Battery cell, battery apparatus, and electric device

Abstract

The present application discloses a battery cell, a battery apparatus, and an electric device. The battery cell comprises an electrode assembly, a casing, a first electrode terminal, and a first sealing member. The electrode assembly comprises a main body portion and a first tab. The casing comprises a first wall, wherein the first wall is located on one side of the electrode assembly in a first direction; the first wall includes a first portion, a second portion, and a first bending portion; in the first direction, the first portion is closer to the main body portion than the second portion; the first bending portion is connected to the first portion and the second portion; the side of the first wall close to the electrode assembly is provided with a first recess; and the bottom surface of the first recess corresponds to the second portion. At least part of the first tab is accommodated in the first recess. The casing is provided with a first liquid injection hole in communication with the first recess. In a same plane perpendicular to the axial direction of the first liquid injection hole, the orthographic projection of the first liquid injection hole at least partially overlaps the orthographic projection of the first recess. The first electrode terminal is provided on the first portion. The first sealing member is connected to the casing and seals the first liquid injection hole.

Description

Battery cells, battery devices and electrical equipment

[0001] Cross-references to related applications

[0002] This application claims priority to International Patent Application No. PCT / CN2025 / 085811, filed on March 28, 2025, entitled “Battery Cell, Battery Device and Electrical Equipment”, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application belongs to the field of battery technology, and in particular relates to a battery cell, a battery device, and an electrical device. Background Technology

[0004] Batteries are widely used in electronic devices such as mobile phones, laptops, electric vehicles, electric cars, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes, and power tools, etc.

[0005] In the development of battery technology, improving the reliability of individual battery cells is a key research direction. Summary of the Invention

[0006] This application provides a battery cell, a battery device, and an electrical appliance, which helps to improve the reliability of the battery cell.

[0007] According to a first aspect of this application, a battery cell is provided, comprising an electrode assembly, a housing, a first electrode terminal, and a first seal. The electrode assembly includes a main body and a first tab connected to the main body. The electrode assembly is housed within the housing, which includes a first wall located on one side of the electrode assembly along a first direction. The first wall includes a first portion, a second portion, and a first bend, wherein the first portion is closer to the main body than the second portion along the first direction, and the first bend connects the first portion and the second portion. A first recess is provided on the side of the first wall near the electrode assembly, and the bottom surface of the first recess corresponds to the second portion. At least a portion of the first tab is housed in the first recess. The housing has a first liquid injection hole communicating with the first recess. In the same plane perpendicular to the axial direction of the first liquid injection hole, the orthographic projection of the first liquid injection hole at least partially overlaps with the orthographic projection of the first recess. The first electrode terminal is located in the first portion. The first seal is connected to the housing and seals the first liquid injection hole.

[0008] In this embodiment, the electrolyte injected through the first injection hole can be injected into the first recess. The first tab, housed in the first recess, can block the electrolyte to a certain extent, reducing the impact of the electrolyte on the main body, reducing electrolyte splashing, lowering the risk of short circuit, and improving the reliability of the battery cell. The electrolyte in direct contact with the first tab can, under the promoting effect of the capillary attraction of the first tab, wet the active material of the electrode assembly, which is beneficial to improving the wetting effect and wetting efficiency of the electrolyte.

[0009] In some embodiments, the first injection hole is located in the second portion and extends through the second portion along a first direction. The second portion where the first injection hole is located is at a higher position, which helps to raise the injection surface, increase the injection volume, and improve the problem of limited space available for accommodating electrolyte due to the high energy density of the battery cells.

[0010] In some embodiments, the housing includes a second wall located on one side of the electrode assembly along a second direction and connected to the second portion, the second direction intersecting the first direction; the first wall includes a first protrusion located on the side of the second wall near the electrode assembly along the second direction, pointing from the first wall towards the electrode assembly, the first protrusion protruding from the bottom surface of the first recess and abutting against the main body portion; the first protrusion is provided with a first channel communicating with the first recess and the space between the first protrusion and the second wall. Part of the electrolyte in the first recess can flow through the first channel to the space between the first protrusion and the second wall, then to the gap between the second wall and the electrode assembly, and finally to the bottom space of the housing, wetting the electrode assembly from the bottom, which helps to further improve the wetting effect and efficiency of the electrolyte.

[0011] In some embodiments, in the same plane perpendicular to the first direction, the orthographic projection of the first protrusion and the orthographic projection of the first tab are respectively located on both sides of the orthographic projection of the first injection hole in the second direction. In the second direction, both the first protrusion and the first tab are close to the first injection hole, which can shorten the flow distance of the electrolyte injected from the first injection hole to the first tab and the first channel, reduce the flow resistance of the electrolyte to the first tab and the first channel, and further improve the wetting efficiency and wetting effect of the electrolyte.

[0012] In some embodiments, the housing includes a second wall located on one side of the electrode assembly along a second direction and connected to the second portion, the second direction intersecting the first direction; a first injection hole is disposed on the second wall and extends through the second wall along the second direction. During the assembly of the battery cell, electrolyte can be injected into the housing through the first injection hole while the battery cell is in a state with the second wall facing upwards, which helps to increase the injection surface and increase the injection volume. The first injection hole is located on the second wall, and the first injection hole and the first electrode terminal are not on the same wall, which helps to reduce the risk of electrolyte spilled outside the second wall during the injection process corroding the first electrode terminal, and reduces the risk of electrolyte affecting the adhesion strength of the first wall to other structures (e.g., the battery housing).

[0013] In some embodiments, the first portion and the second portion are arranged along a second direction. During the charging and discharging process of a single battery cell, the wall portion with a larger outer casing area undergoes greater deformation. Placing the first injection hole on the second wall located on the side of the first wall along the second direction helps to reduce the impact of outer casing deformation on the sealing effect of the first injection hole, thereby reducing the risk of leakage.

[0014] In some embodiments, the first wall includes a first protrusion located on the side of the second wall near the electrode assembly along a second direction. Along the direction of the first wall towards the electrode assembly, the first protrusion protrudes beyond the bottom surface of the first recess and abuts against the main body. The first protrusion has a first channel connecting the first recess and the first injection hole. By providing the first channel on the first protrusion, the first injection hole on the second wall can be indirectly connected to the first recess through the first channel. At least a portion of the electrolyte injected from the first injection hole flows into the first recess through the first channel, which helps to reduce the impact of the electrolyte on the main body 11 and the first tab 12.

[0015] In some embodiments, the first protrusion has a plurality of first channels spaced apart along a third direction, with the first direction, second direction, and third direction being perpendicular to each other. In the same plane perpendicular to the second direction, the orthographic projection of a portion of the first channel partially overlaps with the orthographic projection of the first injection hole. The area of ​​the orthographic projection of the first channel overlapping with the orthographic projection of the first injection hole is larger than the area of ​​the orthographic projection of the first channel not overlapping with the orthographic projection of the first injection hole. The larger area of ​​the orthographic projection of the first channel overlapping with the orthographic projection of the first injection hole helps to reduce the obstruction effect of the first protrusion on the electrolyte and improve the wetting efficiency of the electrolyte.

[0016] In some embodiments, a portion of the first seal protrudes from the second wall along the direction pointing towards the electrode assembly. In the same plane perpendicular to the second direction, the orthographic projection of the portion of the first seal protruding from the second wall does not overlap with the orthographic projection of the main body. This protrusion of the first seal from the second wall improves the sealing effect of the first seal on the first injection hole. The fact that the orthographic projection of the portion of the first seal protruding from the second wall does not overlap with the orthographic projection of the main body reduces the possibility of interference between the first seal and the main body. Furthermore, the dimensional design of the first seal protruding from the second wall is more flexible, further enhancing the sealing effect.

[0017] In some embodiments, the second wall includes a wall body and a second protrusion. Along a second direction, the second protrusion protrudes from a first surface of the wall body facing the electrode assembly. A first liquid injection hole penetrates the second protrusion. Along the second direction, the second protrusion is spaced apart from the wall body. At least a portion of the second protrusion protrudes towards the interior of the housing. The penetration of the first liquid injection hole through the second protrusion facilitates increasing the depth of the first liquid injection hole by utilizing the space inside the housing. This increases the contact area between the first liquid injection hole and the first seal without additionally occupying external space, thus improving the sealing effect. The spaced arrangement of the second protrusion from the wall body helps reduce the risk of interference between the second protrusion and the wall body, improves the positional flexibility of the second protrusion in the third direction Z, and reduces the risk of the first seal affecting the connection between the wall body and the first wall.

[0018] In some embodiments, along the first direction, the minimum distance between the edge of the second wall near the first wall and the first injection hole is d, where d ≥ 1 mm. This facilitates the connection between the first and second walls and reduces the risk of interference at the connection position between the first seal and the first and second walls.

[0019] In some embodiments, a second recess is provided on the side of the first wall near the electrode assembly, and the second recess is separated from the first recess; the outer casing is provided with a second injection hole, which communicates with the second recess, and in the same plane perpendicular to the axial direction of the second injection hole, the orthographic projection of the second injection hole and the orthographic projection of the second recess at least partially overlap; the battery cell includes a second seal, which is connected to the outer casing and seals the second injection hole. The outer casing having two injection holes is beneficial for improving injection efficiency. The second recess is separated from the first recess, and when the electrolyte level is higher than the separation structure between the second and first recesses, electrolyte can continue to be injected into the first recess through the first injection hole, and into the second recess through the second injection hole. Neither the first nor the second recess will form a liquid seal, which is beneficial for increasing the injection volume, improving the performance of the battery cell, and extending the cycle life of the battery cell.

[0020] In some embodiments, the electrode assembly includes a second tab connected to the main body, the first tab and the second tab having opposite polarities, and at least a portion of the second tab being accommodated in a second recess. Electrolyte injected through a second injection hole can be injected into the second recess. The second tab located within the second recess can, to a certain extent, block the electrolyte, reducing the impact of the electrolyte on the main body and lowering the risk of short circuits. Electrolyte in direct contact with the second tab can, under the capillary attraction of the second tab, wet into the interior of the electrode assembly, which is beneficial for improving the wetting effect and efficiency of the electrolyte.

[0021] In some embodiments, the first wall includes a third portion and a second bend. Along a second direction, the second and third portions are located on opposite sides of the first portion. The second bend connects the third portion and the first portion. Along a first direction, the first portion is closer to the main body than the third portion. The bottom surface of the second recess corresponds to the third portion. The first portion, the first bend, and the second bend separate the first and second recesses. The second recess provides at least partial accommodating space for the second electrode tab. The second electrode tab and the first electrode terminal can share at least a portion of the space in the first direction, which is beneficial for improving space utilization and increasing the energy density of the battery cell.

[0022] In some embodiments, the second injection hole is located in the third portion and extends through the third portion along the first direction. The third portion, where the second injection hole is located, is at a higher position, which is beneficial for increasing the injection volume and improving the problem of limited space available for containing electrolyte due to the high energy density of the battery cells.

[0023] In some embodiments, the housing includes a third wall located on one side of the electrode assembly along a second direction and connected to a third portion, the second direction intersecting the first direction; a second injection hole is disposed on the third wall and extends through the third wall along the second direction. The second injection hole and the first electrode terminal are not located on the same wall, which helps reduce the risk of electrolyte spilled outside the third wall during the injection process corroding the first electrode terminal, and reduces the risk of the electrolyte affecting the adhesion strength of the first wall to other structures (e.g., the battery housing).

[0024] In some embodiments, the first wall includes a cover and an insulating member. Along a first direction, the insulating member is disposed on the side of the cover closer to the main body. The cover includes a first cover portion, a second cover portion, and a third cover portion. Along the first direction, the first cover portion is closer to the main body than the second cover portion, and the third cover portion connects the first cover portion and the second cover portion. The insulating member includes a first insulating portion, a second insulating portion, and a third insulating portion. Along the first direction, the first insulating portion is closer to the main body than the second insulating portion, and the third insulating portion connects the first insulating portion and the second insulating portion. A first portion includes a first cover portion and a first insulating portion stacked together, a second portion includes a second cover portion and a second insulating portion stacked together, and a first bent portion includes a third cover portion and a third insulating portion stacked together. The insulating member is used to insulate and isolate the cover and the electrode assembly, reducing the risk of short circuits.

[0025] According to a second aspect of this application, this application also provides a battery device comprising a battery cell provided in any of the embodiments.

[0026] According to a third aspect of this application, this application also provides an electrical device that includes a battery device provided in any embodiment, the battery device being used to provide electrical energy. Attached Figure Description

[0027] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 is a schematic diagram of the structure of a vehicle provided in some embodiments of this application.

[0029] Figure 2 is a schematic diagram of the structure of a battery device provided in some embodiments of this application.

[0030] Figure 3 is a schematic diagram of the structure of a battery cell provided in some embodiments of this application.

[0031] Figure 4 is a schematic diagram of the exploded structure of the battery cell shown in Figure 3.

[0032] Figure 5 is a top view of the battery cell shown in Figure 3.

[0033] Figure 6 is a cross-sectional view taken along direction AA in Figure 5.

[0034] Figure 7 is an enlarged structural diagram of region B in Figure 6.

[0035] Figure 8 is a schematic diagram of the exploded structure of the first wall of the battery cell shown in Figure 3.

[0036] Figure 9 is a schematic diagram of the structure of a battery cell provided in some other embodiments of this application.

[0037] Figure 10 is a cross-sectional view of the battery cell shown in Figure 9.

[0038] Figure 11 is an enlarged structural diagram of region C in Figure 10.

[0039] Figure 12 is a schematic diagram of the exploded structure of Figure 11.

[0040] Figure 13 is a partial structural diagram of the first wall of the battery cell shown in Figure 9.

[0041] Figure 14 is a magnified structural diagram of region D in Figure 13.

[0042] Figure 15 is a schematic diagram of the structure of a battery cell provided in some embodiments of this application.

[0043] Figure 16 is a cross-sectional view of the battery cell shown in Figure 15.

[0044] Figure 17 is an enlarged structural diagram of region E in Figure 16.

[0045] Figure 18 is an enlarged structural diagram of region F in Figure 16.

[0046] Figure 19 is a schematic diagram of the structure of a battery cell provided in some embodiments of this application.

[0047] The attached figures are labeled as follows: Vehicle 1, Battery unit 2, Controller 3, Motor 4; Housing 5, First housing section 5a, Second housing section 5b, Accommodation space 5c; Battery cell 6, Electrode assembly 10, Main body 11, First tab 12, Second tab 13, Outer shell 20, Housing 21, Housing opening 211, End cap 22, First wall 23, First part 231, Second part 232, First bend 233, First recess 234, First protrusion 235, First channel 2351, First side wall 2352, First opening 2353, Cavity 2354, Second recess 236, Third part 237, Second bend 238, Protective structure 239, Protective cavity 2391, Cover 23a, First cover section 23a1, Second cover section 23a2. Third cover portion 23a3, fourth cover portion 23a4, fifth cover portion 23a5, insulating member 23b, first insulating portion 23b1, second insulating portion 23b2, third insulating portion 23b3, fourth insulating portion 23b4, fifth insulating portion 23b5, first injection hole 24, first hole segment 241, second hole segment 242, stepped surface 243, second wall 25, wall body 251, first surface 251a, second surface 251b, second protrusion 252, second injection hole 26, third wall 27, first electrode terminal 30, first sealing member 40, second sealing member 50, second electrode terminal 60; first direction X, second direction Y, third direction Z. Detailed Implementation

[0048] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0049] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0050] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms "comprising" and "having," and any variations thereof, in the description, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the description, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy.

[0051] In this application, the reference to "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments.

[0052] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "adhesion" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0053] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0054] In the embodiments of this application, the same reference numerals denote the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width, and other dimensions of various components in the embodiments of this application shown in the accompanying drawings, as well as the overall thickness, length, width, and other dimensions of the integrated device, are merely illustrative and should not constitute any limitation on this application.

[0055] In this application, "multiple" means two or more (including two).

[0056] In the embodiments of this application, "parallel" includes not only the case of absolute parallelism, but also the case of approximate parallelism as commonly understood in engineering; similarly, "perpendicular" also includes not only the case of absolute perpendicularity, but also the case of approximate perpendicularity as commonly understood in engineering.

[0057] In this embodiment of the application, the battery cell can be a secondary battery cell, which refers to a battery cell that can be used again after being discharged by recharging to activate the active materials.

[0058] 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-metal hydride battery cell, a nickel-cadmium battery cell, a lead-acid battery cell, etc., but the embodiments of this application are not limited to this.

[0059] A typical battery cell includes an electrode assembly, a housing, and electrode terminals. The electrode assembly is housed within the housing, and the electrode terminals are located within the housing. The housing encapsulates the electrode assembly and electrolyte components. The electrode assembly includes tabs, which are electrically connected to the electrode terminals via adapters or directly to the electrode terminals. The electrode terminals are used to electrically connect the electrode assembly to external circuitry within the battery cell to enable charging or discharging of the battery cell.

[0060] The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charging and discharging process of a single battery cell, active ions (such as lithium ions) repeatedly insert and extract between the positive and negative electrodes. The separator, positioned between the positive and negative electrodes, prevents short circuits while allowing active ions to pass through.

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

[0062] 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 disposed on at least one surface of the negative electrode current collector.

[0063] In some implementations, the separator is positioned between the positive and negative electrodes.

[0064] In some embodiments, the separator is a separator membrane. This application does not impose any particular limitation on the type of separator membrane; any known porous separator membrane with good chemical and mechanical stability can be selected.

[0065] In some embodiments, the electrode assembly is a wound structure. The positive electrode and the negative electrode are wound into a wound structure.

[0066] In some embodiments, the electrode assembly has a stacked structure.

[0067] The battery device mentioned in the embodiments of this application may include one or more battery cell assemblies for providing voltage and capacity. A battery cell assembly may include multiple battery cells, which are connected in series, parallel, or mixed connections via a busbar.

[0068] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells.

[0069] A battery device typically includes a housing for encapsulating one or more individual battery cells. The housing prevents liquids or other foreign matter from affecting the charging or discharging of the individual battery cells.

[0070] As an example, a battery cell assembly can be a battery module, which is formed by arranging and fixing multiple battery cells into an independent module. As an example, a battery module can be formed by bundling multiple battery cells together with cable ties. The battery cell assembly can be housed within a housing by fixing the battery module within the housing. As an example, the housing can include a top cover, a frame, and a bottom plate. The top cover and bottom plate are respectively connected to the frame, creating a closed space inside the housing to house the battery cell assembly.

[0071] In some embodiments, the housing may be part of the vehicle's chassis structure. For example, a portion of the housing may be at least a part of the vehicle's floor, or a portion of the housing may be at least a part of the vehicle's crossbeams and longitudinal beams.

[0072] In some embodiments, the battery device may be an energy storage device. Energy storage devices include energy storage containers, energy storage cabinets, etc.

[0073] Each battery cell includes an electrolyte, which acts as a conductor of ions between the positive and negative electrodes. The electrolyte includes a liquid electrolyte solution. The casing has an injection port through which the liquid electrolyte is injected into the casing. At least a portion of the injected liquid electrolyte permeates into the electrode assembly through the gap between the electrode plates and the separator, thus continuing its ion-conducting function.

[0074] The electrode assembly includes a main body and tabs. The main body includes a positive current collector, a positive active material, a negative current collector, a negative active material, and a separator. The tabs include a positive tab and a negative tab. The positive tab is connected to or integrally formed with the positive current collector. The positive current collector includes the positive current collector and the positive tab. The negative tab is connected to or integrally formed with the negative current collector. The negative current collector includes the negative current collector and the negative tab.

[0075] In related technologies, the space occupied by the main body is usually increased by reducing the distance between the outer casing wall and the main body. This allows for the placement of more active materials within the main body, improving the internal space utilization and energy density of the battery cell. However, the tabs are typically located between the outer casing wall and the main body. As the distance between the outer casing wall and the main body decreases, the usable space for the tabs also decreases, affecting their current carrying capacity. Furthermore, the outer casing wall has injection holes. During injection, the electrolyte is typically injected into the outer casing at a certain pressure and speed through these holes. As the distance between the outer casing wall and the main body decreases, the distance between the injection holes and the main body also decreases. This causes the electrolyte to impact the main body at a higher speed, potentially leading to bending or inverted insertion of the separators between the electrodes, thus creating a short circuit hazard.

[0076] In view of this, this application provides a technical solution in which a recess is formed on the side of the first wall facing the electrode assembly. The recess can provide at least a partial accommodating space for the tab, and the electrode terminal can share at least a portion of the space with the tab, which is beneficial to improving space utilization and increasing the energy density of the battery cell. The outer casing is provided with an injection hole communicating with the recess. Electrolyte injected through the injection hole can be injected into the recess. The tab accommodated in the recess can block the electrolyte to a certain extent, reducing the impact of the electrolyte on the main body, reducing electrolyte splashing, reducing the risk of short circuit, and improving the reliability of the battery cell. The electrolyte in direct contact with the tab can be wetted into the active material of the electrode assembly under the promotion of the capillary suction of the tab, which is beneficial to improving the wetting effect and wetting efficiency of the electrolyte.

[0077] The technical solutions provided in this application are applicable to battery cells, battery devices, and electrical equipment using battery devices.

[0078] The battery device disclosed in this application can be used in electrical devices that use the battery device as a power source or in various energy storage systems that use the battery device as an energy storage element. The electrical devices can be, but are not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc. Among them, electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc., and spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0079] For ease of explanation, the following embodiments use a vehicle as an example of electrical equipment.

[0080] Figure 1 is a schematic diagram of the structure of a vehicle provided in some embodiments of this application. Referring to Figure 1, vehicle 1 can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. A battery device 2 is installed inside vehicle 1, and the battery device 2 can be located at the bottom, front, or rear of vehicle 1. The battery device 2 can be used to power vehicle 1; for example, the battery device 2 can serve as the operating power source for vehicle 1. Vehicle 1 may also 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 needs of vehicle 1 during starting, navigation, and driving.

[0081] In some embodiments of this application, the battery device 2 can not only serve as the operating power source for the vehicle 1, but also as the driving power source for the vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1.

[0082] Figure 2 is an exploded structural diagram of a battery device provided in some embodiments of this application. Referring to Figure 2, the battery device 2 includes a housing 5 and a battery cell 6, with the battery cell 6 housed within the housing 5. The housing 5 provides a space for the battery cell 6, and the housing 5 can adopt various structures. In some embodiments, the housing 5 may include a first housing portion 5a and a second housing portion 5b, which overlap each other, jointly defining a space 5c for accommodating the battery cell 6. The second housing portion 5b may be a hollow structure with one open end, and the first housing portion 5a may be a plate-like structure, covering the open side of the second housing portion 5b so that the first housing portion 5a and the second housing portion 5b jointly define the space 5c; alternatively, the first housing portion 5a and the second housing portion 5b may both be hollow structures with one open side, with the open side of the first housing portion 5a covering the open side of the second housing portion 5b. Of course, the box 5 formed by the first box part 5a and the second box part 5b can be of various shapes, such as a cylinder, a cuboid, etc.

[0083] To improve the sealing performance after the first housing part 5a and the second housing part 5b are connected, a sealing element, such as sealant or sealing ring, can also be provided between the first housing part 5a and the second housing part 5b.

[0084] Assuming that the first box section 5a covers the top of the second box section 5b, the first box section 5a can also be called the upper box cover, and the second box section 5b can also be called the lower box.

[0085] In the battery device 2, there can be multiple battery cells 6, which can be connected in series, parallel, or in a mixed manner. A mixed connection means that multiple battery cells 6 are connected in both series and parallel configurations. Multiple battery cells 6 can be directly connected in series, parallel, or in a mixed manner, and then the entire assembly of the multiple battery cells 6 is housed within the housing 5. Alternatively, the battery device 2 can also consist of multiple battery cells 6 first connected in series, parallel, or in a mixed manner to form battery modules, and then these battery modules are connected in series, parallel, or in a mixed manner to form a whole, which is also housed within the housing 5. The battery device 2 may also include other structures; for example, it may include a busbar component for electrical connection between the multiple battery cells 6.

[0086] For example, the battery cell 6 may be the smallest unit that makes up the battery device 2.

[0087] Figure 3 is a structural schematic diagram of a battery cell provided in some embodiments of this application, and Figure 4 is an exploded structural schematic diagram of the battery cell shown in Figure 3. Referring to Figures 3 and 4, the battery cell 6 includes an electrode assembly 10 and a housing 20, with the electrode assembly 10 disposed within the housing 20.

[0088] The outer casing 20 is used to encapsulate the electrode assembly 10 and electrolyte components. The outer casing 20 can be made of steel, aluminum, plastic (such as polypropylene), composite metal (such as copper-aluminum composite), or aluminum-plastic film, etc.

[0089] In some embodiments, the housing 20 is a hollow structure, with an internal space for accommodating the electrode assembly 10 and the electrolyte. The shape of the housing 20 can be determined according to the specific shape of the electrode assembly 10. For example, if the electrode assembly 10 has a cuboid structure, a cuboid housing can be selected.

[0090] The outer casing 20 can be made of various materials, such as metal or plastic. Optionally, the outer casing 20 can be made of copper, iron, aluminum, steel, aluminum alloy, etc. For example, the outer casing 20 can be a steel casing, aluminum casing, plastic casing (such as polypropylene), composite metal casing (such as copper-aluminum composite casing), or aluminum-plastic film, etc.

[0091] As an example, the housing 20 includes a housing 21 and an end cap 22, the housing 21 having a housing opening 211 and the end cap 22 for closing the housing opening 211.

[0092] The housing 21 is a component used to fit the end cap 22 to form the internal cavity of the battery cell 6. The formed internal cavity can be used to accommodate the electrode assembly 10, electrolyte, and other components.

[0093] The housing 21 and the end cap 22 can be separate components. For example, a housing opening 211 can be provided on the housing 21, and the end cap 22 can be used to cover the housing opening 211 to form an internal cavity of the battery cell 6.

[0094] The shape of the end cap 22 can be adapted to the shape of the housing 21 to fit the housing 21. The material of the end cap 22 can be the same as or different from the material of the housing 21.

[0095] The end cap 22 can be connected to the housing 21 by welding, bonding, snap-fitting or other means.

[0096] The housing 21 may have an opening 211 at one end or at both ends. For example, the housing 21 may have an opening 211 on one side, with an end cap 22 covering the opening 211 of the housing 21. Alternatively, the housing 21 may have openings 211 on both sides, with two end caps 22 covering the two openings 211 of the housing 21 respectively.

[0097] Figure 5 is a top view of the battery cell shown in Figure 3; Figure 6 is a cross-sectional view taken along direction AA in Figure 5; Figure 7 is an enlarged structural schematic diagram of region B in Figure 6; Figure 8 is an exploded structural schematic diagram of the first wall of the battery cell shown in Figure 3; Figure 9 is a structural schematic diagram of a battery cell provided in some other embodiments of this application; Figure 10 is a cross-sectional view of the battery cell shown in Figure 9; Figure 11 is an enlarged structural schematic diagram of region C in Figure 10; Figure 12 is an exploded structural schematic diagram of Figure 11; Figure 13 is a partial structural schematic diagram of the first wall of the battery cell shown in Figure 9; Figure 14 is an enlarged structural schematic diagram of region D in Figure 13; Figure 15 is a structural schematic diagram of a battery cell provided in some other embodiments of this application; Figure 16 is a cross-sectional view of the battery cell shown in Figure 15; Figure 17 is an enlarged structural schematic diagram of region E in Figure 16; Figure 18 is an enlarged structural schematic diagram of region F in Figure 16; and Figure 19 is a structural schematic diagram of a battery cell provided in some further embodiments of this application.

[0098] Referring to Figures 3 to 19, the battery cell 6 provided in this embodiment includes an electrode assembly 10, a housing 20, a first electrode terminal 30, and a first sealing member 40. The electrode assembly 10 includes a main body 11 and a first tab 12 connected to the main body 11. The electrode assembly 10 is housed within the housing 20. The housing 20 includes a first wall 23 located on one side of the electrode assembly 10 along a first direction X. The first wall 23 includes a first portion 231, a second portion 232, and a first bend 233. Along the first direction X, the first portion 231 is closer to the main body 11 than the second portion 232, and the first bend 233 connects the first portion 231 and the second portion 232. A first recess 234 is provided on the side of the first wall 23 near the electrode assembly 10, and the bottom surface of the first recess 234 corresponds to the second portion 232. At least a portion of the first tab 12 is housed in the first recess 234. The housing 20 is provided with a first liquid injection hole 24, which communicates with the first recess 234. In the same plane perpendicular to the axial direction of the first injection hole 24, the orthographic projection of the first injection hole 24 at least partially overlaps with the orthographic projection of the first recess 234. A first electrode terminal 30 is disposed in the first portion 231. A first seal 40 is connected to the housing 20 and seals the first injection hole 24.

[0099] Electrode assembly 10 is a component in the battery cell 6 where electrochemical reactions occur. The housing 20 may contain one or more electrode assemblies 10.

[0100] The first wall 23 can be one of the walls of the housing 21, or it can be an end cap 22. Optionally, in the embodiment shown in FIG4, the first wall 23 is an end cap 22.

[0101] The first part 231 and the second part 232 are arranged along a second direction Y, which intersects with the first direction X. Optionally, the second direction Y is the length direction of the first wall 23.

[0102] The first bend 233 bends away from the main body 11 relative to the first part 231. The first bend 233 bends towards the main body 11 relative to the second part 232. The first bend 233 extends from the first part 231 to the second part 232 in a direction that gradually moves away from the main body 11.

[0103] Along the first direction X, the distance between the first portion 231 and the main body 11 is different from the distance between the second portion 232 and the main body 11. The positional difference between the first portion 231 and the second portion 232 relative to the main body 11 causes a first recess 234 to be formed on the side of the first wall 23 near the electrode assembly 10. The first recess 234 is recessed into the surface of the first portion 231 near the main body 11.

[0104] The first electrode tab 12 may be entirely housed in the first recess 234, or only a portion of the first electrode tab 12 may be housed in the first recess 234. For example, another portion of the first electrode tab 12 may protrude from the first recess 234 along the first direction X.

[0105] Optionally, at least a portion of the first electrode terminal 30 protrudes from the surface of the first portion 231 away from the main body portion 11. The first electrode terminal 30 is electrically connected to the first tab 12.

[0106] The first recess 234 provides at least a partial accommodating space for the first tab 12. The first tab 12 and the first electrode terminal 30 can share at least a portion of the space in the first direction X, which is beneficial to improving space utilization and increasing the energy density of the battery cell 6.

[0107] The first injection hole 24 connects the first recess 234 and the outside of the outer casing 20. The first injection hole 24 and the first recess 234 can be directly connected or indirectly connected.

[0108] The first recess 234 is enclosed by the second portion 232, the first bend 233, and the other portions of the outer casing 20. In some examples, the first injection hole 24 is provided in the portion of the outer casing 20 that encloses the first recess 234. Along the axial direction of the first injection hole 24, the first injection hole 24 penetrates the portion of the outer casing 20 that encloses the first recess 234, thereby directly communicating between the first recess 234 and the outside of the outer casing 20.

[0109] In other examples, the portion of the housing 20 that encloses the first recess 234 is provided with a channel, and the first injection hole 24 is provided on the wall of the housing 20 near the channel and is indirectly connected to the first recess 234 through the channel.

[0110] Optionally, in the same plane perpendicular to the axial direction of the first injection hole 24, the orthographic projection of the first injection hole 24 is located within the orthographic projection of the first recess 234.

[0111] The first wall 23 includes a protective structure 239. Along the direction of the first wall 23 pointing towards the electrode assembly 10, the protective structure 239 protrudes from the bottom surface of the first recess 234. The protective structure 239 covers the first injection hole 24. The interior of the protective structure 239 defines a protective cavity 2391. The protective structure 239 is provided with a through hole (not shown in the figure). The first injection hole 24 is indirectly connected to the first recess 234 through the protective cavity 2391 and the through hole.

[0112] At least a portion of the first seal 40 can be inserted into the first injection hole 24 and form a seal between it and the hole wall of the first injection hole 24, which helps to improve the sealing effect and reduce the risk of electrolyte leakage.

[0113] Optionally, the first seal 40 may be made of metal, which is beneficial for improving the strength of the first seal 40. For example, the first seal 40 may be an aluminum nail or an aluminum alloy nail.

[0114] The connection methods between the first seal 40 and the housing 20 include, but are not limited to, welding, bonding, and snap-fitting. Optionally, the first seal 40 and the housing 20 are laser welded.

[0115] In this embodiment, the first injection hole 24 is connected to the first recess 234. The orthographic projection of the first injection hole 24 and the orthographic projection of the first recess 234 overlap at least partially. The electrolyte injected through the first injection hole 24 can be injected into the first recess 234. The first tab 12 housed in the first recess 234 can block the electrolyte to a certain extent, reduce the impact of the electrolyte on the main body 11, reduce electrolyte splashing, reduce the risk of short circuit, and improve the reliability of the battery cell 6.

[0116] The electrolyte in direct contact with the first tab 12 can be wetted into the active material of the electrode assembly 10 under the capillary attraction of the first tab 12, which is beneficial to improving the wetting effect and efficiency of the electrolyte.

[0117] In some embodiments, referring to Figures 3 to 8, a first injection hole 24 is provided in the second portion 232 and extends through the second portion 232 along the first direction X.

[0118] The axial direction of the first injection hole 24 is parallel to the first direction X. In the same plane perpendicular to the first direction X, the orthographic projection of the first injection hole 24 lies within the orthographic projection of the first recess 234.

[0119] During the assembly of the battery cell 6, electrolyte can be injected into the outer casing 20 through the first injection hole 24 while the battery cell 6 is in the position of the first wall 23 facing upwards. The second part 232 where the first injection hole 24 is located is at a higher position, which helps to raise the injection surface, increase the injection volume, and improve the problem of limited space available for containing electrolyte due to the high energy density of the battery cell 6.

[0120] In some embodiments, referring to Figures 6 to 8, the housing 20 includes a second wall 25 located on one side of the electrode assembly 10 along the second direction Y. The second wall 25 is connected to the second portion 232, and the second direction Y intersects the first direction X. The first wall 23 includes a first protrusion 235 located on the side of the second wall 25 near the electrode assembly 10 along the second direction Y. Along the direction of the first wall 23 pointing towards the electrode assembly 10, the first protrusion 235 protrudes from the bottom surface of the first recess 234 and abuts against the main body portion 11. The first protrusion 235 is provided with a first channel 2351, which connects the first recess 234 and the space between the first protrusion 235 and the second wall 25.

[0121] Optionally, the second direction Y is perpendicular to the first direction X.

[0122] In some examples, the second direction Y is parallel to the length direction of the first wall 23. In other examples, the second direction Y is parallel to the width direction of the first wall 23, and the second wall 25 is a larger wall portion of the outer shell 20.

[0123] Optionally, the first portion 231 and the second portion 232 are arranged along the second direction Y. Along the second direction Y, one end of the second portion 232 is connected to the first bend 233, and the other end is connected to the second wall 25.

[0124] Optionally, the first channel 2351 extends through the first protrusion 235 along the second direction Y.

[0125] The first protrusion 235 is a component that forms the first recess 234. The first channel 2351 is directly connected to the first recess 234.

[0126] Along the second direction Y, the first protrusion 235 and the second wall 25 are spaced apart, forming a space between the first protrusion 235 and the second wall 25, and the first channel 2351 directly connects the space between the first protrusion 235 and the second wall 25.

[0127] The first protrusion 235 abuts against the main body 11, which helps to limit the shaking of the electrode assembly 10 in the first direction X, improves the structural stability of the battery cell 6, thereby reducing the risk of mechanical damage, internal short circuit, thermal runaway and other issues of the battery cell 6, and improving the reliability of the battery cell 6.

[0128] The first channel 2351 connects the first recess 234 and the space between the first protrusion 235 and the second wall 25. Part of the electrolyte in the first recess 234 can flow through the first channel 2351 to the space between the first protrusion 235 and the second wall 25, and then to the gap between the second wall 25 and the electrode assembly 10, and finally to the bottom space of the outer shell 20, wetting the electrode assembly 10 from the bottom, which helps to further improve the wetting effect and efficiency of the electrolyte.

[0129] In some embodiments, referring to Figures 6 and 7, in the same plane perpendicular to the first direction X, the orthographic projection of the first protrusion 235 and the orthographic projection of the first tab 12 are located on both sides of the orthographic projection of the first injection hole 24 in the second direction Y.

[0130] The orthographic projection of the first protrusion 235 is located on the side of the orthographic projection of the first injection hole 24 that is closer to the second wall 25, and the orthographic projection of the first electrode 12 is located on the side of the orthographic projection of the first injection hole 24 that is farther away from the second wall 25.

[0131] In the second direction Y, the first protrusion 235 and the first tab 12 are both close to the first injection hole 24, which can shorten the flow distance of the electrolyte injected from the first injection hole 24 to the first tab 12 and the first channel 2351, reduce the flow resistance of the electrolyte to the first tab 12 and the first channel 2351, and help to further improve the wetting efficiency and wetting effect of the electrolyte.

[0132] In some embodiments, referring to Figures 9 to 12, the housing 20 includes a second wall 25 located on one side of the electrode assembly 10 along the second direction Y. The second wall 25 is connected to the second portion 232, and the second direction Y intersects the first direction X. A first injection hole 24 is provided on the second wall 25 and extends through the second wall 25 along the second direction Y.

[0133] Optionally, the second direction Y is perpendicular to the first direction X.

[0134] In some examples, the second direction Y is parallel to the length direction of the first wall 23. The first portion 231 and the second portion 232 are arranged along the second direction Y. Along the second direction Y, one end of the second portion 232 is connected to the first bend 233, and the other end is connected to the second wall 25.

[0135] In other examples, the second direction Y is parallel to the width direction of the first wall 23. The second wall 25 is a larger wall portion of the outer casing 20. A portion of the second wall 25 is connected to one edge of the second portion 232 along the second direction Y.

[0136] The axial direction of the first injection hole 24 is parallel to the second direction Y. In the same plane perpendicular to the second direction Y, the orthographic projection of the first injection hole 24 is located within the orthographic projection of the first recess 234, and the orthographic projection of the first injection hole 24 partially overlaps with the orthographic projection of the first recess 234.

[0137] During the assembly of the battery cell 6, electrolyte can be injected into the casing 20 through the first injection hole 24 while the battery cell 6 is in the position with the second wall 25 facing upwards. This helps to increase the injection surface area and the injection volume. The first injection hole 24 is located on the second wall 25, and the first injection hole 24 and the first electrode terminal 30 are not on the same wall. This helps to reduce the risk of electrolyte spilled outside the second wall 25 during the injection process corroding the first electrode terminal 30, and also reduces the risk of electrolyte affecting the bonding strength between the first wall 23 and other structures (such as the battery housing).

[0138] In some embodiments, the first portion 231 and the second portion 232 are arranged along a second direction Y. The second direction Y is parallel to the length direction of the first wall 23. The second wall 25 is not a wall portion of the outer casing 20 with a larger area.

[0139] During the charging and discharging process of the battery cell 6, the deformation of the larger wall portion of the outer casing 20 is relatively large. By placing the first liquid injection hole 24 on the second wall 25 located on the side of the first wall 23 along the second direction Y, it is beneficial to reduce the impact of the deformation of the outer casing 20 on the sealing effect of the first liquid injection hole 24, thereby reducing the risk of leakage.

[0140] In some embodiments, referring to FIGS. 11 to 14, the first wall 23 includes a first protrusion 235. Along the second direction Y, the first protrusion 235 is located on the side of the second wall 25 near the electrode assembly 10. Along the direction from the first wall 23 to the electrode assembly 10, the first protrusion 235 protrudes from the bottom surface of the first recess 234 and abuts against the main body 11. The first protrusion 235 is provided with a first channel 2351, which connects the first recess 234 and the first injection hole 24.

[0141] Optionally, the first channel 2351 extends through the first protrusion 235 along the second direction Y.

[0142] Optionally, the first protrusion 235 includes two first sidewalls 2352 arranged along the second direction Y, each first sidewall 2352 having a first opening 2353, and the interior of the first protrusion 235 forms a cavity 2354, which connects to the first openings 2353 of the two first sidewalls 2352. The first channel 2351 includes the cavity 2354 and the first opening 2353.

[0143] The first protrusion 235 is a component that forms the first recess 234, and the first channel 2351 is directly connected to the first recess 234.

[0144] The first protrusion 235 abuts against the main body 11, which helps to limit the shaking of the electrode assembly 10 in the first direction X, improves the structural stability of the battery cell 6, thereby reducing the risk of mechanical damage, internal short circuit, thermal runaway and other issues of the battery cell 6, and improving the reliability of the battery cell 6.

[0145] By providing a first channel 2351 in the first protrusion 235, the first injection hole 24 provided in the second wall 25 can be indirectly connected to the first recess 234 through the first channel 2351. At least part of the electrolyte injected from the first injection hole 24 flows into the first recess 234 through the first channel 2351, which helps to reduce the impact of the electrolyte on the main body 11 and the first tab 12.

[0146] In some embodiments, referring to FIG14, the first protrusion 235 is provided with a plurality of first channels 2351 spaced apart along a third direction Z, wherein the first direction X, the second direction Y, and the third direction Z are mutually perpendicular. In the same plane perpendicular to the second direction Y, the orthographic projection of a portion of the first channel 2351 overlaps with the orthographic projection of the first injection hole 24. The area of ​​the orthographic projection of the first channel 2351 that overlaps with the orthographic projection of the first injection hole 24 is larger than the area of ​​the orthographic projection of the first channel 2351 that does not overlap with the orthographic projection of the first injection hole 24.

[0147] Optionally, the area of ​​the first opening 2353 of the first channel 2351 facing the second wall 25 that overlaps with the orthographic projection of the first injection hole 24 is greater than the area of ​​the first opening 2353 of the first channel 2351 facing the second wall 25 that does not overlap with the orthographic projection of the first injection hole 24.

[0148] The area of ​​the first channel 2351, which overlaps with the orthographic projection of the first injection hole 24, is larger, which helps to reduce the obstruction effect of the first protrusion 235 on the electrolyte and improve the wetting efficiency of the electrolyte.

[0149] In some embodiments, referring to FIG11, a portion of the first seal 40 protrudes from the second wall 25 in the direction pointing from the second wall 25 toward the electrode assembly 10. In the same plane perpendicular to the second direction Y, the orthographic projection of the portion of the first seal 40 protruding from the second wall 25 does not overlap with the orthographic projection of the main body 11.

[0150] Optionally, the portion of the first seal 40 protruding from the second wall 25 is spaced apart from the main body 11 along the first direction X.

[0151] A portion of the first seal 40 protrudes from the second wall 25, which helps to improve the sealing effect of the first seal 40 on the first injection hole 24. The orthographic projection of the portion of the first seal 40 protruding from the second wall 25 does not overlap with the orthographic projection of the main body 11, which can reduce the possibility of interference between the first seal 40 and the main body 11. The size design of the first seal 40 protruding from the second wall 25 is more flexible, which is more conducive to improving the sealing effect.

[0152] In some embodiments, referring to FIGS. 11 and 12, the second wall 25 includes a wall body 251 and a second protrusion 252. At least a portion of the second protrusion 252 protrudes from a first surface 251a of the wall body 251 toward the electrode assembly 10 along a second direction Y. A first injection hole 24 penetrates the second protrusion 252. The second protrusion 252 is spaced apart from the body portion 11 along the second direction Y.

[0153] The wall body 251 is connected to the first wall 23 by welding, bonding or other suitable means. Optionally, the wall body 251 is laser welded to the first wall 23.

[0154] In the same plane perpendicular to the second direction Y, the orthographic projection of the second protrusion 252 and the orthographic projection of the main body 11 may at least partially overlap, or they may not overlap.

[0155] At least a portion of the second protrusion 252 protrudes toward the interior of the housing 20, and the first injection hole 24 penetrates the second protrusion 252. This allows for the use of the space inside the housing 20 to increase the depth of the first injection hole 24. Without taking up additional space outside the housing 20, the contact area between the first injection hole 24 and the first seal 40 can be increased, thereby improving the sealing effect.

[0156] The second protrusion 252 is spaced apart from the main body 11, which helps to reduce the risk of interference between the second protrusion 252 and the main body 11, improves the positional flexibility of the second protrusion 252 in the third direction Z, and reduces the risk that the first seal 40 will affect the connection between the wall body 251 and the first wall 23.

[0157] In some embodiments, referring to Figures 11 and 12, at least a portion of the first seal 40 is accommodated in the first injection hole 24. Along the direction of the electrode assembly 10 toward the second wall 25, the first seal 40 does not extend beyond the wall body 251 away from the second surface 251b of the electrode assembly 10.

[0158] The first injection hole 24 includes a first hole segment 241 and a second hole segment 242 arranged along a second direction Y. The first hole segment 241 is located on the side of the second hole segment 242 closer to the electrode assembly 10. The first injection hole 24 includes a stepped surface 243 facing the second hole segment 242. The stepped surface 243 connects the inner peripheral wall of the first hole segment 241 and the inner peripheral wall of the second hole segment 242.

[0159] A portion of the first seal 40 is accommodated in the second bore 242 and connected to the stepped surface 243.

[0160] The first seal 40 does not extend beyond the second surface 251b. The first seal 40 does not occupy additional external space of the housing 20, which is beneficial for the stacking of multiple battery cells 6 and the connection between the battery cells 6 and the housing.

[0161] In some embodiments, along the first direction X, the minimum distance between the edge of the second wall 25 near the first wall 23 and the first injection hole 24 is d, where d ≥ 1 mm.

[0162] Optionally, along the first direction X, d is less than the distance between the edge of the second wall 25 near the first wall 23 and the main body 11.

[0163] In this embodiment, d is set to be greater than or equal to 1 mm, which is beneficial to the connection between the first wall 23 and the second wall 25, and can also reduce the risk of interference between the connection position of the first seal 40 and the first wall 23 and the second wall 25.

[0164] In some embodiments, referring to Figures 15 to 19, a second recess 236 is provided on the side of the first wall 23 near the electrode assembly 10. The second recess 236 is spaced apart from the first recess 234. The housing 20 is provided with a second liquid injection hole 26, which communicates with the second recess 236. In the same plane perpendicular to the axial direction of the second liquid injection hole 26, the orthographic projection of the second liquid injection hole 26 and the orthographic projection of the second recess 236 at least partially overlap. The battery cell 6 includes a second seal 50, which is connected to the housing 20 and seals the second liquid injection hole 26.

[0165] The separation between the second recess 236 and the first recess 234 means that a partition structure is provided between the second recess 236 and the first recess 234, and the second recess 236 and the first recess 234 are not connected through the partition structure. When no electrolyte is injected into the outer casing 20, the first recess 234 and the second recess 236 can be indirectly connected through the gap between the partition structure and the main body 11. With the first wall 23 facing upwards, when the electrolyte level inside the outer casing 20 is higher than the partition structure, the first recess 234 and the second recess 236 are not connected.

[0166] The second injection hole 26 connects the second recess 236 and the outside of the outer casing 20. The second injection hole 26 and the second recess 236 can be directly connected or indirectly connected.

[0167] Optionally, in the same plane perpendicular to the axial direction of the second injection hole 26, the orthographic projection of the second injection hole 26 is located within the orthographic projection of the second recess 236.

[0168] The connection methods between the second seal 50 and the housing 20 include, but are not limited to, welding, bonding, and snap-fitting. Optionally, the second seal 50 is laser-welded to the housing 20.

[0169] The structure of the second seal 50 is similar to that of the first seal 40, and will not be described in detail here.

[0170] The outer casing 20 is provided with two injection holes, which helps to improve the injection efficiency. The second recess 236 is separated from the first recess 234. When the electrolyte level is higher than the separation structure between the second recess 236 and the first recess 234, electrolyte can continue to be injected into the first recess 234 through the first injection hole 24, and into the second recess 236 through the second injection hole 26. Neither the first recess 234 nor the second recess 236 will form a liquid seal, which helps to increase the injection volume, improve the performance of the battery cell 6, and extend the cycle life of the battery cell 6.

[0171] In some embodiments, referring to FIG16, the electrode assembly 10 includes a second tab 13 connected to the body portion 11, the first tab 12 and the second tab 13 having opposite polarities, and at least a portion of the second tab 13 being accommodated in a second recess 236.

[0172] The second electrode tab 13 may be entirely housed in the second recess 236, or only a portion of the second electrode tab 13 may be housed in the second recess 236. For example, another portion of the second electrode tab 13 may protrude from the second recess 236 along the first direction X.

[0173] Electrolyte injected through the second injection hole 26 can be injected into the second recess 236. The second tab 13 located in the second recess 236 can block the electrolyte to a certain extent, reducing the impact of the electrolyte on the main body 11 and lowering the risk of short circuit. Electrolyte in direct contact with the second tab 13 can be promoted by the capillary attraction of the second tab 13 to wet the interior of the electrode assembly 10, which is beneficial to improving the wetting effect and efficiency of the electrolyte.

[0174] In some embodiments, referring to Figures 16 to 18, the first wall 23 includes a third portion 237 and a second bend 238. Along the second direction Y, the second portion 232 and the third portion 237 are located on opposite sides of the first portion 231, and the second bend 238 connects the third portion 237 and the first portion 231. Along the first direction X, the first portion 231 is closer to the main body 11 than the third portion 237, and the bottom surface of the second recess 236 corresponds to the third portion 237. The first portion 231, the first bend 233, and the second bend 238 separate the first recess 234 and the second recess 236.

[0175] In other words, the partition structure between the first recess 234 and the second recess 236 includes a first portion 231, a first bend 233, and a second bend 238.

[0176] The battery cell 6 includes a second electrode terminal 60, which is located in the first portion 231. The second electrode terminal 60 is electrically connected to the second tab 13.

[0177] The second bend 238 bends relative to the first portion 231 in a direction gradually moving away from the main body portion 11. The second bend 238 bends relative to the third portion 237 in a direction gradually moving closer to the main body portion 11. The second bend 238 extends from the first portion 231 to the third portion 237 in a direction gradually moving away from the main body portion 11.

[0178] The second recess 236 provides at least a partial accommodating space for the second tab 13. The second tab 13 and the first electrode terminal 30 can share at least a portion of the space in the first direction X, which is beneficial to improving space utilization and increasing the energy density of the battery cell 6.

[0179] In some embodiments, referring to FIG19, the second injection hole 26 is provided in the third portion 237 and extends through the third portion 237 along the first direction X.

[0180] The axial direction of the second injection hole 26 is parallel to the first direction X. In the same plane perpendicular to the first direction X, the orthographic projection of the second injection hole 26 lies within the orthographic projection of the third part 237.

[0181] During the assembly of the battery cell 6, electrolyte can be injected into the outer casing 20 through the second injection hole 26 while the battery cell 6 is in the position of the first wall 23 facing upwards. The third part 237, where the second injection hole 26 is located, is at a higher position, which helps to increase the amount of electrolyte injected and improves the problem of limited space available to hold electrolyte due to the high energy density of the battery cell 6.

[0182] In some embodiments, referring to Figures 15 and 16, the housing 20 includes a third wall 27 located on one side of the electrode assembly 10 along a second direction Y, which intersects with a first direction X. The third wall 27 is connected to a third portion 237. A second injection hole 26 is disposed on the third wall 27 and extends through the third wall 27 along the second direction Y.

[0183] The second wall 25 and the third wall 27 are arranged along the second direction Y. The second wall 25 and the third wall 27 are respectively connected to the two edges of the first wall 23 along the second direction Y.

[0184] In the second direction Y, the second wall 25 is closer to the first recess 234 and the first injection hole 24 than the third wall 27. The third wall 27 is closer to the second recess 236 and the second injection hole 26 than the second wall 25.

[0185] The second injection hole 26 is located on the third wall 27. The second injection hole 26 and the first electrode terminal 30 are not on the same wall, which helps to reduce the risk of electrolyte spilled outside the third wall 27 during the injection process corroding the first electrode terminal 30, and reduces the risk of electrolyte affecting the bonding strength of the first wall 23 with other structures (such as the battery housing).

[0186] In some embodiments, referring to Figures 8, 17, and 18, the first wall 23 includes a cover 23a and an insulating member 23b. Along the first direction X, the insulating member 23b is disposed on the side of the cover 23a closer to the main body portion 11. The cover 23a includes a first cover portion 23a1, a second cover portion 23a2, and a third cover portion 23a3. Along the first direction X, the first cover portion 23a1 is closer to the main body portion 11 than the second cover portion 23a2, and the third cover portion 23a3 connects the first cover portion 23a1 and the second cover portion 23a2. The insulating member 23b includes a first insulating portion 23b1, a second insulating portion 23b2, and a third insulating portion 23b3. Along the first direction X, the first insulating portion 23b1 is closer to the main body portion 11 than the second insulating portion 23b2. The third insulating portion 23b3 connects the first insulating portion 23b1 and the second insulating portion 23b2. The first part 231 includes a first cover part 23a1 and a first insulating part 23b1 stacked together, the second part 232 includes a second cover part 23a2 and a second insulating part 23b2 stacked together, and the first bending part 233 includes a third cover part 23a3 and a third insulating part 23b3 stacked together.

[0187] Optionally, the cover 23a may be made of metal to improve the structural strength of the cover 23a and reduce the deformation of the cover 23a.

[0188] Insulator 23b is used to insulate and isolate cover 23a and electrode assembly 10, reducing the risk of short circuit.

[0189] The third cover portion 23a3 bends away from the main body portion 11 relative to the first cover portion 23a1, and bends closer to the main body portion 11 relative to the second cover portion 23a2.

[0190] The third insulating portion 23b3 is bent away from the main body portion 11 relative to the first insulating portion 23b1, and the third cover portion 23a3 is bent towards the main body portion 11 relative to the second insulating portion 23b2.

[0191] The first cover portion 23a1 and the first insulating portion 23b1 are stacked along the first direction X, the second cover portion 23a2 and the second insulating portion 23b2 are stacked along the first direction X, and the stacking direction of the third cover portion 23a3 and the third insulating portion 23b3 intersects with the first direction X.

[0192] Optionally, the cover 23a further includes a fourth cover portion 23a4 and a fifth cover portion 23a5. Along the first direction X, the first cover portion 23a1 is closer to the main body portion 11 than the fourth cover portion 23a4, and the fifth cover portion 23a5 connects the first cover portion 23a1 and the fourth cover portion 23a4. Exemplarily, along the second direction Y, the fifth cover portion 23a5 is symmetrically arranged with the third cover portion 23a3.

[0193] The insulating member 23b further includes a fourth insulating portion 23b4 and a fifth insulating portion 23b5. Along the first direction X, the first insulating portion 23b1 is closer to the main body portion 11 than the fourth insulating portion 23b4, and the fifth insulating portion 23b5 connects the first insulating portion 23b1 and the fourth insulating portion 23b4. Exemplarily, along the second direction Y, the fifth insulating portion 23b5 is symmetrically arranged with the third insulating portion 23b3.

[0194] The third part 237 includes a fourth cover portion 23a4 and a fourth insulating portion 23b4 stacked together. The second bent portion 238 includes a fifth cover portion 23a5 and a fifth insulating portion 23b5 stacked together.

[0195] Both the cover 23a and the insulating component 23b have a bending structure, and the bending trends of their bending structures are the same.

[0196] According to a second aspect of this application, embodiments of this application also provide a battery device 2. Referring to FIG2, the battery device 2 includes a battery cell 6 provided according to any embodiment of the first aspect of this application.

[0197] According to a third aspect of this application, embodiments of this application also provide an electrical device, which includes a battery device 2 provided according to any embodiment of the second aspect of this application, the battery device 2 being used to provide electrical energy.

[0198] This application provides a battery cell 6, which includes an electrode assembly 10, a housing 20, a first electrode terminal 30, a second electrode terminal 60, a first seal 40, and a second seal 50. The electrode assembly 10 includes a main body 11 and a first tab 12 and a second tab 13 connected to the main body 11. The electrode assembly 10 is housed within the housing 20. The housing 20 includes a first wall 23, a second wall 25, and a third wall 27. The first wall 23 is located on one side of the electrode assembly 10 along a first direction X, and the second wall 25 and the third wall 27 are located on both sides of the electrode assembly 10 along a second direction Y, which intersects with the first direction X. The first wall 23 includes a first portion 231, a second portion 232, a third portion 237, a first bend 233, and a second bend 238. Along the first direction X, the first portion 231 is closer to the main body 11 than the second portion 232 and the third portion 237. A first bend 233 connects the first portion 231 and the second portion 232, and a second bend 238 connects the third portion 237 and the first portion 231. The first wall 23 has a first recess 234 and a second recess 236 on the side near the electrode assembly 10. The bottom surface of the first recess 234 corresponds to the second portion 232, and the bottom surface of the second recess 236 corresponds to the third portion 237. The first portion 231, the first bend 233, and the second bend 238 separate the first recess 234 and the second recess 236. At least a portion of the first tab 12 is accommodated in the first recess 234. At least a portion of the second tab 13 is accommodated in the second recess 236. A second wall 25 is connected to the second portion 232, and a third wall 27 is connected to the third portion 237. The second part 232 is provided with a first injection hole 24, which communicates with the first recess 234. In the same plane perpendicular to the first direction X, the orthographic projection of the first injection hole 24 at least partially overlaps with the orthographic projection of the first recess 234. The third part 237 or the third wall 27 is provided with a second injection hole 26, which communicates with the second recess 236. In the same plane perpendicular to the axial direction of the second injection hole 26, the orthographic projection of the second injection hole 26 at least partially overlaps with the orthographic projection of the second recess 236. A first electrode terminal 30 and a second electrode terminal 60 are provided in the first part 231. A first seal 40 is connected to the second part 232 and seals the first injection hole 24. A second seal 50 is connected to the housing 20 and seals the second injection hole 26.

[0199] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A single battery cell, comprising: An electrode assembly includes a main body and a first electrode tab connected to the main body; as well as The housing contains the electrode assembly. The housing includes a first wall located on one side of the electrode assembly along a first direction. The first wall includes a first portion, a second portion, and a first bend. Along the first direction, the first portion is closer to the main body than the second portion. The first bend connects the first portion and the second portion. The first wall has a first recess on the side near the electrode assembly, and the bottom surface of the first recess corresponds to the second portion. At least a portion of the first tab is accommodated in the first recess. The housing also has a first injection hole communicating with the first recess. In the same plane perpendicular to the axial direction of the first injection hole, the orthographic projection of the first injection hole at least partially overlaps with the orthographic projection of the first recess. The first electrode terminal is disposed in the first part; as well as A first seal is attached to the housing and seals the first injection port.

2. The battery cell according to claim 1, wherein, The first injection hole is located in the second part and extends through the second part along the first direction.

3. The battery cell according to claim 2, wherein, The housing includes a second wall located on one side of the electrode assembly along a second direction and connected to the second portion, the second direction intersecting the first direction; The first wall includes a first protrusion along the second direction, the first protrusion being located on the side of the second wall closer to the electrode assembly, and along the direction of the first wall pointing towards the electrode assembly, the first protrusion protrudes from the bottom surface of the first recess and abuts against the main body portion; The first protrusion is provided with a first channel, which connects the first recess and the space between the first protrusion and the second wall.

4. The battery cell according to claim 3, wherein, In the same plane perpendicular to the first direction, the orthographic projection of the first protrusion and the orthographic projection of the first tab are respectively located on both sides of the orthographic projection of the first injection hole in the second direction.

5. The battery cell according to claim 1, wherein, The housing includes a second wall located on one side of the electrode assembly along a second direction and connected to the second portion, the second direction intersecting the first direction; The first injection hole is located on the second wall and penetrates the second wall along the second direction.

6. The battery cell according to claim 5, wherein, The first part and the second part are arranged along the second direction.

7. The battery cell according to claim 6, wherein, The first wall includes a first protrusion along the second direction, the first protrusion being located on the side of the second wall closer to the electrode assembly, and along the direction of the first wall pointing towards the electrode assembly, the first protrusion protrudes from the bottom surface of the first recess and abuts against the main body portion; The first protrusion is provided with a first channel, which connects the first concave portion and the first injection hole.

8. The battery cell according to claim 7, wherein, The first protrusion is provided with a plurality of first channels spaced apart along a third direction, wherein the first direction, the second direction, and the third direction are perpendicular to each other; In the same plane perpendicular to the second direction, a portion of the orthographic projection of the first channel overlaps with a portion of the orthographic projection of the first injection hole, and the area of ​​the orthographic projection of the first channel that overlaps with the orthographic projection of the first injection hole is greater than the area of ​​the orthographic projection of the first channel that does not overlap with the orthographic projection of the first injection hole.

9. The battery cell according to any one of claims 5-8, wherein, Along the direction of the second wall toward the electrode assembly, a portion of the first seal protrudes from the second wall, and in the same plane perpendicular to the second direction, the orthographic projection of the portion of the first seal protruding from the second wall does not overlap with the orthographic projection of the main body.

10. The battery cell according to any one of claims 5-9, wherein, The second wall includes a wall body and a second protrusion. Along the second direction, the second protrusion protrudes from a first surface of the wall body facing the electrode assembly. The first injection hole penetrates the second protrusion. Along the second direction, the second protrusion is spaced apart from the main body.

11. The battery cell according to any one of claims 5-10, wherein, Along the first direction, the minimum distance between the edge of the second wall near the first wall and the first injection hole is d, where d ≥ 1 mm.

12. The battery cell according to any one of claims 1-11, wherein, The first wall has a second recess on the side near the electrode assembly, and the second recess is separated from the first recess; The outer casing is provided with a second injection hole, which is connected to the second recess. In the same plane perpendicular to the axis of the second injection hole, the orthographic projection of the second injection hole and the orthographic projection of the second recess at least partially overlap. The battery cell includes a second seal, which is connected to the housing and seals the second injection hole.

13. The battery cell according to claim 12, wherein, The electrode assembly includes a second tab connected to the main body, the first tab and the second tab having opposite polarities, and at least a portion of the second tab being accommodated in the second recess.

14. The battery cell according to claim 12 or 13, wherein, The first wall includes a third part and a second bend. Along the second direction, the second part and the third part are located on both sides of the first part. The second bend connects the third part and the first part. Along the first direction, the first part is closer to the main body than the third part. The bottom surface of the second recess corresponds to the third part. The first portion, the first bend, and the second bend separate the first recess and the second recess.

15. The battery cell according to claim 14, wherein, The second injection hole is located in the third part and extends through the third part along the first direction.

16. The battery cell according to claim 14, wherein, The housing includes a third wall located on one side of the electrode assembly along a second direction and connected to the third portion, the second direction intersecting the first direction; The second injection hole is located on the third wall and penetrates the third wall along the second direction.

17. The battery cell according to any one of claims 1-16, wherein, The first wall includes a cover and an insulating member, wherein the insulating member is disposed on the side of the cover near the main body along the first direction; The cover includes a first cover portion, a second cover portion, and a third cover portion. Along the first direction, the first cover portion is closer to the main body portion than the second cover portion, and the third cover portion connects the first cover portion and the second cover portion. The insulating component includes a first insulating portion, a second insulating portion, and a third insulating portion. Along the first direction, the first insulating portion is closer to the main body portion than the second insulating portion, and the third insulating portion connects the first insulating portion and the second insulating portion. The first part includes a first cover portion and a first insulating portion stacked together, the second part includes a second cover portion and a second insulating portion stacked together, and the first bent portion includes a third cover portion and a third insulating portion stacked together.

18. A battery device comprising a plurality of battery cells according to any one of claims 1-17.

19. An electrical device comprising a battery device according to claim 18, the battery device being used to provide electrical energy.

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