KR20010061298A - Li-ION BATTERY USING BALL TYPE SAFETY VENT - Google Patents

Abstract

PURPOSE: A safety valve of a lithium ion battery is provided which effectively cuts off electricity when the pressure of the cell inside increases to stop charging or discharging and further works to discharge the internal pressure when the pressure is continuously increased. CONSTITUTION: The safety valve of a lithium ion battery comprises: (i) a gasket(12) which has a hole on the center of the inside lower side and a catching ring jaw on the inside lower side; (ii) a circular shaped positive temperature coefficient element(16) which is combined to the upper side of the catching ring jaw of the gasket and has a hole on the center; (iii) a circular shaped secondary safety valve(17) which is combined with the upper side of the positive temperature coefficient element and has a hole on the center; (iv) an upper cap(19) which has a hole for discharging gas; (v) a safety valve film(20) which is positioned between the upper side of the secondary safety valve and the upper cap; (vi) a globular ball(11), which is positioned on the inside lower side hole of the gasket and the lower part of which is connected to a cathode terminal; and (vii) an aluminum foil(15), one side of which is welded to the upper side of the globular ball and the other side of which is welded to the positive temperature coefficient element.

Description

Li-ion battery with spherical safety plate {Li-ION BATTERY USING BALL TYPE SAFETY VENT}

The present invention relates to a lithium ion battery provided with a spherical safety plate. The present invention prevents further internal pressure rise by cutting off the current by breaking the terminal which is previously grooved when the internal pressure of the battery increases due to battery misuse, and then operates the secondary safety plate when there is a continuous pressure increase. A battery having a safety plate device for releasing pressure.

With the explosion of portable electronic devices, the development of lighter and more durable products has been required. However, lithium ion batteries, which are lighter than conventional nickel-metal hydride batteries or nickel cadmium batteries, and have high energy, contain explosion hazards instead of high energy, and thus require a separate safety device. In order to incorporate safety devices into the cell, a great deal of consideration has been required in the cell design, and a commonly adopted method is to install a positive temperature coefficient element inside the cell cap or dig a groove outside the bottom of the can to pressurize the cell. Releasing gas upon rise.

The present invention relates to a safety plate that cuts off the current by blocking the electric current by breaking the aluminum foil which has been previously grooved when the internal pressure of the battery increases due to battery misuse.

An object of the present invention is to cut off the current primarily when the internal pressure rises due to battery misuse, and if the internal pressure rises even after the current is cut off, the safety valve is broken so that the internal pressure is released to the outside. As a result of the safety plate made by the dual system of the first and second systems, when the internal pressure of the battery reaches a certain level according to the operation of the safety plate of the battery, the battery is prevented from being charged or discharged further. It is intended to prevent damage to the device and direct exposure to the human body.

1 is a cross-sectional view of a safety plate according to the present invention.

2 is a cross-sectional view of the aluminum foil of the safety plate.

3 is a cross-sectional view of another safety plate of the present invention.

<Explanation of symbols for main parts of drawing>

11: spherical aluminum ball

12, 32: Gasket

13: sealant

14, 33: positive terminal

15, 34: aluminum foil

16, 35 positive element coefficient

17, 36: 2nd safety valve

18, 37: hole for gas discharge

19, 38: upper cap

20, 39: safety valve

31: Oval Aluminum Ball

The present invention to achieve the above object,

In the safety plate of the lithium ion battery,

a) A hole is formed in the center of the inner bottom and a hooking jaw is formed in the inner lower side.

Gaskets;

b) is coupled to the upper surface of the gripping ring projection of the gasket and formed with a hole in the center

Disk-shaped constant temperature coefficient elements;

c) mounted and coupled to the top surface of the constant temperature coefficient element and having a hole in the center thereof.

Secondary safety plate of the disc shape;

d) an upper cap having a hole for gas discharge formed in the circumferential surface;

e) safety plate membrane located between the upper surface of the secondary safety plate and the upper cap;

Here, the safety valve is broken when the pressure inside the battery continues to increase.

Releasing pressure;

f) is located in the inner bottom hole of the gasket and the lower part is connected to the positive terminal

Spherical Balls--Spherical balls are inserted into the mold during the gasket injection molding

It is formed integrally with the gasket, and the spherical ball and the hole of the gasket are sealed with

Sealed; And

g) one side is welded on top of the spherical ball and the other is different from the positive temperature coefficient element.

Aluminum Foil One Side Welded

It provides a spherical safety plate of the lithium ion battery comprising a.

Preferably, the aluminum foil has a groove formed therein so as to cut off when the internal pressure of the battery increases, and the spherical ball is made of aluminum. In addition, the explosion pressure of the secondary safety plate is preferably 15 ± 3 kgf / ㎠, the aluminum foil is preferably broken at a pressure of 8 ~ 10 kgf / ㎠.

In another aspect, the present invention provides a safety plate of a lithium ion battery, an oval safety plate of a lithium ion battery including an elliptical ball instead of the spherical ball.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

First, Figure 1 is a cross-sectional view of Embodiment 1 according to the present invention.

Example 1

In the safety plate of FIG. 1, the spherical aluminum ball 11 is located in the hole of the gasket 12 in which a hole is formed in the center of the flat inner bottom and a locking ring jaw is formed in the inner lower side. Here, the gasket 12 having a thickness of 0.5 mm is manufactured by injection molding. At this time, since the spherical aluminum ball 11 having a diameter of 6 mm is inserted into the mold and then injected, the gasket 12 is made of aluminum balls 11. It is formed integrally with The gasket 12 and the aluminum ball 11 are sealed with a sealant (for example, epoxy) 13 to reinforce the electrolyte and gas leak prevention. The lower part of the aluminum ball 11 is ultrasonically welded with the positive electrode terminal 14, and the upper part of the aluminum ball 11 is ultrasonically welded to one side of the aluminum foil 15. And the other side of the aluminum foil 15 is welded to the positive temperature coefficient element 16. Here, as shown in FIG. 2, the aluminum foil 15 has a groove formed therein to cut off when the internal pressure of the battery rises to block the current.

In addition, a disc-shaped secondary safety plate 17 having a hole in the center is mounted on the upper surface of the constant temperature coefficient element 16. A safety plate membrane 20 is positioned between the secondary safety plate 17 and the upper cap 19 having holes 18 for gas discharge formed in the circumferential surface. Here, the safety plate membrane 20 has a thickness of 0.03 mm on the secondary safety plate 17 having a thickness of 0.4 mm so that the pressure inside the battery continues to increase to 15 ± 3 kgf / ㎠ to be crushed to release the internal pressure of the battery. The thin aluminum having is made by cold rolling.

The operation of Embodiment 1 according to the present invention configured as described above is as follows.

First, in the case of normal battery use, current is transmitted from the positive electrode terminal 14 to the aluminum foil 15 through the aluminum ball 11, and the positive temperature coefficient element 16, the secondary safety valve 17, and It passes through the safety valve membrane 20 to the upper cap 19.

However, a battery such as an electric current link and an electrode abnormality reaction between the aluminum ball 11 and the positive terminal 14 of the jelly roll (not shown), and between the aluminum ball 11 and the positive temperature coefficient element 16. When the internal pressure of the battery increases due to misuse, the aluminum ball 11 rises upward under the influence of the internal pressure of the battery. At this time, the groove portion made in advance in the aluminum foil 15 connected to the aluminum ball 11 is broken, so that the current no longer flows.

In general, the safety plate of the present invention stops the operation of the battery without leakage of material inside the battery since there is no further increase in the internal pressure of the battery due to the current interruption. However, when the pressure inside the battery continues to increase despite the current interruption, the safety plate membrane 13 located above the safety plate is crushed to release the internal pressure to prevent the battery from exploding.

3 is a cross-sectional view of Embodiment 2 according to the present invention.

Example 2

The spherical shape used in Example 1 to further complement the stability of welding and the convenience of welding when welding the joint (ie, aluminum foil) 34 between the positive temperature coefficient element 35 and the aluminum ball 31. The aluminum ball 11 was removed, and a flat disc (diameter 6 mm) was formed on the top and replaced with an aluminum ball 31 having an elliptical longitudinal section to insert the gasket 12 into the mold during injection molding. At this time, the size of the aluminum ball 31 having an elliptical longitudinal section is 3 mm in diameter and 5 mm in height, and the bottom thickness of the manufactured gasket 32 is 0.5 mm. On the other hand, unlike the first embodiment, the gasket 32 is integrally injection-molded so that the center protrudes in the form of enclosing the upper portion of the aluminum ball 31, which does not include a flat disc formed on the upper portion of the aluminum ball. strong. Therefore, the gasket 32 and the aluminum ball 31 having an elliptical longitudinal section do not need a separate sealant to prevent leakage of the electrolyte and the gas. The shape and assembly of the positive electrode terminal 33, the aluminum foil 34, the positive temperature coefficient element 35, the secondary safety plate 36, the upper cap 38 and the safety plate membrane 39 of the second embodiment are carried out. Since it is the same as Example 1, it abbreviate | omits description.

Since the operation of the second embodiment according to the present invention configured as described above is the same as that of the first embodiment, a description thereof is omitted.

When the internal pressure rises due to battery misuse, the current is first cut off. If the internal pressure rises even after the current is cut off, the safety valve is broken so that the internal pressure is released to the outside. As a result of the safety plate made of the first and second dual systems, damage to electronic devices and direct exposure to the human body due to leakage of the internal material of the battery due to the operation of the safety plate of the battery can be prevented.

Claims (10)

In the safety plate of the lithium ion battery, a) A hole is formed in the center of the inner bottom and a hooking jaw is formed in the inner lower side. Gaskets; b) is coupled to the upper surface of the gripping ring projection of the gasket and formed with a hole in the center Disk-shaped constant temperature coefficient elements; c) mounted and coupled to the top surface of the constant temperature coefficient element and having a hole in the center thereof. Secondary safety plate of the disc shape; d) an upper cap having a hole for gas discharge formed in the circumferential surface; e) safety plate membrane located between the upper surface of the secondary safety plate and the upper cap; Here, the safety valve is broken when the pressure inside the battery continues to increase. Releasing internal pressure; f) is located in the inner bottom hole of the gasket and the lower part is connected to the positive terminal Spherical Balls--Spherical balls are inserted into the mold during the gasket injection molding It is formed integrally with the gasket, and the spherical ball and the hole of the gasket are sealed with Sealed; And g) one side is welded on top of the spherical ball and the other is different from the positive temperature coefficient element. Aluminum Foil One Side Welded Spherical safety plate of the lithium ion battery comprising a. The method of claim 1, The aluminum foil is a spherical safety plate of a lithium ion battery having a groove therein so as to cut off when the pressure inside the battery rises. The method according to claim 1 or 2, A spherical safety plate of a lithium ion battery, wherein the spherical ball is made of aluminum. The method of claim 1, A spherical safety plate of a lithium ion battery having an explosion pressure of 15 ± 3 kgf / cm 2 of the secondary safety plate. The method of claim 1, A spherical safety plate of a lithium ion battery, wherein the aluminum foil breaks at a pressure of 8 to 10 kgf / cm 2. In the safety plate of the lithium ion battery, a) a hole is formed in the protrusion formed in the center of the inner bottom and the inner lower side A gasket formed with a locking ring; b) is coupled to the upper surface of the gripping ring projection of the gasket and formed with a hole in the center Disk-shaped constant temperature coefficient elements; c) mounted and coupled to the top surface of the constant temperature coefficient element and having a hole in the center thereof. Secondary safety plate of the disc shape; d) an upper cap having a hole for gas discharge formed in the circumferential surface; e) safety plate membrane located between the upper surface of the secondary safety plate and the upper cap; Here, the safety valve is broken when the pressure inside the battery continues to increase. Releasing internal pressure; f) is located in the hole of the protrusion formed in the center of the gasket, the lower part of the positive electrode Balls connected to the terminal, having a flat disc on the top and oval in cross section Where the oval ball is inserted into the mold during the gasket injection molding to Integrally formed with; And g) one side is welded to the top of the conical ball and the other is different from the positive temperature coefficient element. Aluminum Foil One Side Welded Oval safety plate of a lithium ion battery comprising a. The method of claim 6, The aluminum foil is an elliptical safety plate of a lithium ion battery having a groove therein to cut off current when the pressure inside the battery rises. The method according to claim 6 or 7, Elliptical safety plate of a lithium ion battery wherein the elliptical ball is made of aluminum. The method of claim 6, An elliptical safety plate of a lithium ion battery having an explosion pressure of 15 ± 3 kgf / cm 2 of the secondary safety plate. The method of claim 6, An oval safety plate of a lithium ion battery in which the aluminum foil breaks at a pressure of 8 to 10 kgf / cm 2.