An explosion-proof valve assembly, battery and vehicle

Abstract

The utility model relates to a kind of explosion-proof valve assembly, battery and vehicle, explosion-proof valve assembly includes explosion-proof valve body, explosion-proof valve body is set in the explosion-proof hole of battery top cover, further include: high molecular polymer film, high molecular polymer film covers explosion-proof valve body.The utility model covers explosion-proof valve body by setting high molecular polymer film, not only can avoid explosion-proof valve body and solid such as foreign particles direct contact, explosion-proof valve body and electrolyte, moisture and other liquids direct contact can also be avoided, reduce the risk of corrosion, dirt and other problems of explosion-proof valve, to reduce the risk of explosion-proof valve structure failure.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, and in particular to an explosion-proof valve assembly, a battery, and a vehicle. Background Technology

[0002] As a key component of power batteries, the battery top cover has a significant impact on the energy density, economy, and safety of power batteries. The explosion-proof valve structure of the cover plate is the most important safety protection device for lithium batteries. Its main function is to provide a safe pressure release channel when the internal pressure of the battery rises abnormally, so as to prevent the battery from exploding. In the actual production and use of lithium batteries, it has been found that the explosion-proof valve of lithium batteries often fails due to electrolyte contamination, valve opening, corrosion, etc. These failures often lead to functional loss of the explosion-proof valve structure, making it unable to function properly. Utility Model Content

[0003] To address the aforementioned technical problems, this utility model provides an explosion-proof valve assembly, battery, and vehicle that can reduce the risk of electrochemical corrosion failure of the explosion-proof valve due to direct contact between the explosion-proof valve and liquid.

[0004] In a first aspect, this utility model provides an explosion-proof valve assembly, which includes an explosion-proof valve body disposed in the explosion-proof hole of the battery top cover, and further includes a polymer membrane covering the explosion-proof valve body.

[0005] Optionally, the polymer membrane includes a first polymer membrane and a second polymer membrane; the explosion-proof valve body is disposed between the first polymer membrane and the second polymer membrane.

[0006] Optionally, the edges of both the first and second polymer films are attached to the circumferential edge of the explosion-proof valve body; or, the edge of the first polymer film is attached to the upper surface of the battery top cover to seal one end of the explosion-proof hole, and the edge of the second polymer film is attached to the lower surface of the battery top cover to seal the other end of the explosion-proof hole.

[0007] Optionally, the first polymer membrane is a polytetrafluoroethylene (PTFE) coated film; the thickness of the first polymer membrane is 0.03 mm to 0.4 mm; the porosity of the first polymer membrane is 65% to 80%; the pore size of the first polymer membrane is 0.5 μm to 2 μm; the elastic modulus of the first polymer membrane is 20 MPa to 40 MPa; and the contact angle of the first polymer membrane is greater than 150°.

[0008] Optionally, the second polymer membrane is a polytetrafluoroethylene (PTFE) coated film; the thickness of the second polymer membrane is 0.5 mm-2 mm; the porosity of the second polymer membrane is 80%-90%; the pore size of the second polymer membrane is 1 μm-10 μm; the elastic modulus of the second polymer membrane is 80 MPa-150 MPa; and the contact angle of the second polymer membrane is greater than 150°.

[0009] Optionally, the explosion-proof valve assembly also includes an explosion-proof valve patch; the explosion-proof valve patch is disposed above the first polymer film, and the edge of the explosion-proof valve patch is attached to the edge of the first polymer film.

[0010] Optionally, the explosion-proof valve patch is provided with vent holes, which protrude towards the end away from the battery top cover.

[0011] Optionally, the explosion-proof valve patch is made of polyethylene terephthalate.

[0012] Secondly, this utility model provides a battery, including a battery top cover with an explosion-proof hole; an explosion-proof valve assembly as described in any of the above, wherein the explosion-proof valve assembly is disposed at the explosion-proof hole; and a plastic under the battery top cover, which is connected to the battery top cover.

[0013] Thirdly, this utility model provides a vehicle including the battery described above.

[0014] Compared with the prior art, the above-mentioned technical solution of this utility model has the following advantages: by setting a polymer membrane to cover the explosion-proof valve body, it can not only avoid direct contact between the explosion-proof valve body and solids such as foreign particles, but also avoid direct contact between the explosion-proof valve body and liquids such as electrolytes and water, thereby reducing the risk of corrosion, dirt and other problems of the explosion-proof valve, and thus reducing the risk of explosion-proof valve structural failure. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the overall structure of the explosion-proof valve assembly provided by this utility model;

[0017] Figure 2 This is a bottom view of the overall structure of the explosion-proof valve assembly of this utility model;

[0018] Figure 3 This is a front view of the overall structure of the explosion-proof valve assembly of this utility model;

[0019] Figure 4 This is a top view of the overall structure of the explosion-proof valve assembly of this utility model;

[0020] Figure 5 This is a schematic diagram of the overall structure of the battery of this utility model.

[0021] Explanation of reference numerals on the accompanying drawings:

[0022] Explosion-proof valve body 100, polymer film 200, first polymer film 201, second polymer film 202, explosion-proof valve patch 300, vent hole 301, battery top cover 1, explosion-proof hole 2, explosion-proof valve assembly 3, and plastic under battery top cover 4. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0024] In the description of this utility model, it should be noted that, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," "front end," "rear end," "head," "tail," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0025] In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0026] It should be noted that the technical solutions of the various embodiments can be combined with each other, but only if they are based on the ability of a person skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0027] According to a specific embodiment of this utility model, refer to Figures 1-4 An explosion-proof valve assembly is provided, including: an explosion-proof valve body 100 disposed in the explosion-proof hole 2 of the battery top cover 1; and a polymer membrane 200 covering the explosion-proof valve body 100.

[0028] It should be noted that, as Figure 1 As shown, one end of the battery top cover 1 is provided with a through groove that penetrates the inner and outer walls of the battery top cover 1. This through groove is the explosion-proof hole 2. The shape of the explosion-proof hole 2 is adapted to the shape of the explosion-proof valve body 100. The explosion-proof valve body 100 is fixedly installed in the explosion-proof hole 2 of the battery top cover 1 by welding. The polymer membrane 200 is a semi-permeable membrane with selective permeability made of polymer material. It has a microporous structure and belongs to microporous membranes. It has air permeability and water impermeability.

[0029] Specifically, by covering the explosion-proof valve body 100 with a polymer film 200, it is possible to avoid direct contact between the explosion-proof valve body 100 and solids such as electrode material falling out of the battery cell or foreign particles during the production process. It is also possible to avoid direct contact between the explosion-proof valve body 100 and liquids such as electrolyte and water. This avoids corrosion of the explosion-proof valve body 100 by external corrosive liquids and reduces the risk of electrochemical corrosion of the explosion-proof valve body 100 leading to structural failure.

[0030] In some specific implementations, such as Figure 1 As shown, the polymer membrane 200 includes a first polymer membrane 201 and a second polymer membrane 202; the explosion-proof valve body 100 is disposed between the first polymer membrane 201 and the second polymer membrane 202.

[0031] Specifically, by placing the explosion-proof valve body 100 between the first polymer membrane 201 and the second polymer membrane 202, the polymer membrane 200 can cover the explosion-proof valve body 100, thereby reducing the risk of corrosion, dirt and other problems to the explosion-proof valve body 100.

[0032] In some specific implementations, such as Figure 1As shown, the edges of the first polymer film 201 and the second polymer film 202 are both attached to the circumferential edge of the explosion-proof valve body 100; or, the edge of the first polymer film 201 is attached to the upper surface of the battery top cover 1 to cover one end of the explosion-proof hole 2, and the edge of the second polymer film 202 is attached to the lower surface of the battery top cover 1 to cover the other end of the explosion-proof hole 2.

[0033] Specifically, an adhesive layer is provided on the edge of the first polymer film 201 and the second polymer film 202 near the battery top cover 1. This adhesive layer is used to bond the first polymer film 201 and the second polymer film 202 to the outermost circumferential edge of the explosion-proof valve body 100, respectively, to cover the explosion-proof valve body 100. Alternatively, the adhesive layer is used to bond the edges of the first polymer film 201 and the second polymer film 202 to the upper and lower surfaces of the battery top cover 1, respectively, to seal both ends of the explosion-proof hole 2, ensuring that the explosion-proof hole 2 is only accessible through... The breathable sealing condition achieves the effect of covering the explosion-proof valve body 100. Based on the setting of the first polymer film 201 and the second polymer film 202, it can not only avoid direct contact between the explosion-proof valve body 100 and solids such as electrode material falling out of the battery cell and foreign particles in the production process, but also avoid direct contact between the explosion-proof valve body 100 and liquids such as electrolyte and water. It avoids corrosion of the explosion-proof valve body 100 by corrosive liquids outside the battery cell, and reduces the risk of electrochemical corrosion of the explosion-proof valve body 100 leading to structural failure.

[0034] In some specific embodiments, both the first polymer membrane 201 and the second polymer membrane 202 are polytetrafluoroethylene (PTFE) coated films. Specifically, the first polymer membrane 201 is a PTFE coated film; the thickness of the first polymer membrane 201 is 0.03 mm to 0.4 mm; the porosity of the first polymer membrane 201 is 65% to 80%; the pore size of the first polymer membrane 201 is 0.5 μm to 2 μm; and the elastic modulus of the first polymer membrane 201 is 20 MPa to 40 MPa. MPa; the first polymer membrane 201 has a contact angle greater than 150°; the second polymer membrane 202 is a polytetrafluoroethylene (PTFE) coated film; the thickness of the second polymer membrane 202 is 0.5 mm-2 mm; the porosity of the second polymer membrane 202 is 80%-90%; the pore size of the second polymer membrane 202 is 1 μm-10 μm; the elastic modulus of the second polymer membrane 202 is 80 MPa-150 MPa; the contact angle of the second polymer membrane 202 is greater than 150°.

[0035] Specifically, the polytetrafluoroethylene (PTFE) coated film has excellent waterproof performance. Its micropore size is 1 / 5000-1 / 20000 of the diameter of a water droplet, which can effectively prevent liquid permeation. At the same time, its high porosity and microporous structure allow water vapor molecules to pass through freely, maintaining air permeability. Based on this single filtration structure, it can effectively prevent electrolytes and other liquids from remaining and permeating on the PTFE membrane surface. Furthermore, the performance parameters of the first polymer membrane 201 and the second polymer membrane 202 generally include thickness, porosity, membrane pore size, elastic modulus, and hydrophobicity. Among them, the contact angle is a direct indicator of the hydrophobicity of the material surface, which is measured by the static wetting morphology of droplets on the membrane surface. According to the Young's equation, the larger the contact angle, the stronger the hydrophobicity. The selection range of the performance parameters of the first polymer membrane 201 and the second polymer membrane 202 is shown in Table 1.

[0036] Table 1: Performance parameters of polymer membrane 200.

[0037] Performance parameters First Polymer Film 201 Second polymer membrane 202 Thickness / mm 0.03-0.4 0.5-2 Porosity / % 65-80 80-90 Membrane pore size / μm 0.5-2 1-10 Elastic modulus / MPa 20-40 80-150 Contact angle / ° ＞150 ＞150

[0038] As shown in Table 1, the thickness of the first polymer film 201 is less than the thickness of the second polymer film 202. The thickness of the first polymer film 201 can be selected as any value among 0.03 mm, 0.04 mm, 0.3 mm, 0.4 mm, or 0.03 mm - 0.4 mm. The thickness of the second polymer film 202 can be selected as any value among 0.5 mm, 0.51 mm, 0.6 mm, 2 mm, or 0.5 mm - 2 mm. The porosity of the first polymer membrane 201 is less than or equal to the porosity of the second polymer membrane 202. The porosity of the first polymer membrane 201 can be selected as any other value among 65%, 75%, 80%, or 65%-80%. The porosity of the second polymer membrane 202 can be selected as any other value among 80%, 85%, 90%, or 80%-90%. The elastic modulus of the first polymer membrane 201 is less than the elastic modulus of the second polymer membrane 202. The elastic modulus can be selected as any value among 20 MPa, 25 MPa, 40 MPa, or 20 MPa-40 MPa. The elastic modulus of the second polymer film 202 can be selected as any value among 80 MPa, 100 MPa, 150 MPa, or 80 MPa-150 MPa. The contact angle of the first polymer film 201 and the second polymer film 202 have the same range of values. The contact angle of the first polymer film 201 can be selected as 160°. The contact angle of the second polymer membrane 202 can be selected as 160°, 165°, or any other value greater than 150°, and the pore size of the first polymer membrane 201 can be selected as 0.5μm, 0.6μm, 2μm, or any other value between 0.5μm and 2μm. The pore size of the second polymer membrane 202 can be selected as 1μm, 3μm, 10μm, or any other value between 1μm and 10μm. Based on this, such as Figure 1 As shown, the first polymer membrane 201 is disposed on the outside of the battery top cover 1, making it easier to come into contact with liquids such as electrolyte. Through the above performance parameter settings, compared with the second polymer membrane 202, the first polymer membrane 201 has a better effect in isolating foreign objects. The second polymer membrane 202 is disposed inside the battery top cover 1, and its probability of contact with electrolyte is relatively small. Through the above performance parameter settings, compared with the second polymer membrane 202, the second polymer membrane 202 has better air permeability. In the event of safety risks such as thermal runaway of the battery, the gas can be quickly released through the second polymer membrane 202, thereby improving the safety performance of the battery.

[0039] In some specific implementations, such as Figure 1 , Figure 3 and Figure 4As shown, the explosion-proof valve assembly also includes an explosion-proof valve patch 300; the explosion-proof valve patch 300 is disposed above the first polymer film 201, and the edge of the explosion-proof valve patch 300 is attached to the edge of the first polymer film 201.

[0040] Specifically, an adhesive layer is provided on the circumferential edge of the first polymer film 201 near the explosion-proof valve patch 300. This adhesive layer is used to bond the first polymer film 201 and the explosion-proof valve patch 300. The explosion-proof valve patch 300 can further improve the sealing performance and wear resistance of the explosion-proof valve body 100.

[0041] In some specific embodiments, the explosion-proof valve patch 300 is provided with a vent hole 301, which protrudes towards the end away from the battery top cover 1.

[0042] Specifically, such as Figure 3 As shown, the vent 301 protrudes to the side opposite to the battery top cover 1. The protrusion height and the number of vents 301 can be set according to actual needs and are not limited here. The vents 301 can effectively prevent external liquids (such as electrolytes in the cell production process and external air moisture condensate) from entering the inner cavity of the explosion-proof valve body 100 through the vents 301 of the explosion-proof valve patch 300, reducing the risk of direct contact between liquids and the explosion-proof valve body 100. In addition, when the battery is heated, such as during battery aging or high-temperature baking, the gas expands due to heat and can be vented through the vents 301, so that the internal and external air pressures are basically consistent, avoiding the problem of damage and failure of the explosion-proof valve patch 300 due to excessive pressure difference or excessive airflow, thus improving the safety performance of the battery.

[0043] In some specific embodiments, the explosion-proof valve patch 300 is made of polyethylene terephthalate.

[0044] Specifically, polyethylene terephthalate (PET) has good heat and cold resistance, and its mechanical strength is higher than that of general films. It also has good tensile and impact strength. Since the explosion-proof valve patch 300 is part of the explosion-proof valve body 100, it needs to work in high-pressure and high-temperature environments. The excellent heat resistance and mechanical strength of PET ensure that the explosion-proof valve body 100 can release pressure in time when the pressure is too high, preventing explosion accidents. The chemical stability of PET ensures that it can still work normally in various harsh environments, thereby improving the safety performance of the explosion-proof valve body 100 and reducing maintenance costs.

[0045] According to a specific embodiment of this utility model, refer to Figure 5A battery is provided, including a battery top cover 1 with an explosion-proof hole 2; and an explosion-proof valve assembly 3 as described in the above embodiment, which is disposed at the explosion-proof hole 2; and a plastic 4 under the battery top cover, which is connected to the battery top cover 1. By providing the plastic 4 under the battery top cover, direct contact between the battery top cover 1 and the battery casing is avoided, thereby reducing the risk of battery short circuit.

[0046] Since the battery includes the explosion-proof valve assembly 3 of this utility model, it also has the characteristics of the explosion-proof valve assembly 3 described above. To avoid repetition, it will not be described again here.

[0047] According to a specific embodiment of the present invention, a vehicle is provided, including the battery described above.

[0048] Since the vehicle includes the battery of this invention, it has the same characteristics as the battery, which will not be described again here.

[0049] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention. The scope of the present invention is determined by the scope of the appended claims.

Claims

1. An explosion-proof valve assembly, the explosion-proof valve assembly comprising an explosion-proof valve body (100), the explosion-proof valve body (100) being disposed within an explosion-proof hole (2) of a battery top cover (1), characterized in that, Also includes: A polymer membrane (200) covers the explosion-proof valve body (100), and the polymer membrane (200) includes a first polymer membrane (201) and a second polymer membrane (202). The explosion-proof valve body (100) is disposed between the first polymer membrane (201) and the second polymer membrane (202), and the explosion-proof valve assembly further includes an explosion-proof valve patch (300). The explosion-proof valve patch (300) is disposed above the first polymer film (201), and the edge of the explosion-proof valve patch (300) is attached to the edge of the first polymer film (201).

2. The explosion-proof valve assembly according to claim 1, characterized in that, include: The edges of the first polymer film (201) and the second polymer film (202) are both attached to the circumferential edge of the explosion-proof valve body (100); Alternatively, the edge of the first polymer film (201) is attached to the upper surface of the battery top cover (1) to seal one end of the explosion-proof hole (2), and the edge of the second polymer film (202) is attached to the lower surface of the battery top cover (1) to seal the other end of the explosion-proof hole (2).

3. The explosion-proof valve assembly according to claim 1 or 2, characterized in that, include: The first polymer film (201) is a polytetrafluoroethylene coated film; The thickness of the first polymer film (201) is 0.03 mm to 0.4 mm; The porosity of the first polymer membrane (201) is 65%-80%; The pore size of the first polymer membrane (201) is 0.5 μm-2 μm; The elastic modulus of the first polymer film (201) is 20 MPa-40 MPa; The contact angle of the first polymer film (201) is greater than 150°.

4. The explosion-proof valve assembly according to claim 1 or 2, characterized in that, include: The second polymer film (202) is a polytetrafluoroethylene coated film; The thickness of the second polymer film (202) is 0.5mm-2mm; The porosity of the second polymer membrane (202) is 80%-90%; The pore size of the second polymer membrane (202) is 1μm-10μm; The elastic modulus of the second polymer film (202) is 80 MPa-150 MPa; The contact angle of the second polymer film (202) is greater than 150°.

5. The explosion-proof valve assembly according to claim 1, characterized in that, The explosion-proof valve patch (300) is provided with a vent hole (301), and the vent hole (301) protrudes to the end away from the battery top cover (1).

6. The explosion-proof valve assembly according to claim 1, characterized in that, include: The explosion-proof valve patch (300) is made of polyethylene terephthalate.

7. A battery, characterized in that, include: Battery top cover (1), wherein the battery top cover (1) is provided with explosion-proof holes (2); The explosion-proof valve assembly (3) as described in any one of claims 1-6 is disposed at the explosion-proof hole (2); The lower plastic part (4) of the battery top cover is connected to the battery top cover (1).

8. A vehicle, characterized in that, Includes the battery as described in claim 7.

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