Battery cell, battery and electric device

Abstract

The utility model relates to a battery monomer, a battery and an electric device. The battery monomer comprises an electrode terminal; the first battery cell unit comprises a first tab; the second battery cell unit comprises a second tab; the first tab and the second tab are laminated and connected to one side, facing the second battery cell unit, of the electrode terminal; and a first guard; and at least part of the first protection part is arranged between the first tab and the second battery cell unit in a blocking manner. According to the battery monomer, the battery and the power utilization device provided by the embodiment of the invention, the situations that the battery monomer is short-circuited and the tab is punctured can be effectively avoided, and the stable function is ensured.

Description

Technical Field

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

[0002] Existing battery cells typically use wound electrode assemblies, which are composed of positive electrode sheets, negative electrode sheets, and separators. During the assembly of a battery cell, multiple layers of conductive foil on the positive and negative electrode sheets need to be connected to the electrode terminals. The connection method is usually crimping. However, crimping can cause the end of the outermost layer of conductive foil to bend, which can lead to short circuits or puncture of the electrode tabs in the battery cell, posing a safety hazard. Utility Model Content

[0003] Therefore, it is necessary to provide a battery cell, a battery, and an electrical device to address the problems of easy short circuits in battery cells and easy puncture of the tabs.

[0004] A first aspect of this application provides a battery cell, comprising: an electrode terminal; a first cell unit including a first tab; a second cell unit including a second tab; the first tab and the second tab being stacked and connected to the side of the electrode terminal facing the second cell unit; and a first protective member; at least a portion of the first protective member being disposed between the first tab and the second cell unit.

[0005] By setting a first protective component, when the first and second battery cell units are connected to the electrode terminals, the first and second tabs are stacked and connected on the side of the electrode terminals facing the second battery cell unit. At least part of the first protective component is disposed between the first tab and the second battery cell unit. In this way, the first protective component can effectively prevent the end of the first tab from bending towards the second battery cell unit during the crimping process, thereby separating the second battery cell unit from the first tab. This can prevent the second battery cell unit 140 from being accidentally touched by the end of the first tab 131, causing a short circuit. It can also prevent the second tab 141 of the second battery cell unit 140 from being punctured or torn by the first tab 131, thereby preventing the overcurrent capacity of the second tab 141 from being affected and ensuring the functional stability of the battery cell.

[0006] In one embodiment, the second cell unit includes at least one second electrode assembly; each second electrode assembly includes a second winding body and multiple second conductive foils extending from the second winding body; all the second conductive foils are stacked to form a second tab; the second electrode assembly adjacent to the first cell unit further includes multiple third conductive foils extending from the second winding body; all the third conductive foils are stacked to form a first protective member; the first tab, the first protective member, and the second tab are stacked sequentially, and the second tab is pressed onto the side of the electrode terminal facing the second cell unit. By providing multiple third conductive foils on the second electrode assembly adjacent to the first cell unit, and using all the third conductive foils on the second electrode assembly to form the first protective member, there is no need to set a separate structure for the first protective member. Instead, the existing conductive foil structure is used as the first protective member. In the punching process of the second conductive foil, the third conductive foil and the second conductive foil can be punched in the same line by adjusting the mold structure. This has very little impact on the production process and cost adjustment of the second electrode assembly, and makes the structure of the second electrode assembly simpler and clearer, suitable for mass production.

[0007] In one embodiment, the second cell unit includes at least one second electrode assembly; each second electrode assembly includes a second winding body, multiple second conductive foils extending from the second winding body, and multiple third conductive foils extending from the second winding body; wherein the third conductive foils are located on the inner side of the second electrode assembly near the first cell unit, and the second conductive foils are located on the outer side of the second electrode assembly away from the first cell unit; the third conductive foils of the second electrode assemblies adjacent to the first cell unit are stacked to form the first protective member; the third conductive foils of the remaining second electrode assemblies are stacked with all the second conductive foils to form the second tab; the first tab, the first protective member, and the second tab are stacked sequentially, and the second tab is pressed onto the side of the electrode terminal facing the second cell unit. By providing multiple third conductive foils on all the second electrode assemblies, that is, regardless of whether the second electrode assembly adjacent to the first cell unit or other second electrode assemblies are provided with the same third conductive foil, it is ensured that each second electrode assembly is structurally identical. In this way, the different types of materials in the production process can be reduced, production efficiency can be improved, the confusion between second electrode assemblies can be prevented, and production quality can be ensured.

[0008] In one embodiment, the third conductive foil is located on the inner side of the second winding body near the first cell unit, and the second conductive foil is located on the outer side of the second winding body away from the first cell unit. This arrangement allows the third conductive foil on the inner side to block the first tab, thereby preventing the bent end of the first tab from touching the end face of the second winding body during crimping; ultimately, it effectively separates the second winding body of the second cell unit from the first tab, preventing short circuits in the second cell unit and ensuring the functional stability of the battery cell.

[0009] In one embodiment, the center of the second winding body along its thickness direction is used as the dividing line, and the second conductive foil and the third conductive foil are located on opposite sides of the dividing line. Thus, during battery cell assembly, the third conductive foil can be positioned as far away from the second conductive foil as possible, so that the end face of the second winding body is located within the range between the third and second conductive foils; the third conductive foil, located on the inner side, blocks the first tab, thereby preventing the bent end of the first tab from touching the end face of the second winding body during crimping; ultimately, the second winding body of the second cell unit is effectively separated from the first tab, preventing short circuits in the second cell unit and ensuring the functional stability of the battery cell.

[0010] In one embodiment, the second electrode assembly includes a positive electrode, a negative electrode, and a separator, the separator separating the positive electrode and the negative electrode; the positive electrode, the negative electrode, and the separator are wound into a second wound body; the second conductive foil and the third conductive foil are both connected to the positive electrode; or, the second conductive foil and the third conductive foil are both connected to the negative electrode.

[0011] In one embodiment, the number of the third conductive foils is one piece; and / or, the third conductive foil is a copper foil or an aluminum foil.

[0012] In one embodiment, the third conductive foil is coated with a protective adhesive near the root of the second winding body.

[0013] In one embodiment, the thickness of the protective adhesive ranges from 10µm to 200µm.

[0014] In one embodiment, the length of the protective adhesive is A, and the length of the third conductive foil is B, satisfying 0.1*B≤A≤0.8*B. Thus, by limiting the length ratio of the protective adhesive to the third conductive foil, the protective adhesive effectively strengthens the overall strength of the third conductive foil, resulting in better protection; at the same time, it prevents the protective adhesive from being too long, thus preventing the portion of the third conductive foil containing the protective adhesive from being pressed together with the second and first tabs, thereby avoiding the protective adhesive affecting the welding quality.

[0015] In one embodiment, the first protective element is a plastic film. By distributing at least a portion of the first protective element between the first tab and the second cell unit, the end of the first tab can be effectively prevented from bending toward the second cell unit during the crimping process, thereby separating the second cell unit from the first tab. This prevents the second cell unit from being accidentally touched by the end of the first tab, thus avoiding a short circuit. It also prevents the second tab of the second cell unit from being punctured or torn by the first tab, thereby preventing the overcurrent capacity of the second tab from being affected and ensuring the functional stability of the battery cell.

[0016] In one embodiment, the first cell unit includes at least one first electrode assembly, each first electrode assembly including a first winding body and a plurality of first conductive foils extending from the first winding body; all the first conductive foils are stacked to form the first tab. Thus, when all the first conductive foils are stacked to form the first tab, and the first tab, first protective member, and second tab are stacked in sequence, the second tab is pressed against the side of the electrode terminal facing the second cell unit, and the first protective member can block the bent end of the first tab during pressing to avoid short circuit in the second cell unit.

[0017] In one embodiment, the first cell unit includes a second protective member and at least one first electrode assembly; the second protective member, the first tab, the first protective member, and the second tab are stacked sequentially, with the second tab pressed against the side of the electrode terminal facing the second cell unit; each first electrode assembly includes a first winding body and multiple first conductive foils extending from the first winding body; all the first conductive foils are stacked to form the first tab; the first electrode assembly adjacent to the second cell unit further includes multiple fourth conductive foils extending from the first winding body; all the fourth conductive foils are stacked to form the second protective member. When the second protective member, the first tab, the first protective member, and the second tab are stacked sequentially, with the second tab pressed against the side of the electrode terminal facing the second cell unit; the second protective member is located on the uppermost side, which can prevent external structures from contacting the end face of the first cell unit, thereby preventing short circuits in the first cell unit and ensuring the functional stability of the battery cell.

[0018] In one embodiment, the first cell unit includes a second protective member and at least one first electrode assembly; the second protective member, the first electrode tab, the first protective member, and the second electrode tab are stacked sequentially, with the second electrode tab pressed against the side of the electrode terminal facing the second cell unit; each first electrode assembly includes a first winding body, multiple first conductive foils extending from the first winding body, and multiple fourth conductive foils extending from the first winding body; wherein the fourth conductive foils are located on the inner side of the first electrode assembly near the second cell unit, and the first conductive foils are located on the outer side of the first electrode assembly away from the second cell unit; the fourth conductive foils of the first electrode assemblies adjacent to the second cell unit are stacked to form the first protective member; the fourth conductive foils of the remaining first electrode assemblies are stacked with all the first conductive foils to form the first electrode tab. This reduces the types of different materials used in the production process, improves production efficiency, prevents confusion between first electrode assemblies with and without fourth conductive foils, and ensures production quality.

[0019] In one embodiment, the battery cell further includes a housing and an end cap having an opening at one end; the end cap closes to the opening of the housing to form an internal environment; the electrode terminals are disposed on the end cap; the first battery cell is housed in the internal environment; and the second battery cell is housed in the internal environment.

[0020] A second aspect of this application provides a battery comprising the aforementioned battery cell.

[0021] A third aspect of this application provides an electrical device including the battery described above, the battery being used to provide electrical energy.

[0022] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0023] Figure 1 The diagram shows the structure of a vehicle provided in some embodiments of this application.

[0024] Figure 2 This is an exploded structural diagram of a battery provided in some embodiments of this application.

[0025] Figure 3 This is a schematic diagram of the structure of a battery module provided in some embodiments of this application.

[0026] Figure 4This is an exploded structural diagram of a battery cell provided in some embodiments of this application.

[0027] Figure 5 This is a schematic diagram showing the connection between the electrode sheet and the electrode terminal of a battery cell in related technologies.

[0028] Figure 6 This is a schematic diagram of the structure of a battery cell provided in the first embodiment of this application, wherein the casing and end cap are omitted.

[0029] Figure 7 This is a schematic diagram showing the orientation of the second electrode assembly and the first battery cell unit provided in some embodiments of this application.

[0030] Figure 8 for Figure 7 The diagram shows a C-direction view of the structure, where the front view of the first cell unit and the second conductive foil is omitted to show the front of the second electrode assembly.

[0031] Figure 9 for Figure 8 Top view of the structure shown;

[0032] Figure 10 This is a schematic diagram of the structure of a battery cell provided in the second embodiment of this application, wherein the casing and end cap are omitted.

[0033] Figure 11 This is a schematic diagram of the structure of a battery cell provided in the third embodiment of this application, wherein the casing and end cap are omitted.

[0034] Figure 12 This is a schematic diagram of the structure of a battery cell provided in the fourth embodiment of this application, wherein the casing and end cap are omitted.

[0035] Figure 13 This is a schematic diagram of the structure of a battery cell provided in the fifth embodiment of this application, wherein the casing and end cap are omitted. Detailed Implementation

[0036] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0037] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein 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 specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0038] In the description of the embodiments of this application, if the technical terms such as "first" and "second" appear, these terms are used only for descriptive purposes to distinguish different objects, and should not be construed as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features.

[0039] In this document, the term "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 throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0040] In the description of the embodiments 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, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0041] In the description of the embodiments of this application, if the term "multiple" appears, "multiple" means at least two (including two), such as two, three, etc., unless otherwise explicitly specified. Similarly, if the term "multiple sets" appears, "multiple sets" refers to two or more sets (including two sets), and if the term "multiple pieces" appears, "multiple pieces" refers to two or more pieces (including two pieces).

[0042] In the description of the embodiments of this application, if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0043] In the description of the embodiments of this application, unless otherwise explicitly specified and limited, the technical terms "installation," "connection," "joining," "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application according to the specific circumstances.

[0044] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0045] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.

[0046] Currently, judging from market trends, the application of power batteries is becoming increasingly widespread. Power batteries are not only used in energy storage systems such as hydropower, thermal power, wind power, and solar power plants, but also widely applied in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in aerospace and other fields. With the continuous expansion of power battery applications, market demand is also constantly increasing.

[0047] In related technologies, a single battery cell may include multiple electrode assemblies, with conductive metal foils of the electrode assemblies stacked to form tabs. Especially in battery cells without adapters, since no adapters are provided, the tabs of different electrode assemblies are stacked and connected to the electrode terminals by pressure welding; see [reference needed]. Figure 5 As shown, Figure 5This is a schematic diagram illustrating the connection between the electrode plates and electrode terminals of a battery cell in related technologies. During the assembly of the battery cell, the tabs 131' of electrode assembly 130', the tabs 141' of electrode assembly 140', and the electrode terminals 125' need to be stacked and pressed together sequentially. During the pressure welding process, due to the layer-by-layer pressure application and non-uniform force, the outermost conductive foil of the tab 131' of electrode assembly 130' undergoes plastic deformation under the concentrated pressure, forming a warp 132' at the end. The warp 132' at the end is not covered by the pressure head and is not obstructed by any external object, so it can freely bend outward and upward, which may cause it to touch another electrode assembly 140' and the tab, resulting in a short circuit in the battery cell or puncturing the tab, affecting the user experience.

[0048] To mitigate the problem of short circuits in battery cells, a protective component can be added to the design of specific electrode assemblies during pressure welding. The tabs of these specific electrode assemblies are positioned relatively closer to the electrode terminals during pressure welding. The protective component blocks the bent ends of the upper tabs during pressure welding, thereby isolating the tabs from the specific electrode assembly. This can prevent short circuits in the specific electrode assembly and also prevent the tabs from being punctured, ensuring the functional stability of the battery cell.

[0049] This application provides a battery cell, a battery, and an electrical device. The electrical device can be, but is not limited to, a mobile phone, tablet, laptop, electric toy, power tool, electric vehicle, electric car, ship, spacecraft, energy storage product, etc. Electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys. Spacecraft can include airplanes, rockets, space shuttles, and spacecraft. Energy storage products can include energy storage stations, etc.

[0050] It should be understood that the technical solutions described in the embodiments of this application are not limited to the batteries and electrical devices described above, but can also be applied to all batteries including housings and electrical devices using batteries. However, for the sake of brevity, an embodiment of this application using a vehicle 1000 as an example will be used for illustration.

[0051] Please refer to Figure 1 , Figure 1This is a schematic diagram of the structure of a vehicle 1000 provided in some embodiments of this application. The vehicle 1000 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 100 is disposed inside the vehicle 1000, and the battery 100 can be located at the bottom, front, or rear of the vehicle 1000. The battery 100 can be used to power the vehicle 1000; for example, the battery 100 can serve as the operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300. The controller 200 is used to control the battery 100 to supply power to the motor 300, for example, to meet the power needs of the vehicle 1000 during startup, navigation, and driving.

[0052] In some embodiments of this application, the battery 100 can not only serve as the operating power source for the vehicle 1000, but also as the driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0053] Figure 2 Exploded views of battery 100 provided in some embodiments of this application; Figure 3 This is a schematic diagram of the structure of a battery module provided in some embodiments of this application. Please refer to... Figure 2 and Figure 3 To meet different power demands, the battery 100 may include multiple battery cells 121 and a housing 110. A battery cell 121 refers to the smallest unit that makes up the battery module 120 or battery pack. Multiple battery cells 121 may be connected in series and / or in parallel via electrode terminals for various applications.

[0054] The housing 110 is used to house the battery cell 121 or battery module 120 to prevent liquids or other foreign objects from affecting the charging or discharging of the battery cell 121.

[0055] The housing 110 can adopt various structures. In some embodiments, the housing 110 may include a first part 111 and a second part 112, which overlap each other, and together define a receiving space for accommodating the battery cell 121. The second part 112 may be a hollow structure with one end open, and the first part 111 may be a plate-like structure, with the first part 111 covering the open side of the second part 112 so that the first part 111 and the second part 112 together define the receiving space; the first part 111 and the second part 112 may also be hollow structures with one side open, with the open side of the first part 111 covering the open side of the second part 112. Of course, the housing 110 formed by the first part 111 and the second part 112 can be of various shapes, such as a simple three-dimensional structure such as a cuboid, cylinder, or sphere, or a complex three-dimensional structure composed of simple three-dimensional structures such as cuboids, cylinders, or spheres. The embodiments of this application are not limited in this respect. The material of the housing 110 can be an alloy material such as aluminum alloy or iron alloy, or a polymer material such as polycarbonate or polyisocyanurate foam, or a composite material such as glass fiber and epoxy resin. The embodiments of this application are not limited to this.

[0056] In the embodiments of this application, multiple battery cells 121 can be directly assembled into a battery pack, or they can first be assembled into a battery module 120, and then the battery modules 120 can be assembled into a battery pack. Specifically, multiple battery cells 121 can be directly connected in series, in parallel, or in a mixed manner to form a whole, and then the whole composed of multiple battery cells 121 can be housed in a housing 110. Alternatively, multiple battery cells 121 can first be connected in series, in parallel, or in a mixed manner to form a battery module 120, and then multiple battery modules 120 can be connected in series, in parallel, or in a mixed manner to form a whole, and housed in a housing 110.

[0057] The battery 100 may also include other structures, for example, the battery 100 may also include a busbar for realizing electrical connection between multiple battery cells 121.

[0058] Each battery cell 121 can be a secondary battery or a primary battery; it can also be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited to these. The battery cell 121 can be cylindrical, flat, cuboid, or other shapes. Battery cells 121 are generally classified into three types according to their packaging method: cylindrical battery cells, cuboid battery cells, and pouch battery cells; the embodiments of this application are not limited to these. However, for the sake of brevity, the following embodiments will use a cuboid lithium-ion battery cell 121 as an example for description.

[0059] Figure 4 This is an exploded structural diagram of a battery cell 121 provided in some embodiments of this application. Figure 5 This is a schematic diagram showing the connection between the electrode sheet and the electrode terminal of a battery cell in related technologies. Figure 6 This is a schematic diagram of the structure of a battery cell provided in the first embodiment of this application. Figure 7 This is a schematic diagram showing the orientation of the second electrode assembly and the first battery cell unit provided in some embodiments of this application. Figure 8 for Figure 7 The structure shown is viewed from direction C. Figure 9 for Figure 8 Top view of the structure shown. Figure 10 This is a schematic diagram of the structure of a battery cell provided in the second embodiment of this application. Figure 11 This is a schematic diagram of the structure of a battery cell provided in the third embodiment of this application. Figure 12 This is a schematic diagram of the structure of a battery cell provided in the fourth embodiment of this application. Figure 13 This is a schematic diagram of the structure of a battery cell provided in the fifth embodiment of this application.

[0060] See Figures 1 to 4 ,as well as Figures 6 to 13 As shown, the first aspect of this application provides a battery cell 121.

[0061] The battery cell 121 includes electrode terminals 125, a first cell unit 130, a second cell unit 140, and a first protective component 142. The first cell unit 130 includes a first tab 131; the second cell unit 140 includes a second tab 141.

[0062] At least a portion of the first protective element 142 is disposed between the first tab 131 and the second cell unit 140.

[0063] Each of the first and second battery cell units 130 contains at least one electrode assembly. The electrode assembly in the first battery cell unit 130 and the electrode assembly in the second battery cell unit 140 may be the same or different. The electrode assembly is the component in the battery cell 121 where the electrochemical reaction occurs. The electrode assembly is mainly formed by winding positive and negative electrode sheets, and a separator is usually provided between the positive and negative electrode sheets. The portions of the positive and negative electrode sheets containing active material constitute the wound body of the electrode assembly, while the portions of the positive and negative electrode sheets without active material serve as multilayer conductive foils and are laminated to form tabs. The tabs of the positive and negative electrodes may be located together at one end of the wound body or at opposite ends of the wound body.

[0064] Electrode terminals 125 can be used for electrical connection with the first battery cell unit 130 and the second battery cell unit 140 to output or input electrical energy to the battery cell 121. The shape of electrode terminals 125 can be configured in various geometric shapes to adapt to different connection requirements, such as stepped cones, frustum shapes, or irregular curved surface structures. The material of electrode terminals 125 can be aluminum or copper, and this application embodiment does not impose any special limitations on this.

[0065] In this embodiment, by providing a first protective member 142, when the first battery cell unit 130 and the second battery cell unit 140 are connected to the electrode terminal 125, the first tab 131 and the second tab 141 are stacked and connected on the side of the electrode terminal 125 facing the second battery cell unit 140; at least a portion of the first protective member 142 is disposed between the first tab 131 and the second battery cell unit 140; thus, the first protective member 142 can effectively prevent the end of the first tab 131 from bending toward the second battery cell unit 140 during the crimping process, thereby separating the second battery cell unit 140 from the first tab 131, thereby preventing the second battery cell unit 140 from being accidentally touched by the end of the first tab 131 and causing a short circuit, and also preventing the second tab 141 of the second battery cell unit 140 from being punctured or torn by the first tab 131, thereby preventing the overcurrent capacity of the second tab 141 from being affected, and ensuring the functional stability of the battery cell.

[0066] In this embodiment, the end of the first tab 131 refers to the far end of the first tab 131 that is away from the first cell unit 130.

[0067] It should be clarified that the battery cell 121 generally has a positive electrode and a negative electrode. Corresponding to the embodiments of this application, the second cell unit 140 has two second tabs 141 and two first protective members 142. The first second tab 141 serves as the positive electrode tab, and the first first protective member 142 protects the positive electrode tab. The other second tab 141 serves as the negative electrode tab, and the second first protective member 142 protects the negative electrode tab. Similarly, the first cell unit 130 has two first tabs 131, one serving as the positive electrode tab and the other as the negative electrode tab. Likewise, the electrode terminals 125 also have two, one serving as the positive electrode terminal and the other as the negative electrode terminal.

[0068] The positive electrode tab of the first battery cell unit 130, the first protective element 142 of the second battery cell unit 140, and the positive electrode tab of the second battery cell unit 140 are stacked in sequence; the positive electrode tab of the second battery cell unit 140 is pressed onto the positive electrode terminal; similarly, the negative electrode tab of the first battery cell unit 130, the second protective element 142 of the second battery cell unit 140, and the negative electrode tab of the second battery cell unit 140 are stacked in sequence, and the negative electrode tab of the second battery cell unit 140 is pressed onto the negative electrode terminal.

[0069] For ease of understanding and simplification of description, in the various embodiments of this application, unless the positive or negative electrode is specified, the structure is described as that of the positive electrode. However, it should be understood that the relevant structural design, connection method and specific process of the negative electrode are similar to or the same as those of the positive electrode.

[0070] In some possible embodiments, see Figures 1 to 4 ,as well as Figures 6 to 13 As shown, the first cell unit 130 and the second cell unit 140 are disposed opposite each other in the housing 123 of the battery cell 121, that is, the electrode assemblies of the first cell unit 130 and the second cell unit 140 should be stacked along their thickness direction. The electrode terminal 125 is located above and in the middle of the first cell unit 130 and the second cell unit 140 to facilitate connection with the second tab 141 and the first tab 131.

[0071] In some possible embodiments, the first protective element 142 is a plastic film.

[0072] Specifically, the first protective component 142 may be made of materials such as polyethylene, polytetrafluoroethylene, or polypropylene.

[0073] By placing at least a portion of the first protective member 142 between the first tab 131 and the second cell unit 140, the end of the first tab 131 can be effectively prevented from bending toward the second cell unit 140 during the crimping process, thereby separating the second cell unit 140 from the first tab 131. This can prevent the second cell unit 140 from being accidentally touched by the end of the first tab 131, thus avoiding a short circuit. It can also prevent the second tab 141 of the second cell unit 140 from being punctured or torn by the first tab 131, thereby preventing the overcurrent capacity of the second tab 141 from being affected and ensuring the functional stability of the battery cell.

[0074] Understandably, the first protective component 142 is made of plastic film, which can be fixed to the second battery cell 140 by adhesive or to the first battery cell 130 by adhesive; the first protective component 142 can also be placed manually during the crimping process, subject to the design, and this application does not limit it.

[0075] Unlike using a plastic film as the first protective element 142, in some other embodiments, an additional conductive foil can be used as the first protective element 142.

[0076] In some possible embodiments, see Figures 1 to 4 , Figures 6 to 12 As shown, the second cell unit 140 includes at least one second electrode assembly 143. Each second electrode assembly 143 includes a second winding body 143a and a plurality of second conductive foils 141a extending from the second winding body 143a; all the second conductive foils 141a are stacked to form a second tab 141; the second electrode assembly 143 adjacent to the first cell unit 130 also includes a plurality of third conductive foils 142a extending from the second winding body 143a; all the third conductive foils 142a are stacked to form a first protective member 142.

[0077] The first tab 131, the first protective member 142, and the second tab 141 are stacked in sequence, with the second tab 141 pressed onto the side of the electrode terminal 125 facing the second cell unit 140.

[0078] Thus, the first protective member 142 is positioned on the path where the end of the first tab 131 bends toward the second cell unit 140; the first protective member 142 can effectively prevent the end of the first tab 131 from bending toward the second winding body 143a (mentioned below) of the second cell unit 140 during the crimping process, thereby separating the second winding body 143a of the second cell unit 140 from the first tab 131, thereby preventing the second winding body 143a of the second cell unit 140 from being accidentally touched by the end of the first tab 131 and causing a short circuit, thus ensuring the functional stability of the battery cell.

[0079] The first protective member 142 is connected to the electrode tab in a similar manner. That is to say, one end of the first protective member 142 is directly connected to the second winding body 143a, and the far end of the first protective member 142 away from the second winding body 143a extends outward.

[0080] Specifically, a portion of the distal end of the first protective member 142 is press-fitted and fixed to the electrode terminal 125. The section of the first protective member 142 from the electrode terminal 125 to the second winding body 143a forms an effective barrier section. This barrier section is located on the path where the end of the first tab 131 bends toward the second cell unit 140, thereby preventing the second winding body 143a of the second cell unit 140 from being accidentally touched by the end of the first tab 131, which could cause a short circuit and ensure the functional stability of the battery cell.

[0081] Thus, by setting multiple third conductive foils 142a on the second electrode assembly 143 adjacent to the first battery cell 130, and stacking all the third conductive foils 142a on the second electrode assembly 143 to form the first protective element 142, there is no need to set a separate structure for the first protective element 142. Instead, the existing conductive foil structure is used as the first protective element 142. In the punching process of the second conductive foil 141a, the third conductive foil 142a and the second conductive foil 141a can be punched in the same line by adjusting the mold structure. This has very little impact on the production process and cost adjustment of the second electrode assembly 143, and makes the structure of the second electrode assembly 143 simpler and clearer, suitable for mass production. When the first electrode tab 131, the first protective element 142 and the first protective element 142 are stacked together, the first protective element 142 and the first protective element 142 are stacked together. The second tabs 141 are stacked in sequence and pressed onto the side of the electrode terminal 125 facing the second cell unit 140. The first protective member 142 is used to block the bent end of the first tab 131 during the pressing process to avoid short circuit of the second cell unit 140. The first protective member 142 itself is a conductive foil, and the material of the third conductive foil 142a can be designed. The second conductive foil 141a and the conductive foil of the first tab 131 have the same electrochemical characteristics (e.g., both are aluminum-based materials and have the same surface treatment process). While blocking the bent end of the first tab 131, the first protective member 142 will not introduce the potential difference of the heterogeneous material interface, thereby avoiding the generation of parasitic current and not affecting the battery performance, ensuring the functional stability of the battery cell 121.

[0082] It should be noted that, in this embodiment, the third conductive foil 142a is only disposed on the second electrode assembly 143 adjacent to the first battery cell 130. That is to say, the second electrode assembly 143 adjacent to the first battery cell 130 has an additional third conductive foil 142a in its structure compared to other second electrode assemblies 143.

[0083] In this embodiment, the first tab 131 is punctured or torn by the extra third conductive foil 142a in the form of a scapegoat, so as to avoid the second tab 141 of the second cell unit 140 being punctured or torn by the first tab 131, thereby preventing the overcurrent capacity of the second tab 141 from being affected; it can also prevent the second winding body 143a of the second cell unit 140 from being accidentally touched by the end of the first tab 131, thus ensuring the functional stability of the battery cell.

[0084] In some possible embodiments, see Figures 1 to 4 , Figures 6 to 9 ,as well as Figure 13As shown, the second cell unit 140 includes at least one second electrode assembly 143. Each second electrode assembly 143 includes a second winding body 143a, a plurality of second conductive foils 141a extending from the second winding body 143a, and a plurality of third conductive foils 142a extending from the second winding body 143a.

[0085] The third conductive foil 142a is located on the inner side of the second electrode assembly 143 near the first battery cell 130, and the second conductive foil 141a is located on the outer side of the second electrode assembly 143 away from the first battery cell 130.

[0086] The third conductive foil 142a of the second electrode assembly 143 adjacent to the first battery cell 130 is stacked to form the first protective member 142. The third conductive foil 142a of the remaining second electrode assemblies 143 are stacked with all the second conductive foils 141a to form the second tab 141.

[0087] The first tab 131, the first protective member 142, and the second tab 141 are stacked in sequence, with the second tab 141 pressed onto the side of the electrode terminal 125 facing the second cell unit 140.

[0088] By providing multiple third conductive foils 142a on all the second electrode assemblies 143, that is, whether it is the second electrode assembly 143 adjacent to the first cell unit 130 or other second electrode assemblies 143, the same third conductive foil 142a is provided, ensuring that each second electrode assembly 143 is structurally identical. In this way, the different types of materials in the production process can be reduced, production efficiency can be improved, the confusion between the second electrode assemblies 143 can be prevented, and production quality can be ensured.

[0089] During production, the first protective element 142 is formed by stacking the third conductive foil 142a on the second electrode assembly 143 adjacent to the first cell unit 130. There is no need to separately construct the first protective element 142; instead, the existing conductive foil structure is used as the first protective element 142. This results in minimal adjustments to the production process of the second electrode assembly 143, minimal impact on cost, and a simpler, more defined structure suitable for mass production. The remaining third conductive foils 142a on the second electrode assemblies 143 not adjacent to the first cell unit 130 are stacked with all the second conductive foils 141a to form the second tab 141. The third conductive foil 142a, as part of the second tab 141, does not affect battery performance, ensuring the functional stability of the battery cell 121.

[0090] In some possible embodiments, see Figures 1 to 4 , Figures 6 to 13As shown, the third conductive foil 142a is located on the inner side of the second winding body 143a near the first cell unit 130, and the second conductive foil 141a is located on the outer side of the second winding body 143a away from the first cell unit 130.

[0091] Both the third conductive foil 142a and the second conductive foil 141a are metallic conductive foils. The third conductive foil 142a is located on the inner side of the second winding body 143a of the second electrode assembly 143, close to the first cell unit 130, while the second conductive foil 141a is located on the outer side of the second winding body 143a, away from the first cell unit 130. The section of the first protective member 142 from the electrode terminal 125 to the second winding body 143a forms an effective barrier section. Since the third conductive foil 142a is always located on the side of the second winding body 143a closer to the first cell unit 130, and the second conductive foil 141a is located on the other side away from the first cell unit 130, the barrier section is inclined and located exactly on the path where the end of the first electrode tab 131 bends toward the second cell unit 140; thus, the end face of the second winding body 143a is located on the third conductive foil. Within the range between 142a and the second conductive foil 141a, for the second electrode assembly 143 adjacent to the first cell unit 130, the first tab 131 is blocked by the third conductive foil 142a located on the inside, thereby preventing the bent end of the first tab 131 from touching the end face of the second winding body 143a during crimping; ultimately effectively separating the second winding body 143a of the second cell unit 140 from the first tab 131, preventing the second cell unit 140 from short-circuiting, and ensuring the functional stability of the battery cell 121.

[0092] In some possible embodiments, see Figures 1 to 4 , Figures 6 to 13 As shown, projected along the height direction, the second winding body 143a of the second electrode assembly 143 typically has a flat structure. Wherein, combined with Figure 9 In terms of orientation, the direction in which the flat structure is relatively longer is the length direction, and the direction in which the flat structure is relatively shorter is the thickness direction.

[0093] With the center of the second winding body 143a along its thickness direction as the dividing line L, the second conductive foil 141a and the third conductive foil 142a are located on opposite sides of the dividing line L.

[0094] The second conductive foil 141a and the third conductive foil 142a are located on opposite sides of the boundary line L of the second winding body 143a of the second electrode assembly 143. When assembling the battery cell 121, the third conductive foil 142a can be positioned as far away from the second conductive foil 141a as possible, so that the end face of the second winding body 143a is located within the range between the third conductive foil 142a and the second conductive foil 141a. For the second electrode assembly 143 adjacent to the first cell unit 130, the third conductive foil 142a located on the inner side blocks the first tab 131, thereby preventing the bent end of the first tab 131 from touching the end face of the second winding body 143a during crimping. Ultimately, this effectively separates the second winding body 143a of the second cell unit 140 from the first tab 131, preventing a short circuit in the second cell unit 140 and ensuring the functional stability of the battery cell 121.

[0095] In some possible embodiments, see Figures 1 to 4 , Figures 6 to 13 As shown, the second electrode assembly 143 includes a positive electrode 11, a negative electrode 12, and a separator 13, with the separator 13 separating the positive electrode 11 and the negative electrode 12; the positive electrode 11, the negative electrode 12, and the separator 13 are wound into a second wound body 143a. The second conductive foil 141a and the third conductive foil 142a are both connected to the positive electrode 11; or, the second conductive foil 141a and the third conductive foil 142a are both connected to the negative electrode 12.

[0096] In the second electrode assembly 143, the positive electrode 11, the negative electrode 12, and the separator 13 are wound into a second winding body 143a. The portions of the positive electrode 11 and the negative electrode 12 with active material constitute the winding body of the electrode assembly, while the portions of the positive electrode 11 and the negative electrode 12 without active material serve as conductive foil.

[0097] Specifically, in combination Figure 9 As shown, for the positive electrode 11, both the second conductive foil 141a and the third conductive foil 142a are connected to the positive electrode 11. The portion of the positive electrode 11 without active material serves as the conductive foil; a portion of this conductive foil forms the second conductive foil 141a on the positive electrode tab, and the other portion forms the third conductive foil 142a, thus forming a second protective element to protect the positive electrode tab.

[0098] Similarly, for the negative electrode 12, both the second conductive foil 141a and the third conductive foil 142a are connected to the negative electrode 12. The portion of the negative electrode 12 without active material serves as the conductive foil. One part of the conductive foil is formed as the second conductive foil 141a on the negative electrode tab, and the other part is formed as the third conductive foil 142a, thereby forming a second protective element for protecting the negative electrode tab.

[0099] In some possible embodiments, see Figures 1 to 4 , Figures 6 to 13 As shown, the number of third conductive foils 142a is 1 to 6.

[0100] Specifically, in a second electrode assembly 143, the number of third conductive foils 142a is 1 to 6. The number of third conductive foils 142a can also be 1 to 6, 2 to 3, etc., depending on the design. The third conductive foils 142a can be used to form the first protective element 142; by forming the first protective element 142 through this part of the third conductive foils 142a, the first protective element 142 is blocked from the bent end of the first electrode tab 131 during crimping, thereby separating the second winding body 143a of the second cell unit 140 from the first electrode tab 131, thereby preventing the second cell unit 140 from short-circuiting and ensuring the functional stability of the battery cell 121.

[0101] Optionally, in a second electrode assembly 143, the number of second conductive foils 141a is 2 to 100; the number of third conductive foils 142a can also be 10 to 5, 20 to 40, etc., depending on the design.

[0102] In some possible embodiments, see Figures 1 to 4 , Figures 6 to 13 As shown, the third conductive foil 142a is a copper foil or an aluminum foil, possessing good conductivity and welding strength. The surface of the third conductive foil 142a may also be coated to further improve its performance; this application does not impose any limitations on this.

[0103] Optionally, the second conductive foil 141a is a copper foil or an aluminum foil; it has good conductivity and welding strength. The surface of the second conductive foil 141a may also be coated to further improve its performance, but this application does not limit this.

[0104] In some possible embodiments, see Figures 1 to 4 , Figures 6 to 13 As shown, the third conductive foil 142a can be configured in various geometric shapes to adapt to different connection requirements; for example, the third conductive foil 142a can be square, semi-circular, trapezoidal, etc.

[0105] Optionally, the second conductive foil 141a may be square, semi-circular, trapezoidal, etc.

[0106] In some possible embodiments, see Figures 1 to 4 , Figures 6 to 13 As shown, the third conductive foil 142a is coated with protective adhesive 144 near the root of the second winding body 143a.

[0107] The protective adhesive 144 can be silicone or polyurethane structural adhesive, etc. By coating the root of the third conductive foil 142a near the second winding body 143a with the protective adhesive 144, the protective strength of the third conductive foil 142a can be effectively enhanced, resulting in better protection.

[0108] The thickness of the protective adhesive 144 can be set from 10µm to 200µm, which can effectively enhance the protective strength of the third conductive foil 142a, resulting in better protection. Furthermore, the thickness of the protective adhesive 144 can be set from 20µm to 100µm. Alternatively, the thickness can be set from 15µm to 25µm, depending on the design.

[0109] Optionally, the second conductive foil 141a is coated with an adhesive layer near the root of the second winding body 143a; the adhesive layer may be silicone or polyurethane structural adhesive, etc.; by coating the second conductive foil 141a with an adhesive layer near the root of the second winding body 143a, the strength of the second conductive foil 141a can be effectively strengthened and tearing can be avoided.

[0110] The thickness of the adhesive layer on the second conductive foil 141a can be set to 10µm-200µm, which can effectively enhance the strength of the second conductive foil 141a and prevent tearing. Further, the thickness of the adhesive layer on the second conductive foil 141a can be set to 20µm-100µm; additionally, the thickness of the adhesive layer on the second conductive foil 141a can be set to 15µm-25µm, depending on the design.

[0111] In some possible embodiments, see Figures 1 to 4 , Figures 6 to 13 As shown, the length of the protective adhesive 144 is A, and the length of the third conductive foil 142a is B, satisfying 0.1*B≤A≤0.8*B. Furthermore, the lengths A and B of the protective adhesive 144 and the third conductive foil 142a can satisfy: 1 / 5*B≤A≤2 / 3*B; additionally, the lengths A and B of the protective adhesive 144 and the third conductive foil 142a can also satisfy 1 / 5*B≤A≤3 / 5*B.

[0112] Thus, by limiting the length ratio range of the protective adhesive 144 and the third conductive foil 142a, the protective adhesive 144 can effectively enhance the overall strength of the third conductive foil 142a, resulting in better protection; at the same time, it avoids the protective adhesive 144 from being too long, preventing the portion of the third conductive foil 142a containing the protective adhesive 144 from being pressed together with the second tab 1 and the first tab 131, thereby preventing the protective adhesive 144 from affecting the welding quality.

[0113] Optionally, combined Figure 9The length of the adhesive layer on the second conductive foil 141a is usually 1 / 5 to 3 / 5 of the length of the second conductive foil 141a. The adhesive layer can effectively strengthen the second conductive foil 141a and prevent tearing. At the same time, it can also prevent the adhesive layer on the second conductive foil 141a from being too long, preventing the part of the second conductive foil 141a containing the adhesive layer from being pressed, thereby preventing the adhesive layer from affecting the welding quality.

[0114] In some possible embodiments, see Figures 1 to 4 , Figures 6 to 10 As shown, the first cell unit 130 includes at least one first electrode assembly 133, each first electrode assembly 133 including a first winding body 133a and multiple first conductive foils 131a extending from the first winding body 133a; all the first conductive foils 131a are stacked to form a first tab 131.

[0115] Thus, all the first conductive foils 131a are stacked to form the first tab 131. When the first tab 131, the first protective member 142, and the second tab 141 are stacked in sequence, the second tab 141 is pressed onto the side of the electrode terminal 125 facing the second cell unit 140. The first protective member 142 can block the bent end of the first tab 131 during pressing to avoid short circuit in the second cell unit 140. In addition, the materials of the first protective member 142 and the third conductive foil 142a, and the second conductive foil 141a and the first conductive foil 131a can have the same electrochemical characteristics (e.g., both are aluminum-based materials and have the same surface treatment process). While blocking the bent end of the first tab 131, the first protective member 142 will not introduce a potential difference at the interface of heterogeneous materials, thereby avoiding the generation of parasitic current and not affecting the battery performance, ensuring the functional stability of the battery cell 121.

[0116] In this embodiment, each first electrode assembly 133 has the same structure, avoiding the existence of two different models of the first electrode assembly 133, which facilitates assembly and enables mass production.

[0117] In some possible embodiments, see Figures 1 to 4 , Figure 11 and Figure 12 As shown, the first cell unit 130 includes a second protective member 132 and at least one first electrode assembly 133.

[0118] The second protective member 132, the first electrode tab 131, the first protective member 142, and the second electrode tab 141 are stacked sequentially. The second electrode tab 141 is pressed onto the side of the electrode terminal 125 facing the second cell unit 140. Each first electrode assembly 133 includes a first winding body 133a and multiple first conductive foils 131a extending from the first winding body 133a. All the first conductive foils 131a are stacked to form the first electrode tab 131. The first electrode assembly 133 adjacent to the second cell unit 140 also includes multiple fourth conductive foils 132a extending from the first winding body 133a. All the fourth conductive foils 132a are stacked to form the second protective member 132.

[0119] Thus, by setting multiple fourth conductive foils 132a on the first electrode assembly 133 adjacent to the second battery cell 140, and stacking all the fourth conductive foils 132a on the first electrode assembly 133 to form the second protective member 132, there is no need to set a separate structure for the second protective member 132. Instead, the existing conductive foil structure is used as the second protective member 132. In the punching process of the first conductive foil 131a, the fourth conductive foil 132a and the first conductive foil 131a can be punched in the same line by adjusting the mold structure. The impact on the production process and cost adjustment of the first electrode assembly 133 is very small, which is suitable for mass production.

[0120] When the second protective member 132, the first tab 131, the first protective member 142, and the second tab 141 are stacked sequentially, the second tab 141 is pressed onto the side of the electrode terminal 125 facing the second cell unit 140. The first protective member 142 is used to prevent the end of the first tab 131 from bending during pressing to avoid short circuit in the second cell unit 140. The second protective member 132 is located on the uppermost side, which can prevent the external structure from contacting the end face of the first cell unit 140, thereby preventing short circuit in the first cell unit 130 and ensuring the functional stability of the battery cell 121.

[0121] In this embodiment, the materials of the fourth conductive foil 132a, the third conductive foil 142a, the second conductive foil 141a, and the first conductive foil 131a can be designed to have the same electrochemical characteristics, such as being aluminum-based materials and having the same surface treatment process. In this way, no heterogeneous material interface potential difference will be introduced between the various structures, thereby avoiding the generation of parasitic currents, which will not affect the battery performance and ensure the functional stability of the battery cell 121.

[0122] It should be noted that, in the embodiments of this application, in conjunction with Figure 11 and Figure 12As shown, the fourth conductive foil 132a is only disposed on the first electrode assembly 133 adjacent to the second battery cell 140. That is to say, the first electrode assembly 133 adjacent to the second battery cell 140 has an additional fourth conductive foil 132a in its structure compared to other first electrode assemblies 133.

[0123] In some possible embodiments, see Figures 1 to 4 , Figure 11 as well as Figure 13 As shown, the first cell unit 130 includes a second protective member 132 and at least one first electrode assembly 133.

[0124] The second protective member 132, the first electrode tab 131, the first protective member 142, and the second electrode tab 141 are stacked sequentially, with the second electrode tab 141 pressed against the side of the electrode terminal 125 facing the second cell unit 140. Each first electrode assembly 133 includes a first winding body 133a, multiple first conductive foils 131a extending from the first winding body 133a, and multiple fourth conductive foils 132a extending from the first winding body 133a.

[0125] The fourth conductive foil 132a is located on the inner side of the first electrode assembly 133 near the second battery cell 140, and the first conductive foil 131a is located on the outer side of the first electrode assembly 133 away from the second battery cell 140.

[0126] The fourth conductive foil 132a of the first electrode assembly 133 adjacent to the second cell unit 140 is stacked to form the first protective member 142; the fourth conductive foil 132a of the remaining first electrode assemblies 133 are stacked with all the first conductive foils 131a to form the first tab 131.

[0127] By providing multiple fourth conductive foils 132a on all first electrode assemblies 133, that is, on all first electrode assemblies 133 adjacent to the second cell unit 140 and on other first electrode assemblies 133, the same fourth conductive foil 132a is provided, ensuring that each first electrode assembly 133 is structurally identical. In addition, each second electrode assembly 143 is provided with the same third conductive foil 142a, making each first electrode assembly 133 and each second electrode assembly 143 structurally identical. In this way, the types of different materials in the production process can be reduced, production efficiency can be improved, and confusion between first electrode assemblies 133 with and without the fourth conductive foil 132a can be prevented, as well as confusion between first electrode assemblies 133 and second electrode assemblies 143, ensuring production quality.

[0128] Combination Figure 11 and Figure 13As shown, during production and assembly, the second protective element 132 is formed only by stacking the fourth conductive foil 132a on the first electrode assembly 133 adjacent to the second cell unit 140. There is no need to separately construct the second protective element 132; instead, the existing conductive foil structure is used as the second protective element 132. This results in minimal adjustments to the production process of the first electrode assembly 133, making it suitable for mass production. The remaining fourth conductive foils 132a on the first electrode assemblies 133 that are not adjacent to the second cell unit 140 are stacked with all the first conductive foils 131a to form the first tab 131. The fourth conductive foil 132a, as part of the first tab 131, does not affect battery performance, ensuring the functional stability of the battery cell 121.

[0129] In the embodiments of this application, each first electrode assembly 133 and each second electrode assembly 143 have the same structure. This avoids the existence of two different models of the first electrode assembly 133 and the second electrode assembly 143. During mass production, only one specification of electrode assembly needs to be prepared, which is convenient for assembly and can organize mass production.

[0130] In some possible embodiments, see Figures 1 to 4 , Figures 6 to 13 As shown, the first cell unit 130 includes a plurality of first electrode assemblies 133 arranged side by side; the second cell unit 140 includes a plurality of second electrode assemblies 143 arranged side by side; the number of first electrode assemblies 133 and second electrode assemblies 143 are equal. Thus, the internal structure of the battery cell 121 is symmetrically arranged, with each first electrode assembly 133 arranged side by side on one side of the battery cell 121, and each second electrode assembly 143 arranged side by side on the other side of the battery cell 121.

[0131] In some possible embodiments, the basic structure of the first electrode assembly 133 is the same as that of the second electrode assembly 143. For example, it can be combined with Figure 9 The structure of the first electrode assembly 133 also includes a positive electrode plate, a negative electrode plate, and a separator, with the separator separating the positive and negative electrode plates; the positive electrode plate, the negative electrode plate, and the separator are wound into a first wound body 133a. The fourth conductive foil 132a and the first conductive foil 131a are both connected to the positive electrode plate; or, the second conductive foil 141a and the third conductive foil 142a are both connected to the negative electrode plate.

[0132] Specifically, for the positive electrode, both the fourth conductive foil 132a and the first conductive foil 131a are connected to the positive electrode. The portion of the positive electrode without active material serves as the conductive foil; one portion of the conductive foil is formed as the first conductive foil 131a on the positive electrode tab, and the other portion is formed as the fourth conductive foil 132a.

[0133] Similarly, for the negative electrode 12, both the second conductive foil 141a and the third conductive foil 142a are connected to the negative electrode 12. The portion of the negative electrode 12 without active material serves as the conductive foil, with one part of the conductive foil forming the second conductive foil 141a on the negative electrode tab and the other part forming the third conductive foil 142a, used to protect the negative electrode tab.

[0134] Similarly, for the negative electrode, both the fourth conductive foil 132a and the first conductive foil 131a are connected to the negative electrode. The portion of the negative electrode without active material serves as the conductive foil; a portion of this conductive foil forms the first conductive foil 131a on the negative electrode tab, and the other portion forms the fourth conductive foil 132a, thus forming the first protective element to protect the negative electrode tab. The identical structure of the first electrode assembly 133 and the second electrode assembly 143 will not be described further here.

[0135] In some possible embodiments, see Figures 1 to 4 , Figures 6 to 13 As shown, in a first electrode assembly 133, the number of fourth conductive foils 132a is 1 to 6. The number of fourth conductive foils 132a can also be 1 to 6, 2 to 3, etc., depending on the design. The fourth conductive foils 132a can be used to form a second protective element 132; through these fourth conductive foils 132a forming the second protective element 132, the external structure is prevented from contacting the end face of the first battery cell 140, thereby preventing a short circuit in the first battery cell 130 and ensuring the functional stability of the battery cell 121.

[0136] Optionally, in a first electrode assembly 133, the number of first conductive foils 131a is 2 to 100; the number of first conductive foils 131a can also be 10 to 5, 20 to 40, etc., depending on the design.

[0137] In some possible embodiments, see Figures 1 to 4 , Figures 6 to 13 As shown, the fourth conductive foil 132a and the first conductive foil 131a can both be copper foil or both are aluminum foil; they have good conductivity and welding strength. The surfaces of the fourth conductive foil 132a and the first conductive foil 131a can also be coated with corresponding layers to further improve their performance, but this application does not limit this.

[0138] In some possible embodiments, the fourth conductive foil 132a and the first conductive foil 131a can be configured in various geometric shapes to adapt to different connection requirements; for example, the fourth conductive foil 132a and the first conductive foil 131a can be square, semi-circular, trapezoidal, etc.

[0139] In some possible embodiments, the fourth conductive foil 132a is coated with an adhesive layer near the root of the first winding body 133a; the adhesive layer may be silicone or polyurethane structural adhesive, etc.; by coating the fourth conductive foil 132a with an adhesive layer near the root of the first winding body 133a, the strength of the fourth conductive foil 132a can be effectively strengthened and tearing can be avoided.

[0140] The thickness of the adhesive layer on the fourth conductive foil 132a can be set to 10um-200um, which can effectively enhance its strength and prevent tearing. Further, the thickness of the adhesive layer on the fourth conductive foil 132a can be set to 20um-100um; additionally, the thickness of the adhesive layer on the fourth conductive foil 132a can be set to 15um-25um, subject to design.

[0141] In some possible embodiments, combined Figure 9 The length of the adhesive layer on the fourth conductive foil 132a is usually 1 / 5 to 3 / 5 of the length of the fourth conductive foil 132a. The adhesive layer can effectively strengthen the strength of the fourth conductive foil 132a and prevent tearing. At the same time, it also prevents the adhesive layer on the fourth conductive foil 132a from being too long, preventing the part of the fourth conductive foil 132a containing the adhesive layer from being pressed, thereby preventing the adhesive layer from affecting the welding quality.

[0142] The design of the adhesive layer on the first conductive foil 131a can be referenced from the fourth conductive foil 132a, and will not be repeated here.

[0143] In some possible embodiments, the battery cell further includes a housing 123 with an opening at one end and an end cap 122; the end cap 122 closes to the opening of the housing 123 to form an internal environment; electrode terminals 125 are disposed on the end cap 122; a first cell unit 130 is housed in the internal environment; and a second cell unit 140 is housed in the internal environment.

[0144] The end cap 122 closes onto the opening of the housing 123 to isolate the internal environment from the external environment. The shape of the end cap 122 can be adapted to the shape of the housing 123 to fit it. Optionally, the end cap 122 can be made of a material with a certain hardness and strength (such as aluminum alloy), so that the end cap 122 is less prone to deformation under pressure and impact, allowing the battery cell 121 to have higher structural strength and improved safety performance. In some embodiments, the end cap 122 may also be provided with a pressure relief mechanism for releasing internal pressure when the internal pressure or temperature of the battery cell 121 reaches a threshold. The material of the end cap 122 can also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and this application embodiment does not impose any special limitations on this. In some embodiments, an insulating member may also be provided on the inner side of the end cap 122. The insulating member can be used to isolate the electrical connection components inside the housing 123 from the end cap 122 to reduce the risk of short circuit. For example, the insulating member can be plastic, rubber, etc.

[0145] The housing 123 is used to cooperate with the end cap 122 to form the internal environment of the battery cell 121. This internal environment can accommodate the first battery cell 130, the second battery cell 140, the electrolyte, and other components. An opening is provided on the housing 123, and the end cap 122 closes the opening to form the internal environment of the battery cell 121. The housing 123 can have various shapes and sizes, such as cuboid, cylindrical, or hexagonal prism. Specifically, the shape of the housing 123 can be determined based on the specific shape and size of the first electrode assembly 133 and the second electrode assembly 143. The material of the housing 123 can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, or plastic; this embodiment does not impose any special limitations on this.

[0146] Electrode terminals 125 are disposed on end caps 122. During the charging and discharging process of the battery, the positive active material on the positive electrode plate and the negative active material on the negative electrode plate react with the electrolyte. The positive electrode tabs of the first electrode assembly 133 and the second electrode assembly 143 are connected to the positive electrode terminal, and the negative electrode tabs of the first electrode assembly 133 and the second electrode assembly 143 are connected to the negative electrode terminal. Thus, the positive electrode terminal and the negative electrode terminal are respectively connected to the two ends of the external structure to form a current loop.

[0147] A second aspect of this application provides a battery 100, including the battery cell 121 described above.

[0148] A third aspect of this application provides an electrical device 1000, including the battery 100 described above, which is used to provide electrical energy to the electrical device 1000.

[0149] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0150] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A battery cell, characterized by, The battery cell comprises: an electrode terminal (125); a first electrode unit (130) comprising a first tab (131); a second electrode unit (140) comprising a second tab (141); the first tab (131) and the second tab (141) are laminated and connected to one side of the electrode terminal (125) facing the second electrode unit (140); and a first protective piece (142); at least part of the first protective piece (142) is arranged to block between the first tab (131) and the second electrode unit (140).

2. The battery cell of claim 1, wherein, The second electrode unit (140) comprises at least one second electrode assembly (143); Each second electrode assembly (143) comprises a second winding main body (143a) and a plurality of second conductive foils (141a) extending from the second winding main body (143a); All the second conductive foils (141a) are laminated to form the second tab (141); The second electrode assembly (143) adjacent to the first electrode unit (130) further comprises a plurality of third conductive foils (142a) extending from the second winding main body (143a); All the third conductive foils (142a) are laminated to form the first protective piece (142); The first tab (131), the first protective piece (142) and the second tab (141) are laminated in sequence, and the second tab (141) is crimped on one side of the electrode terminal (125) facing the second electrode unit (140).

3. The battery cell of claim 1, wherein, The second electrode unit (140) comprises at least one second electrode assembly (143); Each second electrode assembly (143) comprises a second winding main body (143a), a plurality of second conductive foils (141a) extending from the second winding main body (143a), and a plurality of third conductive foils (142a) extending from the second winding main body (143a); Wherein, the third conductive foils (142a) are located on the inner side of the second electrode assembly (143) close to the first electrode unit (130), and the second conductive foils (141a) are located on the outer side of the second electrode assembly (143) away from the first electrode unit (130); The third conductive foils (142a) of the second electrode assembly (143) adjacent to the first electrode unit (130) are laminated to form the first protective piece (142); The third conductive foils (142a) of the remaining second electrode assemblies (143) are laminated with all the second conductive foils (141a) to form the second tab (141); The first tab (131), the first protective piece (142) and the second tab (141) are laminated in sequence, and the second tab (141) is crimped on one side of the electrode terminal (125) facing the second electrode unit (140).

4. The battery cell of claim 2, wherein, The third conductive foil (142a) is located on the inner side of the second winding body (143a) close to the first battery cell unit (130), and the second conductive foil (141a) is located on the outer side of the second winding body (143a) away from the first battery cell unit (130).

5. The battery cell of claim 2, wherein, The second conductive foil (141a) and the third conductive foil (142a) are located on opposite sides of the center of the second winding body (143a) along the thickness direction of the second winding body (143a).

6. The battery cell of claim 5, wherein, The second electrode assembly (143) comprises a positive plate (11), a negative plate (12) and a separator (13), and the separator (13) separates the positive plate (11) and the negative plate (12); the positive plate (11), the negative plate (12) and the separator (13) are wound into the second winding body (143a); The second conductive foil (141a) and the third conductive foil (142a) are both connected with the positive plate (11); or the second conductive foil (141a) and the third conductive foil (142a) are both connected with the negative plate (12).

7. The battery cell of claim 2, wherein, The number of the third conductive foil (142a) is 1-6; and / or, The third conductive foil (142a) is a copper foil or an aluminum foil.

8. The battery cell of claim 2, wherein, The third conductive foil (142a) is coated with a protective glue (144) close to the root of the second winding body (143a).

9. The battery cell of claim 8, wherein, The thickness of the protective glue (144) ranges from 10um to 200um.

10. The battery cell of claim 8, wherein, The length of the protective glue (144) is A, and the length of the third conductive foil (142a) is B, satisfying 0.1*B≤A≤0.8*B.

11. The battery cell of claim 1, wherein, The first protective member (142) is a plastic film.

12. The battery cell of any one of claims 1 to 11, wherein, The first battery cell unit (130) comprises at least one first electrode assembly (133), each first electrode assembly (133) comprising a first winding body (133a) and a plurality of first conductive foils (131a) extending from the first winding body (133a); all the first conductive foils (131a) are laminated to form the first tab (131).

13. The battery cell of any one of claims 1 to 11, wherein, The first battery cell unit (130) comprises a second protective member (132) and at least one first electrode assembly (133); The second protective member (132), the first tab (131), the first protective member (142) and the second tab (141) are laminated in sequence, and the second tab (141) is crimped on the side of the electrode terminal (125) facing the second battery cell unit (140); Each first electrode assembly (133) comprises a first winding body (133a) and a plurality of first conductive foils (131a) extending from the first winding body (133a); All the first conductive foils (131a) are laminated to form the first tab (131). The first electrode assembly (133) adjacent to the second battery cell unit (140) further comprises a plurality of fourth conductive foils (132a) extending from the first winding body (133a); All the fourth conductive foils (132a) are laminated to form the second protective member (132).

14. The battery cell of any one of claims 1 to 11, wherein, The first electrode cell (130) comprises a second protective member (132) and at least one first electrode assembly (133); The second protective member (132), the first tab (131), the first protective member (142) and the second tab (141) are laminated in sequence, and the second tab (141) is crimped on a side of the electrode terminal (125) facing the second electrode cell (140); Each first electrode assembly (133) comprises a first winding body (133a), a plurality of first conductive foils (131a) extending from the first winding body (133a), and a plurality of fourth conductive foils (132a) extending from the first winding body (133a); The fourth conductive foils (132a) are located on the inner side of the first electrode assembly (133) close to the second electrode cell (140), and the first conductive foils (131a) are located on the outer side of the first electrode assembly (133) away from the second electrode cell (140); The fourth conductive foils (132a) of the first electrode assembly (133) adjacent to the second electrode cell (140) are laminated to form the first protective member (142); The fourth conductive foils (132a) of the remaining first electrode assemblies (133) and all the first conductive foils (131a) are laminated to form the first tab (131).

15. The battery cell of any one of claims 1 to 11, wherein, The battery cell further comprises a housing (123) having an opening at one end and an end cover (122); The end cover (122) covers the opening of the housing (123) to form an internal environment; The electrode terminal (125) is arranged on the end cover (122), the first electrode cell (130) is contained in the internal environment, and the second electrode cell (140) is contained in the internal environment.

16. A battery, characterized by The battery cell as claimed in any one of claims 1 to 15.

17. An electrical device, comprising: The battery as claimed in claim 16 is used to provide electric energy.

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