Battery cell, battery, electrical device and device for a battery cell

Abstract

A battery cell, comprising: a connector; an electrode assembly comprising a main body and an electrode tab extending from the main body, wherein the electrode tab comprises a root section and a connecting section, the root section being connected to the main body and the connecting section being connected to the connecting piece; a protective film comprising a first sticky area, a second sticky area and a non-sticky area between the first sticky area and the second sticky area, wherein the first sticky area adheres to the main body, the second sticky area adheres to the connecting section and the non-sticky area covers the root section.

Description

TECHNICAL AREA

[0001] The present application relates to the field of battery technology, in particular a battery cell, a battery, an electrical device and a device for a battery cell. STATE OF THE ART

[0002] Energy saving and emission reduction are key to the sustainable development of the automotive industry. Electric vehicles have become an important component of this sustainable development due to their advantages in terms of energy saving and environmental protection. Battery technology, in turn, is a crucial factor in the development of electric vehicles.

[0003] In the development of battery technology, in addition to increasing battery safety, battery lifespan is a significant issue. Therefore, the question of how to extend battery lifespan is a pressing technical problem in battery technology that needs to be addressed. CONTENT OF THE INVENTION

[0004] The purpose of this application is to provide a battery cell, a battery, an electrical device, and a device for a battery cell. This battery cell can increase the lifespan.

[0005] This registration is implemented through the following technical solutions:

[0006] In the first aspect, this application offers a battery cell, comprehensively: a connector; an electrode assembly comprising a main body and an electrode tab extending from the main body, wherein the electrode tab comprises a root section and a connecting section, the root section being connected to the main body and the connecting section being connected to the connecting piece; a protective film comprising a first sticky area, a second sticky area and a non-sticky area between the first sticky area and the second sticky area, wherein the first sticky area adheres to the main body, the second sticky area adheres to the connecting section and the non-sticky area covers the root section.

[0007] According to the battery cell of the embodiment of this application, the non-adhesive area of ​​the protective film covers the root section of the electrode tab. When the protective film adheres to the electrode assembly, this can reduce the tensile force of the protective film on the root section of the electrode tab, reduce the formation of cracks in the electrode tab, ensure the current-carrying capacity of the electrode tab, prevent a cracked electrode tab from puncturing the protective film and thus causing a short circuit, and increase the service life of the battery cell.

[0008] According to some embodiments of this application, the non-sticky area extends beyond the boundary between the root section and the main body.

[0009] In the solution described above, a lateral boundary of the non-adhesive area extends beyond the interface between the root section and the main body, so that the non-adhesive area covers this interface. Since the interface between the root section and the main body is a weak point of the root section, having the non-adhesive area cover both the root section and part of the main body reduces the likelihood of electrode tab cracking when the protective film is applied.

[0010] According to some embodiments of this application, the non-sticky area extends beyond the boundary between the root section and the connecting section to cover part of the connecting section.

[0011] In the solution mentioned above, the boundary of the non-sticky area at the end connected to the second sticky area extends beyond the interface between the root section and the connecting section, so that the non-sticky area covers the interface between the root section and the connecting section, which can reduce the likelihood of cracks in the electrode tab at the interface between the root section and the connecting section when the protective film is applied.

[0012] According to some embodiments of this application, the area of ​​the connecting section S1 covered by the non-sticky area is, and the total area of ​​the connecting section is S2, where 1 / 3 ≤ S1 / S2 ≤ 2 / 3 is satisfied.

[0013] In the above-mentioned solution, the percentage covered by the non-sticky area of ​​the joint section can reduce the pulling of the protective film at the interface between the root section and the joint section during bonding, decrease the likelihood of cracking at this interface during bonding, and at the same time ensure that the second sticky area has a larger contact area with the joint section, thus ensuring the bond stability between the protective film and the joint section.

[0014] According to some embodiments of this application, part of the second sticky area adheres to the connecting section and another part to the connecting piece.

[0015] In the above-mentioned solution, the second adhesive area adheres to the connecting section and the connector, which increases the connection stability between the electrode tab and the connector and ensures a firm bond between the protective film and the electrode assembly and the connector.

[0016] According to some embodiments of this application, the electrode assembly comprises a first end face and a first side face, wherein the first end face is perpendicular to the first side face, the electrode tab projects beyond the first end face and the protective film extends to the first side face.

[0017] In the solution described above, the first side surface is connected to the edge of the first end surface. The protective film extends from the first end surface to the first side surface, giving the protective film a larger contact area with the main body, increasing the stability of the connection between the protective film and the main body, and ensuring a firm bond between the protective film and the main body.

[0018] According to some embodiments of this application, the first sticky area comprises a first section and a second section, wherein the first section adheres to the first side surface and the second section adheres to the first end surface.

[0019] In the above-mentioned solution, the first section adheres to the first side surface and the second section to the first end surface, giving the first sticky area connection positions on two surfaces of the electrode assembly, increasing the connection stability between the first sticky area and the main body and ensuring a firm connection of the first sticky area to the main body.

[0020] According to some embodiments of this application, the dimension of the first section in a direction perpendicular to the first end surface is L1, and the dimension of the first side surface in a direction perpendicular to the first end surface is L2, where 1 / 7 ≤ L1 / L2 ≤ 1 / 5 is satisfied.

[0021] In the above-mentioned solution, the percentage share that the first section occupies on the first side face in a direction perpendicular to the first end face ensures the bond strength between the first section and the first side face.

[0022] According to some embodiments of this application, a bending point is provided at the root section in order to align the connecting piece parallel to the first end surface.

[0023] In the solution mentioned above, the bending point at the root section allows the connector to be aligned parallel to the first end surface, which reduces the space between the main body and the connector, reduces the installation space occupied by the electrode tab and increases the energy density of the battery cell.

[0024] According to some embodiments of this application, the protective film comprises a protective film body and a cover element, wherein the protective film body has an adhesive side, the cover element covers part of the adhesive side to form the non-adhesive area, and the parts of the adhesive side not covered by the cover element form the first adhesive area and the second adhesive area.

[0025] In the solution described above, the protective film body can be an adhesive tape, and the cover element covers the protective film body to form the non-stick area. The structure is simple and processing is facilitated.

[0026] In the second aspect, this application offers a battery comprising the battery cell from the above-mentioned embodiments.

[0027] In the third aspect, this application provides an electrical device comprising the battery cell from the above-mentioned embodiments, wherein the battery cell serves to provide electrical energy.

[0028] In an unclaimed aspect, this application provides a manufacturing process for a battery cell, comprising: Providing a connector; Providing an electrode assembly, wherein the electrode assembly comprises a main body and an electrode tab extending from the main body, the electrode tab comprising a root section and a connecting section, and the root section being connected to the main body; Providing a protective film comprising a first sticky area, a second sticky area and a non-sticky area situated between the first sticky area and the second sticky area; Connecting the connecting section to the connector, bonding the first sticky area to the main body, bonding the second sticky area to the connecting section, with the non-sticky area covering the root section.

[0029] In the fifth aspect, this application offers a manufacturing device for a battery cell, comprising:

[0030] Providing a module for providing a connector, for providing an electrode assembly and for providing a protective film, wherein the electrode assembly comprises a main body and an electrode tab extending from the main body, the electrode tab comprises a root section and a connector section, the root section being connected to the main body, and the protective film comprising a first sticky area, a second sticky area and a non-sticky area situated between the first sticky area and the second sticky area; a mounting module for connecting the connecting section to the connector, for bonding the first sticky area to the main body, for bonding the second sticky area to the connecting section, wherein the non-sticky area covers the root section.

[0031] The above description is merely an overview of the technical solution of this application. To better understand the technical means of this application, they can be implemented according to the content of the description, and to make the above-mentioned and other objectives, features and advantages of this application clearer and more understandable, specific implementation methods of this application are listed below. FIGURES

[0032] To more clearly explain the technical solution of the embodiments of this application, the figures required in these embodiments are briefly presented below. It is obvious that the figures described below represent only some embodiments of this application. A person skilled in the art can derive further figures from these without any creative effort. Fig. Figure 1 shows a schematic structural view of a vehicle according to some embodiments of this application; Fig. 2 shows an exploded view of a battery according to some embodiments of this application; Fig. Figure 3 shows an exploded view of a battery cell according to some embodiments of this application; Fig. Figure 4 shows a section through a battery cell according to some embodiments of this application; Fig. Figure 5 shows a first schematic representation of the connection of an electrode assembly with a connecting piece according to some embodiments of this application; Fig. Figure 6 shows a second schematic representation of the connection of an electrode assembly with a connecting piece according to some embodiments of this application; Fig. Figure 7 shows a schematic representation of the connection of a protective film with a connecting section according to some embodiments of this application; Fig. Figure 8 shows a schematic representation of the connection of a second sticky area with a connecting section according to some embodiments of this application; Fig. Figure 9 shows a schematic representation of the connection of an electrode assembly with a protective film according to some embodiments of this application; Fig. Figure 10 shows a schematic structural view of a protective film according to some embodiments of this application; Fig. Figure 11 shows a schematic structural view of a protective film according to further embodiments of this application; Fig. Figure 12 shows a schematic structural view of an electrode assembly according to some embodiments of this application; Fig. Figure 13 shows a schematic representation of the connection of two electrode assemblies according to some embodiments of this application; Fig. Figure 14 shows a schematic flowchart of an unclaimed manufacturing process for a battery cell according to some embodiments of this application; Fig. Figure 15 shows a schematic block diagram of a manufacturing device for a battery cell according to some embodiments of this application;

[0033] The figures are not drawn to scale.

[0034] Reference symbols: 100 - Battery; 10 - Box; 11 - First part; 12 - Second part; 20 - Battery cell; 21 - End cap; 22 - Housing; 23 - Electrode assembly; 231 - Main body; 232 - Electrode tab; 2321 - Root section; 2322 - Connecting section; 2323 - Bend point; 233 - First end face; 234 - First side face; 235 - Second end face; 236 - Second side face; 237 - Positive electrode plate; 238 - Negative electrode plate; 239 - Separator; 24 - Connecting piece; 25 - Electrode terminal; 26 - Protective film; 261 - First sticky area; 2611 - First section; 2612 - Second section; 262 - Second sticky area; 263 - Non-sticky area; 264 - Protective film body; 2641 - Adhesive side; 265 - Cover element; 266 - Carrier material; 267 - Adhesive layer; F1 - First separation line; F2 - Second separation line; Z - Thickness direction; 200 - Controller; 300 - Motor; 1000 - Vehicle. EXAMPLES OF EXECUTION

[0035] The following are detailed descriptions of the embodiments of the technical solution of this application, in conjunction with the figures. These embodiments serve only to clarify the technical solution of this application and should therefore be considered merely as examples that must not restrict the scope of protection of this application.

[0036] Unless otherwise defined, all technical and scientific terms used in this document have the same meaning as they are generally understood by those skilled in the technical field of this application. The terms used in this document serve only to describe certain embodiments and are not intended to limit this application. The terms "comprise" and "feature" and any variations thereof in the description, the claims, and the above-mentioned description of figures in this application are designed to cover non-exclusive inclusion.

[0037] In the description of embodiments of this application, technical terms such as "first", "second", etc., serve only to distinguish different objects and must not be understood as indicating or implying relative importance or as implicitly specifying the number, specific order, or main-subsidiary relationship of the technical features mentioned. In the description of embodiments of this application, "several" means more than two, unless expressly defined otherwise.

[0038] The mention of "embodiment" in this text means that a particular feature, structure, or property described in connection with the embodiment may be included in at least one embodiment of this application. The appearance of this phrase in different places in the description does not necessarily refer to the same embodiment, nor does it imply an independent or alternative embodiment that is mutually exclusive with other embodiments. Those skilled in the art understand, expressly and implicitly, that the embodiments described herein may be combined with other embodiments.

[0039] In the description of the embodiments of this application, the term "and / or" merely denotes an associative relationship between associated objects and means that three relationships are possible. For example, A and / or B can mean: only A exists, both A and B exist simultaneously, or only B exists. Furthermore, the character " / " in this document generally indicates that the associated objects mentioned before and after it are in an "or" relationship.

[0040] In the description of embodiments of this application, the term "several" refers to more than two (including two). Similarly, "several groups" refers to more than two groups (including two groups), and "several parts" refers to more than two parts (including two parts).

[0041] In the description of the embodiments of this application, technical terms such as "center", "longitudinal", "transverse", "length", "width", "thickness", "top", "bottom", "front", "back", "left", "right", "vertical", "horizontal", "upper part", "lower part", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the figures. They serve only to describe the embodiments of this application and to simplify the description, and do not indicate or imply that the device or component in question must have a specific orientation, be designed and operated in a specific orientation. Therefore, they are not to be understood as limiting the embodiments of this application.

[0042] In the description of the embodiments of this application, unless expressly stated and defined otherwise, technical terms such as "assemble," "connect," "connect," "fasten," etc., should be understood broadly. For example, they may refer to a permanent or detachable connection, or they may form a whole; they may refer to a mechanical or electrical connection; they may refer to a direct connection or an indirect connection via an intermediate medium; they may refer to the internal connection of two elements or to the interaction relationship between two elements. For the person skilled in the art, the aforementioned terms can understand their specific meaning in the embodiments of this application depending on the particular situation.

[0043] In this application, the term "battery" refers to a single physical module containing one or more battery cells to provide a higher voltage and capacity. For example, the battery referred to in this application may comprise a battery module or a battery pack, etc.

[0044] A battery cell comprises an electrode assembly and electrolyte, with the electrode assembly consisting of a positive electrode plate, a negative electrode plate, and a separator. The battery cell functions primarily through the movement of metal ions between the positive and negative electrode plates. The positive electrode plate includes a positive current collector and a positive active material layer. The positive active material layer is applied to the surface of the positive current collector. The portion of the current collector not coated with positive active material extends beyond the coated portion and serves as the positive electrode tab. For example, in a lithium-ion battery, the positive current collector material could be aluminum, and the positive active material could be cobalt oxide, lithium iron phosphate, ternary lithium, lithium manganese oxide, etc.The negative electrode plate comprises a negative current collector and a negative active material layer. The negative active material layer is applied to the surface of the negative current collector. The portion of the current collector not coated with negative active material extends beyond the coated portion and serves as the negative electrode tab. The negative current collector material can be copper, and the negative active material can be carbon, silicon, etc. To ensure that high currents can be carried without melting, the number of positive electrode tabs is multiple and stacked on top of each other; similarly, the number of negative electrode tabs is multiple and stacked on top of each other. The separator material can be PP (polypropylene) or PE (polyethylene), etc.

[0045] In this application, the electrode assembly comprises a main body and an electrode tab extending from the main body. The electrode tab has a root section and a connecting section, wherein the root section is connected to the main body and the connecting section serves for connection to a connector.

[0046] The development of battery technology must simultaneously consider several design aspects, such as performance parameters like energy density, discharge capacity, charge and discharge rate, etc. Furthermore, the battery's lifespan must also be taken into account.

[0047] Many factors influence the lifespan of a battery cell, such as ambient temperature, damage to components caused by assembly (like cracks in the electrode tab), lithium deposition, etc. Through research, the inventors have determined that numerous factors in the battery production process can lead to cracks in the electrode tab, such as welding the electrode tab, bending the electrode tab, and applying adhesive tape to the electrode tab. The inventors further discovered that applying adhesive tape to the electrode tab after it has been welded to the connector can easily cause cracks in the electrode tab.

[0048] In the battery production process, to prevent a short circuit, a protective film (e.g., adhesive tape) must be applied to the front and back of the electrode tab after it has been welded to the connector, in order to prevent a short circuit. Currently, in automated gluing machines, adhesive units pick up a protective film of specific dimensions during the gluing process and successively cover the edge of the large surface of the electrode assembly, the separator at the end face of the electrode assembly, the root section of the electrode tab, and the connector section of the electrode tab. To ensure a strong bond between the protective film and the electrode tab, the root section of the electrode tab is typically rolled to guarantee that the protective film adheres tightly to the electrode tab.Since the root section of the electrode tab is a sensitive area, the protective film exerts a tensile force on it during the bonding process when the electrode tab is rolled. This tensile force can easily cause cracks in the electrode tab. Once the electrode tab is cracked, its current-carrying capacity decreases, which can easily lead to a temperature increase in the battery cell. Simultaneously, the cracked parts of the electrode tab can easily puncture the protective film, causing a short circuit and reducing the battery cell's lifespan.

[0049] In light of this, and to solve the problem of electrode tab cracking, the inventors, after extensive research, designed a battery cell comprising a connector, an electrode assembly, and a protective film. The electrode assembly includes a main body and an electrode tab extending from the main body. The electrode tab comprises a root section and a connector section, the root section being connected to the main body and the connector section being connected to the connector. The protective film includes a first adhesive area, a second adhesive area, and a non-adhesive area located between the first and second adhesive areas. The first adhesive area adheres to the main body, the second adhesive area adheres to the connector section, and the non-adhesive area covers the root section, preventing it from being stuck.

[0050] In such a battery cell, because the non-adhesive area covers the root section, the non-adhesive area and the root section do not pull against each other when the protective film is bonded to the electrode assembly. This reduces the tensile force of the protective film on the root section, reduces the formation of cracks in the electrode tab, and ensures the current-carrying capacity of the electrode tab. At the same time, it prevents a cracked electrode tab from puncturing the protective film and causing a short circuit, thus increasing the battery cell's lifespan.

[0051] In this application, the battery cell may comprise a lithium-ion secondary battery, a lithium-ion primary battery, a lithium-sulfur battery, a sodium-lithium-ion battery, a sodium-ion battery or a magnesium-ion battery, etc., which is not limited in the embodiments of this application.

[0052] The battery cell disclosed in the embodiments of this application can, but need not, be used in electrical devices such as vehicles, ships, or aircraft, etc. A power supply system containing the battery cell disclosed in this application can be used for the electrical device.

[0053] The embodiments of this application provide an electrical device that uses a battery as a power source. The electrical device can be, but need not be, a mobile phone, tablet computer, laptop, electric toy, power tool, electric bicycle, electric motorcycle, electric vehicle, ship, spacecraft, etc. Electric toys can include stationary or mobile electric toys, such as game consoles, electric toy cars, electric toy ships, and electric toy airplanes, etc. Spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0054] For the sake of simplicity, in the following examples a vehicle is cited as an example of an electrical device according to an embodiment of this application.

[0055] Please refer to Fig. Figure 1, showing a schematic structural view of a vehicle 1000 according to some embodiments of this application. The vehicle 1000 can be a motor vehicle with an internal combustion engine, a gas-powered car, or a new vehicle, wherein the new vehicle can be a pure electric vehicle, a hybrid vehicle, or a range extender vehicle, etc. Inside the vehicle 1000, a battery 100 is arranged, which can be located at the bottom, at the front, or at the rear of the vehicle 1000. The battery 100 can be used to supply power to the vehicle 1000; for example, the battery 1000 can serve as the operating current source for the vehicle 1000's electrical system, e.g., for starting, navigation, and the operating current requirements during the vehicle 1000's operation.

[0056] The vehicle 1000 can also include a controller 200 and a motor 300. The controller 200 serves to control the power supply to the motor 300 from the battery 100, for example for starting, navigation and driving the vehicle 1000.

[0057] In some embodiments of this application, the battery 100 can serve not only as an operating current source for the vehicle 1000, but also as a drive current source to replace fuel or natural gas wholly or partially and to supply the vehicle 1000 with drive power.

[0058] Please refer to Fig. Figure 2, showing an exploded view of a battery 100 according to some embodiments of this application. The battery 100 comprises a box 10 and battery cells 20, the battery cells 20 being housed in the box 10. The box 10 serves to provide a receiving space for the battery cells 20, and the box 10 can have various structures. In some embodiments, the box 10 can comprise a first part 11 and a second part 12, the first part 11 and the second part 12 being joined together and jointly defining the receiving space intended for receiving the battery cells 20.The second part 12 can be a hollow structure with an opening side, the first part 11 can be a plate-shaped structure placed on the opening side of the second part 12, so that the first part 11 and the second part 12 together define the recording space; the first part 11 and the second part 12 can also both be hollow structures with an opening side, with the opening side of the first part 11 placed on the opening side of the second part 12.

[0059] Battery 100 can contain multiple battery cells 20, which can be connected in series, parallel, or mixed configurations. Mixed configuration means that multiple battery cells 20 are connected in both series and parallel configurations. Multiple battery cells 20 can be directly connected in series, parallel, or mixed configurations and then housed as a whole in the box 10. Alternatively, battery 100 can consist of multiple battery cells 20 that are first connected in series, parallel, or mixed configurations to form battery modules, with multiple battery modules then again connected in series, parallel, or mixed configurations to form a whole and housed in the box 10. Battery 100 can include other structures, such as busbars to provide electrical connections between multiple battery cells 20.

[0060] Each battery cell 20 can be a secondary battery or a primary battery; it can also be a lithium-sulfur battery, sodium-ion battery or magnesium-ion battery, but is not limited to these.

[0061] Please see Fig. 3, which shows an exploded view of a battery cell 20 according to some embodiments of this application. The battery cell 20 refers to the smallest unit of which the battery 100 consists. As in Fig. As shown in Figure 3, the battery cell 20 comprises an end cap 21, a housing 22, an electrode assembly 23, a connector 24 and an electrode terminal 25.

[0062] The end cap 21 refers to the component that is placed on the opening of the housing 22 to seal the internal environment of the battery cell 20 from the external environment. The shape of the end cap 21 can be adapted to the shape of the housing 22 to fit it. Optionally, the end cap 21 can be made of a material with a certain hardness and strength (e.g., aluminum alloy) so that the end cap 21 is less likely to deform under pressure or impact, thus providing the battery cell 20 with greater structural strength and potentially improving its safety characteristics. A pressure relief device can be attached to the end cap 21 to release internal pressure when the internal pressure or temperature in the battery cell 20 reaches a threshold. The material of the end cap 21 can also be varied, e.g., copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.which is not specifically limited in the embodiments of this application. In some embodiments, an insulating piece may also be attached to the inside of the end cap 21, which serves to insulate electrically conductive connecting parts in the housing 22 from the end cap 21 in order to reduce the risk of a short circuit. By way of example, the insulating piece may be made of plastic, rubber, etc.

[0063] The housing 22 is the component that, together with the end cap 21, forms the internal environment of the battery cell 20. This internal environment serves to accommodate the electrode assembly 23, electrolyte, and other components. The housing 22 and the end cap 21 can be independent components. The housing 22 may have an opening that is closed by placing the end cap 21 on top to form the internal environment of the battery cell 20. Alternatively, the end cap 21 and the housing 22 may be formed as a single piece. In particular, the end cap 21 and the housing 22 may initially form a common interface before other components are inserted, and when the interior of the housing 22 is to be sealed, the end cap 21 is placed onto the housing 22. The shape of the housing 22 can be determined by the specific shape and size of the electrode assembly 23. The material of the housing 22 can be of various types, e.g.,Copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., which is not specifically limited in the embodiments of this application.

[0064] The electrode assembly 23 is the component in the battery cell 20 in which electrochemical reactions take place. The housing 22 can contain one or more electrode assemblies 23. The electrode assembly 23 is mainly formed by winding or layering a positive electrode plate and a negative electrode plate, with a separator typically arranged between the positive and negative electrode plates. The portions of the positive and negative electrode plates containing active material form the main body 231 of the electrode assembly 23. The portions of the positive and negative electrode plates that do not contain active material each form an electrode tab 232. The positive electrode tab and the negative electrode tab can be arranged together at one end of the main body 231 or at each of the two ends of the main body 231.During the charging and discharging process of the battery 100, the positive active material and the negative active material react with the electrolyte, and the electrode tab 232 is connected to the electrode terminal 25 via the connecting piece 24 to form an electrical circuit.

[0065] The electrode connection 25 is attached to the end cap 21 and is electrically connected to the electrode assembly 23 via the connecting piece 24 in order to supply electrical energy from or into the battery cell 20.

[0066] According to some embodiments of this application, see Fig. 4 and beyond Fig. 5, where Fig. 4 shows a section through a battery cell 20 according to some embodiments of this application and Fig. Figure 5 represents a first schematic representation of the connection of an electrode assembly 23 with a connecting piece 24 according to some embodiments of this application. Fig. Figure 5 shows a schematic representation after the connection of the electrode tab 232 to the connecting piece 24 and before the bending of the electrode tab 232. This application provides a battery cell 20. As shown in the Fig. 4 and Fig. As shown in Figure 5, the battery cell 20 comprises a connector 24, an electrode assembly 23, and a protective film 26. The electrode assembly 23 comprises a main body 231 and an electrode tab 232 extending from the main body 231. The electrode tab 232 comprises a root section 2321 and a connecting section 2322, wherein the root section 2321 is connected to the main body 231 and the connecting section is connected to the connector 24. The protective film 26 comprises a first sticky area 261, a second sticky area 262, and a non-sticky area 263 located between the first sticky area 261 and the second sticky area 262. The first sticky area 261 adheres to the main body 231, the second sticky area 262 adheres to the connecting section 2322, and the non-sticky area 263 covers the root section 2321.

[0067] Fig. Figure 5 is a schematic representation after the protective film 26 adheres to the electrode tab 232 and before the electrode tab 232 is bent. To simplify the description of the non-sticky area 263, a first dividing line F1 in the figure is the boundary between the first sticky area 261 and the non-sticky area 263, and a second dividing line F2 is the boundary between the non-sticky area 263 and the second sticky area 262.

[0068] The connecting piece 24 is a conductive part that serves to realize the electrical connection between the electrode tab 232 and the electrode terminal 25, in order to conduct the electrical energy of the electrode assembly 23 via the electrode terminal 25 when the battery cell 20 is discharged, or to feed the electrical energy into the electrode assembly 23 via the electrode terminal 25 when the battery cell 20 is charged.

[0069] The electrode assembly 23 comprises a positive electrode plate 237 and a negative electrode plate 238, which are wound into a coil-like structure. A separator 239 is arranged between the positive electrode plate 237 and the negative electrode plate 238 for insulation. The electrode assembly 23 is flat, with one electrode tab 232 provided for each winding. In the thickness direction Z of the electrode assembly 23, the electrode tab 232 is located on one side of the winding axis of the electrode assembly 23. For example, as shown in Fig. As shown in Figure 5, multilayer electrode tabs 232 are arranged in the lower part of the electrode assembly 23 in the thickness direction Z of the electrode assembly 23. For the sake of simplicity, unless otherwise specified, the term electrode tab 232 in the embodiments of this application refers to the entirety of the multilayer electrode tabs 232.

[0070] The connecting section 2322 of the electrode tab 232 is electrically connected to the connecting piece 24, e.g. by welding the connecting section 2322 to the connecting piece 24 or by a conductive adhesive bond, etc. Optionally, the connecting section 2322 is welded to the connecting piece 24 to ensure the connection strength between connecting section 2322 and connecting piece 24.

[0071] The protective film 26 is a component for protecting the electrode tab 232 to prevent an internal short circuit of the battery cell 20. The protective film 26 can be an insulating adhesive tape.

[0072] The non-sticky area 263 is the area of ​​the protective film 26 that lacks adhesive properties. When the protective film 26 interacts with the electrode tab 232, the non-sticky area 263 covers the root section 2321 of the electrode tab 232, but the non-sticky area 263 does not exert any tensile force on the root section 2321. Once the protective film 26 is connected to the electrode tab 232, rolling the protective film 26 serves to press it tightly against the electrode tab 232. Because the non-sticky area 263 and the root section 2321 are not bonded together, the rolling force is absorbed only by the protective film 26. When the protective film 26 is stretched, the tensile force is not readily transferred to the root section 2321, thus reducing the likelihood of the electrode tab 232 tearing.

[0073] The non-sticky area 263 is located between the first sticky area 261 and the second sticky area 262. In other words, the first sticky area 261 and the second sticky area 262 are located on opposite sides of the non-sticky area 263. For example, the first sticky area 261, the non-sticky area 263, and the second sticky area 262 can be distributed sequentially along the direction of extension of the protective film 26. The direction of extension of the protective film 26 can be the direction of extension of the electrode tab 232. The protective film 26 covers the entire electrode tab 232 and extends beyond it to provide protection for the electrode tab 232.

[0074] According to the battery cell 20 of the embodiment of this application, the non-adhesive area 263 of the protective film 26 covers the root section 2321 of the electrode tab 232. When the protective film 26 adheres to the electrode assembly 23, the non-adhesive area 263, since it is not bonded to the root section 2321, exerts less tensile force on the root section 2321 of the electrode tab 232, reduces the formation of cracks in the electrode tab 232, ensures its current-carrying capacity, and at the same time prevents a cracked electrode tab 232 from penetrating the protective film 26 and thus causing a short circuit, thereby increasing the service life of the battery cell 20.

[0075] Please see Fig. 6, which shows a second schematic representation of the connection of an electrode assembly 23 with a connecting piece 24 according to some embodiments of this application. Fig. Figure 6 is a schematic representation after the connection of the electrode tab 232 to the connecting piece 24 and before the bending of the electrode tab 232. According to some embodiments of this application, optionally, as in the Fig. 5 and Fig. As shown in Figure 6, the non-sticky area 263 extends beyond the boundary between the root section 2321 and the main body 231.

[0076] The non-sticky region 263 has two relative ends, one end being connected to the first sticky region 261 and the other end being connected to the second sticky region 262. Since the first sticky region 261 adheres to the main body 231 and the root section 2321 of the electrode tab 232 is connected to the main body 231, "the non-sticky region 263 extends beyond the interface between the root section 2321 and the main body 231" means that the end of the non-sticky region 263 connected to the first sticky region 261 extends beyond the interface between the root section 2321 and the main body 231.

[0077] If the end of the non-sticky area 263 connected to the first sticky area 261 covers the interface between the root section 2321 and the main body 231, this means that the non-sticky area 263 covers the root section 2321 and part of the main body 231. Since the interface between the root section 2321 and the main body 231 is a weak point of the root section 2321, if the non-sticky area 263 covers the root section 2321 and part of the main body 231, the probability of cracks in the electrode tab 232 during the bonding of the protective film 26 can be reduced.

[0078] According to some embodiments of this application, optionally, as in the Fig. 5 and Fig. As shown in Figure 6, the non-sticky area 263 extends beyond the boundary between the root section 2321 and the connecting section 2322 to cover part of the connecting section 2322.

[0079] The non-sticky region 263 has two relative ends, one of which is connected to the second sticky region 262. Since the second sticky region 262 adheres to the connecting section, "the non-sticky region 263 extends beyond the boundary between the root section 2321 and the connecting section 2322" means that the end of the non-sticky region 263 connected to the second sticky region 262 extends beyond the boundary between the root section 2321 and the connecting section 2322, i.e., the non-sticky region 263 covers the boundary between the root section 2321 and the connecting section 2322.

[0080] If the non-sticky area 263 covers the interface between the root section 2321 and the connecting section 2322, this area can be protected, which reduces the likelihood of cracks at the interface between the root section 2321 and the connecting section 2322 when the protective film 26 is applied.

[0081] Please see Fig. 7, which shows a schematic representation of the connection of a protective film 26 with a connecting section 2322 according to some embodiments of this application. According to some embodiments of this application, optionally, as in Fig. As shown in Figure 7, the area of ​​the connecting section 2322 covered by the non-sticky area 263 is S1, and the total area of ​​the connecting section 2322 is S2, where 1 / 3 ≤ S1 / S2 ≤ 2 / 3 is satisfied.

[0082] The area of ​​the connecting section 2322 covered by the non-sticky area 263 is S1, i.e., the area of ​​the part of the non-sticky area 263 that covers the connecting section 2322 is S1. S1 / S2 means S1 divided by S2 and represents the ratio of S1 to S2.The smaller the value of S1 / S2, the smaller the area of ​​the connection section 2322 covered by the non-sticky area 263, and the smaller the area covered by the non-sticky area 263 at the interface between the root section 2321 and the connection section 2322, resulting in a poorer protective effect for this interface; the larger the value of S1 / S2, the larger the area of ​​the connection section 2322 covered by the non-sticky area 263, and the smaller the adhesive area between the connection section 2322 and the second sticky area 262, which impairs the bond strength between the second sticky area 262 and the connection section 2322.

[0083] The ratio between the area of ​​the connecting section 2322 covered by the non-sticky area 263 and the total area of ​​the connecting section 2322 in this area can reduce the pulling of the protective film 26 at the interface between the root section 2321 and the connecting section 2322 when the protective film 26 is bonded, decrease the probability of cracks at this interface when the protective film 26 is bonded, and at the same time ensure that the second sticky area 262 has a larger contact area with the connecting section 2322, thus ensuring the bond stability between the protective film 26 and the connecting section 2322.

[0084] Alternatively, S1 / S2 = 1 / 2, which ensures both that the non-sticky area 263 can cover a larger area of ​​the connecting section 2322, and that the second sticky area 262 is firmly connected to the connecting section 2322.

[0085] Please see Fig. Figure 8, which shows a schematic representation of the connection of the second sticky area 262 with the connecting section 2322 according to some embodiments of this application. According to some embodiments of this application, optionally, as in Fig. As shown in Figure 8, part of the second sticky area 262 adheres to the connecting section 2322, and another part adheres to the connecting piece 24.

[0086] Part of the second sticky area 262 adheres to the connecting section 2322, and another part adheres to the connecting piece 24. In other words, the two ends of the second sticky area 262 each adhere to the connecting section 2322 and the connecting piece 24, such that the second sticky area 262 covers the end of the electrode tab 232 facing away from the main body 231, and the second sticky area 262 has an increased extension length.

[0087] The second sticky area 262 adheres to the connecting section 2322 and the connecting piece 24. The second sticky area 262 covers the end of the electrode tab 232 to prevent the multilayer electrode tabs 232 from separating, increases the connection stability between the electrode tab 232 and the connecting piece 24, and ensures a firm bond between the protective film 26 and the electrode assembly 23 and the connecting piece 24.

[0088] Please see Fig. 9, which shows a schematic representation of the connection of an electrode assembly 23 with a protective film 26 according to some embodiments of this application. Fig. Figure 9 is a schematic representation after the connection of the electrode tab 232 to the connecting piece 24 and before the bending of the electrode tab 232. According to some embodiments of this application, optionally, as in Fig. As shown in Figure 9, the electrode assembly 23 comprises a first end surface 233 and a first side surface 234, wherein the first end surface 233 is perpendicular to the first side surface 234, the electrode tab 232 extends beyond the first end surface 233 and the protective film 26 extends to the first side surface 234.

[0089] The electrode assembly 23 is a wound structure and has a flat shape. It has a thickness direction Z and a width direction. The electrode assembly 23 further comprises a second end surface 235. The second end surface 235 and the first end surface 233 are the two relative surfaces in the width direction of the electrode assembly 23, with the first end surface 233 being the end surface from which the electrode tab 232 of the electrode assembly 23 extends.

[0090] The electrode assembly 23 further comprises a second side surface 236. The first side surface 234 and the second side surface 236 are the two relative surfaces in the thickness direction Z of the electrode assembly 23. Along the thickness direction Z of the electrode assembly 23, the root section 2321 of the electrode tab 232 lies close to the second side surface 236 and away from the first side surface 234. Both the first side surface 234 and the second side surface 236 are connected to the first end surface 233 and the second end surface 235, respectively. The first side surface 234 is perpendicular to the first end surface 233, and the second side surface 236 is perpendicular to the first end surface 233. The first side surface 234 is connected to the edge of the first end surface 233, and the second side surface 236 is connected to the edge of the first end surface 233.

[0091] The protective film 26 extends from the first end surface 233 to the first side surface 234, which gives the protective film 26 a larger contact area with the main body 231, increases the connection stability between the protective film 26 and the main body 231 and ensures a firm connection between the protective film 26 and the main body 231.

[0092] According to some embodiments of this application, optionally, as in Fig. As shown in Figure 9, the first sticky area 261 comprises a first section 2611 and a second section 2612. The first section 2611 adheres to the first side surface 234, and the second section 2612 adheres to the first end surface 233.

[0093] The first section 2611 and the second section 2612 are arranged adjacent to each other. When the first sticky area 261 is bonded to the main body 231, the first section 2611 adheres to the first side surface 234 and the second section 2612 to the first end surface 233, which provides the first sticky area 261 with connection positions on two surfaces of the electrode assembly 23, increases the connection stability between the first sticky area 261 and the main body 231, and ensures a firm connection of the first sticky area 261 to the main body 231.

[0094] According to some embodiments of this application, optionally, as in Fig. As shown in Figure 9, the dimension of the first section 2611 in a direction perpendicular to the first end surface 233 is L1, and the dimension of the first side surface 234 in a direction perpendicular to the first end surface 233 is L2, where 1 / 7 ≤ L1 / L2 ≤ 1 / 5 is satisfied.

[0095] The dimension L1 of the first section 2611 in a direction perpendicular to the first end surface 233 refers to the length of the projection of the first section 2611 in the plane perpendicular to the first end surface 233 along the direction perpendicular to the first end surface 233, i.e. the extension length of the first section 2611 on the first side surface 234.

[0096] The dimension L2 of the first side surface 234 in a direction perpendicular to the first end surface 233 refers to the dimension of the first side surface 234 in the width direction of the electrode assembly 23. L1 / L2 means L1 divided by L2 and represents the ratio of L1 to L2.

[0097] If 1 / 7 ≤ L1 / L2 ≤ 1 / 5, the connection strength between the first section 2611 and the first side face 234 can be ensured. If L1 / L2 is too large, the first section 2611 occupies too large a proportion in the direction perpendicular to the first end face 233, which increases the cost; if L1 / L2 is too small, the first section 2611 occupies too small a proportion in the direction perpendicular to the first end face 233, which impairs the connection stability between the first section 2611 and the first side face 234.

[0098] Alternatively, L1 / L2 = 1 / 6 to ensure a stable connection between the first section 2611 and the first side surface 234.

[0099] According to some embodiments of this application, as in Fig. As shown in Figure 4, optionally a bending point 2323 is provided at the root section 2321 in order to align the connecting piece 24 parallel to the first end surface 233.

[0100] The bending point 2323 is the bending point that forms in the root section 2321 after the electrode tab 232 has been bent.

[0101] The bending point 2323 at the root section 2321 allows the connecting piece 24 to be aligned parallel to the first end surface 233, which reduces the space between the main body 231 and the connecting piece 24, reduces the installation space occupied by the electrode tab 232 and increases the energy density of the battery cell 20.

[0102] Please see Fig. 10, which shows a schematic structural view of a protective film 26 according to some embodiments of this application. According to some embodiments of this application, optionally, as in Fig. As shown in Figure 10, the protective film 26 comprises a protective film body 264 and a cover element 265. The protective film body 264 has an adhesive side 2641, and the cover element 265 covers part of the adhesive side 2641 to form the non-adhesive area 263. The parts of the adhesive side 2641 not covered by the cover element 265 form the first adhesive area 261 and the second adhesive area 262.

[0103] The protective film body 264 has an adhesive side 2641 and can be an adhesive tape. The cover element 265 serves to cover the adhesive side 2641. The side of the cover element 265 facing the adhesive side 2641 can be adhesive or non-adhesive. If the side of the cover element 265 facing the adhesive side 2641 is adhesive, the cover element 265 can be an adhesive tape to increase the bond strength between the cover element 265 and the protective film body 264.

[0104] The side of the cover element 265 facing away from the sticky side 2641 is not sticky. After the cover element 265 has covered the sticky side 2641, the cover element 265 adheres to the protective film body 264, and the area of ​​the protective film body 264 covered by the cover element 265 forms the non-sticky area 263.

[0105] In the solution described above, the protective film body 264 can be an adhesive tape, and the cover element 265 covers the protective film body 264 to form the non-adhesive area 263. The structure is simple and facilitates processing. The adhesive tape can be a single-sided adhesive structure, and its material can be, but does not have to be, polyvinyl chloride, polyethylene, polypropylene, polyethylene terephthalate, etc.

[0106] Please see Fig. 11, which shows a schematic structural view of a protective film 26 according to further embodiments of this application. According to some embodiments of this application, optionally, as in Fig. As shown in Figure 11, the protective film 26 comprises a carrier material 266 and an adhesive layer 267. The adhesive layer 267 is applied to both sides of the same surface of the carrier material 266 to form the first sticky area 261 and the second sticky area 262. The area of ​​the carrier material 266 that is not coated with the adhesive layer 267 forms the non-sticky area 263.

[0107] The carrier material 266 can, but does not have to, consist of materials such as polyvinyl chloride, polyethylene, polypropylene, polyethylene terephthalate, etc.

[0108] Please see Fig. Figure 12, which shows a schematic structural view of an electrode assembly 23 according to some embodiments of this application. According to some embodiments of this application, optionally, the electrode assembly 23 comprises two electrode tabs 232, one electrode tab 232 being a positive electrode tab and the other a negative electrode tab. As in Fig. As shown in Figure 9, the two electrode tabs 232 can extend from one end of the main body 231; as in Fig. As shown in Figure 12, the two electrode tabs 232 can also extend from both ends of the main body 231.

[0109] Please see Fig. 13, which shows a schematic representation of the connection of two electrode assemblies 23 according to some embodiments of this application. According to some embodiments of this application, optionally, as in Fig. As shown in Figure 13, the battery cell 20 comprises two electrode assemblies 23, each of which is connected by a connecting piece 24.

[0110] According to some embodiments of this application, this application also provides a battery 100 comprising the battery cell 20 according to one of the solutions mentioned above.

[0111] According to some embodiments of this application, this application also provides an electrical device comprising the battery cell 20 according to one of the solutions mentioned above, wherein the battery cell 20 serves to provide electrical energy to the electrical device.

[0112] The electrical device can be any of the aforementioned devices or systems that use the 100 battery.

[0113] According to some embodiments of this application, see Fig. 9. This application provides a battery cell 20. The battery cell 20 comprises a connector 24, an electrode assembly 23, and a protective film 26. The electrode assembly 23 comprises a main body 231 and an electrode tab 232 extending from the main body 231. The main body 231 comprises a first end face 233 and a first side face 234. The electrode tab 232 projects beyond the first end face 233 and comprises a root section 2321 and a connecting section 2322. The root section 2321 is connected to the main body 231, and the connecting section is welded to the connector 24. The protective film 26 comprises a first sticky area 261, a second sticky area 262, and a non-sticky area 263 located between the first sticky area 261 and the second sticky area 262. The first sticky area 261 comprises a first section 2611 and a second section 2612.The first section 2611 adheres to the first side surface 234, and the second section 2612 adheres to the first end surface 233. The second sticky area 262 adheres to the connecting section 2322 and the connecting piece 24. The non-sticky area 263 covers the root section 2321, and the two ends of the non-sticky area 263 extend beyond the interface between the root section 2321 and the main body 231, and beyond the interface between the root section 2321 and the connecting section 2322.

[0114] The non-sticky area 263 of the protective film 26 covers the root section 2321 of the electrode tab 232. When the protective film 26 adheres to the electrode assembly 23, this can reduce the tensile force of the protective film 26 on the root section 2321 of the electrode tab 232, reduce the formation of cracks in the electrode tab 232, ensure the current-carrying capacity of the electrode tab 232, and simultaneously prevent a cracked electrode tab 232 from puncturing the protective film 26 and thus causing a short circuit, thereby increasing the service life of the battery cell 20. Furthermore, the non-sticky area 263 is formed by covering the protective film 26 with a cover element 265.

[0115] Fig. Figure 14 shows a schematic flowchart of an unclaimed manufacturing process for a battery cell according to some embodiments of this application. According to some embodiments of this application, this application provides a manufacturing process for a battery cell. As in Fig. As shown in 14, the manufacturing process for the battery cell can include: 401, Providing a connector 24; 402, Providing an electrode assembly 23, wherein the electrode assembly 23 comprises a main body 231 and an electrode tab 232 extending from the main body 231, the electrode tab 232 comprising a root section 2321 and a connecting section 2322, and the root section 2321 being connected to the main body 231; 403, Providing a protective film 26, wherein the protective film 26 comprises a first sticky area 261, a second sticky area 262 and a non-sticky area 263 situated between the first sticky area 261 and the second sticky area 262; 404, Connecting the connecting section 2322 to the connecting piece 24, Bonding the first sticky area 261 to the main body 231, Bonding the second sticky area 262 to the connecting section 2322, wherein the non-sticky area 263 covers the root section 2321.

[0116] Fig. Figure 15 shows a schematic block diagram of a manufacturing device 500 for a battery cell according to some embodiments of this application. According to some embodiments of this application, this application provides a manufacturing device 500 for a battery cell. As in Fig.As shown in Figure 15, the manufacturing device 500 for the battery cell comprises a provisioning module 501 and an assembly module 502. The module 501 provides a connector 24, an electrode assembly 23, and a protective film 26. The electrode assembly 23 comprises a main body 231 and an electrode tab 232 extending from the main body 231. The electrode tab 232 comprises a root section 2321 and a connecting section 2322, the root section 2321 being connected to the main body 231. The protective film 26 comprises a first sticky area 261, a second sticky area 262, and a non-sticky area 263 located between the first sticky area 261 and the second sticky area 262.The assembly module 502 serves to connect the connecting section 2322 to the connecting piece 24, to bond the first sticky area 261 to the main body 231, to bond the second sticky area 262 to the connecting section 2322, with the non-sticky area 263 covering the root section 2321.

[0117] Although this application is described with reference to preferred embodiments, various improvements can be made to it and parts thereof can be replaced by equivalents without departing from the scope of this application. In particular, provided there are no structural conflicts, the technical features mentioned in the various embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed in the text, but encompasses all technical solutions that fall within the scope of the claims.

Claims

[1] A battery cell comprising: a connector; an electrode assembly comprising a main body and an electrode tab extending from the main body, wherein the electrode tab comprises a root section and a connecting section, the root section being connected to the main body and the connecting section being connected to the connecting piece; a protective film comprising a first sticky area, a second sticky area and a non-sticky area between the first sticky area and the second sticky area, wherein the first sticky area adheres to the main body, the second sticky area adheres to the connecting section and the non-sticky area covers the root section. [2] The battery cell according to claim 1, wherein the non-sticky area extends beyond the interface between the root section and the main body. [3] The battery cell according to claim 1 or 2, wherein the non-sticky area extends beyond the interface between the root section and the connection section to cover part of the connection section. [4] The battery cell according to claim 3, wherein the area of ​​the connecting section S1 covered by the non-sticky area is the total area of ​​the connecting section S2 and 1 / 3 ≤ S1 / S2 ≤ 2 / 3 is satisfied. [5] The battery cell according to claim 3, wherein part of the second sticky area adheres to the connecting section and another part adheres to the connecting piece. [6] The battery cell according to one of claims 1-5, wherein the electrode assembly comprises a first end face and a first side face, the first end face is perpendicular to the first side face, the electrode tab extends beyond the first end face and the protective film extends to the first side face. [7] The battery cell according to claim 6, wherein the first sticky area comprises a first section and a second section, the first section adhering to the first side surface and the second section adhering to the first end surface. [8] The battery cell according to claim 7, wherein the dimension of the first section in a direction perpendicular to the first end surface is L1, the dimension of the first side surface in a direction perpendicular to the first end surface is L2 and 1 / 7 ≤ L1 / L2 ≤ 1 / 5 is satisfied. [9] The battery cell according to one of claims 6-8, wherein a bending point is provided at the root section to align the connecting piece parallel to the first end surface. [10] The battery cell according to one of claims 1-9, wherein the protective film comprises a protective film body and a cover element, the protective film body having an adhesive side, the cover element covering part of the adhesive side to form the non-adhesive area, and the parts of the adhesive side not covered by the cover element forming the first adhesive area and the second adhesive area. [11] A battery comprising the battery cell according to any one of claims 1-10. [12] An electrical device comprising the battery cell according to any one of claims 1-10, wherein the battery cell serves to provide electrical energy. [13] A manufacturing apparatus for a battery cell, comprising: Providing a module for providing a connector, for providing an electrode assembly and for providing a protective film, wherein the electrode assembly comprises a main body and an electrode tab extending from the main body, the electrode tab comprises a root section and a connector section, the root section being connected to the main body, and the protective film comprising a first sticky area, a second sticky area and a non-sticky area situated between the first sticky area and the second sticky area; a mounting module for connecting the connecting section to the connector, for bonding the first sticky area to the main body, for bonding the second sticky area to the connecting section, wherein the non-sticky area covers the root section.

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