JP2000208023A - Explosion-proof protection device with fuse function, rechargeable battery using same, and portable electronic apparatus using the rechargeable battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an explosion-proof protection device with a fuse function, capable of coping not only with pressure but also with temperature and overcurrent, and high in safety. SOLUTION: This explosion-proof protection device is equipped with a pressure adjustment container 10 having a recessed part 11 formed therein, a fracture plate 20 supported in the recessed part 11 of the pressure adjustment container 10 and generally covering the recessed part 11, a pair of electrodes 30 electrically connected to a conductor part 21 of the fracture plate 20 generally covering the recessed part 11 of the pressure adjustment container 10, and a film sheet 4 for sealing up the pressure adjustment container 10. The conductor part 21 is formed by connecting, in series, a thermal fuse 21A made of a material melting at temperatures higher than a fixed value and an overcurrent fuse 21B melting when a current larger than a fixed value flows.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an explosion-proof protection device with a fuse function, a rechargeable battery using the same, and a portable electronic device using the rechargeable battery. Specifically, an explosion-proof protection device with a fuse function suitable for the safety mechanism of a rechargeable battery such as a lithium-ion battery, a rechargeable battery such as a lithium-ion battery using the explosion-proof protection device with a fuse function, and a rechargeable battery The present invention relates to a portable electronic device such as a mobile phone using a battery.

[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 electrolytic solution is decomposed, gas is generated, 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 hole is provided and the vicinity of the perforated portion is covered with a fluorine-based resin.

[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 sealing member closing an upper part of a battery is provided with a pressure release hole, and a thin film provided with a valve membrane corresponding to the hole is provided outside the sealing member. 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.

Further, there is a rechargeable battery having a protection function of detecting a current value to prevent an overcurrent and interrupting the current when the overcurrent flows.

[0007]

However, in order to detect a current value, it is necessary to configure a PTC or a polyswitch, and there is a problem that the number of components for configuring these components increases. A mechanism for detecting a current value;
It is necessary to incorporate two mechanisms, that is, a mechanism for detecting an increase in battery internal pressure, into the rechargeable battery, and there is a problem that it is impossible to meet the demand for downsizing the rechargeable battery.

Further, since the PTC and the polyswitch are reversible functional parts, when the overcurrent is eliminated, the current starts to flow again. However, there is a situation in which the root cause where the overcurrent has flown is restored without being repaired, and when the overcurrent flows again, the danger increases.

The present invention has been made in view of the above circumstances, and has a high safety explosion-proof protection device with a fuse function that can cope with not only pressure but also temperature and overcurrent, and uses the same. It is an object to provide a rechargeable battery and a portable electronic device using the rechargeable battery.

[0010]

An explosion-proof protection device with a fuse function according to the present invention comprises a pressure regulating container having a recess formed therein, and a recess provided with a conductor and supported in the recess of the pressure regulating container. A crushing plate to cover, a pair of electrode portions electrically connected to a conductor portion of the crushing plate almost covering the concave portion of the pressure adjusting container, and a film sheet sealing the pressure adjusting container, The conductor portion is formed of a material that melts when the temperature exceeds a predetermined temperature or a material that melts when a current exceeding a predetermined value flows.

Further, a rechargeable battery according to the present invention is a battery provided with a positive or negative electrode current collector and an output electrode, wherein the current collector and the output electrode are protected by the explosion-proof protection with a fuse function. It is electrically connected via the device.

[0012] Further, the portable electronic device according to the present invention includes:
A portable electronic device provided with a battery, wherein the rechargeable battery is used as the battery.

[0013]

FIG. 1 is a schematic sectional view of an explosion-proof protection device with a fuse function according to a first embodiment of the present invention, and FIG. 2 is a diagram with a fuse function according to the first embodiment of the present invention. FIG. 3 is a schematic exploded perspective view of the explosion-proof protection device, FIG. 3 is a schematic perspective view of a crush plate used in the explosion-proof protection device with a fuse function according to the first embodiment of the present invention, and FIG. FIG. 5 is a schematic perspective view of a crush plate used in an explosion-proof protection device with a fuse function according to an embodiment. FIG. 5 is a schematic view of a crush plate used in an explosion-proof protection device with a fuse function according to a third embodiment of the present invention. It is a perspective view.

FIG. 6 is a schematic sectional view of an explosion-proof protection device with a fuse function according to a fourth embodiment of the present invention.
FIG. 7 is a schematic bottom view of a crush plate used for an explosion-proof protection device with a fuse function according to a fourth embodiment of the present invention;
FIG. 8 is a schematic sectional view of a rechargeable battery using the explosion-proof protection device with a fuse function according to the embodiment of the present invention.

An explosion-proof protection device A with a fuse function shown in FIG. 1 includes a pressure adjusting container 10 having a concave portion 11 formed therein and a concave portion 11 having a conductor portion 21 and supported in the concave portion 11 of the pressure adjusting container 10. A crushing plate 20 that substantially covers, a pair of electrode portions 30 that is electrically connected to the conductor portion 21 of the crushing plate 20 that almost covers the concave portion 11 of the pressure adjusting container 10,
The conductor section 21 is provided with a temperature fuse section 21A made of a material which is blown when a predetermined temperature or higher, and is blown when a predetermined current or more flows. An overcurrent fuse portion 21B made of a material is formed in series.

The pressure adjusting container 10 has a recess 11 inside.
It is shaped like a rectangle. At both ends of the concave portion 11, a pair of support portions 12 for supporting the crush plate 20
Are formed. Therefore, the pressure adjusting container 10 has a structure in which the recess 11 is almost covered by the crush plate 20 supported by the support portion 12. Moreover, the support portion 12
Is set such that the upper surface of the crush plate 20 supported by the support portion 12 is at a position equal to or lower than the upper surface of the pressure adjusting container 10.

The pressure adjusting container 10 is made of, for example, ceramics, glass, plastic, or the like, and has a size according to the purpose of use, for example, a length of 10 mm, a width and a height of several mm each. In particular, by manufacturing both the pressure adjusting container 10 and the crush plate 20 from ceramics, it is possible to obtain the pressure adjusting container 10 and the crush plate 20 with high accuracy, and to obtain a small and highly reliable explosion-proof protection device with a fuse function. A can be obtained.

Further, a crush plate 20 is provided in the pressure adjusting container 10.
Are provided with a pair of electrode portions 30 which are electrically connected to the connection portions 22 provided in the first and second portions, respectively. As shown in FIG. 2, each of the electrode portions 30 has one end portion 31, one end of the support portion 12.
It is exposed on the upper surface of.

The crushing plate 20 is mounted on the pressure adjusting container 10.
Which is approximately the same size as or slightly smaller than the opening 13 of the pressure adjusting container 10 and is made to the extent that it can be fitted into the recess 11. The crush plate 20 is broken by an external pressure applied to the explosion-proof protection device A with a fuse function. For this reason, it is made of a material having relatively low strength, such as ceramics, glass, and plastic, and is designed to have a thickness such that it is broken at a predetermined operating pressure, for example, about 0.1 to 0.3 mm.

It is desirable that the crush plate 20 is not fitted into the opening 13 without any gap, but that a small gap is provided between the crush plate 20 and the opening 13. This is because the crush plate 20 is cantilevered in the pressure regulating container 10, and if there is no gap, the broken crush plate 20 may not fall into the recess 11 and may not be able to cut off the electrical connection after all. is there.

On the other hand, if the crush plate 20 is too small, it is difficult to set the strength of the film sheet 40. For this reason, it is preferable that the crush plate 20 is manufactured to such an extent that the crush plate 20 can be appropriately fitted into the recess 11.

On the lower surface of the crush plate 20, a conductor portion 21 electrically connected to the pair of electrode portions 30 is formed.
The conductor portion 21 includes a temperature fuse portion 21A made of a material that melts when the temperature exceeds a predetermined temperature, and an overcurrent fuse portion 21 made of a material that melts when a current of a predetermined value or more flows.
B is in series.

The thermal fuse 21A is, for example, 165
If it melts at 138 ° C., Pb is 43% by weight, Sn is 43% by weight, Bi is 14% by weight, and if it melts at 138 ° C., Pb is 37% by weight and Sn is 37.5%.
% Of In and 25% by weight of In, and if it melts at 117 ° C., the composition ratio of Sn is 50% by weight and In is 50% by weight. As described above, by appropriately adjusting the components and the component ratios, it is possible to obtain the thermal fuse 21A that blows at a desired temperature.

On the other hand, by appropriately adjusting the components and the component ratio of the overcurrent fuse 21B, the overcurrent fuse 21B can be blown when a current exceeding a predetermined value flows.

The conductor 21 comprising the thermal fuse 21A and the overcurrent fuse 21B is manufactured as follows. First, a material to be an overcurrent fuse 21B is deposited on the back surface of a ceramic plate or the like as a material for the crush plate 20. At this time, the material to be the overcurrent fuse 21B is formed from one end to the center.

Further, a material for the thermal fuse 21A is deposited on the back side of the ceramic plate or the like. At this time, the overcurrent fuse 21B and the thermal fuse 21A are
It is important to overlap at the center of a ceramic plate or the like. That is, both are electrically connected in series by overlapping the two.

Explosion-proof protection device A with such a fuse function
The crushing plate 20 is supported at both ends in a state where both ends of the crush plate 20 are placed on the support portion 12, and is fitted into the concave portion 11 so as to substantially cover the concave portion 11. In addition, the conductive portion 21 and the electrode portion 30 are electrically connected by using the conductive adhesive 24 or using cream solder. As a result, the crush plate 20 is supported by the support portion 12 in a doubly supported manner.

Further, a film sheet 40 is placed on the upper surface of the pressure adjusting container 10, and the peripheral edge of the film sheet 40 is placed on the upper end surface around the opening 13 of the pressure adjusting container 10 so as to seal the pressure adjusting container 10. It is adhered by an adhesive or thermal bonding.

The film sheet 40 is not particularly limited as long as it can seal the pressure control container 10, and is made of, for example, various plastic materials such as polyethylene, polypropylene and polyvinyl chloride.
Further, the film sheet 40 must be capable of applying an external pressure to the crushing plate 20 via the film sheet 40, and preferably has a certain degree of flexibility.

The explosion-proof protection device A with a fuse function thus obtained is installed in a state of being immersed in the electrolyte 150 of the rechargeable battery 100, as shown in FIG. The rechargeable battery 100 includes an outer can 110 also serving as a negative electrode (or a positive electrode), a current collector 120 connected to a number of positive electrodes (or negative electrodes), and an output electrode electrically connected to the current collector 120. 130. A sealing body 140 is securely attached to the opening 111 of the outer can 110 by laser welding or the like.
50 are filled. In the center of the sealing body 140, an insulating material 1 such as glass around the output electrode 130 is provided.
70 is hermetically sealed and hermetically sealed,
The insulation between the electrode 130 and the outer can 110 is achieved. In the explosion-proof protection device A with a fuse function, one of the electrode portions 30 is electrically connected to the current collector 120 and one of the electrode portions 30 remaining on the output electrode 130.
Are electrically connected. That is, the current collector 120 and the output electrode 130 are electrically connected via the explosion-proof protection device A with a fuse function.

In this rechargeable battery 100, for example,
When the electrolyte 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 explosion-proof protection device A with a fuse function and the pressure in the pressure regulating container 10 increases, and the film sheet increases. 40 is bent inward, and the crush plate 20 is bent by the bent film sheet 40.
Is damaged. As a result, the conductor 21 of the crush plate 20 is broken, and the electrical conduction 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.

In addition, the rechargeable battery 100
When the internal temperature of the conductor 21 rises and reaches a preset temperature, that is, the temperature at which the thermal fuse 21A is blown, the thermal fuse 21A of the conductor portion 21 is blown, so that the current is cut off.

Further, when a current exceeding a preset value for some reason, that is, an overcurrent flows, when the temperature reaches a temperature at which the overcurrent fuse 21B is blown, the conductor 2
Since the one overcurrent fuse 21B is blown, the current is cut off.

In a portable electronic device using a rechargeable battery having such a configuration, for example, a mobile phone or a notebook personal computer, the leakage of the electrolyte 150 of the rechargeable battery is eliminated. Can be prevented.

In the above-described embodiment, the conductor 21 of the crush plate 20 has the temperature fuse 21A and the overcurrent fuse 21B in series, but the present invention is not limited to this. is not.

For example, as shown in FIG. 4, the conductor portion 21 can be configured as a temperature fuse 21A made of a material that melts at a predetermined temperature or higher.
As shown in (1), the conductor portion 21 can be configured as an overcurrent fuse 21B made of a material that is blown when a predetermined current or more flows.

Further, in the above-described embodiment, the crush plate 20 is supported on both sides of the support portion 12, but may be supported on one side as shown in FIG. In this case, since the support portion 12 is formed only on one side, the pair of electrode portions 30 is also formed on only one side. For this reason, the crush plate 2
The 0 conductor portion 21 is formed in a substantially U shape as shown in FIG.

The conductive portion 21 of the crush plate 20 and the electrode portion 3
At the time of connection with 0, a force is applied in the direction of arrow Y shown in FIG. 6 by a jig (not shown) so that the crush plate 20 is supported by the support portion 12 in a cantilever manner.

As described above, when the crushing plate 20 is supported in a cantilever manner, the crushing plate 20 is damaged by a weaker pressure than in the case of the two-sided support, which contributes to improvement in sensitivity.

[0040]

According to the first aspect of the present invention, there is provided an explosion-proof protection device with a fuse function, comprising: a pressure regulating container having a recess formed therein; and a crushing device having a conductor and substantially covering the recess supported in the recess of the pressure regulating container. Plate, a pair of electrode portions electrically connected to the conductor portion of the crushing plate almost covering the concave portion of the pressure adjustment container, and a film sheet for sealing the pressure adjustment container, the conductor portion, , And is formed of a material that melts when the temperature exceeds a predetermined temperature.

Therefore, the explosion-proof protection device with a fuse function has a function of interrupting not only current by pressure but also current by temperature. In particular, it is advantageous that this function can be realized without increasing the number of components while keeping the size small.

According to a second aspect of the present invention, there is provided an explosion-proof protection device with a fuse function, comprising: a pressure adjusting container having a concave portion; and a crushing device having a conductor portion and substantially covering the concave portion supported in the concave portion of the pressure adjusting container. Plate, a pair of electrode portions electrically connected to the conductor portion of the crushing plate almost covering the concave portion of the pressure adjustment container, and a film sheet for sealing the pressure adjustment container, the conductor portion, , And is formed of a material that melts when a predetermined current or more flows.

For this reason, this explosion-proof protection device with a fuse function has a function of interrupting the current not only by the pressure but also by the flow of an overcurrent. In particular, it is advantageous that this function can be realized without increasing the number of components while keeping the size small.

Further, an explosion-proof protection device with a fuse function according to a third aspect of the present invention provides a pressure-adjusting container having a recess formed therein,
A crush plate having a conductor portion and substantially covering the concave portion supported in the concave portion of the pressure regulating container, and a pair of electrodes electrically connected to the conductor portion of the crush plate substantially covering the concave portion of the pressure regulating container. And a film sheet that seals the pressure regulating container, wherein the conductor is formed in series with a material that melts when a predetermined temperature or more and a material that melts when a predetermined current or more flows. Have been.

The explosion-proof protection device with the fuse function configured as described above can handle not only pressure but also temperature and overcurrent. In addition, the ability to realize such a function without increasing the number of parts also contributes to the miniaturization of the device.

On the other hand, when the crushing plate is supported in a cantilever manner, the crushing plate is damaged by a weaker pressure than in the case of the two-sided support, which contributes to improvement in sensitivity to pressure.

Incidentally, in a battery provided with a positive or negative electrode current collector and an output electrode, a rechargeable battery in which the current collector and the output electrode are electrically connected via the explosion-proof protection device with a fuse function. For example, when the battery is overcharged, the conductor is melted when the internal temperature rises, and the crush plate is damaged when the internal pressure of the battery rises. Electrical continuity with the electrodes is interrupted. As a result, charging is stopped, and heat generation and deformation of the rechargeable battery can be prevented.

Further, since the portable electronic device according to the present invention uses the battery, even if the battery is overcharged, the temperature rises or the internal pressure rises, the battery generates heat or deforms. Or not. For this reason, it is possible to prevent abnormal operation due to heat generation of the battery and the like.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of an explosion-proof protection device with a fuse function according to a first embodiment of the present invention.

FIG. 2 is a schematic exploded perspective view of the explosion-proof protection device with a fuse function according to the first embodiment of the present invention.

FIG. 3 is a schematic perspective view of a crush plate used in the explosion-proof protection device with a fuse function according to the first embodiment of the present invention.

FIG. 4 is a schematic perspective view of a crush plate used for an explosion-proof protection device with a fuse function according to a second embodiment of the present invention.

FIG. 5 is a schematic perspective view of a crush plate used in an explosion-proof protection device with a fuse function according to a third embodiment of the present invention.

FIG. 6 is a schematic sectional view of an explosion-proof protection device with a fuse function according to a fourth embodiment of the present invention.

FIG. 7 is a schematic bottom view of a crush plate used for an explosion-proof protection device with a fuse function according to a fourth embodiment of the present invention.

FIG. 8 is a schematic sectional view of a rechargeable battery using the explosion-proof protection device with a fuse function according to the embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Pressure adjustment container 11 Concave part 12 Support part 20 Crush plate 21 Conductor part 30 Electrode part 40 Film sheet

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Keiji Mine, Inventor 1-4-3, Kitakyuho-ji Temple, Yao-shi, Osaka Ho-Siden Co., Ltd. (72) Seisaku Hirai 1-4-33 Kitakyuhoji, Yao-shi, Osaka No. F-term in Hosiden Corporation (reference) 5G013 AA02 AA09 BA01 CA02 CA03 5G502 AA02 AA15 BB13 BD06 CC14 FF08 5H030 AA06 AS11

Claims (6)

[Claims] 1. A pressure regulating container having a recess formed therein, a crush plate having a conductor portion and substantially covering the recess supported in the recess of the pressure regulating container, and substantially covering the recess of the pressure regulating container. It has a pair of electrode parts electrically connected to the conductor part of the crush plate, and a film sheet that seals the pressure regulating container, and the conductor part is formed from a material that melts when a predetermined temperature or more is reached. An explosion-proof protection device with a fuse function. 2. A pressure regulating container having a recess formed therein, a crush plate having a conductor portion and substantially covering the recess supported in the recess of the pressure regulating container, and substantially covering the recess of the pressure regulating container. A material that is provided with a pair of electrode portions electrically connected to a conductor portion of a crush plate and a film sheet that seals the pressure regulating container, wherein the conductor portion is cut off when a predetermined or more current flows. An explosion-proof protection device with a fuse function, characterized by being formed from: 3. A pressure regulating container having a recess formed therein, a crushing plate having a conductor portion and substantially covering the recess supported in the recess of the pressure regulating container, and substantially covering the recess of the pressure regulating container. A pair of electrode portions electrically connected to the conductor portion of the crushing plate, and a film sheet that seals the pressure regulating container, wherein the conductor portion is cut off at a predetermined temperature or more, An explosion-proof protection device with a fuse function, wherein a material that melts when a predetermined current or more flows is formed in series. 4. The explosion-proof protection device with a fuse function according to claim 1, wherein the crush plate is supported in a cantilever manner. 5. The explosion-proof protection device with a fuse function according to claim 1, wherein the battery includes a positive or negative electrode current collector and an output electrode. A rechargeable battery electrically connected via a battery. 6. A portable electronic device provided with a battery,
A portable electronic device, wherein the battery is the rechargeable battery according to claim 5.