JPH10275546A - Mounting structure of temperature fuse and temperature fuse in secondary battery - Google Patents

Abstract

(57) Abstract: Provided is a thin temperature fuse that can be attached to a secondary battery without increasing a space for accommodating the secondary battery. A ring-shaped insulating plate is provided with a hole formed therethrough.
The low melting point fusible alloy particles 2 and the flux 4 were accommodated in 3, the electrodes 4 were fixed to both surfaces of the insulating plate 1, and each electrode 4 was brought into contact with the low melting point fusible alloy particles 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a temperature fuse, and more particularly to a temperature fuse used by being attached to a sealed secondary battery.

[0002]

2. Description of the Related Art Recently, as a power source for portable electronic devices, etc.,
Large-capacity batteries such as lithium-ion batteries and nickel-metal hydride batteries are increasingly being used. FIG. 6 shows an example of these secondary batteries, in which a spirally wound body E of a positive electrode p and a negative electrode n via a separator s is accommodated in a negative electrode can 51 'and the bottom surfaces of the negative electrode n and the negative electrode can 51' And the negative electrode can 51 ′
A positive electrode collector 53 'is provided in the upper end of the negative electrode 51' to electrically connect the positive electrode 53 'to the collector electrode 52', and a safety valve 52 'and a gas discharge hole 541' are provided at the upper end of the negative electrode can 51 '.
4 ′ is sealed via a gasket 55 ′, and the central recess 521 of the safety valve 52 is electrically connected to the positive electrode collecting electrode 53. Thus, when the internal pressure rises abnormally, the safety valve 52 'is opened to release gas from the gas discharge holes 541' of the positive electrode cover 54 ', and the electrical conduction between the safety valve 52' and the positive electrode collecting electrode 52 'is cut off. Is done.

[0003] In the above-mentioned lithium ion battery, nickel hydride battery and the like, the capacity is large and a considerably large current flows during charging and discharging, and when a charger or a main unit fails, an overcurrent flows to cause abnormal heat generation. May be done.
Conventionally, a temperature fuse is attached to the secondary battery for such abnormal heat generation, and when the heat is abnormally generated, the temperature fuse is blown off to stop charging or discharging without waiting for the operation of the safety valve. It is known. in this case,
There is an advantage that release and scattering of the electrolyte of the secondary battery can be prevented, and contamination of the surrounding electrolyte can be avoided.

[0004]

However, conventionally, a temperature fuse is mounted on the outer surface of a cathode can of a secondary battery, so that the space for accommodating the secondary battery must be increased, and portable electronic equipment is required. Is disadvantageous for miniaturization.

An object of the present invention is to provide a thin temperature fuse that can be mounted on a secondary battery without increasing the space for accommodating the secondary battery, and a mounting structure of the temperature fuse in the secondary battery. .

[0006]

SUMMARY OF THE INVENTION A temperature hue according to the present invention is provided.
A hole is formed in the annular insulating plate, the low melting point fusible alloy particles and the flux are accommodated in the hole, electrodes are fixed to both sides of the insulating plate, and each electrode and the low melting point fusible alloy particles are connected. This is a configuration characterized by being brought into contact. A temperature fuse mounting structure for a secondary battery according to the present invention is characterized in that the temperature fuse is sandwiched between a peripheral end of a safety valve and a peripheral end of a positive electrode cover of the secondary battery. It is.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing an example of the temperature fuse according to the first aspect. In FIG.
Reference numeral 1 denotes an insulating plate, for example, a plastic plate, a ceramic plate, or the like. The intermediate plate 11 having a small-diameter hole 111 and the upper and lower plates 12 and 12 having a large-diameter hole 121 are laminated by adhesive or fusion to form a multi-stage hole. 13 is pierced. 2
Is a low melting point fusible alloy particle accommodated in the hole 13 of the insulating plate 1, and is held at the small diameter portion 111 of the hole. Reference numeral 3 denotes a flux filled in the holes 13. Reference numerals 4 and 4 denote electrodes fixed above and below the hole 13 of the insulating plate 1 and fixed by an adhesive or fusion, and are brought into contact with the low melting point fusible alloy particles 2.

In the above temperature fuse, the low melting point fusible alloy particles 2 are melted by heating, and the molten alloy is subjected to the activation action of the already melted flux, and as shown in FIG. The electrode 4 is wetted and spread on the surface of the electrode 4 facing 121 and is divided between the electrodes 4 and 4. As the low melting point fusible alloy particles, a low melting point fusible alloy ball is usually appropriate.
Although a plurality of balls can be used, any other ball can be used as long as it can be held and fixed at a small diameter portion of the hole and a sufficient flux filling gap can be secured at a large diameter portion. is there.

FIG. 3 (a) shows a temperature hue according to a third aspect.
FIG. 3 (B) is a cross-sectional view taken along the line of FIG. 3 (A), showing an annular insulating plate (ceramic plate,
A multi-stage hole 13 is formed in a plastic plate 1 in the same manner as described above (in FIG. 3B, 11 is a central plate, 12,
12 are upper and lower plates), the low melting point fusible alloy particles 2 and the flux 3 are accommodated in the holes 13 in the same manner as described above, and the metal foil electrodes 4 are fixed to both surfaces of the insulating plate 1. In the above, the insulating plate 1
The multi-stage hole 13 may have a two-stage multi-stage structure of a small diameter and a large diameter as shown in FIG. FIG. 4B shows the operating state of the temperature fuse under the multi-stage hole structure. It is desirable to use an insulating plate 1 that is easily repelled by a molten alloy so that the electrodes are easily separated. In the above, a metal that is not easily wetted by the molten alloy for one electrode, for example, Ni, and a metal that is easily wettable for the molten alloy, for example, Cu, can be used for the other electrode.In this case, the area of the electrode facing the hole is It is desirable to enlarge the metal side that is easily wetted by the molten alloy.

FIG. 5 shows a mounting structure of the temperature fuse secondary battery according to the third aspect. In FIG. 5, reference numeral 51 denotes a negative electrode can. Reference numeral 52 denotes a metal safety valve (including a pressure relief plate with a cut in the middle of the plate thickness), and a central concave portion 521 is brought into electrical contact with the positive electrode collecting electrode 53. Reference numeral 54 denotes a metal positive electrode lid, which has a gas release hole 541 formed therein. A is the temperature fuse shown in the above figure,
The safety valve 52 is sandwiched between the peripheral end of the positive electrode lid 53 and the peripheral end of the positive electrode lid 53, and the upper end opening of the negative electrode can 51 is inserted through the gasket 55 at the peripheral end of the temperature fuse A and the positive electrode lid 541. The electrodes 4 and 4 of the temperature fuse A are electrically connected to the safety valve 52 and the positive electrode lid 53. In the above, the contour shape of the annular insulating plate 1 of the temperature fuse is not limited to a circle, but may be square, hexagonal, octagonal or the like, depending on the inner shape of the negative electrode can 51.

The secondary battery to which the temperature fuse according to the present invention is attached is a secondary battery having a large capacity such as a lithium-ion battery or a nickel-metal hydride battery. When the device or main unit fails, an overcurrent may flow and generate heat. Due to this heat generation, the low melting point fusible alloy particles 2 having the temperature fuse A are melted,
As shown in FIG. 2 or (b) of FIG.
It spreads over the surface and the conduction is interrupted. In this case, by increasing the diameter of the large-diameter side of the multistage hole of the insulating plate, the molten alloy can be spread widely on the electrode surface, that is, the molten alloy can be spread with a small thickness. Even if the depth of the insulating plate is made shallow, and therefore, the insulating plate is made thin, it is possible to cut off the current. Therefore, the temperature fuse can be reduced in thickness, the size of the separation between the safety valve and the positive electrode cover can be reduced, and the increase in the storage space of the secondary battery can be kept small. In addition, since the temperature fuse insulating plate is formed in a ring shape, the pressure release mechanism formed by the safety valve of the secondary battery and the positive electrode cover with the gas discharge hole can be maintained, so that the internal pressure of the secondary battery increases unexpectedly. Also, by operating the safety valve, gas can be released from the gas discharge hole of the positive electrode cover, so that explosion of the secondary battery can be prevented.

[0012]

According to the temperature fuse of the present invention,
It can be made thinner, and it is attached to the secondary battery by sandwiching it between the peripheral end of the safety valve of the secondary battery and the peripheral end of the positive electrode lid.
Almost no space for accommodating the secondary battery is increased. Therefore, the compactness of the portable electronic device can be well maintained. Further, in such mounting, since the temperature fuse is formed in an annular shape to maintain the pressure release mechanism of the secondary battery, the safety valve can be reliably operated against an unexpected increase in the internal pressure of the secondary battery.

[Brief description of the drawings]

FIG. 1 is a view showing an embodiment of a temperature fuse according to claim 1;

FIG. 2 is a view showing an operation state of the temperature fuse of FIG. 1;

FIG. 3 is a view showing an embodiment of a temperature fuse according to claim 3;

FIG. 4 is a drawing showing an embodiment of a temperature fuse according to claim 2;

FIG. 5 is a view showing an embodiment of a temperature fuse mounting structure in a secondary battery according to claim 4;

FIG. 6 is a view showing a secondary battery.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Insulating plate 13 Multi-stage hole 2 Low melting point fusible alloy particle 3 Flux 4 Electrode A Temperature fuse 52 Safety valve 54 Positive electrode cover 55 Gasket

Claims (4)

[Claims] 1. A low melting point fusible alloy particle and a flux are accommodated in a hole of an insulating plate provided with a hole, electrodes are fixed to both surfaces of the insulating plate, and each electrode and the low melting point fusible alloy particle are connected to each other. Temperature fuse characterized by contacting. 2. The temperature fuse according to claim 1, wherein the holes of the insulating plate are small-diameter and large-diameter multistage holes for holding the low-melting-point fusible alloy particles. 3. The temperature fuse according to claim 1, wherein the insulating plate is annular. 4. A temperature fuse according to claim 3, wherein the temperature fuse is sandwiched between the peripheral end of the safety valve and the peripheral end of the positive electrode cover of the secondary battery. Construction.