Explosion-proof valve, cover plate structure, battery cell, battery pack and electric device

Abstract

The application provides an explosion-proof valve, a cover plate structure, a battery cell, a battery pack and an electric device. The explosion-proof valve comprises an opening part, a connecting part and a buffer part. The opening part has a to-be-broken part at the edge thereof, and the to-be-broken part extends along the circumference of the opening part; the connecting part surrounds the outer periphery of the opening part; the buffer part is connected between the outer edge of the opening part and the inner edge of the connecting part; the buffer part comprises at least one arching section, and the arching section arches towards one side in the thickness direction of the explosion-proof valve; at least part of the arching section is located on the side away from the center of the opening part; and the at least one arching section has an energy absorption part. In this way, when the connecting part is welded with the cover plate and stress is generated and conducted towards the to-be-broken part, the stress can be absorbed by the arching shape of the arching section and the deformation of the energy absorption part, the stress is prevented from being conducted to the to-be-broken part, the structural strength of the to-be-broken part is affected, and then the reliability of the explosion-proof valve is improved, and the safety performance of the battery cell is improved.

Description

Technical Field

[0001] This application relates to the field of electrical equipment technology, specifically to an explosion-proof valve, a cover structure, a battery cell, a battery pack, and electrical equipment. Background Technology

[0002] A battery is a device that provides power to electrical equipment. A battery cell typically includes a casing, electrode arrays, and a cover structure. The electrode arrays are located inside the casing, and the cover structure seals the casing and provides electrical connection between the electrode arrays and external electrical components. The cover structure includes a cover plate and an explosion-proof valve welded to the cover plate.

[0003] In related technologies, during the production of the cover plate, the stress generated when welding the explosion-proof valve to the cover plate can affect the part of the explosion-proof valve to be disconnected, resulting in a reduction in the structural strength of the part to be disconnected, which in turn reduces the stability of the opening pressure of the explosion-proof valve and affects the safety performance of the battery cell. Utility Model Content

[0004] This application provides an explosion-proof valve, a cover plate structure, a battery cell, a battery pack, and electrical equipment to solve the problem that the stress generated during the welding of the explosion-proof valve and the cover plate affects the structural strength of the part to be disconnected.

[0005] To achieve the above objectives, the embodiments of this application adopt the following technical solutions: In a first aspect, embodiments of this application provide an explosion-proof valve, comprising: an opening portion, a connecting portion, and a buffer portion. The opening portion has a portion to be disconnected at its edge, extending circumferentially along the opening portion; the connecting portion surrounds the outer periphery of the opening portion; the buffer portion connects the outer edge of the opening portion and the inner edge of the connecting portion; the buffer portion includes at least one arched section, the arched section arching towards one side in the thickness direction of the explosion-proof valve; at least a portion of the arched section is located on the side of the portion to be disconnected away from the center of the opening portion; wherein, at least one arched section has an energy-absorbing portion.

[0006] In some possible implementations of the first aspect, there are multiple arched sections, which are arranged along the arrangement direction of the opening and the connecting parts.

[0007] In some possible implementations of the first aspect, the arching directions of any two adjacent arched segments are opposite; and / or, each arched segment has an energy-absorbing section.

[0008] In some possible implementations of the first aspect, the arched section includes: two connecting sections opposite each other along the arrangement direction of the opening and the connecting section, and a straight section connected between the two connecting sections, the straight section having an energy-absorbing part; and / or, the energy-absorbing part being a groove; and / or, the part to be broken being a grooved groove.

[0009] In some possible implementations of the first aspect, the width L1 of the arched section along the arrangement direction of the opening and connecting parts satisfies: 0.5mm≤L1≤5mm; and / or, the dimension L2 of the arched section along the thickness direction of the explosion-proof valve satisfies: 0.45mm≤L2≤1.9mm.

[0010] In some possible implementations of the first aspect, the energy-absorbing part is a groove; wherein the material thickness H of the buffer part satisfies: 0.15mm≤H≤0.4mm; the groove depth h satisfies: 0.2≤h / H≤0.6; and / or, the groove width W satisfies: 0.2mm≤W≤1.0mm.

[0011] In some possible implementations of the first aspect, both the buffer section and the arched section are annular.

[0012] In some possible implementations of the first aspect, the energy-absorbing part is annular.

[0013] Secondly, this application also provides a cover plate structure, which includes: a cover plate and an explosion-proof valve according to any of the aforementioned implementations, the cover plate having an explosion-proof hole; and a connecting part connected to the cover plate to allow the explosion-proof valve to block the explosion-proof hole.

[0014] Thirdly, embodiments of this application also provide a battery cell, comprising: a housing and a cover structure according to any of the foregoing implementations. The housing has an opening. The cover structure is connected to the housing and seals the opening.

[0015] Fourthly, embodiments of this application also provide a battery pack, which includes a casing and battery cells according to any of the foregoing implementations. The battery cells are installed in the casing.

[0016] Fifthly, embodiments of this application also provide an electrical device, which includes an electrical user body and a battery pack according to any of the aforementioned implementations. The battery pack is electrically connected to the electrical user body.

[0017] The explosion-proof valve, cover structure, battery cell, battery pack, and electrical equipment provided in this application have the following beneficial effects: The explosion-proof valve provided in this application has a buffer section between the connecting part and the part to be disconnected, and the buffer section includes at least one arched section. In this way, when the connecting part is welded to the cover plate and stress is generated and transmitted toward the part to be disconnected, the deformation at the arched section and the energy-absorbing part can absorb the stress and prevent the stress from being transmitted to the part to be disconnected and affecting the structural strength of the part to be disconnected. This is beneficial to improving the reliability of the explosion-proof valve and improving the safety performance of the battery cell. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of an electrical device provided for some embodiments of this application.

[0019] Figure 2 for Figure 1 The diagram shows a cross-sectional view of the battery pack of the electrical device.

[0020] Figure 3 for Figure 2 The diagram shows the structural structure of the battery cells in the battery pack.

[0021] Figure 4 for Figure 3 The exploded view of the battery cell shown.

[0022] Figure 5 for Figure 4 The diagram shows a top view of the explosion-proof valve.

[0023] Figure 6 for Figure 5 The explosion-proof valve shown is a cross-sectional view at line AA.

[0024] Figure 7 for Figure 6 A magnified view of the area within box B.

[0025] Figure 8 for Figure 7 A magnified view of the area within box C.

[0026] Explanation of reference numerals in the attached figures: Electrical equipment 1000; battery pack 100; main electrical unit 200; outer casing 20; battery compartment 1001; Battery cell 10; cover structure 1; cover 11; explosion-proof hole 11a; housing 2; pole post 3; cover plate 13; explosion-proof valve 12; opening part 121; disconnection part 1211; connecting part 122; buffer part 123; arched section 1231; energy absorption part 1231a; connecting section 1231b; straight section 1231c. Detailed Implementation

[0027] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0028] In this application, the accompanying drawings are not necessarily drawn to scale, and local features may be enlarged or reduced to more clearly show the details of the local features.

[0029] Unless otherwise stated, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to limit the scope of this application. The term "and / or" as used in this application includes any and all combinations of one or more of the associated listed items. The singular forms "a," "the," and "the" as used in this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0030] In the description of this application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified. In the description of this application, "several" means one or more, unless otherwise explicitly specified.

[0031] In the description of this application, the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "height", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the purpose of simplifying the description of this application and do not indicate that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. In other words, they should not be construed as limitations on this application.

[0032] In the description of this application, unless otherwise expressly defined, the terms "installation," "connection," "linking," "fixing," "setting," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral part; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can also refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0033] In the description of this application, unless otherwise expressly defined, the terms "above," "over," "on top of," "below," "below," "under," or "below" for "first feature over second feature" can refer to the first and second features being in direct contact, or to the first and second features being in indirect contact through an intermediate medium. Furthermore, "above," "below," and "over" for "first feature over second feature" can mean the first feature is directly above or diagonally above the second feature, or simply indicates that the horizontal height of the first feature is higher than the horizontal height of the second feature. Similarly, "below," "below," and "below" for "first feature over second feature" can mean the first feature is directly below or diagonally below the second feature, or simply indicates that the horizontal height of the first feature is lower than the horizontal height of the second feature.

[0034] A battery is a device that provides power to electrical equipment. A battery cell typically includes a casing, electrode arrays, and a cover structure. The electrode arrays are located inside the casing, and the cover structure seals the casing and provides electrical connection between the electrode arrays and external electrical components. The cover structure includes a cover plate and an explosion-proof valve welded to the cover plate.

[0035] It is understandable that stress is generated during the welding of the explosion-proof valve to the cover plate during the production process. This stress often needs to be released. Since the disconnection point of the explosion-proof valve is relatively close to the weld point between the valve and the cover plate, welding stress inevitably gets released to this disconnection point. This disconnection point is the most vulnerable location on the explosion-proof valve to disconnect in the event of thermal runaway in the battery cell. The structural strength of this disconnection point is relatively low compared to other parts of the explosion-proof valve, and the combined effect of welding stress further reduces its structural strength. This, in turn, reduces the stability of the explosion-proof valve's opening pressure, affecting the safety performance of the battery cell.

[0036] To address the aforementioned issues, this application provides a cover plate structure, a battery cell, a battery pack, and an electrical device. By providing a buffer portion between the opening portion and the connecting portion of the explosion-proof valve, which has a portion to be disconnected, the buffer portion is constructed to include at least one arched section, and an energy-absorbing portion is formed on the arched section. On the one hand, the arched shape of the arched section itself can absorb the stress generated during the welding of the connecting portion and the cover plate. On the other hand, the energy-absorbing portion on the arched section can further absorb the stress generated during the welding of the connecting portion and the cover plate, thereby preventing the stress generated during the welding of the connecting portion and the cover plate from being transmitted to the portion to be disconnected and affecting the structural strength of the portion to be disconnected, which is beneficial to improving the stability of the opening pressure of the explosion-proof valve.

[0037] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings.

[0038] Please see Figure 1 , Figure 1 This is a schematic diagram of an electrical device 1000 provided in some embodiments of this application. Figure 1 In the illustrated embodiment, an electric vehicle is used as an example of the electrical device 1000 for illustrative purposes, which should not be construed as a specific limitation of this application. In other embodiments, the electrical device may also be a mobile phone, a laptop computer, a mobile charging station, or other similar devices.

[0039] Please continue reading. Figure 1 The electrical device 1000 includes a power-consuming body 200 and a battery pack 100. The battery pack 100 is fixed to the power-consuming body 200 and electrically connected to the power-consuming components of the power-consuming body 200 to supply power to the power-consuming components of the power-consuming body 200. Specifically, the electrical device 1000 may have a battery compartment 1001, and the battery pack 100 is fixed inside the battery compartment 1001.

[0040] Please see Figure 2 , Figure 2 for Figure 1 A cross-sectional structural diagram of the battery pack 100 of the electrical device 1000 shown.

[0041] The battery pack 100 may include a housing 20 and at least one battery cell 10. The battery cell 10 is electrically connected to the aforementioned power-consuming body 200. The battery cell 10 is fixed inside the housing 20, which protects the battery cell 10 from external forces causing vibration and impact that could damage it. The housing 20 may be a metal housing or a plastic housing.

[0042] Cell 10 is the most basic electrochemical unit, capable of storing and releasing electrical energy. Cell 10 can be a lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, nickel-cadmium battery, lead-acid battery, etc., and this application embodiment does not limit it to this.

[0043] Figure 2 In the battery pack 100 shown, there are multiple battery cells 10. These multiple battery cells 10 can be electrically connected in series, in parallel, or in a mixed configuration. A mixed configuration means that the multiple battery cells 10 are connected in both series and parallel relationships, which can be specifically designed according to the power requirements of the electrical device 1000. In some other embodiments, the battery pack 100 may contain only one battery cell 10.

[0044] Please refer to the following: Figure 3 and Figure 4 , Figure 3 for Figure 2 A schematic diagram of the structure of the battery cell 10 in the battery pack 100 shown; Figure 4 for Figure 3The exploded view of the battery cell 10 shown; the battery cell 10 includes a housing 2, an electrode group (not shown in the figure), a cover plate structure 1, and a terminal post 3.

[0045] The housing 2 has a receiving cavity (not shown in the figure) and an opening communicating with the receiving cavity. The receiving cavity is used to receive the electrode assembly and electrolyte, and the opening is used to place the electrode assembly inside the receiving cavity.

[0046] Figure 3 In the illustrated embodiment, the housing 2 can be a rigid component, and the housing 2 can be generally rectangular in shape so that the battery cell 10 is generally rectangular in shape. The housing 2 can be a metal housing.

[0047] In some examples, the housing 2 can be an aluminum alloy housing to make it lighter, which is beneficial for the weight reduction of the battery cell 10, and thus for the overall weight reduction of the electrical equipment 1000. In other examples, the housing 2 can also be a stainless steel housing to make it stronger, which in turn gives the battery cell 10 better overall strength and stronger resistance to puncture and vibration damage. In still other embodiments, the housing 2 can also be a flexible component.

[0048] The electrode assembly is disposed within a receiving cavity and immersed in an electrolyte. The electrode assembly includes a positive electrode (not shown), a negative electrode (not shown), and a separator (not shown). The positive electrode can be formed from a positive current collector and a positive active material coated on the current collector. In some examples, the positive current collector can be aluminum foil, and the positive active material can be lithium cobalt oxide (LCO), ternary materials (NCM / NCA), lithium iron phosphate (LFP), etc. Based on this, the electrode assembly also includes a positive electrode tab (not shown), which is connected to the positive electrode and electrically conductive. Specifically, the positive electrode tab can be fixed to the positive current collector by welding or integrally formed with the positive current collector.

[0049] The negative electrode sheet can be formed from a negative current collector and a negative active material coated on the negative current collector. In some examples, the negative current collector can be copper foil, and the negative active material can be graphite, silicon-carbon composite material, etc. Based on this, the electrode assembly also includes a negative electrode tab (not shown in the figure), which is connected to the negative electrode sheet and is electrically conductive. The negative electrode tab and the positive electrode tab are used to electrically connect the electrode assembly to the circuit. Specifically, the negative electrode tab can be fixed to the negative current collector by welding, or it can be integrally formed with the negative current collector.

[0050] A separator is placed between the positive and negative electrode plates to isolate them and prevent short circuits. The separator can be made of porous polyethylene (PE) or polypropylene (PP), etc.

[0051] Please continue reading. Figures 3-5The cover structure 1 includes a cover plate 11, an explosion-proof valve 12, and a cover plate 13.

[0052] The cover plate 11 is connected to the housing 2 and seals the opening to protect the electrode assembly and prevent electrolyte leakage. Figure 3 and Figure 4 In the illustrated embodiment, the cover plate 11 is generally rectangular flat. In other embodiments, the cover plate 11 may also be circular, triangular, or other shapes.

[0053] The electrode post 3 is disposed on the cover plate 11. Specifically, the cover plate 11 may have an electrode post hole (not shown in the figure). The electrode post 3 may pass through the electrode post hole and be fixed to the cover plate 11. Figure 3 In the embodiment shown, there are two poles 3, which are arranged along the length of the cover plate 11. The aforementioned positive electrode tab is electrically connected to one pole 3, and the aforementioned negative electrode tab is electrically connected to the other pole 3.

[0054] The cover plate 11 can be a metal structural component, connected to the housing 2 by welding, bonding, or snap-fitting. In some examples, the cover plate 11 can be an aluminum alloy structural component, which is beneficial for the weight reduction of the battery cell 10 and the electrical equipment 1000. In other examples, the cover plate 11 can be a stainless steel component, so that the cover plate 11 has high strength, and thus the battery cell 10 has high strength.

[0055] The cover plate 11 has an explosion-proof hole 11a extending through the cover plate 11 along its thickness direction. The explosion-proof valve 12 is adapted to the shape of the explosion-proof hole 11a, and is connected to the cover plate 11, thus blocking the explosion-proof hole 11a.

[0056] In some embodiments, the inner wall of the explosion-proof hole 11a may be stepped. The dimension of the end of the explosion-proof hole 11a facing the inside of the housing 2 is larger than the dimension of the end of the explosion-proof hole 11a facing the outside of the housing 2. The explosion-proof valve 12 is disposed at the stepped surface of the explosion-proof hole 11a of the cover plate 11 and seals the explosion-proof hole 11a.

[0057] The explosion-proof valve 12 can be a metal structural component. For example, the explosion-proof valve 12 can be an aluminum alloy structural component (such as a manganese-aluminum alloy component), which is beneficial for the weight reduction of the battery cell 10 and the electrical equipment 1000. Alternatively, the explosion-proof valve 12 can also be a stainless steel structural component, so that the explosion-proof valve 12 has higher strength, which in turn makes the battery cell 10 have higher strength.

[0058] In some embodiments, the explosion-proof hole 11a may also be formed in the housing 2. In this case, the explosion-proof valve 12 may also be connected to the housing 2 to block the explosion-proof hole 11a. This application does not limit this.

[0059] The cover plate 13 is attached to the outer surface of the cover plate 11 by adhesive backing and is located on the side of the explosion-proof valve 12 away from the center of the housing 2, to block at least a portion of the explosion-proof hole 11a. This prevents external moisture, dust, and other impurities from entering the battery cell 10 through the explosion-proof hole 11a and the explosion-proof valve 12, thus affecting the operational stability of the battery cell 10. The cover plate 13 can be made of plastic (such as PET, PC, or PE), which can reduce the weight of the battery cell 10. In addition, plastic parts have poor electrical conductivity. Therefore, when the battery cell 10 experiences thermal runaway and the thermal runaway gas pushes open the cover plate 13, the plastic cover plate 13 will not cause a short circuit inside the battery cell 10 or between the battery cell and other battery cells, thereby improving the safety performance of the battery cell 10.

[0060] It is understandable that the shape of the cover plate 13 is not completely compatible with the explosion-proof hole 11a. Therefore, when the cover plate 13 is placed on the side of the explosion-proof valve 12 away from the center of the housing 2, a certain gap will be defined between the cover plate 11 and the cover plate 13 along the direction of the center of the cover plate 13 and the outer edge of the cover plate 13. This allows the cover plate 13 to play a certain role in dust prevention and avoids the cover plate 13 from excessively increasing the opening pressure of the explosion-proof valve 12, which would affect the stability of the opening of the explosion-proof valve 12.

[0061] Please refer to the following: Figures 5-8 , Figure 5 for Figure 4 The top view of the explosion-proof valve shown; Figure 6 for Figure 5 The explosion-proof valve shown is a cross-sectional view at line AA. Figure 7 for Figure 6 A magnified view of the area within box B in the image; Figure 8 for Figure 7 A magnified view of a portion of box C in the image. The explosion-proof valve 12 includes an opening part 121, a connecting part 122, and a buffer part 123.

[0062] The opening portion 121 has a part to be broken 1211 at its edge, and the part to be broken 1211 extends circumferentially along the opening portion.

[0063] Specifically, the edge of the opening portion 121 refers to the position of the opening portion 121 away from the center. For example, the line formed by the midpoint of the line connecting the center of the opening portion 121 and all the points on the outer edge of the opening portion 121 is defined as the baseline, and the part of the opening portion 121 located on the baseline away from the center of the opening portion 121 is the edge of the opening portion 121.

[0064] In some embodiments, the part to be disconnected 1211 is a groove.

[0065] The portion to be disconnected 1211 can be a closed loop extending circumferentially along the opening portion 121, or an open loop. The portions to be disconnected 1211 can also be multiple portions spaced apart circumferentially along the opening portion 121. Figure 5 In the specific example shown, the part to be disconnected 1211 is an open ring extending circumferentially along the opening part 121.

[0066] The connecting portion 122 surrounds the outer periphery of the opening portion 121. The connecting portion 122 is connected to the cover plate 11. For example, the connecting portion 122 is fixedly connected to the cover plate 11 by welding. For example, the connecting portion 122 is spaced apart from the opening portion 121.

[0067] A buffer portion 123 is connected between the outer edge of the opening portion 121 and the inner edge of the connecting portion 122. The buffer portion 123 includes at least one arched section 1231. The arched section 1231 arches towards one side of the explosion-proof valve 12 in the thickness direction. The thickness direction of the explosion-proof valve 12 can be found in [reference needed]. Figure 4 and Figure 6 The Z direction is shown. At least a portion of the arched section 1231 is located on the side of the part to be disconnected 1211 away from the center of the opening part 121.

[0068] The buffer portion 123 can be a closed loop extending circumferentially along the opening portion 121, or an open loop. The buffer portion 123 can also be a plurality of portions spaced apart circumferentially along the opening portion 121.

[0069] In some examples, the arched section 1231 may correspond to the part to be broken 1211 and be disposed on the side of the part to be broken 1211 away from the center of the opening part 121. In other examples, such as Figure 5 As shown, the arched section 1231 can be arranged around the opening portion 121, that is, the arched section 1231 is annular. In this case, the buffer portion 123 can also be arranged around the opening portion 121, that is, the buffer portion 123 is annular.

[0070] It is understandable that stress is generated during the welding of the connecting part 122 and the cover plate 11, and this stress often needs to be released. Since the disconnectable part 1211 of the explosion-proof valve 12 is relatively close to the weld point between the explosion-proof valve 12 and the cover plate 11, welding stress will inevitably be released onto the disconnectable part 1211. The disconnectable part 12111 is the most likely point on the explosion-proof valve 12 to disconnect in the event of thermal runaway of the battery cell 10. The structural strength of the disconnectable part 1211 itself is relatively low compared to other parts of the explosion-proof valve 12. Combined with the effect of welding stress, the structural strength of the disconnectable part 1211 is reduced, which in turn reduces the stability of the opening pressure of the explosion-proof valve 12, affecting the safety performance of the battery cell 10. Therefore, a buffer portion 123 is provided between the connecting portion 122 and the portion to be disconnected 1211, and the buffer portion 123 includes at least one arched section 1231. In this case, when the connecting portion 122 is welded to the cover plate 11 and stress is generated and transmitted toward the portion to be disconnected 1211, the arched shape of the arched section 1231 itself and a certain degree of deformation can absorb the stress and prevent the stress from being transmitted to the portion to be disconnected 1211 and affecting the structural strength of the portion to be disconnected 1211. This is beneficial to improving the reliability of the explosion-proof valve 12 and improving the safety performance of the battery cell.

[0071] In some embodiments, see Figure 7 and Figure 8 At least one arched section 1231 has an energy-absorbing portion 1231a. For example, the energy-absorbing portion 1231a can be a groove. Thus, when the arched section 1231 deforms under welding stress, the groove can provide a certain deformation space for the arched section 1231, which is more conducive to the deformation of the arched section 1231, can increase the deformation amplitude of the arched section 1231, enhance the stress absorption effect of the buffer portion 123, prevent the stress from being transmitted to the part to be disconnected 1211, further improve the reliability of the explosion-proof valve 12, and improve the safety performance of the battery cell. For example, the energy-absorbing portion 1231a is annular.

[0072] In some embodiments, the arched section 1231 has a first surface and a second surface arranged along the thickness direction of the explosion-proof valve 12, and the first surface and / or the second surface of the arched section 1231 has an energy-absorbing portion 1231a.

[0073] In some embodiments, the energy-absorbing portion 1231a may also be a filler disposed in the arched section 1231. For example, the energy-absorbing portion 1231a may be a rubber part or an elastic plastic part, which is not limited in this application.

[0074] In some embodiments, see Figure 6 and Figure 7There are multiple arched sections 1231, which are arranged along the direction of the opening part 121 and the connecting part 122. In this way, when the connecting part 122 is welded to the cover plate 11 and stress is generated and transmitted towards the part to be disconnected 1211, the multiple arched sections 1231 can absorb energy through deformation, thereby further improving the buffering effect of the buffer part 123 on the stress, improving the reliability of the explosion-proof valve 12, and improving the safety performance of the battery cell.

[0075] In some embodiments, see Figures 6-8 Each arched section 1231 has an energy-absorbing part 1231a. Thus, when the welding stress is large, the energy-absorbing parts 1231a in multiple arched sections 1231 can undergo a large deformation to absorb the welding stress, thereby further improving the buffering effect of the buffer part 123 on the stress and improving the reliability of the explosion-proof valve 12.

[0076] In some embodiments, see Figure 6 and Figure 7 The arching directions of any two adjacent arched sections 1231 are opposite. This allows the buffer section 123 to be roughly wavy, which helps to improve the smoothness and structural strength of the buffer section 123, thereby improving the buffering effect of the buffer section 123 against force.

[0077] In some embodiments, see Figure 7 The arched section 1231 includes two connecting sections 1231b opposite each other along the arrangement direction of the opening portion 121 and the connecting portion 122, and a straight section 1231c connected between the two connecting sections 1231b. The straight section 1231c has an energy-absorbing portion 1231a. It is understood that, compared with a curved surface, the straight surface of the straight section 1231c is more convenient to form the energy-absorbing portion 1231a by means of cutting or die casting, without affecting the energy absorption effect of the arched section 1231, thereby reducing the production cost of the explosion-proof valve 12 and improving the production efficiency of the explosion-proof valve 12.

[0078] In some embodiments, the connection between the connecting segment 1231b and the straight segment 1231c is rounded, and the radius r of the arc satisfies: 0.2mm ≤ r ≤ 1mm. For example, the radius r of the arc is 0.2mm, 0.4mm, 0.6mm, 0.8mm, or 1mm. It is understood that the rounded transition at the connection between the connecting segment 1231b and the straight segment 1231c can distribute the welding stress more evenly throughout the arched segment 1231, thereby improving the buffering effect of the arched segment 1231 on welding stress.

[0079] In some embodiments, see Figure 7The width L1 of the arched section 1231 along the arrangement direction of the opening portion 121 and the connecting portion satisfies: 0.5mm≤L1≤5mm. For example, the width L1 of the arched section 1231 along the arrangement direction of the opening portion 121 and the connecting portion is: 0.5mm, 1mm, 2mm, 3mm or 5mm.

[0080] Understandably, if L1 < 0.5 mm, the width L1 of the arched section 1231 is too small, which will reduce the deformation capacity of the arched section 1231 and thus reduce its buffering effect on welding stress. If L1 > 5 mm, the width L1 of the arched section 1231 is too large, which will cause the arched section 1231 to occupy a large size in the explosion-proof valve 12. Without changing the overall size of the explosion-proof valve 12, this will easily lead to a reduction in the size of the opening part 121, which will reduce the opening area of ​​the explosion-proof valve 12 in the event of thermal runaway of the battery cell 10, thereby affecting the explosion-proof performance of the explosion-proof valve 12.

[0081] Therefore, when the width L1 of the arched section 1231 along the arrangement direction of the opening part 121 and the connecting part satisfies 0.5mm≤L1≤5mm, it is beneficial to improve the buffering effect of the arched section 1231 on welding stress and can ensure that the explosion-proof performance of the explosion-proof valve is not affected.

[0082] In some embodiments, see Figure 7 The dimension L2 of the arched section 1231 along the thickness direction of the explosion-proof valve 12 satisfies: 0.45mm≤L2≤1.9mm. For example, the dimension L2 of the arched section 1231 along the thickness direction of the explosion-proof valve 12 is: 0.45mm, 0.7mm, 1mm, 1.45mm or 1.9mm.

[0083] Understandably, if L2 < 0.45 mm, the size L2 of the arched section 1231 is too small, which will reduce the deformation capacity of the arched section 1231 and thus reduce its buffering effect on welding stress. If L2 > 1.9 mm, the size L2 of the arched section 1231 is too large, which will cause interference between the arched section 1231 and other components in the battery cell 10, thereby increasing the size and weight of the battery cell 10.

[0084] Therefore, when the dimension L2 of the arched section 1231 along the thickness direction of the explosion-proof valve 12 satisfies: 0.45mm≤L2≤1.9mm, it is beneficial to improve the buffering effect of the arched section 1231 on welding stress and can avoid interference with other components in the battery cell 10 due to the excessive size of the arched section 1231.

[0085] In some embodiments, see Figure 7 and Figure 8The energy-absorbing part 1231a is a groove. The material thickness H of the buffer part satisfies: 0.15mm≤H≤0.4mm; for example, the material thickness H of the buffer part is: 0.15mm, 0.2mm, 0.25mm, 0.3mm or 0.4mm.

[0086] The thickness U of the part to be broken 1211 satisfies: 0.04mm≤U≤0.15mm; for example, the thickness U of the part to be broken 1211 is: 0.04mm, 0.08mm, 0.12mm or 0.15mm.

[0087] The depth h of the groove satisfies: 0.2≤h / H≤0.6; for example, the ratio of h to H is 0.2, 0.3, 0.4, 0.5 or 0.6.

[0088] Understandably, if the ratio of the groove depth h to the buffer thickness H is less than 0.2, the groove depth h is too small relative to the buffer thickness H, which reduces the deformation capacity of the energy-absorbing part 1231a and thus reduces the buffering effect of the arched section 1231 on welding stress. If the ratio of the groove depth h to the buffer thickness H is greater than 0.6, the groove depth h is too large relative to the buffer thickness H, i.e., the material thickness of the energy-absorbing part 1231a is too small (e.g., it may be smaller than the material thickness U of the part to be disconnected 1211), the explosion-proof valve 12 may disconnect at the energy-absorbing part 1231a during welding instead of at the part to be disconnected 1211, resulting in reduced stability of the opening pressure of the explosion-proof valve and affecting the safety performance of the battery cell.

[0089] Therefore, when the ratio of the groove depth h to the buffer thickness H satisfies: 0.2≤h / H≤0.6, it is beneficial to improve the buffering effect of the arched section 1231 on welding stress, and can prevent the explosion-proof valve 12 from disconnecting at the energy absorption section 1231a during welding, thereby improving the safety performance of the battery cell 10.

[0090] In some embodiments, see Figure 7 and Figure 8 The groove width W satisfies the following condition: 0.2mm ≤ W ≤ 1.0mm. For example, the groove width W can be 0.2mm, 0.4mm, 0.6mm, 0.8mm, or 1mm.

[0091] Understandably, if W < 0.2 mm, the groove width W is too small, which will reduce the deformation capacity of the energy-absorbing part 1231a, thereby reducing the buffering effect of the arched section 1231 on welding stress. If W > 1 mm, it may affect the structural strength of the arched section.

[0092] Therefore, when the groove width W satisfies: 0.2mm≤W≤1.0mm, it is beneficial to improve the buffering effect of the arched section 1231 on welding stress and to ensure the structural strength of the arched section.

[0093] It is understood that in the various embodiments of this application, the sequence number of each process does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0094] It is understood that the various implementation methods described in this application can be implemented individually or in combination, and the embodiments of this application are not limited in this respect.

[0095] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the aforementioned method implementations, and will not be repeated here.

[0096] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An explosion-proof valve, characterized in that, include: An opening portion, wherein the edge of the opening portion has a portion to be disconnected, the portion to be disconnected extending circumferentially along the opening portion; A connecting portion, the connecting portion surrounding the outer periphery of the opening portion; A buffer section is connected between the outer edge of the opening section and the inner edge of the connecting section; the buffer section includes at least one arched section that arches toward one side of the explosion-proof valve in the thickness direction; at least a portion of the arched section is located on the side of the part to be disconnected away from the center of the opening section; At least one of the arched sections has an energy-absorbing section.

2. The explosion-proof valve according to claim 1, characterized in that, The arched sections are multiple, and the multiple arched sections are arranged along the arrangement direction of the opening part and the connecting part.

3. The explosion-proof valve according to claim 2, characterized in that, Any two adjacent arched segments have opposite arching directions; and / or, Each of the arched sections has the energy-absorbing section.

4. The explosion-proof valve according to claim 1, characterized in that, The arched section includes: two connecting sections opposite each other along the arrangement direction of the opening and the connecting section, and a straight section connecting the two connecting sections, the straight section having the energy-absorbing portion; and / or, The energy-absorbing part is a groove; and / or, The part to be broken is a groove.

5. The explosion-proof valve according to claim 1, characterized in that, The width L1 of the arched section along the arrangement direction of the opening and the connecting portion satisfies: 0.5mm ≤ L1 ≤ 5mm; and / or, The dimension L2 of the arched section along the thickness direction of the explosion-proof valve satisfies: 0.45mm ≤ L2 ≤ 1.9mm; and / or, The energy-absorbing part is a groove; the material thickness H of the buffer part satisfies: 0.15mm ≤ H ≤ 0.4mm; the depth h of the groove satisfies: 0.2 ≤ h / H ≤ 0.6; and / or, The energy-absorbing part is a groove; the groove width W satisfies: 0.2mm≤W≤1.0mm.

6. The explosion-proof valve according to claim 1, characterized in that, Both the buffer section and the arched section are annular; or... The buffer section and the arched section are both annular, and the energy-absorbing section is also annular.

7. A cover plate structure, characterized in that, The cover plate structure includes: A cover plate having explosion-proof holes; and An explosion-proof valve, wherein the explosion-proof valve is any one of claims 1-6; the connecting part is connected to the cover plate so that the explosion-proof valve blocks the explosion-proof hole.

8. A battery cell, characterized in that, include: A housing having an opening; A cover plate structure, wherein the cover plate structure is the cover plate structure according to claim 7, the cover plate structure is connected to the housing and seals the opening.

9. A battery pack, characterized in that, include: shell; and The battery cell is the battery cell according to claim 8, and the battery cell is installed inside the housing.

10. An electrical appliance, characterized in that, include: Electricity-consuming entities; as well as The battery pack is the battery pack according to claim 9, and the battery pack is electrically connected to the power-consuming body.

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