Soft package battery with automatic pressure relief function

Abstract

The utility model discloses a soft package battery with a self-pressure-relief function, which comprises a battery shell, a soft package battery main body is arranged in the battery shell, battery tabs are respectively arranged at the upper end of the battery shell, a sealing shell is arranged on one side of the battery shell in a sealing manner, and a pressure relief valve is arranged in the sealing shell. The pressure relief valves are formed by stacking symmetrically-arranged semicircular pressure relief petals, the pressure relief petals are mutually extruded and sealed at the stacking positions of the pressure relief petals, and the pressure relief petals bend and extend towards one end of the sealing shell. The sealable pressure release valve is additionally arranged on the soft package battery shell, so that the effect of automatically releasing pressure when the battery is inflated is realized, the battery can be continuously kept sealed after pressure release, and the subsequent use is not influenced. The pressure relief device is made of a non-metal pipe, so that an exhaust method adopting a metal pipe and a sealing piece during pressure relief of a traditional battery is avoided, the sealing performance between the pressure relief valve and the battery shell is improved, and the pressure relief device has the advantages of being simple in process, convenient to operate and convenient for industrial production.

Description

Technical Field

[0001] The utility model belongs to the technical field of soft-pack batteries, and in particular relates to a soft-pack battery with a self-pressure relief function. Background Art

[0002] Soft-pack batteries are widely used in mobile phones, computers, new energy vehicles and other fields. The outer packaging material of soft-pack batteries is a soft aluminum-plastic film material. In actual application scenarios, under the influence of long-term high temperature environment or in the middle and late stages of service life, gas will be generated inside the battery. The continuously accumulated gas causes the internal pressure of the battery to gradually increase, causing the aluminum-plastic film to deform and swell until it bursts, resulting in safety accidents such as battery leakage. In order to avoid excessive internal gas pressure, it is necessary to install a pressure relief device on the soft-pack battery. When a certain pressure is reached, the internal gas is discharged in time, thereby achieving the purpose of ensuring the safe operation of the battery while extending the battery life.

[0003] The patent with publication number CN114204205A discloses a soft-pack battery and a soft-pack battery heat-sealing method, including a battery cell, an aluminum-plastic film, a sealing member and a metal tube, wherein two layers of aluminum-plastic film are sealed and connected to each other along a sealing line to form a receiving space, and both ends of the metal tube are open, one end is located in the receiving space, and the other end extends out of the receiving space.

[0004] The patent with announcement number CN217740727U discloses an exhaust valve and a soft-pack battery with an exhaust valve, including a battery body and a shell wrapped around the battery body. The shell is provided with an exhaust valve, and the exhaust valve includes an air inlet and an air outlet. A filter plate made of polymer material is welded inside the exhaust valve. The filter plate is used to generate exhaust pressure so that the gas inside the battery can be discharged through the exhaust valve all the time.

[0005] In the prior art, the exhaust method using metal tubes and seals is manual, that is, the seal needs to be opened manually after the battery produces gas, and then closed manually after the exhaust is completed, which is not only labor-intensive but also cannot ensure good sealing between the metal tube and the aluminum-plastic film. In addition, the method of using a polymer filter exhaust valve in the prior art can achieve the function of self-exhaustion, but when the battery does not produce gas, the exhaust valve will continue to generate negative pressure inside the battery, and the gas molecules generated by the volatilization of the electrolyte solvent under the negative pressure state will be discharged to the outside, which will eventually cause the electrolyte to dry up and affect the battery performance.

[0006] Therefore, in view of the above problems, it is urgent to design a soft-pack battery with a self-pressure relief function to achieve automatic pressure relief of the battery and increase the service life of the soft-pack battery. Utility Model Content

[0007] The purpose of the utility model is to provide a soft pack battery with a self-depressurization function to solve the problems raised in the above background technology. The following technical solution is provided: A soft pack battery with a self-depressurization function, comprising:

[0008] A battery shell has a soft-pack battery body inside, battery pole ears are respectively provided at the upper ends of the battery shell, the battery pole ears are electrically connected to the soft-pack battery body, and a sealing shell is sealed on one side of the battery shell, and a pressure relief valve is provided inside the sealing shell.

[0009] The pressure relief valve is formed by symmetrically placed semicircular pressure relief flaps stacked on each other, and the pressure relief flaps are squeezed and sealed against each other at the overlapping part of the pressure relief flaps, and are bent and extended toward one end of the sealing shell. The pressure relief flap is made of rubber.

[0010] In this technical solution, by adding a sealable automatic pressure relief device pressure relief valve to the battery shell of the soft-pack battery, when the battery is working, when the gas production inside the battery is high and the pressure is high, the pressure relief valve can be used to achieve pressure relief, and when the internal and external pressures are balanced, the battery can be sealed again with the outside world. This avoids the traditional battery pressure relief method of using metal tubes and seals for exhaust (the exhaust method is manual, that is, the seal needs to be opened manually after the battery produces gas, and then manually closed after the exhaust is completed), which can not only ensure the airtightness between the pressure relief valve and the battery, but also have the effect of self-pressure relief when the battery produces more gas.

[0011] In any of the above technical solutions, further, a sealing portion is provided at the ring end of the sealing shell, and the sealing portion and the battery housing are sealed by a sealant.

[0012] In the technical solution, the sealing portion is filled with sealant to achieve a sealed connection between the battery housing and the sealing shell, thereby ensuring isolation between the inside of the battery and the outside world.

[0013] In any of the above technical solutions, further, the inner wall of the sealing shell is in a uniform cylindrical shape. The first and second water-blocking membranes are respectively sealed at both ends of the sealing shell, and the first and second water-blocking membranes allow gas to pass through. The first and second water-blocking membranes are made of expanded polytetrafluoroethylene microporous membranes.

[0014] In the technical solution, the pressure relief valve is connected to the battery housing through a sealing shell and communicates with the internal air pressure of the battery, and the airtightness of the two is achieved by potting sealant at the connection.

[0015] When the gas pressure inside the battery increases to a certain value, a pressure difference is generated between the inside of the battery and the outside. At this time, the gas will enter the sealed shell from the inside of the battery through the second water-proof membrane. At this time, the air pressure lifts the pressure relief flap, and the pressure relief flap will automatically open to exhaust. Then the gas flows through the first water-proof membrane and is discharged to the outside of the battery until the pressure inside and outside the battery drops to a balanced state. At this time, the pressure relief flap will automatically close and remain closed. The pressure relief flap is made of rubber material with elasticity, which ensures that the pressure relief flap can be automatically closed after exhaust. The function of the pressure relief valve is to automatically open and release gas to the outside when the internal pressure of the battery is too high, reduce the internal pressure of the battery, and maintain sealing when the internal and external pressures are balanced. And the number of pressure relief flaps is ≥ 2 pairs. The purpose of increasing the number of pressure relief flaps is to further avoid the possibility of water molecules entering the battery cell through the pressure relief valve by diffusion.

[0016] In addition, the first water-proof membrane and the second water-proof membrane adopt expanded polytetrafluoroethylene microporous membrane (e-PTFE membrane), whose function is to ensure the passage of gas while preventing liquid from passing through, thereby ensuring that the electrolyte inside the battery will not be reduced as the gas is discharged, and isolating external moisture from invading the interior of the battery.

[0017] The beneficial effects of the utility model are as follows: the utility model realizes the effect of automatic pressure relief when the battery is bloated by adding a sealable pressure relief valve to the soft pack battery shell, and the battery can continue to remain sealed after the pressure relief, which does not affect subsequent use. The pressure relief device is made of non-metallic pipes, thereby avoiding the exhaust method of using metal pipes and seals when the traditional battery is depressurized, thereby improving the sealing between the pressure relief valve and the battery shell, and has the advantages of simple process, convenient operation, and convenient industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a front view of a soft pack battery;

[0019] Figure 2 It is a side view of a soft pack battery;

[0020] Figure 3 A cross-sectional view of the connection between the pressure relief valve and the soft-pack battery shell;

[0021] Figure 4 is a side view of the pressure relief valve.

[0022] The reference numerals in the figure are: 10, battery shell; 20, soft-pack battery body; 30, battery tab; 40, sealing shell; 41, sealing part; 50, pressure relief valve; 51, first water-proof membrane; 52, second water-proof membrane; 53, pressure relief flap; 60, sealant. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the present application to clearly describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments in the present application belong to the scope of protection of this application.

[0024] In the description of the present application, it should be noted that the terms used herein are only for describing specific embodiments, and are not intended to limit the exemplary embodiments according to the present application. For ease of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship. The technology, methods and equipment known to ordinary technicians in the relevant field may not be discussed in detail, but in appropriate cases, the technology, methods and equipment should be regarded as part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as merely exemplary, rather than as a limitation. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that similar numbers and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0025] Embodiment 1:

[0026] like Figure 1-3 As shown, this embodiment provides a soft-pack battery with a self-pressure release function, including:

[0027] A battery shell 10 is provided with a soft-pack battery body 20 inside the battery shell 10, and battery pole ears 30 are respectively provided at the upper ends of the battery shell 10, and the battery pole ears 30 are connected to the soft-pack battery body 20, and a sealing shell 40 is sealed on one side of the battery shell 10, and a pressure relief valve 50 is provided inside the sealing shell 40.

[0028] The pressure relief valve 50 is formed by stacking symmetrically placed semicircular pressure relief flaps 53, and the pressure relief flaps 53 are squeezed and sealed at the overlapping position of the pressure relief flaps 53, and are bent and extended toward one end of the sealing shell 40. The pressure relief flaps 53 are made of rubber.

[0029] In this technical solution, by adding a sealable automatic pressure relief device pressure relief valve 50 to the battery shell 10 of the soft-pack battery housing, when the battery is working, when the gas production inside the battery is high and the pressure is high, the pressure relief can be achieved through the pressure relief valve 50, and when the internal and external pressures are balanced, the battery and the outside world can be kept sealed again. This avoids the exhaust method of using metal tubes and seals when the traditional battery is decompressed (the exhaust method is manual, that is, the seal needs to be opened manually after the battery produces gas, and then manually closed after the exhaust is completed), which can not only ensure the airtightness between the pressure relief valve and the battery, but also have the effect of self-decompression when the battery produces more gas.

[0030] The pressure relief valve 50 is composed of four groups of pressure relief flaps 53 (made of rubber sheets), each group of which is composed of two symmetrically placed semicircular rubber sheets, which are superimposed on each other and squeezed toward the outside at the superimposed position to achieve a sealing effect. The number of pressure relief flaps 53 is ≥ 2 pairs. The purpose of increasing the number of pressure relief flaps 53 is to further prevent the possibility of water molecules entering the battery cell through the pressure relief valve by diffusion.

[0031] In a preferred embodiment of the present invention:

[0032] like Figure 4 As shown, specifically, a sealing portion 41 is provided at the ring end of the sealing shell 40 , and the sealing portion 41 and the battery housing 10 are sealed by a sealant 60 .

[0033] In the present technical solution, the sealing portion 41 is filled with the sealant 60 to achieve a sealed connection between the battery housing 10 and the sealing shell 40, thereby ensuring isolation between the inside of the battery and the outside.

[0034] In a preferred embodiment of the present invention:

[0035] like Figure 3-4 As shown, specifically, the inner wall of the sealing shell 40 is in a uniform cylindrical shape. A first water-blocking membrane 51 and a second water-blocking membrane 52 are respectively sealed at both ends of the sealing shell 40, and the first water-blocking membrane 51 and the second water-blocking membrane 52 allow gas to pass through. The first water-blocking membrane 51 and the second water-blocking membrane 52 are made of expanded polytetrafluoroethylene microporous membrane.

[0036] In the present technical solution, the pressure relief valve 50 is connected to the battery housing 10 through the sealing shell 40 and communicates with the internal air pressure of the battery, and the airtightness of the two is achieved by potting sealant 60 at the connection.

[0037] When the gas pressure inside the battery increases to a certain value, a pressure difference is generated between the inside of the battery and the outside. At this time, the gas will pass through the second water-proof membrane 52 from the inside of the battery and enter the sealed shell 40. At this time, the air pressure lifts the pressure relief flap 53, and the pressure relief flap 53 will automatically open to exhaust. Then the gas flows through the first water-proof membrane 51 and is discharged to the outside of the battery until the pressure inside and outside the battery is reduced to a balanced state. At this time, the pressure relief flap 53 will automatically close and remain closed. The pressure relief flap 53 is made of rubber material with elasticity, which ensures that the pressure relief flap 53 can be automatically closed after exhaust. The function of the pressure relief valve 50 is to automatically open and release gas to the outside when the internal pressure of the battery is too high, reduce the internal pressure of the battery, and maintain sealing when the internal and external pressures are balanced.

[0038] In addition, the first water-proof membrane 51 and the second water-proof membrane 52 are made of expanded polytetrafluoroethylene microporous membrane (e-PTFE membrane), which can ensure the passage of gas while preventing liquid from passing through, thereby ensuring that the electrolyte inside the battery will not be reduced as the gas is discharged, and isolating external moisture from invading the battery.

[0039] The embodiments of the present application are described above in conjunction with the accompanying drawings. In the absence of conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present application, ordinary technicians in this field can also make many forms without departing from the purpose of the present application and the scope of protection of the claims, all of which are within the protection of the present application.

Claims

1. A soft pack battery with self-pressure relief function, characterized in that: include: A battery housing (10), wherein a soft-pack battery body (20) is provided inside the battery housing (10), battery tabs (30) are provided at the upper ends of the battery housing (10), the battery tabs (30) are electrically connected to the soft-pack battery body (20), and a sealing shell (40) is provided on one side of the battery housing (10), and a pressure relief valve (50) is provided inside the sealing shell (40).

2. A soft pack battery with self-pressure relief function according to claim 1, characterized in that: The pressure relief valves (50) are respectively formed by symmetrically placed semicircular pressure relief flaps (53) stacked on each other, and the pressure relief flaps (53) are squeezed and sealed against each other at the overlapping positions of the pressure relief flaps (53), and are bent and extended toward one end of the sealing shell (40).

3. The soft pack battery with self-pressure relief function according to claim 2, characterized in that: The pressure relief flaps (53) are made of rubber material, and the number of the pressure relief flaps (53) is ≥ 2 pairs.

4. The soft pack battery with self-pressure relief function according to claim 2, characterized in that: A sealing portion (41) is provided at the ring end of the sealing shell (40), and the sealing portion (41) and the battery housing (10) are sealed by a sealant (60).

5. The soft pack battery with self-pressure relief function according to claim 2, characterized in that: The inner wall of the sealing shell (40) is in a uniform cylindrical shape.

6. The soft pack battery with self-pressure relief function according to claim 4, characterized in that: A first water-proof membrane (51) and a second water-proof membrane (52) are respectively sealed at both ends of the sealing shell (40), and the first water-proof membrane (51) and the second water-proof membrane (52) allow gas to pass through.

7. The soft pack battery with self-pressure release function according to claim 6, characterized in that: The first water-blocking membrane (51) and the second water-blocking membrane (52) are made of expanded polytetrafluoroethylene microporous membrane.

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