Battery cell, battery, and electric device

Abstract

A battery cell (200), a battery (400), and an electric device (500). The battery cell (200) comprises: an electrode assembly (300) comprising a positive electrode sheet and a negative electrode sheet, the positive electrode sheet and the negative electrode sheet form a flat region (301); and a housing (60) comprising a first wall portion (11) and two second wall portions (12), the two second wall portions (12) being respectively located on two sides of the flat region (301) in a first direction. The first wall portion (11) comprises a shell body (111) and a pressure relief portion (112), wherein the shell body (111) is arranged around the periphery of the pressure relief portion (112), a notch groove (113) is formed in the pressure relief portion (112) and has a first groove wall section (114) obliquely extending in the first direction on a bottom wall thereof, and the first groove wall section (114) is at an angle to the first direction.

Description

Battery cells, batteries, and electrical devices

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application is based on the Chinese patent application with application number 202311621580.1 and application date of November 28, 2023, and claims the priority of the above-mentioned Chinese patent application. The entire content of the above-mentioned Chinese patent application is hereby introduced into this application as a reference. Technical Field

[0003] The present application relates to the field of batteries, and in particular to a battery cell, a battery, and an electrical device. Background Art

[0004] In the related art, a battery cell includes a shell and an electrode assembly. The electrode assembly is arranged in the shell, and the shell is provided with a pressure relief part. When the battery cell expands, the large surface of the shell is deformed. The deformation of the large surface of the shell will pull the shell wall of the shell where the pressure relief part is provided, causing the shell wall where the pressure relief part is provided to deform, thereby subjecting the pressure relief part to a pulling force, which can easily cause damage to the pressure relief part, resulting in cracking of the pressure relief part, and affecting the normal use of the pressure relief part.

[0005] Summary of the Invention

[0006] The present application aims to solve one of the technical problems in the related art at least to a certain extent.

[0007] To this end, one object of the present application is to provide a battery cell.

[0008] Another object of the present application is to provide a battery.

[0009] Another object of the present application is to provide an electrical device.

[0010] In a first aspect, an embodiment of the present application provides a battery cell, comprising:

[0011] An electrode assembly comprising a positive electrode sheet and a negative electrode sheet, wherein the positive electrode sheet and the negative electrode sheet are stacked to form a flat region, and at least a portion of the positive electrode sheet and at least a portion of the negative electrode sheet are stacked along a first direction in the flat region;

[0012] A shell for accommodating the electrode assembly, the shell comprising a first wall portion and two second wall portions connected to the first wall portion, the two second wall portions being respectively located on both sides of the straight area along a first direction;

[0013] Among them, the first wall portion includes a shell body and a pressure relief portion. The shell body is arranged around the outer periphery of the pressure relief portion. The pressure relief portion is formed with a notched groove. The bottom wall of the notched groove has a first groove wall section extending obliquely along the first direction, and the first groove wall section forms an angle with the first direction.

[0014] In the above technical solution, the first groove wall section forms an angle with the first direction. When the battery cell expands and pulls the first wall portion, the pressure relief portion is subjected to a pulling force. The first groove wall section can decompose the force, change the force angle of the notched groove, reduce the force on the notched groove, improve the deformation resistance of the notched groove, reduce the risk of cracking of the pressure relief portion, and reduce the influence of external force or deformation on the position of the notched groove of the pressure relief portion.

[0015] In a second aspect, an embodiment of the present application further provides a battery comprising the above-mentioned battery cell.

[0016] In the above technical solution, the first groove wall section forms an angle with the first direction. When the battery cell expands and pulls the first wall portion, the pressure relief portion is subjected to a pulling force. The first groove wall section can decompose the force, change the force angle of the notched groove, reduce the force on the notched groove, improve the deformation resistance of the notched groove, reduce the risk of cracking of the pressure relief portion, and reduce the influence of external force or deformation on the position of the notched groove of the pressure relief portion.

[0017] In a third aspect, an embodiment of the present application further provides an electrical device comprising the above-mentioned battery.

[0018] In the above technical solution, the first groove wall section forms an angle with the first direction. When the battery cell expands and pulls the first wall portion, the pressure relief portion is subjected to a pulling force. The first groove wall section can decompose the force, change the force angle of the notched groove, reduce the force on the notched groove, improve the deformation resistance of the notched groove, reduce the risk of cracking of the pressure relief portion, and reduce the influence of external force or deformation on the position of the notched groove of the pressure relief portion.

[0019] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become obvious from the description below, or will be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] FIG1 is a schematic diagram of an electrical device according to an embodiment of the present application;

[0021] FIG2 is an exploded view of a battery according to an embodiment of the present application;

[0022] FIG3 is a schematic diagram of a battery cell according to the first embodiment of the present application;

[0023] FIG4 is a schematic diagram of a battery cell according to the first embodiment of the present application from another angle;

[0024] FIG5 is an exploded view of a battery cell according to the first embodiment of the present application;

[0025] FIG6 is a schematic diagram of a battery cell according to a second embodiment of the present application;

[0026] FIG7 is a schematic diagram showing a pressure relief portion provided on a bottom wall of a housing according to an embodiment of the present application. DETAILED DESCRIPTION

[0027] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0028] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first" and "second" in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary-secondary relationship.

[0029] References to "embodiments" in this application mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments.

[0030] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connected," and "attached" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0031] The term "and / or" in this application simply describes an association between related objects, indicating that three possible relationships exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this application generally indicates that the related objects are in an "or" relationship.

[0032] In the embodiments of this application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components in different embodiments are omitted. It should be understood that the thickness, length, width, and other dimensions of the various components in the embodiments of this application, as well as the overall thickness, length, width, and other dimensions of the integrated device shown in the drawings are merely illustrative and should not constitute any limitation on this application.

[0033] The term "plurality" used in this application refers to two or more (including two).

[0034] In the embodiment of the present application, the battery cell may be a secondary battery. A secondary battery refers to a battery cell that can be continuously used by activating active materials by charging after the battery cell is discharged.

[0035] The battery cells can be lithium-ion batteries, sodium-ion batteries, sodium-lithium-ion batteries, lithium metal batteries, sodium metal batteries, lithium-sulfur batteries, magnesium-ion batteries, nickel-hydrogen batteries, nickel-cadmium batteries, lead-acid batteries, etc., which are not limited in the embodiments of the present application.

[0036] The battery mentioned in the embodiments of the present application refers to a single physical module including one or more battery cells to provide higher voltage and capacity. When there are multiple battery cells, the multiple battery cells are connected in series, in parallel or in hybrid through a busbar.

[0037] In some embodiments, the battery may be a battery module. When there are multiple battery cells, the multiple battery cells are arranged and fixed to form a battery module.

[0038] In some embodiments, the battery may be a battery pack, which includes a case and battery cells, wherein the battery cells or battery modules are housed in the case.

[0039] In some embodiments, the box body can be used as a part of the chassis structure of the vehicle. For example, part of the box body can become at least a part of the floor of the vehicle, or part of the box body can become at least a part of the cross beam and longitudinal beam of the vehicle.

[0040] In some embodiments, the battery may be an energy storage device, including an energy storage container, an energy storage cabinet, and the like.

[0041] The development of battery technology must take into account multiple design factors at the same time, such as energy density, cycle life, discharge capacity, charge and discharge rate and other performance parameters. In addition, the safety performance of the battery also needs to be considered.

[0042] In a battery cell, to ensure the safety performance of the battery cell, a pressure relief portion may be provided on the outer shell of the battery cell. When the battery cell experiences thermal runaway, the pressure inside the battery cell is released through the pressure relief portion to improve the safety of the battery cell.

[0043] During the charging and discharging process of the battery cell, the electrode assembly will expand hard, causing the shell to swell and deform, and the pressure relief part is arranged on the shell, especially some pressure relief parts are arranged on the wall on the side closer to the electrode assembly. The expansion of the electrode assembly will cause the wall where the pressure relief part is located to deform, thereby pulling the notch of the pressure relief part, causing the pressure relief part to be damaged at the notch and then leaking, etc. As a result, the pressure inside the battery cell will be destroyed before it reaches the detonation pressure of the pressure relief part, causing the pressure relief part to fail and the reliability of the pressure relief part to be low.

[0044] In view of this, an embodiment of the present application provides a battery cell, including an electrode assembly and a shell, the shell is used to accommodate the electrode assembly, the shell includes a first wall portion and two second wall portions connected to the first wall portion, the first wall portion includes a shell body and a pressure relief portion, the shell body is arranged around the outer periphery of the pressure relief portion, the pressure relief portion is formed with a notched groove, the bottom wall of the notched groove has a first groove wall section extending obliquely along a first direction, and the first groove wall section forms an angle with the first direction.

[0045] In such a battery cell, the first groove wall section forms an angle with the first direction. When the battery cell expands and pulls the first wall portion, the pressure relief portion is subjected to a pulling force, which can change the force angle of the notched groove and reduce the force on the notched groove. This can improve the deformation resistance of the notched groove, reduce the risk of cracking of the pressure relief portion, and reduce the influence of external force or deformation on the position of the notched groove of the pressure relief portion.

[0046] The technical solutions described in the embodiments of the present application are applicable to batteries and electrical devices using batteries.

[0047] Electrical devices may include vehicles, mobile phones, portable devices, laptop computers, ships, spacecraft, electric toys, and electric tools, etc. Vehicles may include fuel vehicles, gas vehicles, or new energy vehicles. New energy vehicles may include pure electric vehicles, hybrid vehicles, or extended-range vehicles, etc. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc. Electric toys include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools, and railway electric tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. The embodiments of the present application do not impose any special restrictions on the above-mentioned electrical devices.

[0048] For the convenience of description, the following embodiments are described by taking a vehicle as an example of an electrical device.

[0049] Please refer to Figure 1, which is a schematic diagram of the structure of a vehicle provided in some embodiments of the present application. A battery 400 is disposed within the vehicle, and battery 400 may be located at the bottom, front, or rear of the vehicle. Battery 400 may be used to power the vehicle, for example, as the vehicle's operating power source.

[0050] The vehicle may further include a controller 600 and a motor 700 . The controller 600 is used to control the battery 400 to supply power to the motor 700 , for example, to meet the vehicle's power requirements for starting, navigating, and driving.

[0051] In some embodiments of the present application, the battery 400 can serve not only as the operating power source of the vehicle, but also as the driving power source of the vehicle, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle.

[0052] Please refer to Figure 2, which is an exploded view of a battery 400 provided in some embodiments of the present application. The battery 400 includes a battery cell 200 and a box 401, wherein the box 401 is used to accommodate the battery cell 200.

[0053] The housing 401 is a component that houses the battery cells 200 and provides storage space for the battery cells 200. The housing 401 can have various structures. In some embodiments, the housing 401 can include a first body 402 and a second body 403. The first body 402 and the second body 403 overlap to define a storage space for the battery cells 200. The first body 402 and the second body 403 can have various shapes, such as a rectangular parallelepiped or a cylinder. The first body 402 can be a hollow structure with one side open, and the second body 403 can also be a hollow structure with one side open. The open side of the second body 403 overlaps the open side of the first body 402, forming the housing 401 with storage space. Alternatively, the first body 402 can be a hollow structure with one side open, and the second body 403 can be a plate-like structure. The second body 403 overlaps the open side of the first body 402, forming the housing 401 with storage space. As an example, the battery cell 200 can be a cylindrical battery cell, a prismatic battery cell, a soft-pack battery cell or a battery cell 200 of other shapes. The prismatic battery cell includes a square-shell battery cell, a blade-shaped battery cell, a polygonal battery, and a polygonal battery such as a hexagonal battery, etc. There is no special limitation in this application.

[0054] In the battery 400, there can be one or more battery cells 200. If there are multiple battery cells 200, the multiple battery cells 200 can be connected in series, parallel, or in a hybrid connection. Hybrid connection refers to a combination of series and parallel connections among the multiple battery cells 200. Multiple battery cells 200 can be connected in series, parallel, or in a hybrid connection to form a battery module, which is then connected in series, parallel, or in a hybrid connection to form a single unit and housed within the housing 401. Alternatively, all battery cells 200 can be directly connected in series, parallel, or in a hybrid connection, and then the entire unit formed by all battery cells 200 is housed within the housing 401.

[0055] 3 , 5 and 6 , the battery cell 200 may include a housing 60 and an electrode assembly 300 .

[0056] The housing 60 is used to house the electrode assembly 300 and other components such as the electrolyte. The housing 60 can be made of steel, aluminum, plastic (e.g., polypropylene), a composite metal (e.g., a copper-aluminum composite), or an aluminum-plastic film. For example, a battery cell 200 can include an end cap 20 and a housing 60.

[0057] The housing 60 may be a hollow structure with an opening at one end, or a hollow structure with openings at opposite ends. The housing 60 may be made of a variety of materials, such as copper, iron, aluminum, steel, aluminum alloy, and the like.

[0058] The end cap 20 is a component that closes the opening of the outer shell 60 to isolate the internal environment of the battery cell 200 from the external environment. The end cap 20 and the outer shell 60 together define a storage space for accommodating the electrode assembly 300, the electrolyte, and other components. The end cap 20 can be connected to the outer shell 60 by welding or crimping to close the opening of the outer shell 60. The shape of the end cap 20 can be adapted to the shape of the outer shell 60. For example, if the outer shell 60 is a rectangular parallelepiped structure, the end cap 20 is a rectangular plate structure adapted to the outer shell 60. The material of the end cap 20 can also be various, such as copper, iron, aluminum, steel, aluminum alloy, etc.

[0059] In the battery cell 200, there can be one or two end caps 20. In embodiments where the outer shell 60 is a hollow structure with openings at both ends, two end caps 20 can be provided. The two end caps 20 respectively close the two openings of the outer shell 60, and the two end caps 20 and the outer shell 60 together define a storage space. In embodiments where the outer shell 60 is a hollow structure with an opening at one end, there can be one end cap 20 provided. The end cap 20 closes the opening at one end of the outer shell 60, and the end cap 20 and the outer shell 60 together define a storage space.

[0060] The electrode assembly 300 includes a positive electrode, a negative electrode, and a separator. During the charge and discharge process of the battery cell 200, active ions (such as lithium ions) are inserted and removed between the positive and negative electrodes. The separator is placed between the positive and negative electrodes to prevent short circuits between the positive and negative electrodes while allowing the active ions to pass through.

[0061] In some embodiments, the positive electrode may be a positive electrode sheet, which may include a positive electrode current collector and a positive electrode active material region disposed on at least one surface of the positive electrode current collector, wherein the positive electrode active material region has a positive electrode active material.

[0062] As an example, the positive electrode current collector has two surfaces facing each other in its thickness direction, and the positive electrode active material region is provided on either or both of the two facing surfaces of the positive electrode current collector.

[0063] In some embodiments, the negative electrode may be a negative electrode sheet, which may include a negative electrode current collector and a negative electrode active material region disposed on at least one surface of the negative electrode current collector.

[0064] As an example, the negative electrode current collector has two surfaces facing each other in its thickness direction, and the negative electrode active material region is provided on either one or both of the two facing surfaces of the negative electrode current collector.

[0065] In some embodiments, the material of the positive electrode current collector may be aluminum, and the material of the negative electrode current collector may be copper.

[0066] In some embodiments, the electrode assembly 300 further includes a separator disposed between the positive electrode and the negative electrode.

[0067] In some embodiments, the separator is a separator. The present application has no particular limitation on the type of separator, and any known separator with a porous structure having good chemical and mechanical stability can be selected.

[0068] In some embodiments, the separator is a solid electrolyte, which is disposed between the positive electrode and the negative electrode and serves to transport ions and isolate the positive and negative electrodes.

[0069] In some embodiments, the battery cell 200 further includes an electrolyte, which acts as a conductor of ions between the positive and negative electrodes. This application does not specifically limit the type of electrolyte, and the electrolyte may be selected based on needs. The electrolyte may be liquid, gel, or solid.

[0070] In some embodiments, the electrode assembly 300 is a wound structure in which the positive electrode sheet and the negative electrode sheet are wound into a wound structure.

[0071] In some embodiments, the electrode assembly 300 is a laminated structure.

[0072] As an example, multiple positive electrode sheets and multiple negative electrode sheets can be provided respectively, and the multiple positive electrode sheets and the multiple negative electrode sheets can be alternately stacked.

[0073] As an example, multiple positive electrode sheets may be provided, and the negative electrode sheet is folded to form multiple stacked folded segments, with a positive electrode sheet sandwiched between adjacent folded segments.

[0074] As an example, both the positive electrode sheet and the negative electrode sheet are folded to form a plurality of stacked folded segments.

[0075] As an example, multiple separators may be provided, each of which is provided between any adjacent positive electrode sheets or negative electrode sheets.

[0076] As an example, the separator may be provided continuously, and may be provided between any adjacent positive electrode sheets or negative electrode sheets by folding or winding.

[0077] In some embodiments, the shape of the electrode assembly 300 can be flat or polygonal.

[0078] In some embodiments, the electrode assembly 300 is provided with tabs that can conduct current from the electrode assembly 300. The tabs include a positive tab and a negative tab.

[0079] The electrode assembly 300 includes a plurality of electrode sheets arranged in a wound manner, and an outer peripheral surface of the electrode assembly 300 includes a flat region 301 .

[0080] A plurality of electrode sheets arranged in a wound manner, i.e., positive electrode sheets and negative electrode sheets are stacked and wound around a set axis to form an electrode assembly 300. The straight area 301 refers to the portion of the electrode sheet extending along the plane when wound. The two opposite side surfaces of the electrode assembly 300 along the first direction are formed as the straight area 301.

[0081] The battery cell 200 according to an embodiment of the present application is described below with reference to FIG. 3 to FIG. 7 .

[0082] According to the battery cell 200 of the embodiment of the present application, it includes: an electrode assembly 300, including a positive electrode sheet and a negative electrode sheet, which are stacked to form a flat area 301, and at least a portion of the positive electrode sheet and at least a portion of the negative electrode sheet are stacked along a first direction in the flat area 301; a shell 60, used to accommodate the electrode assembly 300, the shell 60 includes a first wall portion 11 and two second wall portions 12 connected to the first wall portion 11, and the two second wall portions 12 are respectively located on both sides of the flat area 301 along the first direction; wherein, the first wall portion 11 includes a shell body 111 and a pressure relief portion 112, the shell body 111 is arranged around the outer periphery of the pressure relief portion 112, and the pressure relief portion 112 is formed with a notch groove 113, and the bottom wall of the notch groove 113 has a first groove wall section 114 extending obliquely along the first direction, and the first groove wall section 114 forms an angle with the first direction.

[0083] The electrode assembly 300 includes positive and negative electrode sheets. For example, the electrode assembly 300 includes at least one positive electrode sheet and at least one negative electrode sheet. The at least one positive electrode sheet and at least one negative electrode sheet are stacked to form the electrode assembly 300. The positive and negative electrode sheets are stacked to form a flat region 301. In the flat region 301, at least a portion of the positive electrode sheet and at least a portion of the negative electrode sheet are stacked along a first direction. As a result, the expansion of the electrode assembly 300 is primarily in the first direction. When the battery cell 200 is positioned in the orientation shown in FIG. 3 , the first direction refers to the Z direction in FIG. The outer circumference of the electrode assembly 300 has the flat region 301.

[0084] The electrode assembly 300 can also be a wound type. The positive electrode sheet and the negative electrode sheet of the electrode assembly 300 are stacked with the isolation film and then wound to form a straight area 301. In the straight area 301, part of the positive electrode sheet and part of the negative electrode sheet are stacked along the first direction. For example, after winding, each layer of the positive electrode sheet and each layer of the negative electrode sheet can be penetrated by an axis extending along the first direction, so that most of the expansion of the electrode assembly 300 is reflected in the first direction.

[0085] The outer shell 60 defines an open installation cavity 30, and the electrode assembly 300 of the battery cell 200 is installed in the installation cavity 30. The outer shell 60 includes a first wall portion 11 and two second wall portions 12. The two second wall portions 12 are respectively located on both sides of the electrode assembly 300 in the first direction. Most of the expansion of the electrode assembly 300 will act on the second wall portions 12. The first wall portion 11 is located between the two second wall portions 12. The first wall portion 11 is connected between the two second wall portions 12. The first wall portion 11 and the two second wall portions 12 constitute the outer shell 60 of the above embodiment.

[0086] The first wall portion 11 includes a shell body 111 and a pressure relief portion 112. The shell body 111 is arranged around the outer periphery of the pressure relief portion 112. The pressure relief portion 112 is fixed to the shell body 111. The pressure relief portion 112 can be an explosion-proof valve, or the first wall portion 11 has a notched structure to form the pressure relief portion 112 on the first wall portion 11. The pressure relief portion 112 is formed with a notched groove 113. When the internal pressure threshold of the mounting cavity 30 reaches a certain value, the notched groove 113 of the pressure relief portion 112 opens, and the gas and substances inside the battery cell 200 are discharged from the pressure relief portion 112 to achieve a pressure relief effect. The pressure threshold design varies according to different design requirements. The pressure threshold may depend on the material of one or more of the positive electrode sheet, negative electrode sheet, electrolyte and isolation membrane in the battery cell 200.

[0087] When the electrode assembly 300 expands, the first wall portion 11 is less affected by the electrode assembly 300 than the second wall portion 12. Since the pressure relief portion 112 is located on the first wall portion 11, the risk of the pressure relief portion 112 being blocked or damaged by the expansion of the electrode assembly 300 can be reduced.

[0088] As shown in FIG. 7 , the bottom wall of the notched groove 113 has a first groove wall section 114 . The first groove wall section 114 extends obliquely along a first direction, and the first groove wall section 114 forms an angle with the first direction.

[0089] When the electrode assembly expands, the electrode assembly pushes against the outer shell of the battery cell and pushes the outer shell outward, causing the outer shell to deform. The outer shell is the main force-bearing surface and deforms greatly. When the outer shell deforms, the deformation of the outer shell will pull the pressure relief part, causing the pressure relief part to be subjected to pulling force, which can easily cause damage to the pressure relief part and affect the normal use of the pressure relief part.

[0090] In the present application, by making the first groove wall section 114 extend obliquely along the first direction, and the first groove wall section 114 forms an angle with the first direction, when the electrode assembly 300 expands, the straight area 301 of the electrode assembly 300 presses against the second wall portion 12 to support the shell 60 outward, causing the shell 60 to deform, and the second wall portion 12 of the shell 60 to deform greatly. When the second wall portion 12 deforms, the deformation of the second wall portion 12 will pull the first wall portion 11 along the first direction, causing the first wall portion 11 to deform. Since the first groove wall section 114 forms an angle with the first direction, after the first groove wall section 114 is subjected to force, the first groove wall section 114 can decompose the force For the component forces along the first direction and the second direction, the force angle of the notched groove 113 can be changed. The second direction is perpendicular to the first direction, and the second direction is the length direction of the first wall portion 11, as shown in Figures 4, 6 and 7. The second direction is the X direction in Figures 4, 6 and 7, thereby reducing the force on the notched groove 113, improving the deformation resistance of the notched groove 113, reducing the risk of cracking of the pressure relief portion 112, reducing the influence of external force or deformation on the position of the notched groove 113 of the pressure relief portion 112, reducing the risk of leakage of the pressure relief portion 112, and being conducive to maintaining the normal use of the pressure relief portion 112, thereby improving the fatigue life of the pressure relief portion 112.

[0091] In the above technical solution, the first groove wall section 114 forms an angle with the first direction. When the battery cell 200 expands and pulls the first wall portion 11, the pressure relief portion 112 is subjected to a pulling force. The first groove wall section 114 can decompose the force, change the force angle of the notched groove 113, reduce the force on the notched groove 113, and improve the deformation resistance of the notched groove 113, reduce the risk of cracking of the pressure relief portion 112, and reduce the influence of external force or deformation on the position of the notched groove 113 of the pressure relief portion 112.

[0092] According to some embodiments of the present application, as shown in FIG. 7 , the angle between the first slot wall segment 114 and the first direction is greater than or equal to 20° and less than or equal to 70°.

[0093] The first groove wall section 114 can be linear, or similar to a linear shape. As shown in FIG7 , the angle β between the first groove wall section 114 and the first direction satisfies the relationship: 20°≤β≤70°, where β can be a value such as 20°, 30°, 35°, 40°, or 70°. By ensuring that the angle between the first groove wall section 114 and the first direction is greater than or equal to 20° and less than or equal to 70°, the angle between the first groove wall section 114 and the first direction can be optimized. When the electrode assembly 300 expands, the first groove wall section 114 is subjected to force, which can be distributed by the first groove wall section 114, thereby reducing the force on the notched groove 113, further improving the deformation resistance of the notched groove 113, and further reducing the risk of cracking of the pressure relief portion 112.

[0094] In the above technical solution, by making the angle between the first groove wall section 114 and the first direction greater than or equal to 20° and less than or equal to 70°, the angle between the first groove wall section 114 and the first direction can be made appropriate. When the electrode assembly 300 expands, the first groove wall section 114 is subjected to force, and the first groove wall section 114 can decompose the force, which is beneficial to reducing the force on the notched groove 113, and can further enhance the deformation resistance of the notched groove 113, and further reduce the risk of cracking of the pressure relief part 112.

[0095] According to some embodiments of the present application, as shown in FIG. 7 , the first groove wall segment 114 may be multiple segments, and the multiple segments of the first groove wall segment 114 are arranged sequentially along a second direction perpendicular to the first direction.

[0096] Among them, the first groove wall section 114 can be set to multiple sections, and the multiple sections of the first groove wall sections 114 are arranged in sequence along the second direction. The two adjacent first groove wall sections 114 can be set at intervals. The number of the multiple sections of the first groove wall sections 114 can be reasonably selected and set according to the length of the wall of the first wall portion 11 provided with the pressure relief portion 112. By setting the multiple sections of the first groove wall sections 114, when the first wall portion 11 is deformed and the multiple sections of the first groove wall sections 114 are subjected to force, the multiple sections of the first groove wall sections 114 can simultaneously decompose the force into component forces along the first direction and the second direction, thereby further reducing the force on the notched groove 113, further improving the deformation resistance of the notched groove 113, further reducing the risk of cracking of the pressure relief portion 112, further reducing the influence of external force or deformation on the position of the notched groove 113 of the pressure relief portion 112, further reducing the risk of leakage of the pressure relief portion 112, and being conducive to maintaining the normal use of the pressure relief portion 112, thereby further improving the fatigue life of the pressure relief portion 112. Furthermore, by providing multiple first groove wall sections 114 , it is advantageous for the pressure relief portion 112 to be opened fastest when gas is generated at a certain position of the battery cell 200 .

[0097] In the above technical solution, by providing multiple first groove wall sections 114, the multiple first groove wall sections 114 can simultaneously decompose the force into components along the first direction and the second direction, thereby further reducing the force on the scored groove 113, further improving the deformation resistance of the scored groove 113, further reducing the risk of cracking of the pressure relief portion 112, further reducing the impact of external force or deformation on the position of the scored groove 113 of the pressure relief portion 112, further reducing the risk of leakage from the pressure relief portion 112, and facilitating the normal use of the pressure relief portion 112, thereby further improving the fatigue life of the pressure relief portion 112. In addition, when gas is generated at a certain position of the battery cell 200, the pressure relief portion 112 is subjected to the most force and opens the valve quickly.

[0098] Furthermore, some of the multiple first wall sections 114 are parallel to each other, while other portions are parallel to each other, and the extensions of two adjacent first wall sections 114 form an angle. Thus, when the first wall portion 11 deforms and the multiple first wall sections 114 are subjected to force, the multiple first wall sections 114 can simultaneously decompose the force into components along the first and second directions, effectively improving the force applied to the scored groove 113, further enhancing the deformation resistance of the scored groove 113, and further reducing the risk of cracking of the pressure relief portion 112.

[0099] According to some embodiments of the present application, as shown in FIG. 7 , the bottom wall of the notched groove 113 further has a second groove wall segment 115 , and each of two adjacent first groove wall segments 114 is connected to a second groove wall segment 115 .

[0100] The bottom wall of the notched groove 113 may further include a second groove wall section 115 , which is connected between two adjacent first groove wall sections 114 , and can connect multiple first groove wall sections 114 to form a strip structure, which is beneficial to simplifying the notched groove 113 .

[0101] In the above technical solution, since the second groove wall segment 115 is connected between two adjacent first groove wall segments 114 , multiple first groove wall segments 114 can be connected to form a strip structure, which is beneficial to simplifying the notched groove 113 .

[0102] According to some embodiments of the present application, as shown in FIG. 7 , the thickness of the second slot wall segment 115 is greater than the thickness of the first slot wall segment 114 .

[0103] The thickness of the second groove wall segment 115 is greater than the thickness of the first groove wall segment 114. It can also be understood that the minimum thickness of the second groove wall segment 115 is greater than the maximum thickness of the first groove wall segment 114. As shown in FIG7 , the second groove wall segment 115 is perpendicular or substantially perpendicular to the first direction. When the electrode assembly 300 expands, the straight area 301 of the electrode assembly 300 presses against the second wall portion 12 to support the outer shell 60 outward. The deformation of the second wall portion 12 will pull the first wall portion 11 along the first direction. Since the second groove wall section 115 is perpendicular or approximately perpendicular to the first direction, the force applied to the second groove wall section 115 will be greater than the force applied to the first groove wall section 114. Therefore, by setting the thickness of the second groove wall section 115 to be greater than the thickness of the first groove wall section 114, the structural strength at the second groove wall section 115 is not less than the structural strength at the first groove wall section 114, which can enable the second groove wall section 115 to meet the structural strength requirements, which is beneficial to improving the overall structural strength of the notched groove 113, and can improve the deformation resistance of the notched groove 113, and further reduce the risk of cracking of the pressure relief portion 112.

[0104] In the above technical solution, by setting the thickness of the second groove wall section 115 to be greater than the thickness of the first groove wall section 114, the second groove wall section 115 can meet the structural strength requirements, which is beneficial to improving the overall structural strength of the notched groove 113, and can improve the deformation resistance of the notched groove 113, further reducing the risk of cracking of the pressure relief part 112.

[0105] According to some embodiments of the present application, as shown in FIG. 7 , the bottom wall of the notched groove 113 further has an arcuate third groove wall segment 116 , and the third groove wall segment 116 connects the adjacent first groove wall segments 114 and the second groove wall segments 115 .

[0106] The bottom wall of the scored groove 113 has a third groove wall section 116, which has an arcuate structure and connects between the adjacent first groove wall section 114 and second groove wall section 115. By configuring the third groove wall section 116 as an arcuate structure, a transition groove wall section can be formed between the first groove wall section 114 and the second groove wall section 115. When the pressure relief portion 112 is subjected to force, the risk of stress concentration on the bottom wall of the scored groove 113 is reduced, further improving the deformation resistance of the scored groove 113 and reducing the risk of cracking of the pressure relief portion 112.

[0107] In the above technical solution, the third groove wall section 116 is an arc-shaped structure, and the third groove wall section 116 is connected between the adjacent first groove wall section 114 and the second groove wall section 115, so that a transition groove wall can be formed between the first groove wall section 114 and the second groove wall section 115. After the pressure relief portion 112 is subjected to force, it is beneficial to reduce the risk of stress concentration on the bottom wall of the notched groove 113, further improve the deformation resistance of the notched groove 113, and further reduce the risk of cracking of the pressure relief portion 112.

[0108] According to some embodiments of the present application, as shown in FIG. 7 , the third slot wall segment 116 is an arc-shaped structure.

[0109] The third groove wall section 116 can be configured as an arc-shaped structure, and the length of the third groove wall section 116 can be appropriately selected and set according to actual conditions. By configuring the third groove wall section 116 as an arc-shaped structure, a circular arc transition groove wall can be formed between the first groove wall section 114 and the second groove wall section 115, thereby achieving a smooth transition between the first groove wall section 114 and the second groove wall section 115. When the pressure relief portion 112 is subjected to force, the risk of stress concentration on the bottom wall of the notched groove 113 is further reduced, thereby further improving the deformation resistance of the notched groove 113 and further reducing the risk of cracking of the pressure relief portion 112.

[0110] In the above technical solution, by setting the third groove wall section 116 to a circular arc structure, a circular arc transition section groove wall can be formed between the first groove wall section 114 and the second groove wall section 115, so that a smooth transition is made between the first groove wall section 114 and the second groove wall section 115. After the pressure relief portion 112 is subjected to force, it is more conducive to reducing the risk of stress concentration on the bottom wall of the notched groove 113, which can further enhance the deformation resistance of the notched groove 113 and further reduce the risk of cracking of the pressure relief portion 112.

[0111] According to some embodiments of the present application, the thickness of the third groove wall segment 116 gradually increases from the first groove wall segment 114 to the second groove wall segment 115 .

[0112] The thickness of the third wall section 116 gradually increases along the length of the scored groove 113 from the first wall section 114 to the second wall section 115. Since the thickness of the second wall section 115 is greater than that of the first wall section 114, the gradual increase in the thickness of the third wall section 116 from the first wall section 114 to the second wall section 115 allows the groove wall between the first wall section 114 and the second wall section 115 to form a gradual thickness variation structure, resulting in a smooth and gentle transition between the first wall section 114 and the second wall section 115. This further helps reduce the risk of stress concentration on the bottom wall of the scored groove 113 after the pressure relief portion 112 is subjected to force, further improving the deformation resistance of the scored groove 113 and reducing the risk of cracking of the pressure relief portion 112.

[0113] In the above technical solution, by gradually increasing the thickness of the third groove wall section 116 from the first groove wall section 114 to the second groove wall section 115, the groove wall between the first groove wall section 114 and the second groove wall section 115 can form a thickness gradient structure, so that the first groove wall section 114 and the second groove wall section 115 have a smooth and gentle transition. After the pressure relief portion 112 is subjected to force, it is more conducive to reducing the risk of stress concentration on the bottom wall of the notched groove 113, which can further enhance the deformation resistance of the notched groove 113 and further reduce the risk of cracking of the pressure relief portion 112.

[0114] According to some embodiments of the present application, as shown in FIG. 7 , the second groove wall section 115 is arc-shaped, and along the first direction, the second groove wall section 115 protrudes toward the outside of the shell body 111 .

[0115] As shown in FIG7 , the second groove wall section 115 can be configured as an arc. Along the first direction, the second groove wall section 115 protrudes toward the outside of the shell body 111, that is, along the Z direction in FIG7 , the second groove wall section 115 protrudes toward the outside of the shell body 111. By having the second groove wall section 115 protrude toward the outside of the shell body 111 along the first direction, the scored groove 113 can be configured as a wavy structure, which can simplify the structural shape of the scored groove 113, facilitate the processing and formation of the scored groove 113 on the pressure relief portion 112, improve the production efficiency of the pressure relief portion 112, and thus improve the production efficiency of the battery cell 200.

[0116] In the above technical solution, by protruding the second groove wall section 115 toward the outer side of the shell body 111 along the first direction, the notched groove 113 can be constructed into a wavy structure, which can simplify the structural shape of the notched groove 113 and facilitate the processing and formation of the notched groove 113 on the pressure relief portion 112, thereby improving the production efficiency of the pressure relief portion 112 and thus improving the production efficiency of the battery cell 200.

[0117] According to some embodiments of the present application, as shown in FIG. 7 , the second groove wall section 115 is arc-shaped, and the radius of the second groove wall section 115 is greater than or equal to 1 mm and less than or equal to 10 mm.

[0118] The second groove wall section 115 can be configured as an arc-shaped structure, with a radius of the second groove wall section 115 being greater than or equal to 1 mm and less than or equal to 10 mm. The radius of the second groove wall section 115 can be set to values ​​such as 1 mm, 2 mm, 2.5 mm, 5 mm, 9 mm, and 10 mm. By configuring the second groove wall section 115 as an arc-shaped structure, a smooth transition can be formed at the bend of the scored groove 113. When the pressure relief portion 112 is subjected to force, the risk of stress concentration in the second groove wall section 115 can be reduced, which is more conducive to reducing the risk of stress concentration in the bottom wall of the scored groove 113, further improving the deformation resistance of the scored groove 113, and further reducing the risk of cracking of the pressure relief portion 112.

[0119] In the above technical solution, by setting the second groove wall section 115 to a circular arc structure, a smooth transition can be formed at the bending part of the notched groove 113. When the pressure relief part 112 is subjected to force, the risk of stress concentration in the second groove wall section 115 can be reduced, which is more conducive to reducing the risk of stress concentration on the bottom wall of the notched groove 113, and can further enhance the deformation resistance of the notched groove 113, and further reduce the risk of cracking of the pressure relief part 112.

[0120] According to some embodiments of the present application, the second groove wall segment 115 is a linear structure, and the second groove wall segment 115 extends along the second direction.

[0121] The second groove wall section 115 can be configured as a linear structure. It should be noted that the second groove wall section 115 is a linear structure, or the second groove wall section 115 is similar to a linear structure, and the second groove wall section 115 extends along the second direction. By configuring the second groove wall section 115 as a linear structure, the structural shape of the scored groove 113 can be further simplified, reducing the difficulty of processing the scored groove 113, making it easier to process the scored groove 113 on the pressure relief portion 112, further improving the production efficiency of the pressure relief portion 112, and thus further improving the production efficiency of the battery cell 200.

[0122] In the above technical solution, by setting the second groove wall section 115 as a straight structure, the structural shape of the notched groove 113 can be further simplified, the processing difficulty of the notched groove 113 can be reduced, and it is more convenient to process and form the notched groove 113 on the pressure relief part 112, thereby further improving the production efficiency of the pressure relief part 112, thereby further improving the production efficiency of the battery cell 200.

[0123] According to some embodiments of the present application, a ratio of the maximum thickness of the second slot wall segment 115 to the minimum thickness of the first slot wall segment 114 is greater than or equal to 1.1 and less than or equal to 1.8.

[0124] Along the length of the scored groove 113, the thickness of the second groove wall segment 115 can remain constant or gradually change, and the thickness of the first groove wall segment 114 can remain constant or gradually change. The ratio of the maximum thickness of the second groove wall segment 115 to the minimum thickness of the first groove wall segment 114 can be 1.1, 1.2, 1.3, 1.5, 1.8, or other values. As shown in Figure 7, since the second groove wall section 115 is perpendicular or approximately perpendicular to the first direction, when the electrode assembly 300 expands, the straight area 301 of the electrode assembly 300 presses against the second wall portion 12 to support the outer shell 60 outward. The deformation of the second wall portion 12 will pull the first wall portion 11 along the first direction. Since the second groove wall section 115 is perpendicular or approximately perpendicular to the first direction, the force applied to the second groove wall section 115 will be greater than the force applied to the first groove wall section 114. Therefore, by ensuring that the ratio of the maximum thickness of the second groove wall section 115 to the minimum thickness of the first groove wall section 114 is greater than or equal to 1.1 and less than or equal to 1.8, the structural strength of the second groove wall section 115 is not less than the structural strength of the first groove wall section 114, which can enable the second groove wall section 115 to meet the structural strength requirements, which is more conducive to improving the overall structural strength of the notched groove 113, further improving the deformation resistance of the notched groove 113, and further reducing the risk of cracking of the pressure relief portion 112.

[0125] In the above technical solution, the ratio of the maximum thickness of the second groove wall section 115 to the minimum thickness of the first groove wall section 114 is greater than or equal to 1.1 and less than or equal to 1.8, so that the structural strength of the second groove wall section 115 is not less than the structural strength of the first groove wall section 114, which can enable the second groove wall section 115 to meet the structural strength requirements, is more conducive to improving the overall structural strength of the notched groove 113, can further improve the deformation resistance of the notched groove 113, and further reduce the risk of cracking of the pressure relief part 112.

[0126] According to some embodiments of the present application, a ratio of the maximum thickness of the second slot wall segment 115 to the maximum thickness of the shell body 111 is greater than or equal to 0.05 and less than or equal to 0.5.

[0127] The ratio of the maximum thickness of the second slot wall section 115 to the maximum thickness of the shell body 111 is greater than or equal to 0.05 and less than or equal to 0.5. The ratio of the maximum thickness of the second slot wall section 115 to the maximum thickness of the shell body 111 can be 0.05, 0.1, 0.2, 0.15, 0.3, 0.4, 0.5, etc. By ensuring that the ratio of the maximum thickness of the second slot wall section 115 to the maximum thickness of the shell body 111 is greater than or equal to 0.05 and less than or equal to 0.5, when the battery cell 200 experiences thermal runaway, the pressure relief portion 112 can be cracked in the second slot wall section 115 and the first slot wall section 114, thereby achieving a pressure relief effect and reducing the risk of explosion of the battery cell 200.

[0128] In the above technical solution, by making the ratio of the maximum thickness of the second slot wall section 115 to the maximum thickness of the shell body 111 greater than or equal to 0.05 and less than or equal to 0.5, when the battery cell 200 suffers thermal runaway, the pressure relief portion 112 can be cracked in the second slot wall section 115 and the first slot wall section 114 to achieve a pressure relief effect and reduce the risk of explosion of the battery cell 200.

[0129] According to some embodiments of the present application, as shown in FIG. 7 , the shell body 111 is formed with two reinforcing ribs 117 , and both ends of the notched groove 113 are respectively connected to the two reinforcing ribs 117 .

[0130] Among them, the reinforcement rib 117 can be integrally formed with the shell body 111, and the notched groove 113 can be located between the two reinforcement ribs 117. One end of the notched groove 113 is connected to one reinforcement rib 117, and the other end of the notched groove 113 is connected to another reinforcement rib 117. The two ends of the notched groove 113 are respectively connected to the two reinforcement ribs 117. The reinforcement rib 117 plays a structural reinforcement role. When the bottom wall of the notched groove 113 of the pressure relief part 112 cracks to relieve pressure, the risk of continuous tearing of the shell body 111 at both ends of the notched groove 113 can be reduced.

[0131] In the above technical solution, the two ends of the notched groove 113 are respectively connected to two reinforcing ribs 117, and the reinforcing ribs 117 play a structural reinforcement role. When the bottom wall of the notched groove 113 of the pressure relief portion 112 cracks to relieve pressure, the risk of continuous tearing of the shell body 111 at both ends of the notched groove 113 can be reduced.

[0132] According to some embodiments of the present application, as shown in FIG. 7 , two reinforcing ribs 117 are opposite to each other and spaced apart, and the reinforcing ribs 117 are arc-shaped.

[0133] The two reinforcing ribs 117 are arranged opposite each other and spaced apart along the second direction, with the notched groove 113 located between the two reinforcing ribs 117. Each reinforcing rib 117 is arc-shaped, and the reinforcing ribs 117 can be circular arc-shaped. By providing the reinforcing ribs 117 with an arc-shaped structure, the structural strength of the reinforcing ribs 117 can be improved. When the bottom wall of the notched groove 113 of the pressure relief portion 112 cracks to release pressure, the risk of continued tearing of the shell body 111 at both ends of the notched groove 113 can be further reduced.

[0134] In the above technical solution, by setting the reinforcing rib 117 as an arc-shaped structure, the structural strength of the reinforcing rib 117 can be improved. When the bottom wall of the notched groove 113 of the pressure relief portion 112 cracks to relieve pressure, the risk of continuously tearing the shell body 111 at both ends of the notched groove 113 can be further reduced.

[0135] According to some embodiments of the present application, as shown in FIG. 7 , along the first direction, the pressure relief portion 112 is located in the middle of the shell body 111 .

[0136] In the first direction, the pressure relief portion 112 is located in the middle of the shell body 111. The pressure relief portion 112 can be located in the exact center of the shell body 111, and the score groove 113 can have a wavy structure. It should be noted that if the pressure relief portion 112 is offset by 5% of the width of the shell body 111 in the first direction, it can be considered that the pressure relief portion 112 is located in the middle of the shell body 111. By locating the pressure relief portion 112 in the middle of the shell body 111 in the first direction, the force applied to the score groove 113 can be uniform, reducing the force applied to the score groove 113. This facilitates tearing of the score groove 113 at all locations under the same blasting pressure, further increasing the fatigue life of the pressure relief portion 112.

[0137] In the above technical solution, by locating the pressure relief portion 112 in the middle of the shell body 111 along the first direction, the force applied to each position of the notched groove 113 can be uniform, reducing the force applied to the notched groove 113, which is conducive to tearing each position of the notched groove 113 under the same blasting pressure, thereby further increasing the fatigue life of the pressure relief portion 112.

[0138] According to some embodiments of the present application, as shown in FIG. 4 , the shell body 111 has a shell bottom wall 118 opposite to the open end 120 of the outer shell 60 , and the pressure relief portion 112 is provided on the shell bottom wall 118 .

[0139] The housing bottom wall 118 is used to support the electrode assembly 300 and is located below the electrode assembly 300. The first wall portion 11 is connected between the two second wall portions 12 to define a mounting cavity 30 with one end open. The housing body 111 has a housing bottom wall 118, which is disposed opposite the open end 120 of the mounting cavity 30. The end cap 20 is used to close the open end 120 of the mounting cavity 30. The housing bottom wall 118 is disposed adjacent to the second wall portion 12, and the area of ​​the housing bottom wall 118 is smaller than that of the second wall portion 12.

[0140] In the above technical solution, by arranging the pressure relief portion 112 on the bottom wall 118 of the shell, the pressure relief effect of the battery cell 200 toward the bottom can be achieved, which can reduce the risk of high-temperature, high-pressure substances ejected from the battery cell 200 injuring surrounding personnel.

[0141] According to some embodiments of the present application, as shown in FIG. 6 , the shell body 111 has a shell sidewall 119 adjacent to the open end 120 of the outer shell 60 , and the pressure relief portion 112 is provided on the shell sidewall 119 .

[0142] The first wall portion 11 is connected between the two second wall portions 12 to define an installation cavity 30 with one end open. The end cap 20 is used to close the open end 120 of the installation cavity 30. The shell body 111 has a shell side wall 119 adjacent to the end cap 20. It can also be understood that the shell side wall 119 is disposed adjacent to the open end 120 of the installation cavity 30 and is also disposed adjacent to the second wall portion 12. The pressure relief portion 112 is disposed on the shell side wall 119.

[0143] In the above technical solution, by arranging the pressure relief portion 112 on the shell side wall 119 , the battery cell 200 can be pressure-relieved laterally. During the pressure relief process of the battery cell 200 , high-temperature and high-pressure substances in the battery cell 200 can be quickly discharged from the battery cell 200 .

[0144] According to some embodiments of the present application, the present application further provides a battery 400 , comprising the battery cell 200 in the above embodiment.

[0145] According to some embodiments of the present application, the present application further provides an electrical device 500 , comprising the battery 400 in the above embodiment.

[0146] According to some embodiments of the present application, as shown in Figures 4 and 7, the present application provides a battery cell 200, which includes an end cap 20, a housing 60, and an electrode assembly 300. The housing 60 defines a mounting cavity 30, within which the electrode assembly 300 is mounted. The end cap 20 closes the open end 120 of the mounting cavity 30 and is fixedly connected to the housing 60. The housing 6 includes a first wall portion 11 and two second wall portions 12. The two second wall portions 12 are located on either side of the straight region 301 of the electrode assembly 300 along a first direction, and the second wall portions 12 are opposite to the straight region 301 of the electrode assembly 300. A pressure relief portion 112 is provided on the bottom wall 118 of the housing body 111. The pressure relief portion 112 is formed with a notched groove 113. The bottom wall of the notched groove 113 has a first groove wall section 114 extending obliquely along the first direction, with the first groove wall section 114 forming an angle with the first direction. The notched groove 113 can have a wavy structure.

[0147] It should be noted that, unless there is any conflict, the embodiments and features in the embodiments of this application can be combined with each other.

[0148] As shown in FIG4 and FIG6 , the difference between the battery cell 200 of the first embodiment and the battery cell 200 of the second embodiment is that the pressure relief portion 112 of the battery cell 200 of the first embodiment is disposed on the bottom wall 118 of the shell, while the pressure relief portion 112 of the battery cell 200 of the second embodiment is disposed on the side wall 119 of the shell.

[0149] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0150] Although the embodiments of the present application have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and intent of the present application, and that the scope of the present application is defined by the claims and their equivalents.

Claims

1. A battery cell, wherein: include: An electrode assembly, comprising a positive electrode sheet and a negative electrode sheet, wherein the positive electrode sheet and the negative electrode sheet are stacked to form a straight region, and at least a portion of the positive electrode sheet and at least a portion of the negative electrode sheet are stacked in a first direction in the straight region; A shell, used to accommodate the electrode assembly, the shell comprising a first wall portion and two second wall portions connected to the first wall portion, the two second wall portions are respectively located at two sides of the straight area along the first direction; Among them, the first wall portion includes a shell body and a pressure relief portion, the shell body is arranged around the outer circumference of the pressure relief portion, the pressure relief portion is formed with a notched groove, and the bottom wall of the notched groove has a first groove wall section extending obliquely along the first direction, and the first groove wall section forms an angle with the first direction.

2. The battery cell according to claim 1, wherein: An included angle between the first slot wall segment and the first direction is greater than or equal to 20° and less than or equal to 70°.

3. The battery cell according to claim 1 or 2, wherein: The first groove wall segments are multiple segments, and the multiple segments of the first groove wall segments are arranged in sequence along a second direction perpendicular to the first direction.

4. The battery cell according to claim 3, wherein: The bottom wall of the notched groove further has a second groove wall section, and two adjacent first groove wall sections are connected to each other with the second groove wall section.

5. The battery cell according to claim 4, wherein: The thickness of the second groove wall section is greater than the thickness of the first groove wall section.

6. The battery cell according to claim 5, wherein: The bottom wall of the notched groove further has an arc-shaped third groove wall section, and the third groove wall section is connected between the adjacent first groove wall section and the second groove wall section.

7. The battery cell according to claim 6, wherein: The third groove wall section is an arc-shaped structure.

8. The battery cell according to claim 6, wherein: The thickness of the third groove wall section gradually increases from the first groove wall section to the second groove wall section.

9. The battery cell according to any one of claims 4 to 8, wherein: The second groove wall section is arc-shaped, and along the first direction, the second groove wall section protrudes toward the outer side of the shell body.

10. The battery cell according to claim 9, wherein: The second groove wall section is in an arc shape, and a radius of the second groove wall section is greater than or equal to 1 mm and less than or equal to 10 mm.

11. The battery cell according to any one of claims 4 to 8, wherein: The second groove wall section is a linear structure, and the second groove wall section extends along the second direction.

12. The battery cell according to any one of claims 5 to 8, wherein: The ratio of the maximum thickness of the second groove wall section to the minimum thickness of the first groove wall section is greater than or equal to 1.1 and less than or equal to 1.

8.

13. The battery cell according to any one of claims 4 to 8, wherein: The ratio of the maximum thickness of the second groove wall segment to the maximum thickness of the shell body is greater than or equal to 0.05 and less than or equal to 0.

5.

14. The battery cell according to any one of claims 1 to 8, wherein: The shell body is formed with two reinforcing ribs, and the two ends of the notched groove are respectively connected to the two reinforcing ribs.

15. The battery cell according to claim 14, wherein: The two reinforcing ribs are opposite to each other and spaced apart, and the reinforcing ribs are arc-shaped.

16. The battery cell according to any one of claims 1 to 8, wherein: Along the first direction, the pressure relief portion is located in the middle of the shell body.

17. The battery cell according to any one of claims 1 to 8, wherein: The shell body has a shell bottom wall opposite to the open end of the shell, and the pressure relief portion is arranged on the shell bottom wall.

18. The battery cell according to any one of claims 1 to 8, wherein: The shell body has a shell side wall adjacent to the open end of the shell, and the pressure relief portion is arranged on the shell side wall.

19. A battery, wherein: The invention comprises a battery cell according to any one of claims 1 to 18.

20. An electrical device, wherein: Comprising a battery according to claim 19.

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