Battery monomer, battery device and power utilization device

Abstract

The embodiment of the utility model provides a battery monomer, a battery device and a power utilization device. The battery cell includes: a housing; an electrode assembly; the pressure relief mechanism is arranged on a first wall of the shell, and the first wall is parallel to the thickness direction of the battery monomers; wherein an anti-explosion sheet of the pressure relief mechanism comprises a plurality of nicks, the plurality of nicks comprise a plurality of first nick parts, and the plurality of first nick parts extend in the direction perpendicular to the thickness direction of a battery monomer; the residual thickness of the first nick parts is larger than that of the pressure relief nicks and smaller than the thickness of the anti-explosion piece. According to the application, the plurality of nicks are arranged on the anti-explosion sheet of the pressure relief mechanism, so that the stress applied to the pressure relief mechanism in the expansion process of the single battery in daily work can be shared, the anti-explosion sheet of the pressure relief mechanism is prevented from being broken at the pressure relief nicks, and the use safety of the single battery is improved.

Description

Technical Field

[0001] This application relates to the field of batteries, and more specifically, to a battery cell, a battery device, and an electrical device. Background Technology

[0002] During the use of battery devices, individual battery cells expand during daily operation. This expansion applies stress to the pressure relief mechanism, causing it to stretch. During this stretching process, the explosion-proof plate of the pressure relief mechanism is prone to cracking at the pressure relief groove, affecting the normal operation of the battery cells. Utility Model Content

[0003] This application provides a battery cell, a battery device, and an electrical device. By designing multiple grooves with a thickness greater than the pressure relief groove on the explosion-proof plate of the battery cell pressure relief mechanism, the stress concentration at the pressure relief groove can be reduced, the problem of cracking of the pressure relief mechanism during daily use of the battery cell can be improved, and the pressure relief groove can be normally destroyed when the battery cell needs to create a discharge channel due to thermal runaway.

[0004] In a first aspect, a battery cell is provided, including a housing having a receiving space; an electrode assembly housed within the receiving space; and a pressure relief mechanism disposed on a first wall of the housing, the first wall being parallel to the thickness direction of the battery cell. The pressure relief mechanism includes an explosion-proof plate comprising multiple grooves, each groove including multiple first groove portions extending perpendicular to the thickness direction of the battery cell. The explosion-proof plate also includes pressure relief grooves disposed along its edge, the pressure relief grooves being destroyed in the event of thermal runaway of the battery cell to form an opening or channel for releasing internal pressure or temperature within the battery cell. The residual thickness of the multiple first groove portions is greater than the residual thickness of the pressure relief grooves but less than the thickness of the explosion-proof plate.

[0005] In this embodiment, by providing multiple grooves on the explosion-proof plate of the pressure relief mechanism, the stress exerted on the pressure relief mechanism during the daily expansion of the battery cell can be distributed, thereby preventing the explosion-proof plate of the pressure relief mechanism from cracking at the pressure relief grooves and improving the safety of the battery cell in daily use. The multiple grooves include multiple first grooves extending perpendicular to the thickness direction of the battery cell. When the pressure relief mechanism is located on the first wall of the outer casing parallel to the thickness direction of the battery cell, it can distribute the main stress source of the pressure relief mechanism, i.e., the stress parallel to the thickness direction of the battery cell, to a greater extent, thus enhancing the stress distribution effect. By setting the residual thickness of the multiple first grooves to be greater than the residual thickness of the pressure relief grooves but less than the thickness of the explosion-proof plate, the pressure relief grooves can be destroyed normally in the event of thermal runaway of the battery cell, rather than multiple grooves being destroyed. This provides sufficient space for the battery cell to release internal pressure or temperature during thermal runaway, improving the battery cell's emergency response capability for thermal runaway.

[0006] In some embodiments of the first aspect, multiple first grooves are arranged along the thickness direction of the battery cell.

[0007] In this embodiment, by arranging multiple first notches along the thickness direction of the battery cell, the arrangement density of the first notches in the thickness direction of the battery cell can be increased, thereby enhancing the stress distribution effect of the multiple first notches in the thickness direction of the battery cell.

[0008] In some embodiments of the first aspect, the distance L between any two adjacent first groove portions among the plurality of first groove portions is greater than or equal to 2 mm.

[0009] In this embodiment of the application, by setting the distance L between any two adjacent first grooves in the plurality of first grooves to be greater than or equal to 2 mm, the plurality of first grooves can be prevented from being too concentrated in a local area and too dispersed in other areas, thereby improving the uniformity of the distribution of the plurality of first grooves, so that the plurality of first grooves can distribute stress more evenly and enhance the stress distribution effect of the plurality of first grooves.

[0010] In some embodiments of the first aspect, the plurality of first notches include at least five first notches.

[0011] In this embodiment of the application, by providing at least 5 first notches on the explosion-proof sheet, the arrangement density of the first notches in the thickness direction of the battery cell can be increased, thereby enhancing the stress distribution effect of the multiple first notches in the thickness direction of the battery cell.

[0012] In some embodiments of the first aspect, the plurality of grooves further include a plurality of second groove portions extending along the thickness direction of the battery cell.

[0013] In this embodiment, by providing multiple second grooves extending along the thickness direction of the battery cell, the stress perpendicular to the thickness direction of the battery cell can also be distributed to a certain extent, thereby more comprehensively distributing the stress applied to the pressure relief mechanism during the daily working expansion of the battery cell.

[0014] In some embodiments of the first aspect, each of the plurality of second groove portions is an arc-shaped groove connecting the same ends of two first groove portions.

[0015] In this embodiment, by connecting the same ends of the two first notches with arc-shaped second notches, the second notches can fit more closely with the arc-shaped edge of the explosion-proof sheet, thereby enhancing the stress distribution effect in the direction perpendicular to the thickness of the battery cell, and thus comprehensively improving the stress distribution effect of the multiple notches on the pressure relief mechanism applied by the battery cell.

[0016] In some embodiments of the first aspect, the first wall is the wall of the outer shell located at the bottom along the direction of gravity.

[0017] In this embodiment, since the electrode assembly is located closer to the bottommost wall of the casing along the direction of gravity within the housing space of the battery cell, the stress exerted on the bottommost wall of the casing along the direction of gravity is more significant when the battery cell expands. Defining the bottommost wall of the casing along the direction of gravity as the first wall and providing a pressure relief mechanism on the first wall can more significantly demonstrate the stress-distributing effect of the multiple grooves on the pressure relief mechanism exerted by the battery cell.

[0018] In some embodiments of the first aspect, the pressure relief mechanism is connected to the first wall by laser welding.

[0019] In this embodiment, laser welding is used to connect the pressure relief mechanism and the first wall, which can increase the tightness and sealing of the connection between the pressure relief mechanism and the first wall, improve the mechanical strength of the pressure relief mechanism connected to the first wall, and reduce the deformation or even damage to the pressure relief mechanism caused by the stress applied to the pressure relief mechanism during the daily working expansion of the battery cell.

[0020] In some embodiments of the first aspect, the pressure relief mechanism is made of aluminum alloy, stainless steel, or plastic.

[0021] In the embodiments of this application, aluminum alloy, stainless steel or plastic are selected as the material of the pressure relief mechanism, which can make the pressure relief mechanism have both strong mechanical strength and good ductility, so that it will not be easily torn and damaged when subjected to stress during the expansion of the battery cell, that is, improve the stress resistance of the pressure relief mechanism during the daily operation of the battery cell.

[0022] In a second aspect, a battery device is provided, comprising a battery cell as described in any one of the embodiments of the first aspect.

[0023] Thirdly, an electrical device is provided, comprising a plurality of battery cells as described in any one embodiment of the first aspect, or a plurality of battery devices as described in the second aspect, wherein the battery cells or battery devices are used to provide electrical energy. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the vehicle structure provided in an embodiment of this application.

[0025] Figure 2 This is an exploded view of the battery device provided in an embodiment of this application.

[0026] Figure 3 The images provided are exploded views of the battery cell structure and enlarged views of the pressure relief mechanism in the battery cell, which are provided in the embodiments of this application.

[0027] Figure 4 This is a cross-sectional view of the pressure relief mechanism provided in an embodiment of this application.

[0028] Figure 5 This is a schematic diagram of the explosion-proof sheet provided in an embodiment of this application.

[0029] Figure 6 This is another schematic diagram of the explosion-proof sheet provided in the embodiments of this application.

[0030] Figure 7 This is another schematic diagram of the explosion-proof sheet provided in the embodiments of this application.

[0031] Figure 8 This is another schematic diagram of the explosion-proof sheet provided in the embodiments of this application.

[0032] Figure 9 This is another schematic diagram of the explosion-proof sheet provided in the embodiments of this application.

[0033] Figure 10 An exploded view of another battery cell structure and a partially enlarged view of another pressure relief mechanism in the battery cell provided in the embodiments of this application.

[0034] Figure label:

[0035] 1-Vehicle; 10-Battery unit; 11-Box; 111-First box; 112-Second box; 20-Battery cell; 21-Outer shell; 211-Accommodation space; 212-First wall; 22-Electrode assembly; 23-Pressure relief mechanism; 231-Explosion-proof sheet; 2311-Score; 23111-First score; 23112-Second score; 2312-Pressure relief score; 30-Controller; 40-Motor;

[0036] The accompanying drawings are not drawn to scale. Detailed Implementation

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

[0038] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0039] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms "comprising" and "having," and any variations thereof, in the description, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the description, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy.

[0040] In this application, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application can be combined with other embodiments.

[0041] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" 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 direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication 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.

[0042] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0043] In the embodiments of this application, the same reference numerals denote the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width, and other dimensions of various components in the embodiments of this application shown in the accompanying drawings, as well as the overall thickness, length, width, and other dimensions of the integrated device, are merely illustrative and should not constitute any limitation on this application.

[0044] In this application, "multiple" refers to two or more (including two), and similarly, "multiple groups" refers to two or more (including two), and "multiple pieces" refers to two or more (including two).

[0045] In this embodiment of the application, the battery cell can be a secondary battery, which refers to a battery cell that can be recharged to activate the active materials and continue to be used after the battery cell has been discharged.

[0046] The battery cell 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 the embodiments of this application are not limited to this.

[0047] In some embodiments, the battery cell may include a casing. The casing may be a steel casing, an aluminum casing, a plastic casing (such as a polypropylene casing), a composite metal casing (such as a copper-aluminum composite casing), or an aluminum-plastic film, etc. In some embodiments, the casing may be a sealed structure or a non-sealed structure. As an example, when the casing is a non-sealed structure, the casing serves to protect the electrode assembly, and a sealing bag is included between the casing and the electrode assembly to encapsulate the electrode assembly and electrolyte. Specifically, the sealing bag may be a bag-shaped insulating component or an aluminum-plastic film. When the casing is a sealed structure, it is used to encapsulate components such as the electrode assembly and electrolyte.

[0048] As an example, the battery cell can be a cylindrical battery cell, a prismatic battery cell, a pouch battery cell, or a battery cell of other shapes. Prismatic battery cells include prismatic battery cells, blade-shaped battery cells, and multi-prismatic batteries, such as hexagonal prismatic batteries. This application does not have any particular limitations.

[0049] A single battery cell typically includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator, with the separator positioned between the positive and negative electrodes. During the charging and discharging process of a single battery cell, active ions (such as lithium ions) repeatedly insert and extract between the positive and negative electrodes. The separator, positioned between the positive and negative electrodes, prevents short circuits while allowing active ions to pass through.

[0050] In some embodiments, the housing includes an end cap and a housing, the housing having an opening, and the end cap covering the opening. The housing may have one or more openings. The end cap may also have one or more.

[0051] In some embodiments, at least one electrode terminal is provided on the housing, and the electrode terminal is electrically connected to the tab. The electrode terminal can be directly connected to the tab, or it can be indirectly connected to the tab through a current collector. The electrode terminal can be provided on the end cap or on the housing.

[0052] In some embodiments, a pressure relief mechanism is provided on the casing. The pressure relief mechanism is used to release the internal gas of the battery cell.

[0053] As an example, the internal pressure or temperature of a battery cell is actuated to release the internal pressure or temperature when it reaches a predetermined threshold. When the internal pressure or temperature of the battery cell reaches the predetermined threshold, the pressure relief mechanism is activated or a weak structure in the pressure relief mechanism is broken, thereby creating an opening or channel for the internal pressure or temperature to be released. The threshold design varies depending on the design requirements. The threshold may depend on the materials of one or more of the positive electrode, negative electrode, electrolyte, and separator in the battery cell.

[0054] As an example, the pressure relief mechanism can be integrally molded with the housing.

[0055] As an example, the pressure relief mechanism can also be separately installed and connected to the housing.

[0056] The term "actuation" as used in this application refers to the activation or actuation of the pressure relief mechanism to a certain state, thereby releasing the internal pressure and temperature of the battery cell. The actions of the pressure relief mechanism may include, but are not limited to: movement of components within the mechanism to form an exhaust channel, rupture, breakage, tearing, or opening of at least a portion of the mechanism, etc. When the pressure relief mechanism is activated, the high-temperature, high-pressure substances inside the battery cell are discharged as waste from the activated portion. This method allows for pressure and temperature relief of the battery cell under controllable pressure or temperature, thereby preventing potentially more serious accidents.

[0057] In some embodiments, when the housing is a non-sealed structure, the pressure relief mechanism can be configured as a through hole for venting gas inside the battery cell.

[0058] The emissions from battery cells mentioned in this application include, but are not limited to: electrolyte, dissolved or split positive and negative electrode plates, fragments of separators, high-temperature and high-pressure gases generated by the reaction, flames, etc.

[0059] The battery apparatus mentioned in the embodiments of this application may include one or more battery cell assemblies for providing voltage and capacity. A battery cell assembly may include multiple battery cells connected in series, parallel, or mixed connections via a busbar.

[0060] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells.

[0061] As an example, a battery cell assembly can be a battery module, which is formed by arranging and fixing multiple battery cells together to form an independent module. As another example, a battery module can be formed by bundling multiple battery cells together with cable ties.

[0062] In some embodiments, the battery device may be a battery pack, which includes a housing and one or more individual battery cells housed within the housing.

[0063] As an example, the battery cell assembly can be a battery module, and the battery cell assembly can be housed in the housing by fixing the battery module in the housing.

[0064] As an example, battery cell assemblies can also be housed in a housing by directly fixing multiple battery cells to the housing.

[0065] As an example, the enclosure may include a first enclosure and a second enclosure. The first enclosure and the second enclosure are fastened together to form a closed space inside the enclosure to house the individual battery cells. Here, "closed" refers to covering or closing, and can be either sealed or unsealed. The first enclosure may be a top cover or a bottom plate.

[0066] As an example, the enclosure may include a top cover, a frame, and a bottom plate. The top cover and bottom plate are connected to the frame, creating an enclosed space inside the enclosure to house the individual battery cells.

[0067] In some embodiments, the housing may be part of the vehicle's chassis structure. For example, a portion of the housing may be at least a part of the vehicle's floor, or a portion of the housing may be at least a part of the vehicle's crossbeams and longitudinal beams.

[0068] During the use of battery devices, individual battery cells expand during daily operation. This expansion applies stress to the pressure relief mechanism, causing it to stretch. During this stretching process, the explosion-proof plate of the pressure relief mechanism is prone to cracking at the pressure relief groove, affecting the normal operation of the battery cells.

[0069] This application provides a battery cell, a battery device, and an electrical device that can solve the above-mentioned problems. The battery device of this application includes a housing, an electrode assembly, and a pressure relief mechanism. The housing has a receiving space. The electrode assembly is received in the receiving space. The pressure relief mechanism is disposed on a first wall of the housing, the first wall being parallel to the thickness direction of the battery cell. The explosion-proof plate of the pressure relief mechanism includes multiple grooves, each groove including multiple first groove portions extending perpendicular to the thickness direction of the battery cell. The explosion-proof plate also includes pressure relief grooves disposed along its edge, which are designed to be destroyed in the event of thermal runaway of the battery cell, forming an opening or channel for releasing internal pressure or temperature within the battery cell. The residual thickness of the multiple first groove portions is greater than the residual thickness of the pressure relief grooves but less than the thickness of the explosion-proof plate.

[0070] By setting multiple grooves on the explosion-proof plate of the pressure relief mechanism, the stress exerted on the pressure relief mechanism during the expansion of the battery cell during daily operation can be distributed, thus preventing the explosion-proof plate of the pressure relief mechanism from cracking at the pressure relief grooves and improving the safety of the battery cell in daily use. The multiple grooves include multiple first grooves extending perpendicular to the thickness direction of the battery cell. When the pressure relief mechanism is located on the first wall of the outer casing parallel to the thickness direction of the battery cell, it can distribute the main stress source of the pressure relief mechanism to a greater extent, namely the stress parallel to the thickness direction of the battery cell, thereby enhancing the stress distribution effect. By setting the residual thickness of the multiple first grooves to be greater than the residual thickness of the pressure relief grooves but less than the thickness of the explosion-proof plate, the pressure relief grooves can be destroyed normally in the event of thermal runaway of the battery cell, rather than multiple grooves being destroyed. This provides sufficient venting space to release the internal pressure or temperature of the battery cell in the event of thermal runaway, improving the emergency response capability of the battery cell in the event of thermal runaway.

[0071] The technical solutions described in the embodiments of this application are applicable to various electrical devices that use individual battery cells, such as mobile phones, portable devices, laptops, electric vehicles, electric toys, power tools, vehicles, ships, and spacecraft. For example, spacecraft include airplanes, rockets, space shuttles, and spacecraft.

[0072] For ease of explanation, the following embodiments will use a vehicle as an example of an electrical device.

[0073] Figure 1 A schematic diagram of the structure of vehicle 1 according to an embodiment of this application is shown. Figure 1 As shown, vehicle 1 can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. A motor 40, a controller 30, and a battery device 10 can be installed inside vehicle 1. The controller 30 controls the battery device 10 to supply power to the motor 40. For example, the battery device 10 can be installed at the bottom, front, or rear of vehicle 1. The battery device 10 can be used to power vehicle 1; for example, it can serve as the operating power source for vehicle 1's electrical system, such as meeting the power requirements for starting, navigation, and operation. In another embodiment of this application, the battery device 10 can not only serve as the operating power source for vehicle 1 but also as the driving power source, replacing or partially replacing gasoline or natural gas to provide driving power to vehicle 1.

[0074] Figure 2 An exploded view of the structure of a battery device 10 according to an embodiment of this application is shown. Figure 2As shown, the battery apparatus mentioned in the embodiments of this application may include one or more battery cell assemblies for providing voltage and capacity. A battery cell assembly may include multiple battery cells 20, which are connected in series, parallel, or mixed connections via a busbar.

[0075] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells 20.

[0076] As an example, a battery cell assembly can be a battery module, which is formed by arranging and fixing multiple battery cells 20 together. As an example, a battery module can also be formed by bundling multiple battery cells 20 together with cable ties.

[0077] In some embodiments, the battery device may be a battery pack, which includes a housing 11 and one or more individual battery cells housed within the housing.

[0078] As an example, the battery cell assembly can be a battery module, and the battery cell assembly can be housed in the housing 11 by fixing the battery module in the housing 11.

[0079] As an example, the battery cell assembly can also be housed in the housing 11 by directly fixing multiple battery cells 20 to the housing 11.

[0080] As an example, the housing 11 may include a first housing 111 and a second housing 112. The first housing 111 and the second housing 112 are fastened together to form a closed space inside the housing 11 to house the battery cell assembly. Here, "closed" refers to covering or closing, and can be either sealed or unsealed. The first housing 111 may be a top cover or a bottom plate.

[0081] As an example, the housing 11 may include a top cover, a frame, and a bottom plate. The top cover and the bottom plate are respectively connected to the frame, so that the interior of the housing 11 forms an enclosed space to accommodate the battery cell assembly.

[0082] Figure 3 An exploded view of the structure of a battery cell 20 according to an embodiment of this application and a partially enlarged view of the pressure relief mechanism 23 in the battery cell 20 are shown. Figure 4 A cross-sectional view of the pressure relief mechanism 23 according to an embodiment of this application is shown. Figure 3As shown, the battery cell 20 includes: a housing 21 having a receiving space 211; an electrode assembly 22 housed within the receiving space 211; and a pressure relief mechanism 23 disposed on a first wall 212 of the housing 21, the first wall 212 being parallel to the thickness direction of the battery cell 20; wherein, the explosion-proof plate 231 of the pressure relief mechanism 23 includes multiple grooves 2311, the multiple grooves 2311 including multiple first groove portions 23111, and multiple grooves... The first notch portion 23111 extends along the thickness direction perpendicular to the battery cell 20; the explosion-proof sheet 231 also includes a pressure relief notch 2312 provided along the edge of the explosion-proof sheet 231, the pressure relief notch 2312 is used to be destroyed when the battery cell 20 experiences thermal runaway, so as to form an opening or channel for the release of internal pressure or temperature of the battery cell 20; the residual thickness of the multiple first notches portion 23111 is greater than the residual thickness of the pressure relief notch 2312 and less than the thickness of the explosion-proof sheet 231.

[0083] By providing multiple grooves 2311 on the explosion-proof plate 231 of the pressure relief mechanism 23, the stress exerted on the pressure relief mechanism 23 during the expansion of the battery cell 20 during daily operation can be distributed, thereby preventing the explosion-proof plate 231 of the pressure relief mechanism 23 from breaking at the pressure relief grooves 2312 and improving the safety of the battery cell 20 in daily use. The multiple grooves 2311 include multiple first groove portions 23111 extending perpendicular to the thickness direction of the battery cell 20. When the pressure relief mechanism 23 is provided on the first wall 212 of the outer casing 21 parallel to the thickness direction of the battery cell 20, the main stress source of the pressure relief mechanism 23, namely the stress parallel to the thickness direction of the battery cell 20, can be distributed to a greater extent, thereby enhancing the stress distribution effect. By setting the residual thickness of the multiple first notches 23111 to be greater than the residual thickness of the pressure relief notches 2312 and less than the thickness of the explosion-proof sheet 231, the pressure relief notches 2312 can be destroyed normally when the battery cell 20 experiences thermal runaway, instead of the multiple notches 2311 being destroyed. This ensures that the battery cell 20 has sufficient space to release internal pressure or temperature when it experiences thermal runaway, thereby improving the emergency response capability of the battery cell 20 in the event of thermal runaway.

[0084] Specifically, multiple grooves 2311 can be provided on the side of the explosion-proof sheet 231 facing the motor assembly 22 to more effectively distribute the stress applied by the battery cell 20 to the pressure relief mechanism 23.

[0085] It should be understood that the residual thickness of the first notch portion 23111 is the thickness of the first notch portion 23111 in the thickness direction perpendicular to the explosion-proof sheet 231, and the residual thickness of the pressure relief notch 2312 is the thickness of the pressure relief notch 2312 in the thickness direction perpendicular to the explosion-proof sheet 231. Figure 4The cross-sectional view shown is a cross-sectional view obtained along the thickness direction of the battery cell 20. Since the residual thickness of the multiple first grooves 23111 is greater than the residual thickness of the pressure relief grooves 2312, the relatively thinner pressure relief grooves 2312 are preferentially destroyed when the battery cell 20 experiences thermal runaway. At this time, the pressure relief grooves 2312 provided along the edge of the explosion-proof sheet 231 crack, so as to create a release opening as large as possible along the edge of the explosion-proof sheet 231, thereby improving the ability to release internal pressure or temperature of the battery cell 20.

[0086] Specifically, the pressure relief notch 2312 can have different thicknesses in different areas, for example... Figure 4 The pressure relief groove 2312 in the left-hand region is thinner than that in the right-hand region. Each of the multiple first groove portions 23111 can also have a different thickness, and different areas within each first groove portion 23111 can also have different thicknesses. When setting the thickness of the pressure relief groove 2312 and the first groove portion 23111, it is necessary to ensure that the thickness of the thinnest part of the first groove portion 23111 is greater than the thickness of the thinnest part of the pressure relief groove 2312, so that when a venting opening needs to be created, the pressure relief groove 2312 cracks before the first groove portion 23111.

[0087] It should be understood that, in addition to the first notch 23111 extending perpendicular to the thickness direction of the battery cell 20, the multiple notches 2311 may also include notches extending in other directions, such as... Figure 3 The explosion-proof sheet 231 includes a groove 2311 extending parallel to the thickness direction of the battery cell 20.

[0088] It should be understood that when the pressure relief mechanism 23 is subjected to stress from the thermal expansion of the battery cell 20, since the stress parallel to the thickness direction of the battery cell 20 is the main source of stress from the thermal expansion of the battery cell 20, the first notch 23111 extending perpendicular to the thickness direction of the battery cell 20 bears a larger load area than the notch 2311 extending in other directions. Under the condition that the load per unit area is the same, the first notch needs to bear a larger load, thereby bearing the load of the pressure relief notch 2312 to a greater extent.

[0089] Figure 5 A schematic diagram of an explosion-proof sheet 231 according to an embodiment of this application is shown. (As...) Figure 5 As shown, multiple first grooves 23111 are arranged along the thickness direction of the battery cell 20.

[0090] By arranging multiple first notches 23111 along the thickness direction of the battery cell 20, the arrangement density of the first notches 23111 in the thickness direction of the battery cell 20 can be increased, thereby enhancing the stress distribution effect of the multiple first notches 23111 in the thickness direction of the battery cell 20.

[0091] It should be understood that the arrangement of multiple first notches 23111 along the thickness direction of the battery cell 20 means that the arrangement density of the first notches 23111 along the thickness direction of the battery cell 20 is much greater than the arrangement density in other directions.

[0092] It should be understood that the multiple first notches may not be arranged along the thickness direction of the battery cell 20, for example, they may be arranged along the thickness direction perpendicular to the battery cell 20. This application embodiment does not limit this.

[0093] Figure 6 Another schematic diagram of the explosion-proof sheet 231 according to an embodiment of this application is shown. Figure 6 As shown, the distance L between any two adjacent first groove portions 23111 in the plurality of first groove portions 23111 is greater than or equal to 2 mm.

[0094] By setting the spacing L between any two adjacent first score marks 23111 among the multiple first score marks 23111 to be greater than or equal to 2mm, the distribution of the multiple first score marks 23111 in local areas can be prevented from being too concentrated and the distribution in other areas too dispersed. This improves the uniformity of the distribution of the multiple first score marks 23111, allowing the multiple first score marks 23111 to distribute stress more evenly and enhance the stress distribution effect of the multiple first score marks 23111.

[0095] It should be understood that the distance L between any two adjacent first grooves 23111 in the multiple first grooves 23111 can also have a maximum value, so as to achieve the effect of setting an upper limit on the number of first grooves, and avoid the explosion-proof sheet 231 having too many grooves 2312, which would result in low mechanical strength.

[0096] Figure 7 Another schematic diagram of the explosion-proof sheet 231 according to an embodiment of this application is shown. Figure 7 As shown, the plurality of first groove portions 23111 include at least five first groove portions 23111.

[0097] By providing at least five first grooves 23111 on the explosion-proof sheet 231, the arrangement density of the first grooves 23111 in the thickness direction of the battery cell 20 can be increased, thereby enhancing the stress distribution effect of the multiple first grooves 23111 in the thickness direction of the battery cell 20.

[0098] It should be understood that the number of the first notch 23111 can also be set to an upper limit, so as to avoid the explosion-proof sheet 231 having too many notches 2312, which would result in low mechanical strength.

[0099] Figure 8 Another schematic diagram of the explosion-proof sheet 231 according to an embodiment of this application is shown. Figure 9 Another schematic diagram of the explosion-proof sheet 231 according to an embodiment of this application is shown. Figure 8 and Figure 9 As shown, the multiple grooves 2311 also include multiple second groove portions 23112, which extend along the thickness direction of the battery cell 20.

[0100] By setting multiple second grooves 23112 extending along the thickness direction of the battery cell 20, the stress perpendicular to the thickness direction of the battery cell 20 can also be distributed to a certain extent, thereby more comprehensively distributing the stress applied to the pressure relief mechanism 23 during the daily working expansion of the battery cell 20.

[0101] In some embodiments, such as Figure 7 As shown, each of the multiple second score marks 23112 is an arc-shaped score mark that connects the same ends of two first score marks 23111.

[0102] By connecting the arc-shaped second score portion 23112 to the same end of the two first score portions 23111, the second score portion 23112 can fit more closely with the arc-shaped edge of the explosion-proof sheet 231, thereby enhancing the stress distribution effect in the direction perpendicular to the thickness of the battery cell 20, and thus comprehensively improving the stress distribution effect of the multiple score portions 2311 on the stress applied to the pressure relief mechanism 23 by the battery cell 20.

[0103] It should be understood that it can be like Figure 7 As shown, one end of each first scribe portion 23111 is connected to only one second scribe portion 23112. Alternatively, one end of each first scribe portion 23111 may be connected to multiple second scribe portions 23112. This application embodiment does not limit this.

[0104] It should be understood that the second notch 23112 can also be connected to the pressure relief notch 2312. For example... Figure 8 As shown, one side of the pressure relief groove 2312 is connected to multiple second grooves 23112. That is, in Figure 8 In the embodiment shown, the connection point between the first groove 23111 and the multiple second grooves 23112 needs to bear more load. When the battery cell 20 thermally runs away and a discharge opening needs to be created, the connection point is destroyed first, thereby achieving targeted destruction of the pressure relief grooves 2312.

[0105] Figure 10 An exploded view of another structure of the battery cell 20 according to an embodiment of this application and a partially enlarged view of another pressure relief mechanism in the battery cell are shown, as follows: Figure 10 As shown, the first wall 212 is the wall of the outer shell 21 located at the bottom along the direction of gravity.

[0106] Because the electrode assembly 22 is located within the housing space 211 of the battery cell 20, closer to the bottom wall of the outer casing 21 along the direction of gravity, the stress exerted on the bottom wall of the outer casing 21 by the battery cell 20 during expansion is more significant. Defining the bottom wall of the outer casing 21 as the first wall 212 and providing a pressure relief mechanism 23 on the first wall 212 can more effectively demonstrate the stress-distributing effect of the multiple grooves 2311 on the pressure relief mechanism 23 exerted by the battery cell 20.

[0107] It should be understood that the first wall 212 is a wall parallel to the thickness direction of the battery cell 20. That is, the first wall can also be the top wall of the outer casing 21 along the direction of gravity, or the wall of the outer casing 21 located in the middle of the direction of gravity and parallel to the thickness direction of the battery cell 20.

[0108] In some embodiments, the pressure relief mechanism 23 is connected to the first wall 212 by laser welding.

[0109] By connecting the pressure relief mechanism 23 to the first wall 212 by laser welding, the tightness and sealing of the connection between the pressure relief mechanism 23 and the first wall 212 can be increased, and the mechanical strength of the pressure relief mechanism 23 connected to the first wall 212 can be improved, thereby reducing the deformation or even damage to the pressure relief mechanism 23 caused by the stress applied to the pressure relief mechanism 23 during the daily working expansion of the battery cell 20.

[0110] It should be understood that the pressure relief mechanism 23 and the first wall 212 can also be connected by other means such as bonding or integral molding, and this application embodiment does not limit this.

[0111] In some embodiments, the pressure relief mechanism 23 is made of aluminum alloy, stainless steel, or plastic.

[0112] Choosing aluminum alloy, stainless steel or plastic as the material for the pressure relief mechanism 23 can give the pressure relief mechanism 23 both strong mechanical strength and good ductility, so that it will not be easily torn or damaged when subjected to stress during the expansion of the battery cell 20, thus improving the pressure relief mechanism 23's ability to withstand stress during the daily operation of the battery cell 20.

[0113] It should be understood that the material of the pressure relief mechanism 23 may also include magnesium alloy, titanium alloy, etc., and this application embodiment does not limit this.

[0114] According to some embodiments of this application, see Figures 3 to 9 This application provides a battery cell 20, comprising: a housing 21 having a receiving space 211; an electrode assembly 22 housed within the receiving space 211; and a pressure relief mechanism 23 disposed on a first wall 212 of the housing 21, the first wall 212 being parallel to the thickness direction of the battery cell 20; wherein the explosion-proof plate 231 of the pressure relief mechanism 23 includes multiple grooves 2311, the multiple grooves 2311 including multiple first groove portions 23. 111, multiple first grooves 23111 extend along the thickness direction perpendicular to the battery cell 20; the explosion-proof sheet 231 also includes pressure relief grooves 2312 provided along the edge of the explosion-proof sheet 231, the pressure relief grooves 2312 are used to be destroyed when the battery cell 20 is thermally runaway, so as to form an opening or channel for the internal pressure or temperature of the battery cell 20 to be released; the residual thickness of the multiple first grooves 23111 is greater than the residual thickness of the pressure relief grooves 2312 and less than the thickness of the explosion-proof sheet 231.

[0115] Multiple first grooves 23111 are arranged along the thickness direction of the battery cell 20.

[0116] The distance L between any two adjacent first groove portions 23111 in the plurality of first groove portions 23111 is greater than or equal to 2mm.

[0117] The multiple first notches 23111 include at least 5 first notches 23111.

[0118] The multiple grooves 2311 also include multiple second groove portions 23112, which extend along the thickness direction of the battery cell 20.

[0119] Each of the multiple second score marks 23112 is an arc-shaped score mark that connects the same ends of two first score marks 23111.

[0120] The first wall 212 is the wall of the outer shell 21 located at the bottom along the direction of gravity.

[0121] The pressure relief mechanism 23 is connected to the first wall 212 by laser welding.

[0122] The pressure relief mechanism 23 may be made of aluminum alloy, stainless steel or plastic.

[0123] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, characterized in that, The battery cell (20) includes: The outer casing (21) has a receiving space (211); Electrode assembly (22), the electrode assembly (22) being housed in the housing space (211); Pressure relief mechanism (23) is provided on the first wall (212) of the outer casing, and the first wall (212) is parallel to the thickness direction of the battery cell (20); The explosion-proof plate (231) of the pressure relief mechanism (23) includes multiple grooves (2311), each groove (2311) including multiple first groove portions (23111), which extend along the thickness direction perpendicular to the battery cell (20). The explosion-proof plate (231) also includes pressure relief grooves (2312) provided along the edge of the explosion-proof plate (231), which are used to be destroyed when the battery cell (20) experiences thermal runaway, so as to form an opening or channel for releasing internal pressure or temperature of the battery cell (20). The residual thickness of the multiple first groove portions (23111) is greater than the residual thickness of the pressure relief grooves (2312) and less than the thickness of the explosion-proof plate (231).

2. The battery cell according to claim 1, characterized in that, The plurality of first grooves (23111) are arranged along the thickness direction of the battery cell (20).

3. The battery cell according to claim 1, characterized in that, The distance L between any two adjacent first grooves (23111) among the plurality of first grooves (23111) is greater than or equal to 2 mm.

4. The battery cell according to claim 1, characterized in that, The plurality of first notches (23111) includes at least five first notches (23111).

5. The battery cell according to any one of claims 1 to 4, characterized in that, The plurality of grooves (2311) also include a plurality of second groove portions (23112), which extend along the thickness direction of the battery cell (20).

6. The battery cell according to claim 5, characterized in that, Each of the plurality of second scoring sections (23112) is an arc-shaped scoring section that connects the same ends of two first scoring sections (23111).

7. The battery cell according to any one of claims 1 to 4, characterized in that, The first wall (212) is the bottom wall of the outer shell (21) along the direction of gravity.

8. The battery cell according to any one of claims 1 to 4, characterized in that, The pressure relief mechanism (23) is connected to the first wall (212) by laser welding.

9. The battery cell according to any one of claims 1 to 4, characterized in that, The pressure relief mechanism (23) is made of aluminum alloy, stainless steel or plastic.

10. A battery device, characterized in that, It includes multiple battery cells (20) according to any one of claims 1 to 9.

11. An electrical appliance, characterized in that, The electrical device includes: Multiple battery cells (20) according to any one of claims 1 to 9, or Multiple battery devices (10) according to claim 10, The battery cell (20) or the battery device (10) is used to provide electrical energy.

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