JPH066454Y2 - Explosion-proof battery - Google Patents

Description

[Detailed Description of the Invention] << Industrial Application Field >> The present invention relates to an explosion-proof battery, and particularly, in response to an increase in internal pressure, a thin plate that airtightly partitions the inside and outside of the battery bulges and hits a cutting edge, which causes the thin plate to break. Related to the improvement of the explosion-proof structure.

<Prior art> In non-aqueous electrolyte batteries such as lithium batteries, the amount of internal energy is large, so gas generation due to incorrect use such as throwing into fire or reversing connection and the like The risk of rupture is great.

As a measure for preventing this kind of rupture, in the past, for example, the actual exploitation 6
As disclosed in Japanese Unexamined Patent Publication No. 0-65973, a cutting blade is provided inside a terminal plate located above a metal thin plate that separates the inside and the outside of the battery, and the tip of the cutting blade is opposed to the thin plate.

The cutting blade is formed by cutting and raising the inside of the terminal plate, and when an abnormality occurs inside the battery and the gas pressure sharply increases, the thin plate swells and pushes against the cutting blade. When it hits, a puncture occurs and gas escapes from the inside of the battery,
This avoids rupture due to gas generation.

However, in this structure, the thin cutting edge formed by cutting and raising simply faces the thin plate, so when the cutting edge breaks the thin plate, the cutting blade itself penetrates the break hole and breaks the thin plate. Since the blade is pressed from above, the gap between the cutting edge and the rupture hole is small, and it is possible to cope with a sudden rise in pressure and temperature such as when the battery is thrown into a fire. No, despite having a rupture,
It could burst and wasn't completely safe.

In order to solve such a problem, for example, the actual Kaisho No. 54
-108926 or Japanese Utility Model Laid-Open No. 61-15327.
No. 4 or Japanese Utility Model Laid-Open No. 56-146361, the cutting blade is formed into a cylindrical shape, and further, as described in Japanese Utility Model Laid-Open No. 60-174172. It has been proposed that the blades are serrated and arranged in a circle.

<Problems to be solved by the invention> However, in the former case where the cutting blade is formed into a cylindrical shape, the contact portion between the cutting blade and the breaking material is circular, so that the breaking material does not have a relatively large internal pressure. Has a defect that it does not break. Also, in the latter case where the cutting blades are arranged in a sawtooth shape in a circular shape, the contact portion between the cutting blades and the cutting material becomes a plurality of separate points along the circumferential direction, so the internal pressure breaks smaller than in the former case. However, it is conceivable that the cutting blade only pierces the ruptured material with a gap in the circumferential direction.

The present invention solves the above problems, can cope with a rapid increase in internal pressure, does not block a rupture hole due to ejected matter, and is a material to be ruptured even with a relatively small internal pressure. An object of the present invention is to provide an explosion-proof battery in which a thin plate is broken along a predetermined circumference so that the explosion can be reliably prevented in an abnormal state.

<Means for Solving the Problems> In order to achieve the above-mentioned object, the present invention provides a thin plate which is placed in an opening of a battery case to partition the inside and outside of the battery in an airtight manner, and a predetermined space is formed on the surface side of the thin plate. A terminal plate having a first gas vent hole fixed in a laminated state by caulking the periphery of the battery case to the opening of the battery case through a sealing gasket, and having a large diameter on the inner surface of the terminal plate. A cutting piece is formed by obliquely cutting the lower end of the cylindrical shape and a peripheral wall is provided with a second degassing hole, and a tip of the cutting blade that is inclined of the breaking piece is arranged to face the metal thin plate. I did.

<Operation> According to the above configuration, when the thin plate swells due to the gas inside the battery, the pressure at the tip of the inclined cutting edge of the large-diameter breaking piece is applied to one point of the thin plate, so the thin plate has a relatively small internal pressure. When it is broken like this, it flips up like a can of juice juice to open the pull top, and the broken thin plate is peeled off along a predetermined circumference to form a large rupture hole, which is blocked by the ejecta. Without coming off
The internal gas is quickly discharged from the second gas vent hole to the outside through the first gas vent hole, and a sufficient amount of gas can be secured even if the internal pressure rises abruptly.

<< Embodiment >> An embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows the essential parts of an explosion-proof battery according to the present invention.

In the figure, reference numeral 1 denotes a battery case in which a power generating element 2 is housed, that is, a positive electrode can 3, and a peripheral edge of a positive electrode can 1 is crimped to an inner peripheral portion of an opening edge of the positive electrode can 1, and a metal plate 4 and a stainless thin plate 5 are provided at a bottom portion. The sealing gasket 6 held in a laminated state is a negative electrode terminal plate having a peripheral edge inside the sealing gasket 3 and being caulked with the peripheral edge of the stainless thin plate 5 on the inner peripheral edge of the opening edge of the positive electrode can 1.

A negative electrode lead plate 7 is led out from the power generating element 2 and electrically connected to the plate 4, the stainless thin plate 5 and the negative electrode terminal plate 6 through an opening 3a formed in the sealing gasket 3.

The plate 4 supports the thin stainless plate 5, has an opening 4a formed at the center thereof, and communicates with a central opening 3b formed at the center of the sealing gasket 3.

The central portion of the terminal plate 6 is formed to project in a convex shape, and a gas vent hole 6a is formed in the side portion thereof. The cutting piece 8 is spot-welded inside the convex portion.

The breaking piece 8 is formed by obliquely cutting the lower end of a large-diameter cylindrical shape as shown in FIG. 2, and the entire circumference of the opening edge portion thereof is a sharp cutting edge 8a. Cutting edge 8
The tip of a is opposed to and in contact with the peripheral edge of the central portion of the upper surface of the stainless thin plate 5. A hole 8b for venting gas is formed in the side portion of the breaking piece 8.

In the above structure, when the gas pressure inside the battery is suddenly increased due to an abnormal state, the gas presses the stainless thin plate 5 through the openings 3b and 4a, whereby the central part of the stainless thin plate 5 moves upward from the cutting edge 8a. The inner pressure is concentrated on the tip of the cutting blade.
As a result, the stainless thin plate begins to tear from the portion that comes into contact with the tip of the cutting blade, and is flipped up and peeled off along a predetermined circumference as if opening the pull-top of can juice, resulting in a large rupture. Then, the generated gas is discharged to the outside from the broken hole portion through the opening below the cutting edge of the breaking piece 8 above the cutting edge and the gas vent holes 8b and 6a.

The size of the rupture hole is an area corresponding to the inner shape of the transverse cross section of the breaking piece 8, and according to this area, degassing can sufficiently follow a rapid increase in the internal pressure, and the contents are Even if it squirts out, this rupture hole will not be blocked because it has a sufficient opening area.

<< Effect of Device >> As described in detail with reference to the embodiments above, in the explosion-proof battery according to the present invention, when the thin plate swells due to the internal pressure, the pressure at the tip of the inclined cutting blade of the breaking piece is added to one point of the thin plate. Is applied, the sheet is broken by a relatively small internal pressure. Since this breaking piece forms a cutting edge by diagonally cutting the lower end of a large-diameter cylindrical shape, once the thin plate is broken as described above, it flips up to open a pull top such as can juice. , The fractured thin plate is peeled off along a predetermined circumference to form a large rupture hole, which is not blocked by the ejected matter, and the internal gas flows from the second degassing hole to the first degassing hole. The gas can be quickly discharged to the outside through the pipe, and a sufficient amount of gas can be secured even if the internal pressure rises rapidly.

Therefore, according to this invention, it is suitable as a measure for preventing rupture when the internal pressure rises.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part of the present invention, and FIG. 2 is a perspective view showing a broken piece applied to FIG. 1 ... Positive electrode can (battery case) 2 ... Power generating element 3 ... Sealing gasket 5 ... Stainless steel thin plate 6 ... Negative electrode terminal plate 8 ... Breaking piece 8a ... Cutting blade

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hideaki Katsuno, Hideaki Katsuno 5-36-11 Shimbashi, Minato-ku, Tokyo Inside Fuji Electric Chemical Co., Ltd. (56) References 54-108926 (JP, U) Actually opened 60-174172 (JP, U) Actually opened 61-153274 (JP, U) Actually opened 56-146361 (JP, U)

Claims (1)

[Scope of utility model registration request] 1. A thin plate arranged in an opening of a battery case to partition the inside and outside of the battery in an airtight manner, and a thin plate which is fixed in a laminated state with a predetermined space on the surface side of the thin plate and whose peripheral edge is the opening of the battery case. A terminal plate having a first gas vent hole formed by caulking it through a sealing gasket, and forming a cutting edge by diagonally cutting a large-diameter cylindrical lower end on the inner surface of the terminal plate. An explosion-proof battery characterized in that a breaking piece having a second gas vent hole is also provided on the peripheral wall, and the tip of the cutting blade that is inclined in the breaking piece is arranged to face the thin metal plate.