is characterized by being electrically connected via the pressure crushing type protection device according to the present invention described in 3, 4, 5 or 6.

A portable electronic device according to claim 8 of the present invention is a portable electronic device provided with a battery,
The battery is a battery according to the invention of claim 7.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic perspective view of a pressure crush type protection device (hereinafter referred to as "protection device") according to an embodiment of the present invention, FIG. 2 is an exploded perspective view of the protection device, FIG. 3 is a sectional structural view of the protection device, and FIG. 4 is a view showing a crush plate of the protection device. FIG. 3 (a) is a plan view thereof, FIG. 3 (b) is a cross-sectional view thereof, and FIG. c) is a rear view thereof, FIG. 5 is an explanatory view showing advantages of the present invention, FIG. 6 is an internal structural view of a battery according to the present invention, that is, a partially rechargeable battery provided with the protection device,
FIG. 7 is a schematic perspective view of a protection device according to another embodiment of the present invention, FIG. 8 is a schematic perspective view of a protection device according to still another embodiment of the present invention, and FIG. 9 is a crush plate of the protection device. FIG. 10 is a schematic perspective view of a crush plate of a pressure crush type protection device according to still another embodiment of the present invention. Hereinafter, the present invention will be described with reference to the drawings.

The protection device A shown in FIGS. 1 and 2 includes a pressure adjusting container 10 and a crush plate 20 provided with a conductor 21.
And a pair of electrode portions 30 that come into contact with the conductor portion 21 and a film sheet 40 for sealing the pressure adjusting container 10.

The pressure adjusting container 10 has a recess 11 inside.
It is shaped like a rectangle. At both ends in the concave portion 11, supporting portions 12 for supporting the crushing plate 20 in a doubly supported state are formed. Therefore, the pressure regulating container 10
Is formed by the crushing plate 20 supported by the support portion 12.
1 is covered. The pressure regulating container 1
0 is, for example, from ceramics, glass, plastic, or the like, and has a size according to the purpose of use, for example, a length of 10 m.
m, width and height are each manufactured to a size of about several mm. In particular, by manufacturing both the pressure adjusting container 10 and the crushing plate 10 from ceramics, it is possible to obtain the highly accurate pressure adjusting container 10 and the crushing plate 20 and obtain a small and highly reliable protection device A. Can be.

Further, a crush plate 20 is provided in the pressure adjusting container 10.
Are electrically connected to the connection portions 22 provided in
A pair of electrode units 30 is provided. The electrode unit 30 includes:
For example, as shown in FIG. 6, the protection device A is for electrically connecting the protection device A to the current collector 120 of the rechargeable battery or the output electrode 130 of the rechargeable battery. It is made into a plate shape from the metal having the metal.

When the electrode section 30 is provided in a rechargeable battery or the like, the thickness of the electrode section 30 is set to 0.1 mm from the viewpoint of absorbing external impact.
It is preferable to set it to 3 mm or less. The electrode section 30 is provided in the pressure adjusting container 10 by insert molding. By performing the insert molding of the electrode portion 30 in this manner, the number of components is reduced, and the assembly of the protection device A is facilitated.

The crushing plate 20 is a part constituting the lid of the pressure adjusting container 10 and is formed to have substantially the same size as the opening 13 of the pressure adjusting container 10, and has a size such that it can be fitted into the recess 11. It is made. The crush plate 20 is broken by the external pressure applied to the protection device A. For this reason, for example, it is made of a material having relatively low strength such as ceramics, glass, and plastic, and has a thickness such that it is broken at a predetermined operating pressure, for example, 0.1 to 0.3 mm.
Designed to a degree.

Although it is ideal that the crushing plate 20 is made to have a size that allows the crushing plate 20 to be fitted into the opening 13 without any gap and sealed, the crushing plate 20 is easily opened in the present invention. It suffices to be able to fit into the part 13, and a slight gap may be created between the pressure adjusting container 10 and the crush plate 20. That is, in the present invention, it is sufficient if the pressure adjusting container 10 is hermetically sealed by the film sheet 40 bonded to the pressure adjusting container 10 and the crush plate 20 is damaged by the external pressure applied to the protection device A.

On the other hand, if the crush plate 20 is made small and there are large gaps on both sides of the crush plate 20, the film sheet 40
It becomes difficult to set the intensity of the light. For this reason, it is preferable to manufacture the crush plate 20 to such an extent that the crush plate 20 can be appropriately fitted into the recess 11.

A notch 23 is formed on the upper surface of the crushing plate 20. The shape of the notch groove 23 is not limited, but is formed, for example, in a substantially V-shaped cross section, and
0 is easily damaged. The notch groove 23 is provided so as to be substantially parallel to both side portions 24 of the crush plate 20 supported.

That is, since the crushing plate 20 is damaged by the external pressure, by providing the crushing plate 20 in parallel with the supported side portions 24, the crushing direction of the crushing plate 20 is constant as described below, and the stable operating pressure is maintained. Is obtained.
In addition, the notch groove 23 can be formed on the lower surface of the crush plate 20, but when formed on the upper surface of the crush plate 20, the lower surface of the crush plate 20 is formed flush with the conductor portion 21. It also has the advantage of being easy. Further, the notch 2
Notch groove 2 so as to be supported symmetrically about center 3
3 is desirably provided. In this way, the crush plate 20
Is concentrated in the notch groove 23, the crush plate 20 is easily damaged, the sensitivity is improved and the variation in the sensitivity is further reduced.

On the lower surface of the crush plate 20, as will be described later, a conductor portion 21 electrically connected to the pair of electrode portions 30 is provided.
Are formed. The conductor portion 21 is formed of a conductive metal thin film such as copper or aluminum, and is formed by bonding the metal thin film to the crush plate 20, or by metal vapor deposition or sputtering. Also, this conductor portion 21
The conductor portion 21 is formed to a thickness such that the conductor portion 21 is broken by breakage of the crush plate 20.

Further, at both ends of the conductor portion 21, the electrode portions 3 are provided.
A slightly wider connecting portion 22 is formed for connecting to the connection portion 0. In particular, the conductor portion 21 is set so as to cross at least the notch groove 23. That is,
This is because, when the crush plate 20 is damaged from the notch groove 23, it is important that the conductor portion 21 is also necessarily damaged, so that conduction between the electrodes is interrupted.

The protection device A has a structure in which both side portions 24 of the crush plate 20 are supported by the support portion 12 in a doubly supported manner.
Is fitted in the recess 11 so as to cover the cover. At this time, it is desirable to support the side 24 that is parallel to the short axis direction of the crush plate 20 from the viewpoint of the crush plate 20 being easily damaged. Further, between the conductor portion 21 and the electrode portion 30,
As shown in FIG. 3, the conductive adhesive 31 is used or cream solder is used to electrically connect by reflow heat.
At this time, the conductive portion 21 and the electrode portion 30 are
Since it is fixed by 1 or solder, it is not necessary to fix the crushing plate 20 to the support portion 12, but it may be fixed.

Further, a film sheet 40 is placed on the upper surface of the pressure regulating container 10, and the peripheral portion of the film sheet 40 is placed on the upper end surface around the opening 13 of the pressure regulating container 10 so as to seal the pressure regulating container 10. It is adhered by an adhesive or thermal bonding. At this time, it is preferable that the film sheet 40 be adhered under reduced pressure. As a result, the pressure in the pressure adjusting container 10 is reduced, and the crush plate 20 is easily damaged by a small external pressure. As a result, the operating pressure of the protection device A can be set to a small value, and the sensitivity of the protection device A can be improved. This pressure is preferably set in accordance with the desired operating pressure, and varies depending on the structure of the crush plate 20, but from the viewpoint of obtaining a stable operating pressure, it is particularly preferable to set the pressure to 0.5 atm or less. It is.

This film sheet 40 is used for the pressure regulating container 1
The material is not particularly limited as long as it can seal 0, and is made of, for example, various plastic materials such as polyethylene, polypropylene, and polyvinyl chloride. The film sheet 40 must be capable of applying an external pressure to the crush plate 20 via the film sheet 40, and preferably has some flexibility.

Here, as shown in FIG.
0 is fitted into the recess 11, and the periphery thereof is
It is also conceivable to seal the device by supporting it on the support portion 12 formed on the substrate. However, in the case of such a configuration, the entire periphery of the crushing plate 20 is fixed to the pressure adjusting container 10 at the satin portion in FIG. 5, so that the crushing plate 20 is hardly damaged, and a constant crushing pressure is hardly obtained. Become. In this regard, by supporting the crushing plate 20 in a two-sided manner as described above, the portion fixed to the pressure adjusting container 10 is reduced, and the crushing plate 20 is damaged by a smaller crushing pressure and can be set to a more constant operating pressure. .

The protection device A thus obtained is, for example, as shown in FIG.
It is installed in a state of being immersed inside. This rechargeable battery 10
0 is an outer can 110 also serving as a negative electrode (or a positive electrode);
Current collector 120 to which many positive electrodes (or negative electrodes) are connected
And the output electrode 1 electrically connected to the current collector 120
30. In the opening 111 of the outer can 110,
The sealing body 140 is hermetically attached by laser welding or the like, and the inside is filled with an electrolyte 150. In the center of the sealing body 140, an opening 160 for drawing the output electrode 130 to the outside is formed. Opening 160
Is an insulating material 1 such as glass around the output electrode 130.
70 is hermetically sealed and hermetically sealed, and the output electrode 130 and the outer can 110 are insulated.
In the protection device A, one of the electrode portions 30 is electrically connected to the current collector 120, and the output electrode 1
One of the electrode portions 30 remaining at 30 is electrically connected. That is, the current collector 120 is connected via the protection device A.
And the output electrode 130 are electrically connected.

In this rechargeable battery 100, for example,
When the electrolytic solution 150 is decomposed due to overcharging or the like, gas is generated, and the internal pressure of the battery 100 increases, the difference between the external pressure of the protection device A and the pressure in the pressure adjusting container 10 increases,
If the internal pressure of the battery 100 rises above the pressure resistance of the crush plate 20, the crush plate 20 will be damaged. As a result, the conductor portion 21 is broken, and the electrical continuity between the current collector 120 and the output electrode 130 is cut off. As a result, charging is stopped, generation of gas is suppressed, and heat generation and deformation of the rechargeable battery 100 can be suppressed. In addition, it can be installed inside the rechargeable battery 100, and leakage of the electrolyte 150 can be avoided.

Next, in the protection device B shown in FIG. 7, an opening 41 is provided in a region corresponding to the central portion of the crush plate 20 of the film sheet 40. Therefore, in the protection device B, the film sheet 40 is formed on the upper end surface around the opening 13 of the pressure adjusting container 10 and the crush plate 20.
And the pressure adjusting container 10 is hermetically sealed. Thus, the opening 4 is formed in the film sheet 40.
1 and the structure in which the crush plate 20 is exposed, the external pressure of the protection device B is directly applied to the crush plate 20, so that the sensitivity can be improved. Also, the film sheet 40
There is also an advantage that variation in sensitivity due to variation in adhesion can be prevented.

In the protection device C shown in FIG. 8, the pair of electrode portions 30 is insert-molded on the same side of the pressure adjusting container 10. As shown in FIG. 9, the crush plate 20 of the protection device C has a conductor portion 21 formed in a substantially U-shape so as to be connected to the electrode portion 30. In the above, the conductor portion 21 and the electrode portion 30 are electrically connected. The conductor portion 21 is provided across the cutout groove 23 provided in the crush plate 20 in the same manner as the protection device A.

In this protection device C, the electrode section 3
Since 0 is formed on the same side surface of the pressure regulating container 10, it can be made compact as a whole and can greatly contribute to downsizing of the rechargeable battery 100.

As described above, in the protection device according to the present invention, a reliable protection device can be manufactured with a simple configuration, which can greatly contribute to miniaturization of a rechargeable type.

The battery 100 according to the present invention thus obtained
Is widely used in portable electronic devices such as mobile phones and portable computers, and can provide portable electronic devices with higher safety.

Of course, the present invention is not limited to the above embodiments, and can be applied to various devices other than the rechargeable battery 100, and the crush plate 20 may be damaged by external pressure. It can be used as a protection device that can be used in such environments.

In the above embodiment, the notch 2
Although the crush plate 20 in which 3 is formed is shown, a crush plate without a notch groove may be used. Further, as shown in FIG. 10A, a crush plate 51 provided with a notch 511 only at an edge portion,
The same effect can be obtained with the crushing plate 52 formed in a substantially conical shape in plan view as shown in FIG. 10B and the crushing plate 53 having an opening 531 as shown in FIG. is there.

[0042]

According to the first aspect of the present invention, there is provided a pressure crushing type protection device, comprising a pressure regulating container having a concave portion, and a conductor portion, which is supported in a double-ended manner in the concave portion of the pressure regulating container. A crushing plate that covers the concave portion, a pair of electrode portions electrically connected to a conductor portion of the crushing plate that covers the concave portion of the pressure adjusting container, and a film sheet that seals the pressure adjusting container. Therefore, a compact and highly sensitive pressure crushing type protection device can be obtained with a simple configuration.

In the pressure crushing type protection device according to the second aspect, since the opening is provided in the region corresponding to the central portion of the crushing plate of the film sheet, pressure is directly applied to the crushing plate without passing through the film sheet. Therefore, the sensitivity of the protection device can be improved, and the variation in sensitivity due to bonding of the film sheets can be reduced.

In the pressure crushing type protective device according to the third aspect, the notch groove for adjusting the pressure is provided in the crushing plate substantially in parallel with the supported side of the crushing plate, so that the crushing plate can be crushed even by a small pressure. The plate is crushed, and a more secure protection device can be provided.

Further, in the pressure crush type protection device according to the fourth aspect, since the conductor portion is provided so as to cross the notch groove, the conductor portion is always broken when the crush plate is broken. As a result, the protection device can operate reliably.

In the pressure crushing type protection device according to the fifth aspect, since the pair of electrodes is provided on one side end surface of the pressure regulating container, the pressure crushing type protection device can be downsized.

In the pressure crush type protection device according to the sixth aspect, since the electrode portion is insert-molded in the pressure adjusting container, the number of components is reduced, and the pressure crush type protection device can be provided at lower cost.

According to a seventh aspect of the present invention, in the battery provided with a positive electrode or negative electrode current collector and an output electrode, the current collector and the output electrode are connected to each other according to the present invention. It is electrically connected via a pressure crush type protection device.

For this reason, it is assumed that the internal pressure of this battery increases due to, for example, overcharging. The difference between the external pressure of the protective device and the pressure in the pressure regulating container increases, and the internal pressure of the battery rises above the pressure resistance of the crushing plate, which breaks the crushing plate. The electrical conduction between them is interrupted. As a result, charging is stopped and heat generation and deformation of the rechargeable battery can be suppressed.

The portable electronic device according to claim 8 of the present invention is characterized in that, in the portable electronic device provided with a battery, the battery is the battery according to the present invention.

Therefore, in a portable electronic device provided with a battery, for example, a rechargeable battery, even if the rechargeable battery is overcharged, the rechargeable battery does not generate heat or deform. Therefore, the portable electronic device does not cause an abnormal operation due to heat generation of the rechargeable battery or cause a failure.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view of a pressure crush type protection device according to an embodiment of the present invention.

FIG. 2 is an exploded perspective view of the pressure crush type protection device according to the first embodiment.

FIG. 3 is a sectional structural view of the pressure crushing type protective device according to the first embodiment;

FIG. 4 is a view showing a crush plate of the pressure crush type protection device of the above, wherein FIG. 4 (a) is a plan view, FIG. 4 (b) is a cross-sectional view thereof, and FIG. It is.

FIG. 5 is an explanatory diagram showing advantages of the present invention.

FIG. 6 is an internal structural view of a battery according to the present invention, that is, a partially crushed rechargeable battery provided with the pressure-crush type protection device according to the present invention.

FIG. 7 is a schematic perspective view of a protection device according to another embodiment of the present invention.

FIG. 8 is a schematic perspective view of a protection device according to still another embodiment of the present invention.

FIG. 9 is a rear view of a crush plate of the pressure crush protection device of the above.

FIG. 10 is a schematic perspective view of a crush plate of a pressure crush type protection device according to still another embodiment of the present invention.

[Explanation of symbols]

 A, B, C Pressure crushing type protective device according to the present invention 10 Pressure adjusting container 11 Concave portion 12 Supporting portion 13 Opening 20 Crushing plate 21 Conductor portion 22 Connecting portion 23 Notch groove 30 Electrode portion 40 Film sheet 100 Battery according to the present invention 110 outer can 111 opening of outer can 120 current collector 130 output electrode 140 sealing body 141 opening for output electrode 150 electrolytic solution 170 insulating material

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Seisaku Hirai 1-4-33 Kitakyuhoji, Yao-shi, Osaka Ho-Siden Corporation

Claims (8)

[Claims] 1. A pressure adjusting container having a recess formed therein, a crushing plate having a conductor portion and supported in the recess of the pressure adjusting container in a bilateral manner and covering the recess, and a recess of the pressure adjusting container. A pressure crushing type protection device comprising: a pair of electrode portions electrically connected to a conductor portion of a covered crushing plate; and a film sheet for sealing the pressure regulating container. 2. The pressure crushing type protection device according to claim 1, wherein an opening is provided in a region of the film sheet corresponding to a central portion of the crushing plate. 3. A notch groove for adjusting pressure in the crush plate,
3. The pressure crush type protection device according to claim 1, wherein the pressure crush type protection device is provided substantially in parallel with a supported side of the crush plate. 4. The pressure-crush type protection device according to claim 3, wherein the conductor is provided across the notch groove. 5. The pressure crushing type protection device according to claim 4, wherein said pair of electrode portions are provided on one side end surface of said pressure regulating container. 6. The pressure crush type protection device according to claim 1, wherein the electrode portion is insert-molded in the pressure adjusting container. 7. A battery provided with a positive or negative electrode current collector and an output electrode, wherein the current collector and the output electrode are connected to each other.
A battery, wherein the battery is electrically connected via the pressure crushing type protection device according to 4, 5, or 6. 8. A portable electronic device provided with a battery, wherein the battery is the battery according to claim 7.