Pressure relief type laminated battery and battery module

Abstract

The utility model provides a pressure relief type laminated battery and a battery module, the battery comprises a battery cell, a shell, positive tabs, negative tabs, a fuse link and a pressure relief valve, the battery cell comprises a diaphragm, a positive plate and a negative plate, the positive tabs comprise a first positive tab and a second positive tab, the fuse link is respectively connected with the first positive tab and the second positive tab, and the pressure relief valve is connected with the shell. The shell is provided with a positive electrode bonding part and a negative electrode bonding part, the shell is further provided with a pressure relief channel, the pressure relief channel is communicated with the inner cavity, and the pressure relief valve is bonded to and blocks the pressure relief channel. When the battery is short-circuited to cause abnormal temperature rise, the fuse link is fused in a state of reaching a preset temperature, so that the first positive tab and the second positive tab are disconnected to prevent continuous temperature rise caused by the short circuit of the battery, and meanwhile, gas generated in the battery enables internal air pressure to be increased drastically, and the generated gas passes through the pressure relief channel, so that the temperature rise of the battery is reduced. Therefore, explosion and fire caused by further rising of the air pressure in the battery are prevented.

Description

Technical Field

[0001] The present disclosure relates to the field of battery technology, and in particular to a pressure relief type laminated battery and a battery module. Background Art

[0002] Laminated batteries are a very important type of battery and have been widely used in electric vehicles, energy storage systems, drones, smart wearables and portable electronic devices.

[0003] In view of the fact that batteries are prone to heating up under thermal runaway, some patents have been disclosed. For example, the existing patent CN114068865A discloses an electrode structure and a soft-pack battery with a self-fusing function, wherein the tab body includes an A-zone body, a B-zone body and a C-zone body arranged in sequence along its length. When the battery is short-circuited and the overload current is large, the temperature of the B-zone body rises and can self-fuse, thereby acting as a "fuse".

[0004] Although the fuse can be blown when the battery is at an abnormally high temperature, when the battery is in an abnormal state and gas is generated inside the battery, causing the internal air pressure to increase dramatically, the generated gas cannot be released in time. When the air pressure reaches a certain level, the battery will explode and catch fire, which is extremely dangerous. This makes the battery less safe to use and poses a safety hazard. Utility Model Content

[0005] The purpose of the present disclosure is to overcome the deficiencies in the prior art and to provide a pressure relief type laminated battery and a battery module which can be promptly melted under thermal runaway of the battery and can promptly release the gas in the battery.

[0006] The purpose of this disclosure is achieved through the following technical solutions:

[0007] A pressure relief type laminated battery, comprising a battery cell, a shell, a positive electrode ear and a negative electrode ear, wherein the battery cell is located in the inner cavity of the shell, the battery cell comprises a diaphragm, a positive electrode sheet and a negative electrode sheet, the number of the positive electrode sheets and the number of the negative electrode sheets are both multiple, each of the positive electrode sheets is alternately arranged with the adjacent negative electrode sheet through the diaphragm, and the extension parts of the multiple negative electrode sheets are connected to the negative electrode ear after being stacked;

[0008] The pressure relief type laminated battery further includes a fuse and a pressure relief valve, the positive electrode ear includes a first positive electrode ear and a second positive electrode ear, the fuse is connected to the first positive electrode ear and the second positive electrode ear respectively, the fuse and the second positive electrode ear are both located in the inner cavity, and the extension parts of the plurality of positive electrode sheets are stacked and connected to the second positive electrode ear;

[0009] The shell has a positive electrode bonding portion and a negative electrode bonding portion, and the shell is further provided with a pressure relief channel, the pressure relief channel is communicated with the inner cavity, the positive electrode bonding portion wraps a portion of the end surface of the first positive electrode ear, so that a portion of the structure of the first positive electrode ear is located in the inner cavity, and the negative electrode bonding portion wraps a portion of the end surface of the negative electrode ear, so that a portion of the structure of the negative electrode ear is located in the inner cavity;

[0010] The pressure relief valve is bonded and sealed to the pressure relief channel, so that when the battery is in thermal runaway, the gas generated in the housing breaks through the pressure relief valve through the pressure relief channel and is released.

[0011] In one of the embodiments, the shell has a heat-bonding area, which is arranged on the outer side of the shell around the pressure relief channel, and a part of the structure of the pressure relief valve is located in the heat-bonding area.

[0012] In one embodiment, the outer side of the pressure relief valve is flush with the outer sides of the positive electrode bonding portion and the negative electrode bonding portion.

[0013] In one embodiment, the pressure relief valve is a polypropylene pressure relief valve.

[0014] In one of the embodiments, the thickness of the pressure relief valve is 0.1-0.15 mm.

[0015] In one of the embodiments, the pressure relief type laminated battery further includes a positive electrode ear glue, and the positive electrode ear glue wraps a portion of the end surface of the first positive electrode ear.

[0016] In one of the embodiments, a portion of the structure of the positive electrode ear glue is bonded to the positive electrode bonding portion.

[0017] In one of the embodiments, the pressure relief type laminated battery further includes a negative electrode ear glue, and the negative electrode ear glue wraps a portion of the end surface of the negative electrode ear.

[0018] In one embodiment, a portion of the structure of the negative electrode ear glue is bonded to the negative electrode bonding portion.

[0019] A battery module comprises the pressure relief type laminated battery described in any of the above embodiments.

[0020] Compared with the prior art, the present invention has at least the following advantages:

[0021] 1. In the above-mentioned pressure relief type laminated battery, the fuse is arranged at the positive electrode ear, so that it is divided into a first positive electrode ear and a second positive electrode ear. When the battery short circuit causes an abnormal temperature rise, the fuse melts when a predetermined temperature is reached, so that the first positive electrode ear and the second positive electrode ear are disconnected, thereby preventing the temperature from continuing to rise due to the battery short circuit.

[0022] 2. When the battery short circuit causes the temperature to rise abnormally, gas is generated inside the battery, causing the internal air pressure to increase sharply. The gas generated at this time will pass through the pressure relief channel, break through the pressure relief valve and leak to the outside. In this way, the internal gas can be released in time to prevent the internal air pressure of the battery from further rising and causing an explosion and fire. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present disclosure and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0024] Figure 1 This is a schematic structural diagram of a pressure relief type laminated battery in one embodiment;

[0025] Figure 2 for Figure 1 A top view of a pressure relief type laminated battery is shown;

[0026] Figure 3 for Figure 1 A partial structural schematic diagram of a pressure relief type laminated battery is shown.

[0027] Figure numerals: 10, pressure relief type laminated battery; 100, shell; 101, pressure relief channel; 102, hot bonding area; 110, positive electrode bonding part; 120, negative electrode bonding part; 200, positive electrode ear; 210, first positive electrode ear; 220, second positive electrode ear; 300, negative electrode ear; 400, fuse; 500, pressure relief valve; 600, positive electrode ear glue; 700, negative electrode ear glue. DETAILED DESCRIPTION

[0028] In order to facilitate the understanding of the present disclosure, the present disclosure will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present disclosure are given in the drawings. However, the present disclosure can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present disclosure more thoroughly and comprehensively understood.

[0029] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only and do not represent the only implementation method.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present disclosure. The terms used herein in the specification of the present disclosure are only for the purpose of describing specific embodiments and are not intended to limit the present disclosure. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0031] In order to better understand the technical solutions and beneficial effects of the present invention, the present invention is further described in detail below in conjunction with specific embodiments:

[0032] like Figures 1 to 3 As shown, it is a pressure relief type laminated battery 10 according to an embodiment of the utility model, including a battery cell (not shown), a housing 100, a positive electrode ear 200, a negative electrode ear 300, a fuse 400 and a pressure relief valve 500.

[0033] The battery cell is located in the inner cavity of the shell 100, and the battery cell includes a diaphragm, a positive electrode sheet and a negative electrode sheet. There are multiple positive electrode sheets and multiple negative electrode sheets. Each positive electrode sheet is alternately arranged with the adjacent negative electrode sheet through a diaphragm. The extended parts of multiple negative electrode sheets are stacked and connected to the negative electrode ear 300 (not shown in the figure).

[0034] like Figure 3 As shown, the positive electrode ear 200 includes a first positive electrode ear 210 and a second positive electrode ear 220, and the fuse 400 is connected to the first positive electrode ear 210 and the second positive electrode ear 220 respectively, that is, the first positive electrode ear 210, the fuse 400 and the second positive electrode ear 220 are connected in sequence, the fuse 400 and the second positive electrode ear 220 are both located in the inner cavity, and the extended parts of the multiple positive electrode sheets are stacked and connected to the first positive electrode ear 210.

[0035] like Figure 1 As shown, the shell 100 has a positive electrode bonding portion 110 and a negative electrode bonding portion 120, and the shell 100 is also provided with a pressure relief channel 101, which is connected to the inner cavity, and the pressure relief channel 101 is located between the positive electrode bonding portion 110 and the negative electrode bonding portion 120, the positive electrode bonding portion 110 wraps a portion of the end surface of the first positive electrode ear 210, so that a portion of the structure of the first positive electrode ear 210 is located in the inner cavity, and the negative electrode bonding portion 120 wraps a portion of the end surface of the negative electrode ear 300, so that a portion of the structure of the negative electrode ear 300 is located in the inner cavity.

[0036] like Figure 1 and Figure 2 As shown, the pressure relief valve 500 is bonded and sealed to the pressure relief channel 101 , so that when the battery is in thermal runaway, the gas generated in the housing 100 breaks through the pressure relief valve 500 through the pressure relief channel 101 and is released.

[0037] In this embodiment, the fuse 400 is arranged on the positive electrode ear 200, so that it is divided into a first positive electrode ear 210 and a second positive electrode ear 220. When the temperature rises abnormally due to a short circuit of the battery, the fuse 400 melts when a predetermined temperature is reached, so that the first positive electrode ear 210 and the second positive electrode ear 220 are disconnected, thereby preventing the temperature from continuing to rise due to the short circuit of the battery. When the temperature rises abnormally due to a short circuit of the battery, gas is generated inside the battery, causing the internal air pressure to increase sharply. At this time, the gas generated will pass through the pressure relief channel 101, break through the pressure relief valve 500 and leak to the outside, so that the internal gas can be released in time to prevent the internal air pressure of the battery from further rising and causing explosion and fire.

[0038] Furthermore, the melting threshold of the fuse 400 is 110°C. When the battery short circuit causes the temperature to rise abnormally, as long as the temperature exceeds the threshold, the fuse 400 melts, so that the first positive electrode ear 210 and the second positive electrode ear 220 are no longer conductive. However, only providing the fuse 400 cannot solve the problem of timely pressure relief. Therefore, the housing 100 also needs to be provided with a pressure relief channel 101, wherein the pressure relief valve 500 blocks the pressure relief channel 101. Assuming that the maximum air pressure threshold that the pressure relief valve 500 can withstand is about 0.159 MPa, when the battery thermal runaway causes the internal air pressure to increase sharply, if the current air pressure exceeds the maximum air pressure threshold, the gas will break through the pressure relief valve 500 through the pressure relief channel 101 and leak to the outside. Under the joint action of the fuse 400 and the pressure relief valve 500, it is possible to prevent the battery from continuing to work and reduce the possibility of battery explosion and fire.

[0039] In this embodiment, the pressure relief valve 500 is a polypropylene (PP) pressure relief valve. It can be understood that when polypropylene is used as the material, polypropylene has chemical resistance, heat resistance and electrical insulation, and the electrolyte inside the battery is not easy to react with polypropylene, nor is it easy to react with the positive electrode sheet or the negative electrode sheet, and is suitable for making the pressure relief valve 500.

[0040] like Figure 2 As shown, in one embodiment, the housing 100 has a hot-adhesive area 102, which is arranged on the outside of the housing 100 around the pressure relief channel 101, and part of the structure of the pressure relief valve 500 is located in the hot-adhesive area 102. In this embodiment, the hot-adhesive area 102 is located between the positive electrode bonding portion 110 and the negative electrode bonding portion 120. It can be understood that the pressure relief valve 500 heat-seals the pressure relief channel 101, and part of its structure is hot-pressed in the hot-adhesive area 102, so that the pressure relief valve 500 will not be easily detached when the pressure relief channel 101 is blocked, ensuring that the chemical reaction inside the battery is carried out in a closed environment during normal operation.

[0041] Furthermore, combined with Figure 1 and Figure 2As shown, the outer side of the pressure relief valve 500 is flush with the outer sides of the positive electrode bonding portion 110 and the negative electrode bonding portion 120. It can be understood that the outer side of the pressure relief valve 500 is flush with the positive electrode bonding portion 110 and the negative electrode bonding portion 120. In this way, when the pressure relief valve 500 is used, when the pressure relief channel 101 can be blocked, it is not necessary to make the pressure relief valve 500 protrude from the outer horizontal plane of the positive electrode bonding portion 110 and the negative electrode bonding portion 120, which saves the use cost of the pressure relief valve 500 and also makes the flatness of the battery better.

[0042] In one embodiment, the thickness of the pressure relief valve 500 is 0.1-0.15 mm. In this embodiment, the thickness of the pressure relief valve 500 is 0.1 mm, which is relatively thin, so that when the internal gas pressure increases sharply due to thermal runaway of the battery, the gas can break through the pressure relief valve 500 in time and release the pressure, ensuring that the battery will not explode or catch fire.

[0043] like Figure 1 As shown, in one embodiment, the pressure relief type laminated battery 10 further includes a positive electrode ear glue 600, and the positive electrode ear glue 600 wraps a portion of the end surface of the first positive electrode ear 210. It can be understood that when the positive electrode ear glue 600 is wrapped around the end surface of the first positive electrode ear 210, the surface of the first positive electrode ear 210 can be protected, and the positive electrode ear glue 600 has an insulating effect to prevent the first positive electrode ear 210 from contacting the shell 100 in the later process. Further, part of the structure of the positive electrode ear glue 600 is bonded to the positive electrode bonding portion 110. In this embodiment, part of the structure of the positive electrode ear glue 600 is bonded to the positive electrode bonding portion 110, and the rest of the structure is exposed to the outside of the shell 100, so as to further protect the first positive electrode ear 210 and prevent the first positive electrode ear 210 from cutting the shell 100 and causing damage to the surface of the shell 100.

[0044] like Figure 1 As shown, in one embodiment, the pressure relief type laminated battery 10 further includes a negative electrode ear glue 700, and the negative electrode ear glue 700 wraps part of the end surface of the negative electrode ear 300. It can be understood that when the negative electrode ear glue 700 is wrapped around the end surface of the negative electrode ear 300, it can protect the surface of the negative electrode ear 300. At the same time, the negative electrode ear glue 700 has an insulating effect to prevent the negative and positive electrode ears 200 from contacting the outer shell 100 in the later process. Further, part of the structure of the negative electrode ear glue 700 is bonded to the negative electrode bonding portion 120. In this embodiment, part of the structure of the negative electrode ear glue 700 is bonded to the negative electrode bonding portion 120, and the rest of the structure is exposed to the outside of the outer shell 100, so as to further protect the negative electrode ear 300 and prevent the negative electrode ear 300 from cutting the outer shell 100 and causing damage to the surface of the outer shell 100.

[0045] The present disclosure further provides a battery module, comprising the pressure relief type laminated battery 10 of any of the above embodiments.

[0046] Compared with the prior art, the present invention has at least the following advantages:

[0047] 1. In the above-mentioned pressure relief type laminated battery 10, the fuse 400 is arranged on the positive electrode ear 200, so that it is divided into a first positive electrode ear 210 and a second positive electrode ear 220. When the battery short circuit causes an abnormal temperature rise, the fuse 400 melts when a predetermined temperature is reached, so that the first positive electrode ear 210 and the second positive electrode ear 220 are disconnected, thereby preventing the temperature from continuing to rise due to the battery short circuit.

[0048] 2. When the battery short circuit causes the temperature to rise abnormally, gas is generated inside the battery, causing the internal air pressure to increase sharply. The gas generated at this time will pass through the pressure relief channel 101, break through the pressure relief valve 500 and leak to the outside, so that the internal gas can be released in time to prevent the internal air pressure of the battery from further rising and causing explosion and fire.

[0049] The above-mentioned embodiments only express several implementation methods of the present disclosure, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the disclosed patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present disclosure, and these all belong to the protection scope of the present disclosure. Therefore, the protection scope of the disclosed patent shall be subject to the attached claims.

Claims

1. A pressure relief type laminated battery, comprising a battery cell, a shell, a positive electrode ear and a negative electrode ear, wherein the battery cell is located in the inner cavity of the shell, the battery cell comprises a diaphragm, a positive electrode sheet and a negative electrode sheet, the number of the positive electrode sheets and the number of the negative electrode sheets are both multiple, each of the positive electrode sheets is alternately arranged with the adjacent negative electrode sheet through the diaphragm, and the extension parts of the multiple negative electrode sheets are stacked and connected to the negative electrode ear, characterized in that: The pressure relief type laminated battery further includes a fuse and a pressure relief valve, the positive electrode ear includes a first positive electrode ear and a second positive electrode ear, the fuse is connected to the first positive electrode ear and the second positive electrode ear respectively, the fuse and the second positive electrode ear are both located in the inner cavity, and the extension parts of the plurality of positive electrode sheets are stacked and connected to the second positive electrode ear; The shell has a positive electrode bonding portion and a negative electrode bonding portion, and the shell is further provided with a pressure relief channel, the pressure relief channel is communicated with the inner cavity, the positive electrode bonding portion wraps a portion of the end surface of the first positive electrode ear, so that a portion of the structure of the first positive electrode ear is located in the inner cavity, and the negative electrode bonding portion wraps a portion of the end surface of the negative electrode ear, so that a portion of the structure of the negative electrode ear is located in the inner cavity; The pressure relief valve is bonded and sealed to the pressure relief channel, so that when the battery is in thermal runaway, the gas generated in the housing breaks through the pressure relief valve through the pressure relief channel and is released.

2. The pressure relief type laminated battery according to claim 1, characterized in that: The shell has a thermal bonding area, which is arranged on the outer side of the shell around the pressure relief channel, and a part of the structure of the pressure relief valve is located in the thermal bonding area.

3. The pressure relief type laminated battery according to claim 2, characterized in that: The outer side of the pressure relief valve is flush with the outer sides of the positive electrode bonding portion and the negative electrode bonding portion.

4. The pressure relief type laminated battery according to claim 1, characterized in that: The pressure relief valve is a polypropylene pressure relief valve.

5. The pressure relief type laminated battery according to claim 1, characterized in that: The thickness of the pressure relief valve is 0.1-0.15 mm.

6. The pressure relief type laminated battery according to claim 1, characterized in that: The pressure relief type laminated battery further includes a positive electrode ear glue, and the positive electrode ear glue wraps a portion of the end surface of the first positive electrode ear.

7. The pressure relief type laminated battery according to claim 6, characterized in that: Part of the structure of the positive electrode ear glue is bonded to the positive electrode bonding part.

8. The pressure relief type laminated battery according to claim 1, characterized in that: The pressure relief type laminated battery further comprises a negative electrode ear glue, wherein the negative electrode ear glue wraps a part of the end surface of the negative electrode ear.

9. The pressure relief type laminated battery according to claim 8, characterized in that: Part of the structure of the negative electrode ear glue is bonded to the negative electrode bonding part.

10. A battery module, characterized in that: It includes the pressure relief type laminated battery as described in any one of claims 1 to 9.

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