Battery monomer, battery device and electric device

Abstract

The utility model provides a battery monomer, a battery device and a power utilization device. The battery monomer comprises a shell, a pressure relief mechanism and a protection piece, the shell comprises a first wall, and the pressure relief mechanism is arranged on the first wall. The protection piece is arranged on the side, back on to the interior of the battery monomer, of the first wall and covers the pressure relief mechanism, the protection piece comprises a base body and a connecting part, the connecting part is connected between the base body and the first wall and comprises a first part and a second part, and the light transmittance of the first part is larger than that of the second part; the projection of the second part in the thickness direction of the first wall is not overlapped with the projection of the pressure relief mechanism in the thickness direction. According to the invention, the detectability of the battery monomer can be effectively improved.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery cell, a battery device, and an electrical device. Background Art

[0002] With the development of new energy technology, batteries are used more and more widely, for example, in mobile phones, laptops, electric vehicles, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes and power tools.

[0003] During the battery manufacturing process, battery cells must be inspected to confirm whether they meet quality requirements. The detectability of battery cells directly affects the efficiency of testing and the reliability of the end product. Therefore, how to effectively improve the detectability of battery cells is a technical issue that continues to be improved in battery technology. Utility Model Content

[0004] In view of the above problems, the present application provides a battery cell, a battery device and an electrical device, which can effectively improve the detectability of the battery cell.

[0005] In a first aspect, embodiments of the present application provide a battery cell, comprising a housing, a pressure relief mechanism, and a protective member. The housing comprises a first wall, and the pressure relief mechanism is disposed on the first wall. The protective member is disposed on a side of the first wall facing away from the interior of the battery cell and covers the pressure relief mechanism. The protective member comprises a base and a connecting portion, the connecting portion being connected between the base and the first wall. The connecting portion comprises a first portion and a second portion, the light transmittance of the first portion being greater than the light transmittance of the second portion, and the projection of the second portion along the thickness direction of the first wall does not overlap with the projection of the pressure relief mechanism along the thickness direction.

[0006] The first part is mainly used to increase the overall coverage area of ​​the connection part to improve the success rate and firmness of the attachment of the protective part, and the light transmittance of the first part is relatively large, and it is not easy to block the pressure relief mechanism when it is set over a large area. The light transmittance of the second part is relatively small, and it has better observability. It mainly plays an identification role. By observing whether there is a second part at the position of the pressure relief mechanism of the battery cell, it can be judged whether the protective part has been attached to this battery cell, thereby reducing the risk of missing the protective sheet. In addition, the projection of the second part along the thickness direction of the first wall does not overlap with the projection of the pressure relief mechanism along the thickness direction, so as to reduce the risk of the second part blocking the pressure relief mechanism, so that when the pressure relief mechanism has abnormal conditions such as damage or dirt, it can be easily detected. In summary, the above technical solution can effectively improve the detectability of battery cells.

[0007] In some embodiments of the first aspect, a projection of the first portion along the thickness direction at least partially overlaps with a projection of the pressure relief mechanism along the thickness direction.

[0008] The above technical solution can further increase the coverage area of ​​the first part, thereby further improving the attachment success rate and firmness of the protective element.

[0009] In some embodiments of the first aspect, the first portion and the second portion are both substantially disposed around the pressure relief mechanism, and the second portion is connected to an outer peripheral side of the first portion.

[0010] On the one hand, the first and second parts surround the pressure relief mechanism, forming a concentric or quasi-concentric structural layout, which can further increase the coverage of the connection portion, thereby further improving the success rate and firmness of the protective member's attachment. On the other hand, the second part is connected to the first part, which can improve the overall structural strength of the connection and reduce the difficulty of installation. The second part is located on the outer periphery of the first part, which can further reduce the risk of the second part blocking the pressure relief mechanism.

[0011] In some embodiments of the first aspect, a projection of the second portion along the thickness direction does not overlap with a projection of the first portion along the thickness direction.

[0012] The above technical solution can reduce the overall thickness of the connecting portion, thereby reducing the occupation of the protective component on the external space of the battery cell, which is beneficial to reducing the overall volume of the battery cell and improving the energy density of the battery cell.

[0013] In some embodiments of the first aspect, a projection of the second portion along the thickness direction at least partially overlaps with a projection of the first portion along the thickness direction.

[0014] The above technical solution can reduce the difficulty of setting up the second part, thereby helping to reduce the overall preparation cost of the battery cell.

[0015] In some embodiments of the first aspect, the first portion defines a recessed portion that is recessed relative to at least one of two opposite surfaces of the first portion in the thickness direction, and at least a portion of the second portion is accommodated in the recessed portion.

[0016] The above technical solution introduces a recess that can accommodate at least part of the second part. On the one hand, it can reduce the overall space occupancy of the connection part, which is beneficial to improving the energy density of the battery cell; on the other hand, it can also improve the connection strength between the second part and the first part, thereby improving the reliability of the protective part.

[0017] In some embodiments of the first aspect, a boss is provided on the first wall, the boss protrudes from a side surface of the first wall facing away from the interior of the battery cell and is provided around the pressure relief mechanism, and the connecting portion is connected between the boss and the base.

[0018] The above technical solution introduces a boss to connect the protective part to the boss, which can reduce the risk of damage to the pressure relief mechanism caused by interference between the protective part and the pressure relief mechanism during assembly, and can improve the product yield and reliability of the battery cell.

[0019] In some embodiments of the first aspect, a groove is formed on the boss, the groove being recessed relative to a surface of the boss facing away from the first wall. The pressure relief mechanism, the protective member and the boss together define a cavity, and the groove connects the cavity to the external environment.

[0020] The above technical solution can make the battery cell have good sealing performance, reduce the possibility of electrolyte volatilization, and thus the battery cell has higher reliability.

[0021] In some embodiments of the first aspect, the connecting portion has an escape opening corresponding to the groove, and a projection of the groove along the thickness direction is located within a projection of the escape opening along the thickness direction.

[0022] The above technical solution introduces a relief port, which can reduce the risk of the connection portion blocking the groove and causing the airtightness test to be unable to be performed, so that the cavity can maintain communication with the outside world through the groove, thereby improving the reliability of the battery cell.

[0023] In some embodiments of the first aspect, the base and the first portion are both transparent structures, and the second portion includes a color mark.

[0024] The above technical solution can effectively improve the detectability of battery cells at a relatively low cost.

[0025] In a second aspect, the present application provides a battery device comprising the battery cell provided in any embodiment of the first aspect.

[0026] In a third aspect, the present application provides an electrical device, which includes a battery cell provided by any embodiment of the first aspect or a battery device provided by any embodiment of the second aspect, and the battery cell or the battery device is used to store or provide electrical energy.

[0027] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present application. The same reference symbols are used throughout the drawings to represent the same components. In the drawings:

[0029] Figure 1 A schematic structural diagram of a vehicle provided in some embodiments of the present application;

[0030] Figure 2 A schematic diagram of an exploded structure of a battery device provided in some embodiments of the present application;

[0031] Figure 3 A schematic structural diagram of a battery module provided in some embodiments of the present application;

[0032] Figure 4 A schematic diagram of a partial explosion structure of a battery cell provided in some embodiments of the present application;

[0033] Figure 5 for Figure 4 A schematic diagram of the partially enlarged structure at H;

[0034] Figure 6 A schematic top view of a connecting portion of a protective member provided in some embodiments of the present application;

[0035] Figure 7 for Figure 6 Schematic diagram of the cross-section structure along AA;

[0036] Figure 8 A schematic diagram of a partial explosion structure of another battery cell provided in some embodiments of the present application;

[0037] Figure 9 A schematic top view of the connecting portion of another protective member provided in some embodiments of the present application;

[0038] Figure 10 for Figure 9 Schematic diagram of the cross-sectional structure along BB.

[0039] The accompanying drawings in the specific implementation manner are as follows:

[0040] 1. Vehicle; 2. Battery device; 3. Controller; 4. Motor; 5. Housing; 5a. First housing portion; 5b. Second housing portion; 5c. Accommodation space; 6. Battery module; 7. Battery cell;

[0041] 10. housing; 11. first wall;

[0042] 20. Pressure relief mechanism;

[0043] 30. Protective member; 31. Base; 32. Connecting portion; 321. First portion; 322. Second portion; 40. Recess; 50. Boss; 60. Groove; 70. Avoidance opening;

[0044] X, first direction. DETAILED DESCRIPTION

[0045] 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 and completely described below in conjunction with the accompanying 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.

[0046] 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 only for the purpose of describing specific embodiments 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] The term "plurality" used in this application refers to two or more (including two).

[0052] In this application, the term "parallel" includes not only the absolutely parallel situation, but also the roughly parallel situation conventionally recognized in engineering; at the same time, "vertical" also includes not only the absolutely vertical situation, but also the roughly vertical situation conventionally recognized in engineering.

[0053] In the embodiment of the present application, the battery cell may be a secondary battery cell. A secondary battery cell refers to a battery cell that can be continuously used by activating active materials by charging after the battery cell is discharged.

[0054] The battery cell can be a lithium-ion battery cell, a sodium-ion battery cell, a sodium-lithium-ion battery cell, a lithium metal battery cell, a sodium metal battery cell, a lithium-sulfur battery cell, a magnesium-ion battery cell, a nickel-hydrogen battery cell, a nickel-cadmium battery cell, a lead-acid battery cell, etc., and the embodiments of the present application are not limited to this.

[0055] A battery cell typically includes an electrode assembly. This electrode assembly includes a positive electrode and a negative electrode. During the charge and discharge process of a battery cell, active ions (such as lithium ions) are intercalated and released back and forth between the positive and negative electrodes.

[0056] 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 disposed on at least one surface of the positive electrode current collector.

[0057] As an example, the positive electrode current collector has two surfaces facing each other in its thickness direction, and the positive electrode active material is provided on either or both of the two facing surfaces of the positive electrode current collector.

[0058] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0059] As an example, the negative electrode sheet may include a negative electrode current collector and a negative electrode active material disposed on at least one surface of the negative electrode current collector.

[0060] As an example, the negative electrode current collector has two surfaces facing each other in its thickness direction, and the negative electrode active material is provided on either or both of the two facing surfaces of the negative electrode current collector.

[0061] In some embodiments, the electrode assembly further includes a separator disposed between the positive electrode and the negative electrode.

[0062] The electrode assembly may be a wound structure, a laminated structure, or a mixed structure of wound and laminated structures.

[0063] In some embodiments, the electrode assembly is a wound structure, wherein the positive electrode sheet and the negative electrode sheet are wound into the wound structure.

[0064] In some embodiments, the electrode assembly is a laminate structure.

[0065] 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.

[0066] As an example, a plurality of positive electrode sheets may be provided, and the negative electrode sheet may be folded to form a plurality of stacked folded segments, with a positive electrode sheet being sandwiched between adjacent folded segments.

[0067] As an example, both the positive electrode sheet and the negative electrode sheet are folded to form a plurality of stacked folded segments.

[0068] As an example, a plurality of separators may be provided, each of which is disposed between any adjacent positive electrode sheets or negative electrode sheets.

[0069] 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.

[0070] In some embodiments, the shape of the electrode assembly can be cylindrical, flat, or polygonal.

[0071] In some embodiments, the electrode assembly is provided with tabs that can conduct current from the electrode assembly. The tabs include a positive tab and a negative tab.

[0072] In some embodiments, the battery cell may include an outer shell. The outer shell may be a steel shell, an aluminum shell, a plastic shell (such as polypropylene), a composite metal shell (such as a copper-aluminum composite shell), or an aluminum-plastic film. In some embodiments, the outer shell may be a sealed structure or a non-sealed structure. As an example, when the outer shell is a non-sealed structure, the outer shell serves to protect the electrode assembly, and a sealing bag is further included between the outer shell and the electrode assembly, which is used to encapsulate the electrode assembly and the electrolyte. Specifically, the sealing bag may be a bag-shaped insulating member or an aluminum-plastic film. When the outer shell is a sealed structure, it is used to encapsulate components such as the electrode assembly and the electrolyte.

[0073] As an example, the battery cells may be cylindrical, prismatic, soft-pack or other shaped battery cells. Prismatic battery cells include square-shell, blade-shaped, and polygonal batteries. Polygonal batteries may be, for example, hexagonal batteries.

[0074] In some embodiments, the housing includes an end cap and a shell, wherein the shell has an opening and the end cap covers the opening. The shell may have one or more openings. One or more end caps may also be provided.

[0075] In some embodiments, the housing is provided with at least one electrode terminal, which is electrically connected to the tab. The electrode terminal may be directly connected to the tab or indirectly connected to the tab via a current collecting member. The electrode terminal may be provided on an end cap or on the housing.

[0076] The battery apparatus mentioned in the embodiments of the present application may include one or more battery cell assemblies for providing voltage and capacity. The battery cell assembly may include multiple battery cells, which are connected in series, parallel, or hybrid via a busbar.

[0077] In some embodiments, a battery cell assembly is generally formed by arranging a plurality of battery cells.

[0078] As an example, the battery cell assembly may be a battery module, which is formed by arranging and fixing multiple battery cells to form an independent module. As an example, the battery module may be formed by bundling multiple battery cells with a cable tie.

[0079] In some embodiments, the battery device may be a battery pack, which includes a case and one or more battery cell assemblies, wherein the battery cell assemblies are housed in the case.

[0080] As an example, the battery cell assembly may be a battery module, and the battery cell assembly may be accommodated in the box by fixing the battery module in the box.

[0081] As an example, the battery cell assembly may also be housed in the box by directly fixing the plurality of battery cells to the box.

[0082] As an example, the box may include a top cover, a frame, and a bottom plate, wherein the top cover and the bottom plate are respectively connected to the frame to form a closed space inside the box to accommodate the battery cell assembly.

[0083] 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.

[0084] The technical solutions described in the embodiments of the present application are applicable to various electrical devices that use battery cells, such as mobile phones, portable devices, laptop computers, electric vehicles, electric toys, electric tools, vehicles, ships and spacecraft, for example, spacecraft include airplanes, rockets, space shuttles and spacecraft, etc.

[0085] With the development of new energy technology, batteries are used more and more widely, for example, in mobile phones, laptops, electric vehicles, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes and power tools.

[0086] During the battery manufacturing process, battery cells need to be tested to confirm whether they meet quality requirements. The detectability of battery cells will directly affect the detection efficiency of battery cells and the reliability of terminal products.

[0087] At present, battery cells are usually equipped with protective parts to cover the pressure relief mechanism. The protective parts include a transparent substrate and a colored adhesive backing. The colored adhesive backing is arranged around the protective parts. The color of the adhesive backing is to facilitate the detection of missing attachments. In other words, by observing whether there is color at the location of the pressure relief mechanism of the battery cell, it can be determined whether the battery cell has been attached with a protective part.

[0088] However, the colored adhesive backing typically covers a larger area, meaning that the colored adhesive backing overlaps the pressure relief mechanism along the height of the battery cell. This reduces the risk of the protective element misaligning and causing attachment failures, thereby increasing the success rate of attachment. Furthermore, the colored adhesive backing has a relatively low light transmittance, which can partially obscure the pressure relief mechanism. This makes it difficult to detect abnormalities such as damage or contamination, thus severely impacting the detectability of the battery cell.

[0089] Based on the above considerations, an embodiment of the present application provides a battery cell, comprising a housing, a pressure relief mechanism, and a protective member. The housing comprises a first wall, and the pressure relief mechanism is disposed on the first wall. The protective member is disposed on a side of the first wall facing away from the interior of the battery cell and covers the pressure relief mechanism. The protective member comprises a base and a connecting portion, the connecting portion being connected between the base and the first wall. The connecting portion comprises a first portion and a second portion, the light transmittance of the first portion being greater than the light transmittance of the second portion, and the projection of the second portion along the thickness direction of the first wall does not overlap with the projection of the pressure relief mechanism along the thickness direction.

[0090] The first part is mainly used to increase the overall coverage area of ​​the connection part to improve the success rate and firmness of the attachment of the protective part, and the light transmittance of the first part is relatively large, and it is not easy to block the pressure relief mechanism when it is set over a large area. The light transmittance of the second part is relatively small, and it has better observability. It mainly plays an identification role. By observing whether there is a second part at the position of the pressure relief mechanism of the battery cell, it can be judged whether the protective part has been attached to this battery cell, thereby reducing the risk of missing the protective sheet. In addition, the projection of the second part along the thickness direction of the first wall does not overlap with the projection of the pressure relief mechanism along the thickness direction, so as to reduce the risk of the second part blocking the pressure relief mechanism, so that when the pressure relief mechanism has abnormal conditions such as damage or dirt, it can be easily detected. In summary, the above technical solution can effectively improve the detectability of battery cells.

[0091] The battery cells provided in the embodiments of the present application are introduced below with reference to the accompanying drawings.

[0092] Figure 1 A schematic structural diagram of a vehicle provided for some embodiments of the present application.

[0093] Continue to refer Figure 1 The vehicle 1 is provided with a battery device 2 inside. The battery device 2 can be provided at the bottom, head, or tail of the vehicle 1. The battery device 2 can be used to power the vehicle 1. For example, the battery device 2 can serve as an operating power source for the vehicle 1.

[0094] The vehicle 1 may further include a controller 3 and a motor 4 . The controller 3 is used to control the battery device 2 to supply power to the motor 4 , for example, to meet the power requirements of the vehicle 1 during startup, navigation, and driving.

[0095] In some embodiments of the present application, the battery device 2 can not only serve as the operating power source of the vehicle 1, but also serve as the driving power source of the vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1.

[0096] Figure 2 Schematic diagram of an explosion of a battery device provided in some embodiments of the present application.

[0097] Continue to refer Figure 2 The battery device 2 includes a box body 5 and a battery cell, and the battery cell is accommodated in the box body 5.

[0098] The housing 5 is used to house battery cells and can have various structures. In some embodiments, the housing 5 can include a first housing portion 5a and a second housing portion 5b. The first housing portion 5a and the second housing portion 5b overlap each other, and the first housing portion 5a and the second housing portion 5b together define a storage space 5c for accommodating the battery cells. The second housing portion 5b can be a hollow structure with one end open. The first housing portion 5a is a plate-like structure, and the first housing portion 5a overlaps the open side of the second housing portion 5b to form the housing 5 with the storage space 5c. The first housing portion 5a and the second housing portion 5b can also be hollow structures with one end open. The open side of the first housing portion 5a overlaps the open side of the second housing portion 5b to form the housing 5 with the storage space 5c. Of course, the first housing portion 5a and the second housing portion 5b can have various shapes, such as a cylinder, a rectangular parallelepiped, etc.

[0099] In order to improve the sealing performance after the first box body 5a and the second box body 5b are connected, a sealing member, such as a sealant, a sealing ring, etc., may also be provided between the first box body 5a and the second box body 5b.

[0100] Assuming that the first box body portion 5a covers the top of the second box body portion 5b, the first box body portion 5a can also be called an upper box cover, and the second box body portion 5b can also be called a lower box body.

[0101] In the battery device 2, there can be one or more battery cells. If there are multiple battery cells, they can be connected in series, in parallel, or in a hybrid connection. A hybrid connection refers to a combination of series and parallel connections. Multiple battery cells can be directly connected in series, in parallel, or in a hybrid connection, and then the entire battery unit can be housed within the housing 5. Alternatively, multiple battery cells can be first connected in series, in parallel, or in a hybrid connection to form a battery module 6, and then the multiple battery modules 6 can be connected in series, in parallel, or in a hybrid connection to form a single unit and housed within the housing 5.

[0102] Figure 3 for Figure 2 The schematic diagram of the battery module is shown.

[0103] In some embodiments, continue to refer to Figure 3 There are multiple battery cells 7, and the multiple battery cells 7 are first connected in series, in parallel, or in mixed series to form a battery module 6. The multiple battery modules 6 are then connected in series, in parallel, or in mixed series to form a whole, and are accommodated in the box.

[0104] The multiple battery cells 7 in the battery module 6 can be electrically connected via a busbar component to achieve parallel connection, series connection, or mixed connection of the multiple battery cells 7 in the battery module 6 .

[0105] Figure 4 This is a schematic diagram of a partial explosion structure of a battery cell provided in some embodiments of the present application. Figure 5 for Figure 4 The schematic diagram of the local enlarged structure at H, Figure 6 This is a schematic top view of the connecting portion of a protective member provided in some embodiments of the present application. Figure 7 for Figure 6 Schematic diagram of the cross-section structure along AA, Figure 8 A schematic diagram of a partial explosion structure of another battery cell provided in some embodiments of the present application.

[0106] Continue to refer Figures 4 to 8 The embodiment of the present application provides a battery cell 7, which includes a housing 10, a pressure relief mechanism 20, and a protective member 30. The housing 10 includes a first wall 11, and the pressure relief mechanism 20 is disposed on the first wall 11. The protective member 30 is disposed on a side of the first wall 11 that faces away from the interior of the battery cell 7 and covers the pressure relief mechanism 20. The protective member 30 includes a base 31 and a connecting portion 32. The connecting portion 32 is connected between the base 31 and the first wall 11. The connecting portion 32 includes a first portion 321 and a second portion 322. The light transmittance of the first portion 321 is greater than the light transmittance of the second portion 322. The projection of the second portion 322 along the thickness direction of the first wall 11 does not overlap with the projection of the pressure relief mechanism 20 along the thickness direction.

[0107] Exemplarily, the housing 10 is a component used to create an internal environment for the battery cell 7. This internal environment can accommodate the electrode assembly, electrolyte, and other components. Optionally, the housing 10 can be made of, but is not limited to, metal or non-metallic materials. For example, metal materials can include copper, aluminum, or stainless steel; non-metallic materials can include polyethylene, polypropylene, or polyvinyl chloride.

[0108] The pressure relief mechanism 20 is used to discharge the internal gas of the battery cell 7 .

[0109] For example, when the internal pressure or temperature of a battery cell 7 reaches a predetermined threshold, the pressure relief mechanism 20 is activated to release the internal pressure or temperature. When the internal pressure or temperature of the battery cell 7 reaches the predetermined threshold, the pressure relief mechanism 20 actuates or a weakened structure within the pressure relief mechanism 20 is destroyed, thereby forming 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 material of one or more of the positive electrode sheet, negative electrode sheet, electrolyte, and separator in the battery cell 7.

[0110] As an example, the pressure relief mechanism 20 may be integrally formed with the housing 10 .

[0111] As an example, the pressure relief mechanism 20 may also be provided separately from and connected to the housing 10 .

[0112] The "activation" mentioned in this application means that the pressure relief mechanism 20 generates an action or is activated to a certain state, so that the internal pressure and temperature of the battery cell 7 can be released. The action generated by the pressure relief mechanism 20 may include but is not limited to: the components in the pressure relief mechanism 20 move to form an exhaust channel, at least a part of the pressure relief mechanism 20 ruptures, breaks, is torn or opened, etc. When the pressure relief mechanism 20 is actuated, the high-temperature and high-pressure substances inside the battery cell 7 will be discharged outward from the actuated part as exhaust. In this way, the pressure and temperature of the battery cell 7 can be relieved under controllable pressure or temperature, thereby avoiding potential more serious accidents.

[0113] In some examples, when the housing 10 is a non-sealed structure, the pressure relief mechanism 20 can be configured as a through hole for discharging gas inside the battery cell 7 .

[0114] The emissions from the battery cells 7 mentioned in this application include, but are not limited to: electrolyte, dissolved or split positive and negative electrode sheets, separator fragments, high-temperature and high-pressure gases generated by the reaction, flames, and the like.

[0115] The protective member 30 covers the pressure relief mechanism 20 to isolate the pressure relief mechanism 20 from the external environment, thereby protecting the pressure relief mechanism 20 and preventing external force from being directly applied to the pressure relief mechanism 20 .

[0116] The protection member 30 is connected to the first wall 11 via a connecting portion 32 . The connecting portion 32 may be directly connected to the first wall 11 or may be restricted on the connecting portion 32 via other components.

[0117] Alternatively, the connection portion 32 may be an adhesive layer, a clip, or an absorbent member, depending on the actual application environment. For example, the adhesive layer may be foam adhesive or a point adhesive. For clarity of description of the embodiments of the present application, the following description will take the connection portion 32 as an adhesive layer as an example.

[0118] Optionally, the connecting portion 32 may be made of, but is not limited to, epoxy resin, polyethylene, polypropylene, polyvinyl chloride, polyimide, or polyamide.

[0119] The connecting portion 32 may be detachably connected to the base 31 or may be integrally provided on the base 31. The connecting portion 32 may be directly connected to the base 31 or may be restricted on the base 31 by other components.

[0120] In some examples, the base 31 and the connecting portion 32 are integrally formed. This simplifies the manufacturing process by eliminating the need for an additional joining process. Furthermore, the integral structure provides a stronger connection between the base 31 and the connecting portion 32 than would be achieved by an additional joining process.

[0121] Optionally, the substrate may be made of, but not limited to, glass, ceramic, polyethylene, polypropylene, polyvinyl chloride, polyimide, or polyamide.

[0122] In some examples, the first portion 321 and the second portion 322 are as follows Figure 8 In the split structure shown, the second portion 322 is located on a side of the first portion 321 that is away from the pressure relief mechanism 20 along a direction perpendicular to the first direction X.

[0123] In some examples, the first portion 321 is connected to the second portion 322. The second portion 322 can be directly connected to the first portion 321 or can be restricted to the first portion 321 by other components.

[0124] In some examples, the first portion 321 and the second portion 322 are integrally formed. This simplifies the manufacturing process by eliminating the need for an additional joining process. Furthermore, the integrally formed first portion 321 and the second portion 322 provide a stronger connection than would be achieved by an additional joining process.

[0125] Light transmittance indicates the ability of light to pass through an object. The greater the light transmittance, the more light can penetrate the object. In other words, the less likely an object with greater light transmittance is to block other objects. The smaller the light transmittance, the less light can penetrate the object. In other words, the less light transmittance an object has, the more likely it is to block other objects.

[0126] Optionally, the light transmittance of the first portion 321 and the second portion 322 may be measured by, but is not limited to, a spectrophotometer or a laser.

[0127] The first portion 321 is primarily used to increase the overall coverage area of ​​the connection portion 32 to improve the success rate and firmness of attaching the protective member 30. The first portion 321 has a relatively high light transmittance, making it less likely to obstruct the pressure relief mechanism 20 even when installed over a large area. The second portion 322 has a relatively low light transmittance and is relatively observable. It primarily serves an identification function, allowing one to determine whether the protective member 30 has been attached to the battery cell 7 by observing whether the second portion 322 is present at the location of the pressure relief mechanism 20 of the battery cell 7, thereby reducing the risk of missing the protective member. Furthermore, the projection of the second portion 322 along the thickness direction of the first wall 11 does not overlap with the projection of the pressure relief mechanism 20 along the thickness direction, thereby reducing the risk of the second portion 322 obstructing the pressure relief mechanism 20. This allows the pressure relief mechanism 20 to be easily detected when it is damaged or dirty. In summary, the above-mentioned technical solution can effectively improve the detectability of the battery cell 7.

[0128] It should be noted that the second portion 322 can also play a role in connecting the base 31 and the first wall 11 to a certain extent.

[0129] In some embodiments, a projection of the first portion 321 along the thickness direction at least partially overlaps with a projection of the pressure relief mechanism 20 along the thickness direction.

[0130] For example, the projection of the first portion 321 along the thickness direction may partially overlap with the projection of the pressure relief mechanism 20 along the thickness direction, or the projection of the pressure relief mechanism 20 along the thickness direction may be located within the projection of the first portion 321 along the thickness direction.

[0131] The above technical solution can further increase the coverage area of ​​the first portion 321 , thereby further improving the attachment success rate and firmness of the protective member 30 .

[0132] In some embodiments, the first portion 321 and the second portion 322 are both substantially disposed around the pressure relief mechanism 20 , and the second portion 322 is connected to the outer circumference of the first portion 321 .

[0133] On the one hand, the first portion 321 and the second portion 322 form a concentric or quasi-concentric structural layout around the pressure relief mechanism 20, further increasing the coverage of the connecting portion 32, thereby further improving the success rate and firmness of attachment of the protective member 30. On the other hand, the connection between the second portion 322 and the first portion 321 can improve the overall structural strength of the connecting portion 32 and reduce installation difficulty. The second portion 322 is located on the outer periphery of the first portion 321, further reducing the risk of the second portion 322 obstructing the pressure relief mechanism 20.

[0134] In some embodiments, a projection of the second portion 322 along the thickness direction does not overlap with a projection of the first portion 321 along the thickness direction.

[0135] In some examples, the first portion 321 and the second portion 322 are separately provided, and the second portion 322 is located on a side of the first portion 321 away from the pressure relief mechanism 20 along a direction perpendicular to the first direction X.

[0136] In some examples, the first portion 321 and the second portion 322 are connected, and the second portion 322 is located on a side of the first portion 321 away from the pressure relief mechanism 20 along a direction perpendicular to the first direction X.

[0137] In some examples, the first portion 321 is substantially disposed around the pressure relief mechanism 20 , and a plurality of second portions 322 are provided. The plurality of second portions 322 are spaced apart along an extending direction of the first portion 321 .

[0138] In some examples, the first portion 321 is provided in plurality, and the second portion 322 is provided in plurality. The plurality of first portions 321 are spaced apart along the circumference of the pressure relief mechanism 20 , and the plurality of second portions 322 are spaced apart along the circumference of the pressure relief mechanism 20 .

[0139] The above technical solution can reduce the overall thickness of the connecting portion 32 , thereby reducing the space occupied by the protective member 30 outside the battery cell 7 , which is beneficial to reducing the overall volume of the battery cell 7 and improving the energy density of the battery cell 7 .

[0140] In some embodiments, a projection of the second portion 322 along the thickness direction of the first wall 11 at least partially overlaps with a projection of the first portion 321 along the thickness direction.

[0141] For example, the projection of the second portion 322 along the thickness direction of the first wall 11 may partially overlap with the projection of the first portion 321 along the thickness direction, or the projection of the second portion 322 along the thickness direction of the first wall 11 may be located within the projection of the first portion 321 along the thickness direction. In other words, the second portion 322 may be provided on the first portion 321 based on the first portion 321.

[0142] The above technical solution can reduce the difficulty of setting the second portion 322 , thereby being beneficial to reducing the overall manufacturing cost of the battery cell 7 .

[0143] Figure 9 This is a schematic top view of the connecting portion 32 of another protective member 30 provided in some embodiments of the present application. Figure 10 for Figure 9 Schematic diagram of the cross-sectional structure along BB.

[0144] Continue to refer Figures 9 and 10 In some embodiments, the first portion 321 is provided with a recess 40 , which is recessed relative to at least one of the two opposite surfaces of the first portion 321 in the thickness direction, and at least a portion of the second portion 322 is accommodated in the recess 40 .

[0145] Exemplarily, at least a portion of the second portion 322 is accommodated in the recess 40 , which may be understood as a portion of the second portion 322 being accommodated in the recess 40 , or the entire second portion 322 being accommodated in the recess 40 .

[0146] In some examples, the recess 40 is recessed relative to a surface of the first portion 321 facing away from the first wall 11 along the thickness direction.

[0147] In some examples, the recess 40 is recessed relative to a surface of the first portion 321 facing the first wall 11 in the thickness direction.

[0148] In some examples, there are two recesses 40, whose projections along the thickness direction overlap. One of the two recesses 40 is recessed relative to a side surface of the first portion 321 facing away from the first wall 11 along the thickness direction, and the other of the two recesses 40 is recessed relative to a side surface of the first portion 321 facing toward the first wall 11 along the thickness direction. There are two second portions 322, and at least a portion of one of the two second portions 322 is accommodated in one of the two recesses 40, while at least a portion of the other of the two second portions 322 is accommodated in the other of the two recesses 40.

[0149] The above technical solution introduces a recess 40 that can accommodate at least part of the second part 322. On the one hand, it can reduce the overall space occupancy of the connecting part 32, which is beneficial to improving the energy density of the battery cell 7; on the other hand, it can also improve the connection strength between the second part 322 and the first part 321, so as to improve the reliability of the protective member 30.

[0150] Continue to combine Figures 4 and 5 In some embodiments, a boss 50 is provided on the first wall 11 , the boss 50 protrudes from the side surface of the first wall 11 facing away from the interior of the battery cell 7 and is arranged around the pressure relief mechanism 20 , and the connecting portion 32 is connected between the boss 50 and the base 31 .

[0151] For example, the boss 50 can be detachably connected to the first wall 11 or integrally provided on the first wall 11. The boss 50 can be directly connected to the first wall 11 or constrained to the first wall 11 by other components. For example, the boss 50 can be connected to the first wall 11 by, but is not limited to, welding, riveting, or bonding.

[0152] Optionally, the boss 50 may be made of, but is not limited to, metal or non-metal materials. For example, the metal material may be copper, aluminum, or stainless steel; the non-metal material may be polyethylene, polypropylene, or polyvinyl chloride.

[0153] In some examples, the first wall 11 and the boss 50 are integrally formed. This simplifies the manufacturing process by eliminating the need for an additional joining process. Furthermore, compared to joining the first wall 11 and the boss 50 through an additional joining process, the integral structure provides a stronger connection between the first wall 11 and the boss 50.

[0154] The boss 50 is located on the surface of the first wall 11 facing away from the interior of the battery cell 7 and extends outward. The boss 50 is arranged around the edge of the pressure relief mechanism 20. It will be understood that the shape of the annular boss 50 is related to the shape of the pressure relief mechanism 20. For example, if the pressure relief mechanism 20 is elliptical, the boss 50 will correspondingly be in the shape of a racetrack. Alternatively, if the pressure relief mechanism 20 is circular, the boss 50 will correspondingly be in the shape of a circular ring.

[0155] The shape of the connecting portion 32 is adapted to the shape of the boss 50, and the shape of the protective member 30 can also be adapted to the shape of the boss 50. For example, when the pressure relief mechanism 20 is elliptical and the boss 50 is correspondingly runway-shaped, the connecting portion 32 and the protective member 30 are both oblong.

[0156] The above technical solution introduces the boss 50 to connect the protective member 30 with the boss 50, which can reduce the risk of damage to the pressure relief mechanism 20 caused by interference between the protective member 30 and the pressure relief mechanism 20 during assembly, and can improve the product yield and reliability of the battery cell 7.

[0157] In some embodiments, the protective member 30 can be a metal patch made of metal materials such as stainless steel, or a plastic patch made of transparent plastic material. Compared with metal patches, plastic patches not only have higher strength, but also have higher toughness, so that the protective member 30 is not easily damaged by impact to a certain extent, thereby playing a role in protecting the pressure relief mechanism 20.

[0158] In some embodiments, the boss 50 is provided with a groove 60, which is recessed relative to the side of the boss 50 facing away from the first wall 11. The pressure relief mechanism 20, the protective member 30 and the boss 50 together define a cavity, and the groove 60 connects the cavity with the external environment.

[0159] For example, a groove 60 is formed on one side of the boss 50 that is connected to the protective member 30. The cavity communicates with the external environment through the groove 60. The cross-sectional shape of the groove 60 can be varied, for example, the cross-section of the groove 60 can be V-shaped, rectangular, or circular. Of course, the number and design location of the grooves 60 can also be varied, and the boss 50 can be provided with multiple grooves 60.

[0160] In order for the pressure relief mechanism 20 to function effectively, the connection between the pressure relief mechanism 20 and the first wall 11 must be highly airtight. Therefore, it is necessary to perform an airtightness test between the pressure relief mechanism 20 and the first wall 11. If the airtightness between the protective member 30 and the first wall 11 is good, but the airtightness between the pressure relief mechanism 20 and the first wall 11 is poor, the airtightness test results for the pressure relief mechanism 20 may be inaccurate because the protective member 30 seals the pressure relief mechanism 20.

[0161] In this embodiment, a groove 60 is provided on the boss 50, so that the cavity enclosed by the pressure relief mechanism 20 and the protective member 30 is connected to the outside through the groove 60. In this way, during the air tightness test, by detecting whether gas is discharged from the groove 60, it is possible to accurately check whether the air tightness of the connection between the pressure relief mechanism 20 and the first wall 11 is qualified, thereby avoiding inaccurate air tightness testing.

[0162] In this way, the above technical solution can make the battery cell 7 have good sealing performance, reduce the possibility of electrolyte volatilization, and thus the battery cell 7 has higher reliability.

[0163] In some embodiments, the connecting portion 32 has an escape opening 70 corresponding to the groove 60 , and a projection of the groove 60 along the thickness direction is located within a projection of the escape opening 70 along the thickness direction.

[0164] Exemplarily, the connecting portion 32 has an escape opening 70 , that is, the annular connecting portion 32 is an open loop, and the escape opening 70 corresponds to the groove 60 , which means that the setting position and structural shape of the escape opening 70 match the setting position and structural shape of the groove 60 .

[0165] In some examples, the escape opening 70 is disposed on the first portion 321 .

[0166] In some examples, the escape opening 70 is disposed in the second portion 322 .

[0167] In some examples, a first opening is defined on the first portion 321 , and a second opening is defined on the second portion 322 . The first opening and the second opening correspond to each other, and the first opening and the second opening together constitute the avoidance opening 70 .

[0168] The above technical solution introduces the avoidance opening 70, which can reduce the risk of the connection portion 32 blocking the groove 60 and causing the airtightness test to be unable to be performed, so that the cavity can maintain communication with the outside through the groove 60, thereby improving the reliability of the battery cell 7.

[0169] In some embodiments, the base 31 and the first portion 321 are both transparent structures, and the second portion 322 includes a color mark.

[0170] For example, the transparent structure can further reduce the obstruction of the pressure relief mechanism 20 by the base 31 and the first portion 321 , and the color identification refers to a structure that can improve its own observability through color characteristics.

[0171] In some examples, the second portion 322 can be made of colored glue. For example, the second portion 322 can be red, yellow, green, blue, or other colors. This allows, at a low cost, during the manufacturing process of the battery cell 7 , to determine whether the protective member 30 has been attached to the battery cell 7 by observing whether the second portion 322 is present at the location of the pressure relief mechanism 20 of the battery cell 7 .

[0172] The above technical solution can effectively improve the detectability of the battery cell 7 at a relatively low cost.

[0173] In some embodiments, the housing 10 includes an end cover and a shell. The shell has an opening. The end cover covers the opening. The end cover is configured as a first wall 11 .

[0174] The end cap refers to a component that covers the opening of the shell to isolate the internal environment of the battery cell 7 from the external environment. Optionally, the shape of the end cap can be adapted to the shape of the shell to match the shell. Optionally, the end cap can be made of a material with a certain hardness and strength (such as aluminum alloy), so that the end cap is not easily deformed when squeezed or collided, so that the battery cell 7 can have a higher structural strength and the reliability can also be improved. Functional components such as terminal groups can be provided on the end cap. The material of the end cap can also be various. For example, the end cap can be but not limited to being made of metal or non-metallic materials. For example, the metal material can be copper, aluminum or stainless steel, etc.; the non-metallic material can be polyethylene, polypropylene or polyvinyl chloride, etc.

[0175] The shell is a component used to cooperate with the end cap to form the internal environment of the battery cell 7. The internal environment formed can be used to accommodate the electrode assembly, electrolyte and other components. The shell and the end cap can be independent components. An opening can be set on the shell, and the internal environment of the battery cell 7 is formed by covering the opening with the end cap. Optionally, the end cap and the shell can be integrated. Specifically, the end cap and the shell can form a common connection surface before other components are put into the shell. When the interior of the shell needs to be encapsulated, the end cap is covered with the shell. The shell can be of various shapes and sizes, such as rectangular, cylindrical, hexagonal, etc. Specifically, the shape of the shell can be determined according to the specific shape and size of the electrode assembly. The material of the shell can be various. For example, the shell can be made of, but not limited to, metal or non-metallic materials. For example, the metal material can be copper, aluminum or stainless steel, etc.; the non-metallic material can be polyethylene, polypropylene or polyvinyl chloride, etc.

[0176] Optionally, the end cap may be detachably connected to the housing or integrally formed on the housing. The end cap may be directly connected to the housing or secured to the housing via other components. For example, the end cap and the housing may be connected by, but is not limited to, welding, riveting, or bonding.

[0177] The end cap of the above technical solution is designed to imitate the shape of the shell. On the one hand, it can improve the matching degree between the end cap and the shell, thereby improving the consistency of the battery cell 7; on the other hand, the structure of the end cap is relatively simple. Compared with designing the shell according to the shape of the end cap, the end cap is designed to imitate the shape of the shell, which can reduce the difficulty of preparation and help reduce the overall production cost of the battery cell 7.

[0178] According to some embodiments of the present application, the present application further provides a battery device, comprising a battery cell 7 according to any of the above solutions.

[0179] According to some embodiments of the present application, the present application further provides an electrical device, comprising a battery cell 7 or a battery device according to any of the above schemes, wherein the battery cell 7 or the battery device is used to store or provide electrical energy.

[0180] Unless otherwise specified, all embodiments and optional embodiments of the present application can be combined with each other to form a new technical solution. All technical features and optional technical features of the present application can be combined with each other to form a new technical solution.

[0181] In order to better understand the battery cell 7 provided in the embodiment of the present application, based on the same inventive concept, an embodiment of the above-mentioned battery cell 7 in actual application is provided here for illustration.

[0182] An embodiment of the present application provides a battery cell 7, which includes a shell 10, a pressure relief mechanism 20 and a protective member 30. The shell 10 includes a first wall 11, the pressure relief mechanism 20 is arranged on the first wall 11, and a boss 50 is provided on the first wall 11. The boss 50 protrudes from a side surface of the first wall 11 facing away from the interior of the battery cell 7 and is arranged around the pressure relief mechanism 20. The connecting portion 32 is connected between the boss 50 and the base 31. The protective member 30 is arranged on the side of the first wall 11 facing away from the interior of the battery cell 7 and covers the pressure relief mechanism 20. The protective member 30 includes a base 31 and a connecting portion 32. The connecting portion 32 is connected between the base 31 and the boss 50. The connecting portion 32 includes a first portion 321 and a second portion 322. The transmittance of the first portion 321 is greater than the transmittance of the second portion 322. The first portion 321 and the second portion 322 are both roughly arranged around the pressure relief mechanism 20, and the second portion 322 is connected to the outer peripheral side of the first portion 321. The projection of the second portion 322 along the thickness direction of the first wall 11 does not overlap with the projection of the pressure relief mechanism 20 along the thickness direction.

[0183] The boss 50 is provided with a recessed groove 60, which is recessed relative to the boss 50 on the side facing away from the first wall 11. The pressure relief mechanism 20, the protective member 30, and the boss 50 collectively define a cavity, and the recessed groove 60 connects the cavity to the external environment. The connecting portion 32 has a corresponding relief opening 70, with the projection of the recessed groove 60 along the thickness direction located within the projection of the relief opening 70 along the thickness direction.

[0184] The first portion 321 is primarily used to increase the overall coverage area of ​​the connection portion 32 to improve the success rate and firmness of attaching the protective member 30. The first portion 321 has a relatively high light transmittance, making it less likely to obstruct the pressure relief mechanism 20 even when installed over a large area. The second portion 322 has a relatively low light transmittance and is relatively observable. It primarily serves an identification function, allowing one to determine whether the protective member 30 has been attached to the battery cell 7 by observing whether the second portion 322 is present at the location of the pressure relief mechanism 20 of the battery cell 7, thereby reducing the risk of missing the protective member. Furthermore, the projection of the second portion 322 along the thickness direction of the first wall 11 does not overlap with the projection of the pressure relief mechanism 20 along the thickness direction, thereby reducing the risk of the second portion 322 obstructing the pressure relief mechanism 20. This allows the pressure relief mechanism 20 to be easily detected when it is damaged or dirty. In summary, the above-mentioned technical solution can effectively improve the detectability of the battery cell 7.

[0185] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A battery cell, characterized in that: include: a housing comprising a first wall; a pressure relief mechanism, disposed on the first wall; A protective member is arranged on a side of the first wall facing away from the interior of the battery cell and covers the pressure relief mechanism, the protective member includes a base and a connecting portion, the connecting portion is connected between the base and the first wall, the connecting portion includes a first part and a second part, the transmittance of the first part is greater than the transmittance of the second part, and the projection of the second part along the thickness direction of the first wall does not overlap with the projection of the pressure relief mechanism along the thickness direction.

2. The battery cell according to claim 1, wherein: A projection of the first portion along the thickness direction at least partially overlaps with a projection of the pressure relief mechanism along the thickness direction.

3. The battery cell according to claim 1, wherein: The first part and the second part are both arranged substantially around the pressure relief mechanism, and the second part is connected to the outer peripheral side of the first part.

4. The battery cell according to claim 1, wherein: A projection of the second portion along the thickness direction does not overlap with a projection of the first portion along the thickness direction.

5. The battery cell according to claim 1, characterized in that A projection of the second portion along the thickness direction at least partially overlaps with a projection of the first portion along the thickness direction.

6. The battery cell according to claim 5, characterized in that The first portion defines a recessed portion that is recessed relative to at least one of two opposite surfaces of the first portion along the thickness direction, and at least a portion of the second portion is accommodated in the recessed portion.

7. The battery cell according to claim 1, characterized in that A boss is provided on the first wall. The boss protrudes from a surface of the first wall facing away from the interior of the battery cell and surrounds the pressure relief mechanism. The connecting portion is connected between the boss and the base.

8. The battery cell according to claim 7, characterized in that A groove is formed on the boss, and the groove is recessed relative to a surface of the boss facing away from the first wall; The pressure relief mechanism, the protective member and the boss jointly define a cavity, and the groove communicates with the cavity and the external environment.

9. The battery cell according to claim 8, characterized in that The connecting portion has an escape opening corresponding to the groove, and a projection of the groove along the thickness direction is located within a projection of the escape opening along the thickness direction.

10. The battery cell according to any one of claims 1 to 9, characterized in that: The base and the first part are both transparent structures, and the second part includes a color mark.

11. A battery device, characterized in that: The invention comprises a plurality of battery cells according to any one of claims 1 to 10.

12. An electrical device, characterized in that: The battery cell according to any one of claims 1 to 10 or the battery device according to claim 11 is used to store or provide electrical energy.

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