Battery cell, battery device, and electric device

Abstract

The application discloses a battery monomer, a battery device and a power utilization device. The battery monomer comprises a shell, an electrode assembly and a protective layer, the shell is provided with an electrode current leading structure; the electrode assembly is arranged in the interior of the shell, the electrode assembly comprises a main body part and a tab led out from the end of the main body part, the tab is welded with the electrode current leading structure and a welding mark is formed on the side of the tab away from the electrode current leading structure, and the electrode current leading structure is used for conducting current between the electrode assembly and components located outside the shell; the protective layer is arranged on the side of the tab away from the electrode current leading structure, and the protective layer is provided with a via hole for exposing the welding mark. The application improves the reliability of the battery monomer.

Description

Technical Field

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

[0002] Battery cells are widely used in electronic devices such as mobile phones, laptops, electric vehicles, electric cars, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes, and power tools. Battery cells can include nickel-cadmium battery cells, nickel-metal hydride battery cells, lithium-ion battery cells, and rechargeable alkaline zinc-manganese battery cells, among others.

[0003] In the development of battery technology, improving the reliability of individual battery cells is a key research direction. Utility Model Content

[0004] This application provides a battery cell, a battery device, and an electrical device that can improve the reliability of the battery cell.

[0005] In a first aspect, embodiments of this application provide a battery cell, which includes a casing, an electrode assembly, and a protective layer. The casing is provided with an electrode current-guiding structure. The electrode assembly is disposed inside the casing and includes a main body and a tab extending from the end of the main body. The tab is welded to the electrode current-guiding structure and a solder mark is formed on the side of the tab away from the electrode current-guiding structure. The electrode current-guiding structure is used to conduct current between the electrode assembly and a component located outside the casing. The protective layer is disposed on the side of the tab away from the electrode current-guiding structure and has a through hole for exposing the solder mark.

[0006] In the above scheme, by setting a protective layer on the side of the tab away from the electrode current-guiding structure, and the protective layer is provided with through holes for the solder to flow out, when the tab is welded to the current-guiding structure, the protective layer does not affect the tab and the welding, and can protect the tab. For example, it can improve the adverse effect of friction softening of the tab surface by the welding head 70 during ultrasonic welding, avoid the tab from cracking, and ensure that the current-carrying capacity of the tab is not affected to a certain extent, thereby improving the reliability of the battery cell.

[0007] In some embodiments, the vias are arranged circumferentially around the edge of the solder print.

[0008] In the above solution, by placing the via close to the edge of the solder mark, the phenomenon of the electrode tab cracking around the solder mark during welding can be further reduced.

[0009] In some embodiments, the electrode tab includes a connecting end and a free end, the connecting end being connected to the main body portion and the free end being disposed away from the main body portion; a protective layer extends to the connecting end of the electrode tab.

[0010] In the above scheme, by extending the protective layer to the connection end of the electrode, the protection range of the protective layer for the electrode can be increased, and the phenomenon of cracks occurring near the connection end during electrode welding can be reduced.

[0011] In some embodiments, the protective layer extends to the free end of the tab.

[0012] In the above scheme, by extending the protective layer to the free end of the electrode, the protection range of the protective layer on the electrode can be increased, and the phenomenon of cracks occurring near the free end during electrode welding can be reduced.

[0013] In some embodiments, the electrode tab also includes two oppositely disposed sides, the two ends of which are respectively connected to the connecting end and the free end, and the protective layer extends to the two sides of the electrode tab.

[0014] In the above solution, by extending the protective layer to the side of the connection between the free end and the connection end, the protection range of the protective layer for the electrode tab is further increased, reducing the phenomenon of cracks occurring near the side during electrode tab welding.

[0015] In some embodiments, the battery cell further includes insulating tape disposed on the side of the protective layer away from the electrode lead-in structure, and the insulating tape covers the solder marks.

[0016] In the above solution, covering the solder marks with insulating tape can reduce the risk of short circuits caused by exposed solder marks.

[0017] In some embodiments, the insulating tape is bonded to the main body, the solder mark, and the electrode lead-in structure, respectively.

[0018] In the above solution, by using insulating tape to bond the main body, soldering marks, and electrode drainage structure, it is easy to gather and bond the stacked tab layers together.

[0019] In some embodiments, the protective layer is made of the same material as the insulating tape.

[0020] In the above solution, by using the same material for the protective layer and the insulating tape, it is easier to obtain raw materials and reduce costs.

[0021] In some embodiments, the distance between the edge of the protective layer and the solder mark is greater than or equal to 0.5 mm and less than or equal to 2 mm.

[0022] In the above scheme, by limiting the distance between the edge of the protective layer and the solder mark to a suitable range, the cracking rate during electrode welding can be further reduced.

[0023] In some embodiments, the distance between the edge of the protective layer and the solder mark is less than or equal to 1 mm.

[0024] In the above solution, by further reducing the distance between the edge of the protective layer and the solder mark, the area of ​​the solder mark can be guaranteed to a certain extent, thereby improving the welding reliability.

[0025] In some embodiments, the protective layer includes a protective base film and an adhesive layer, wherein the adhesive layer is bonded to the side of the tab away from the electrode drainage structure, and the protective base film is disposed on the side of the adhesive layer away from the tab.

[0026] In the above scheme, the combination of adhesive layer and protective base film facilitates the connection between the protective layer and the tab.

[0027] In some embodiments, the thickness of the adhesive layer is less than or equal to 0.3 mm.

[0028] In the above scheme, by setting the thickness of the adhesive layer to less than or equal to 0.3 mm, the space occupied by the adhesive layer on the battery cell can be reduced, thereby improving the space utilization rate of the battery cell.

[0029] In some embodiments, the thickness of the adhesive layer is greater than or equal to 0.002 mm and less than or equal to 0.005 mm.

[0030] In the above solution, by further limiting the thickness range of the adhesive layer, not only can the bonding effect of the adhesive layer be guaranteed to a certain extent, but the space occupied by the adhesive layer on the battery cell can also be further reduced.

[0031] In some embodiments, the thickness of the protective base film is greater than or equal to 0.005 mm.

[0032] In the above scheme, by setting the thickness of the protective base film to be greater than or equal to 0.005 mm, the protective base film can be guaranteed to a certain extent to protect the tab.

[0033] In some embodiments, the thickness of the protective base film is greater than or equal to 0.01 mm and less than or equal to 0.2 mm.

[0034] In the above scheme, by further limiting the thickness range of the protective base film, it is possible not only to ensure the protective effect of the protective base film on the tabs to a certain extent, but also to reduce the space occupied by the protective base film on the battery cell.

[0035] Secondly, embodiments of this application also provide a battery device, including a battery cell of any of the above embodiments.

[0036] Thirdly, embodiments of this application also provide an electrical device, including the aforementioned battery device, which is used to provide electrical energy.

[0037] 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

[0038] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the drawings without creative effort.

[0039] Figure 1 This application provides structural schematic diagrams of vehicles for some embodiments;

[0040] Figure 2 Exploded views of battery devices provided in some embodiments of this application;

[0041] Figure 3 This is a schematic diagram of the structure of a battery module according to some embodiments of this application;

[0042] Figure 4 This is an exploded structural diagram of a battery cell provided in some embodiments of this application;

[0043] Figure 5 This is a schematic diagram of the structure of the electrode assembly in some embodiments of this application;

[0044] Figure 6 This is a schematic diagram of the structure of the electrode assembly in some other embodiments of this application;

[0045] Figure 7 This is a schematic diagram of the welding of the tab and electrode drainage structure in some embodiments of this application;

[0046] Figure 8 This is a schematic diagram of the structure of the tabs in some embodiments of this application;

[0047] Figure 9 This is a schematic diagram of the structure of the electrode assembly in some other embodiments of this application;

[0048] Figure 10 This is a schematic diagram of the electrode tab structure in some other embodiments of this application;

[0049] Figure 11 This is a cross-sectional schematic diagram of the protective layer of some embodiments of this application.

[0050] The accompanying drawings are not drawn to scale.

[0051] Explanation of icon numbers:

[0052] 1000, Vehicle; 100, Battery Unit; 200, Controller; 300, Motor; 30, Housing; 10, Top Cover; 400, Battery Module; 20, Battery Cell; 22, Housing; 21, End Cap; 24, Outer Shell; 26, Electrode Terminal; 23, Electrode Assembly; 231, Main Body; 232, Tab; 233, Solder Mark; 234, Connecting End; 235, Free End; 236, Side; 40, Protective Layer; 41, Via; 42, Protective Base Film; 43, Adhesive Layer; 50, Electrode Drainage Structure; 51, Adapter Component; 60, Insulating Tape; 70, Welding Head. Detailed Implementation

[0053] The embodiments of this application will be described in further detail below with reference to the accompanying drawings and examples. The detailed description of the following embodiments and the accompanying drawings are used to illustrate the principles of this application by way of example, but should not be used to limit the scope of this application, that is, this application is not limited to the described embodiments.

[0054] In the description of this application, it should be noted that, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," and "outer," etc., indicating orientation or positional relationships, are only for the convenience of describing 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, and therefore should not be construed as a limitation on this application. Furthermore, the terms "first," "second," and "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. "Vertical" is not vertical in the strict sense, but within the allowable tolerance range. "Parallel" is not parallel in the strict sense, but within the allowable tolerance range.

[0055] In this application, the reference to "embodiment" means that a specific 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 mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application can be combined with other embodiments.

[0056] The directional terms used in the following description refer to the directions shown in the figures and are not intended to limit the specific structure of this application. It should also be noted in the description of this application that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0057] In this application, the battery cell may include a lithium-ion secondary battery cell, a lithium-ion primary battery cell, a lithium-sulfur battery cell, a sodium-lithium-ion battery cell, a sodium-ion battery cell, or a magnesium-ion battery cell, etc., and the embodiments of this application are not limited thereto. The battery cell may be cylindrical, flat, cuboid, or other shapes, etc., and the embodiments of this application are not limited thereto. Battery cells are generally classified into three types according to their packaging method: cylindrical battery cells, cuboid / square battery cells, and pouch battery cells, and the embodiments of this application are not limited thereto.

[0058] The battery device mentioned in the embodiments of this application may include one or more battery cell assemblies for providing voltage and capacity. A battery cell assembly may include multiple battery cells, which are connected in series, parallel, or mixed connections via a busbar.

[0059] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells; as an example, a battery cell assembly can be a battery module, which is formed by arranging and fixing multiple battery cells into a single module. As an example, a battery module can be formed by bundling multiple battery cells together with cable ties.

[0060] In some embodiments, the battery device may be a battery pack, which includes a housing and one or more individual battery cell assemblies housed within the housing.

[0061] As an example, the battery cell assembly can be a battery module, which can be housed in a housing by fixing the battery module in the housing.

[0062] As an example, battery cell assemblies can also be housed in a housing by directly fixing multiple battery cells to the housing.

[0063] This application provides an electrical device that uses a battery as a power source. The electrical device can be, but is not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc. Electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0064] For ease of explanation, the following embodiments will be described using a vehicle 1000 as an example of an electrical device according to an embodiment of this application.

[0065] Please refer to Figure 1 , Figure 1This is a schematic diagram of the structure of a vehicle 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 device 100 is installed inside the vehicle 1000, and the battery device 100 can be located at the bottom, front, or rear of the vehicle 1000. The battery device 100 can be used to power the vehicle 1000; for example, the battery device 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 device 100 to supply power to the motor 300, for example, to meet the power needs of the vehicle 1000 during starting, navigation, and driving.

[0066] In some embodiments of this application, the battery device 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.

[0067] Please refer to Figure 2 , Figure 2 This is an exploded view of the apparatus provided in some embodiments of this application. The battery device 100 includes a battery housing and battery cells 20. In some embodiments, the battery housing may include a top cover 10 and a housing 30, with the top cover 10 and housing 30 covering each other, and the top cover 10 and housing 30 together defining a receiving cavity for receiving the battery cells 20. The housing 30 may be a hollow structure with one end open, and the top cover 10 may be a plate-like structure, with the top cover 10 covering the open side of the housing 30 so that the top cover 10 and housing 30 together define the receiving cavity; the top cover 10 and housing 30 may also be hollow structures with one side open, with the open side of the top cover 10 covering the open side of the housing 30. Of course, the battery housing formed by the top cover 10 and housing 30 can be of various shapes, such as a cylinder, a cuboid, etc.

[0068] Figure 3 This is a schematic diagram of the structure of a battery module according to some embodiments of this application. In the battery device 100, there can be multiple battery cells 20, which can be connected in series, parallel, or in a mixed manner. A mixed connection means that multiple battery cells 20 are connected in both series and parallel. Multiple battery cells 20 can be directly connected in series, parallel, or in a mixed manner, and then the whole assembly of multiple battery cells 20 is housed in a housing. Of course, the battery device 100 can also be in the form of multiple battery cells 20 first connected in series, parallel, or in a mixed manner to form a battery module 400, and then multiple battery modules 400 are connected in series, parallel, or in a mixed manner to form a whole and housed in a housing. The battery device 100 may also include other structures. For example, the battery device 100 may also include a busbar component for realizing the electrical connection between multiple battery cells 20.

[0069] Each battery cell 20 can be a secondary battery cell or a primary battery cell; it can also be a lithium-sulfur battery cell, a sodium-ion battery cell, or a magnesium-ion battery cell, but is not limited to these. The battery cell 20 can be cylindrical, flat, cuboid, or other shapes.

[0070] Please refer to Figure 4 , Figure 4 This is an exploded structural diagram of a battery cell provided in some embodiments of this application. A battery cell 20 refers to the smallest unit that makes up a battery. The battery cell 20 includes a casing, electrode assembly 23, and other functional components.

[0071] The outer casing includes an end cap 21 and a housing 22. The end cap 21 is a component that covers the opening of the housing 22 to isolate 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 (such as aluminum alloy), so that the end cap 21 is less prone to deformation under pressure and impact, allowing the battery cell 20 to have higher structural strength and improved safety performance. Functional components such as electrode terminals 26 can be provided on the end cap 21. The electrode terminals 26 can be used to electrically connect to the electrode assembly 23 for outputting or inputting electrical energy into the battery cell 20. In some embodiments, the end cap 21 can also be provided with a pressure relief mechanism for releasing internal pressure when the internal pressure or temperature of the battery cell 20 reaches a threshold. The material of the end cap 21 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 element may be provided on the inner side of the end cap 21. The insulating element can be used to isolate the electrical connection components within the housing 22 from the end cap 21 to reduce the risk of short circuits. For example, the insulating element may be made of plastic, rubber, etc.

[0072] Currently, in pursuit of high energy density and high charge / discharge capacity, very thin materials are used as current collectors, which makes the tabs prone to cracking and other defects during the welding process. For example, during ultrasonic welding of the tabs and adapter components, the tabs and welding head often rub against each other and are excessively stretched and deformed, resulting in cracks in the surface tab layer. This weakens the tab's current carrying capacity, reduces the charge / discharge capacity of the battery cell, and easily generates excessive heat in the welding area of ​​the tab, causing localized ablation of the electrode sheet and reducing the reliability of the battery cell.

[0073] To address the aforementioned technical problems, this application provides a battery cell comprising a casing, an electrode assembly, and a protective layer. The casing has an electrode current-guiding structure. The electrode assembly is disposed inside the casing and includes a main body and tabs extending from the end of the main body. The tabs are welded to the electrode current-guiding structure, and a solder mark is formed on the side of the tabs away from the electrode current-guiding structure. The electrode current-guiding structure is used to conduct current between the electrode assembly and a component located outside the casing. The protective layer is disposed on the side of the tabs away from the electrode current-guiding structure, and the protective layer has through holes for exposing the solder mark.

[0074] In the above scheme, by setting a protective layer on the side of the tab away from the electrode current-guiding structure, and the protective layer is provided with through holes for the solder to flow out, when the tab is welded to the current-guiding structure, the protective layer does not affect the tab and the welding, and can protect the tab. For example, it can improve the adverse effect of friction softening of the tab surface by the welding head 70 during ultrasonic welding, avoid the tab from cracking, and ensure that the current-carrying capacity of the tab is not affected to a certain extent, thereby improving the reliability of the battery cell.

[0075] Figure 5 This is a schematic diagram of the structure of the electrode assembly in some embodiments of this application; Figure 6 This is a schematic diagram of the structure of the electrode assembly in some other embodiments of this application; Figure 7 This is a schematic diagram of the welding of the tab and electrode drainage structure in some embodiments of this application.

[0076] Please refer to the following: Figures 5-7 In a first aspect, embodiments of this application provide a battery cell 20, which includes a housing 24, an electrode assembly 23, and a protective layer 40. The housing 24 is provided with an electrode current-guiding structure 50. The electrode assembly 23 is disposed inside the housing 24 and includes a main body 231 and a tab 232 extending from the end of the main body 231. The tab 232 is welded to the electrode current-guiding structure 50 and a solder mark 233 is formed on the side of the tab 232 away from the electrode current-guiding structure 50. The electrode current-guiding structure 50 is used to conduct current between the electrode assembly 23 and a component located outside the housing 24. The protective layer 40 is disposed on the side of the tab 232 away from the electrode current-guiding structure 50 and has a through hole 41 for exposing the solder mark 233.

[0077] The outer casing 24 may include a housing 22 and an end cap 21. The housing 22 has an opening, and the end cap 21 covers the opening. Alternatively, the outer casing 24 may be a one-piece structure. The outer casing 24 may be cuboid, cylindrical, hexagonal prism, etc. The electrode guiding structure 50 may include electrode terminals 26 and an adapter component 51. The electrode terminals 26 may be provided on the outer casing 24. The tabs 232 may be ultrasonically welded to the adapter component 51, and then the adapter component 51 may be laser welded to the electrode terminals 26 to output the electrical energy of the battery cell 20 to the outside. One adapter component may be welded to only one tab 232 of the battery cell 20, or one adapter component 51 may be welded to the tabs 232 of two battery cells 20 simultaneously. After the tabs 232 are welded to the adapter component 51, solder marks 233 will be formed on the surface away from the adapter component 51. The shape of the solder marks 233 will vary depending on the welding method. Alternatively, the tabs 232 may be directly welded to the electrode terminals 26. The solder mark 233 can be rectangular, trapezoidal, or other shapes.

[0078] The main body 231 can be formed by stacking or winding electrode sheets. The electrode tab 232 can be either a positive electrode tab 232 or a negative electrode tab 232. The positive electrode tab 232 is connected to the positive electrode terminal 26, and the negative electrode tab 232 is connected to the negative electrode terminal 26. The positive and negative electrode tabs 232 can be located on opposite sides of the main body 231. Figure 6 ), or they can be located on the same side ( Figure 5 ).

[0079] An active material can be coated on the main body 231, while the tab 232 is the portion without active material coating. For example, the main body 231 of the positive electrode can be made of aluminum foil, and the main body 231 of the negative electrode can be made of copper foil. Positive electrode active materials such as lithium cobalt oxide, lithium manganese oxide, and lithium iron phosphate can be coated on the main body 231 of the positive electrode, while negative electrode active materials such as graphite, silicon carbide, and lithium titanate can be coated on the main body 231 of the negative electrode. It should be noted that a protective layer 40 is provided on the side of both the positive and negative electrode tabs 232 that faces away from the electrode current-guiding structure 50. For ease of understanding, the term "tab 232" will be used consistently in the following description.

[0080] Each electrode has 232 layers of tabs, which are stacked sequentially and then bent and folded towards the adapter 51. The tabs 232 layers that are in close contact with the adapter 51 are the inner tabs 232 layers, and the tabs 232 layers that are away from the adapter 51 are the outer tabs 232 layers. The protective layer 40 is disposed on the side of the outermost tab 232 layer that faces away from the electrode drainage structure 50.

[0081] Ultrasonic welding utilizes high-frequency vibration waves transmitted to the surfaces of two objects to be welded. Under pressure, the surfaces rub against each other, causing molecular fusion. It offers advantages such as high efficiency, high quality, aesthetic appeal, energy saving, and high weld strength. Ultrasonic welding is a highly efficient method for connecting the battery cell 20 tabs 232 to the adapter component 51. The connection between the battery cell 20 tabs 232 and the adapter component 51 generally employs an overlapping structure. During welding, the ultrasonic welding head 70 is pressed onto the stacked tabs 232, and a certain pressure is applied through the welding head 70. Then, ultrasonic waves are output from the ultrasonic device, achieving atomic resonance and interlocking on adjacent tab 232 layers under high-frequency vibration, thereby connecting the multiple layers of tabs 232 to the adapter component 51.

[0082] When the electrode tab 232 is ultrasonically welded to the adapter component 51, the welding head 70 is aligned with the through hole 41 of the protective layer 40, and the electrode tab 232 and the adapter component 51 are fused together within the through hole 41 to form a weld mark 233. Because the protective layer 40 is present on the side of the electrode tab 232 facing the welding head 70, the protective layer 40 reduces the tensile deformation of the electrode tab 232 and avoids frictional damage to the electrode tab 232 from the welding head 70 at other locations except for the weld mark 233. The protective layer 40 can be made of an insulating material, such as insulating adhesive, which has both protective and insulating functions. Alternatively, the protective layer 40 can be made of an elastic material to increase its wear resistance.

[0083] The protective layer 40 can be applied to all or some of the tabs 232 simultaneously before the electrode sheet is die-cut. Alternatively, the protective layer 40 can be applied to different tabs 232 individually after the electrode sheet is die-cut and before the tabs 232 are welded to the adapter component 51.

[0084] In the above scheme, by setting a protective layer 40 on the side of the tab 232 away from the electrode current-guiding structure 50, and the protective layer 40 is provided with a through hole 41 for the solder 233 to flow out, when the tab 232 is welded to the current-guiding structure, the protective layer 40 does not affect the tab 232 and the welding, and can protect the tab 232. For example, it can improve the adverse effect of friction softening of the surface of the tab 232 by the welding head 70 during ultrasonic welding, avoid the phenomenon of cracking of the tab 232, and to a certain extent ensure that the current-carrying capacity of the tab 232 is not affected, and it is not easy to generate excessive heat in the welding area of ​​the tab 232, thereby reducing the risk of ablation of the electrode layout of the battery cell 20 and improving the reliability of the battery cell 20.

[0085] In some embodiments, the via 41 is arranged circumferentially around the edge of the solder mark 233.

[0086] The via 41 matches the size and shape of the solder mark 233. For example, if the shape of the solder mark 233 is rectangular, square, or elliptical, then the shape of the via 41 will match it. The solder mark 233 of the via 41 can be slightly larger than the size of the solder mark 233 so that the via 41 can fully expose the solder mark 233. During soldering, the solder head 70 is aligned with the area of ​​the via 41 for soldering, and the solder mark 233 is formed within the via 41. The via 41 is arranged around the edge of the solder mark 233, which can also increase the range of the solder mark 233 and improve the reliability of the connection between the tab 232 and the electrode guide structure 50.

[0087] In the above solution, by setting the via 41 close to the edge of the solder mark 233, the phenomenon of the tab 232 cracking around the solder mark 233 during welding can be further reduced.

[0088] Figure 8 This is a schematic diagram of the structure of the tabs in some embodiments of this application.

[0089] like Figure 8 As shown, in some embodiments, the tab 232 includes a connecting end 234 and a free end 235. The connecting end 234 is connected to the main body 231, and the free end 235 is disposed away from the main body 231. The protective layer 40 extends to the connecting end 234 of the tab 232.

[0090] Each tab 232 layer has a connecting end 234 and a free end 235. The protective layer 40 extends to the connecting end 234 of the outermost tab 232 layer. The protective layer 40 can cover all areas of the entire tab 232 except for the solder mark 233, making the tab 232 less susceptible to tensile deformation and friction damage.

[0091] In the above scheme, by extending the protective layer 40 to the connection end 234 of the tab 232, the protection range of the protective layer 40 for the tab 232 can be increased, and the phenomenon of cracks occurring near the connection end 234 during the welding of the tab 232 can be reduced.

[0092] In some embodiments, the protective layer 40 extends to the free end 235 of the tab 232.

[0093] The protective layer 40 can extend not only to the connection end 234 of the outermost tab 232 layer, but also to the free end 235 of the outermost tab 232 layer.

[0094] In the above scheme, by extending the protective layer 40 to the free end 235 of the tab 232, the protection range of the protective layer 40 for the tab 232 can be increased, and the phenomenon of cracks occurring near the free end 235 during the welding of the tab 232 can be reduced.

[0095] In some embodiments, the tab 232 further includes two oppositely disposed sides 236, the two ends of which are connected to the connecting end 234 and the free end 235 respectively, and the protective layer 40 extends to the two sides 236 of the tab 232.

[0096] The width of the connecting end 234 can be greater than the width of the free end 235. The two sides 236 move closer to each other from the connecting end 234 to the free end 235. The entire tab 232 is trapezoidal in shape, which increases the width of the connection between the connecting section and the main body 231, thereby enhancing the stability of the connection between the tab 232 and the main body 231.

[0097] Alternatively, the tab 232 can also be rectangular, square, or other shapes, and the width of the connecting end 234 is equal to the width of the free end 235.

[0098] The protective layer 40 extends to the two sides 236 of the outermost tab 232 layer. The protective layer 40 can extend to the connecting end 234 and the free end 235, or it can extend to the two sides 236.

[0099] In the above scheme, by extending the protective layer 40 to the side 236 connecting the free end 235 and the connecting end 234, the protection range of the protective layer 40 for the tab 232 is further increased, reducing the phenomenon of cracks occurring near the side 236 during the welding of the tab 232.

[0100] Figure 9 This is a schematic diagram of the structure of an electrode assembly according to other embodiments of this application.

[0101] like Figure 9 As shown, in some embodiments, the battery cell 20 further includes an insulating tape 60, which is disposed on the side of the protective layer 40 away from the electrode lead structure 50, and covers the solder mark 233.

[0102] The solder mark 233 is the metal fusion area formed after the tab 232 and the electrode current-guiding structure 50 are welded together. Its surface may have burrs, sharp edges, or exposed metal layers. If the solder mark 233 is directly exposed, it may come into contact with the main body 231, the outer casing 24, or other conductive parts, causing a short circuit in the battery cell 20. Covering it with insulating tape 60 can block this electrical connection path.

[0103] Insulating tape 60 can be made of materials such as polypropylene, polyimide, and fluororubber, which can withstand high temperatures and have good insulation effects.

[0104] The larger dimension of the insulation layer is larger than the dimension of the solder mark 233 so that the edge of the solder mark 233 can be covered by the insulating tape 60. The insulating tape 60 is directly adhered to the protective layer 40, which facilitates the manufacturing process.

[0105] In the above solution, by covering the solder mark 233 with insulating tape 60, the risk of short circuit caused by exposed solder mark 233 can be reduced.

[0106] In some embodiments, the insulating tape 60 is bonded to the main body 231, the solder mark 233 and the electrode drain structure 50 respectively.

[0107] The first end of the insulating tape 60 is bonded to the main body 231, then extends to the tab 232, covers the solder mark 233, and the last end is bonded to the electrode drainage structure 50.

[0108] In the above solution, by using insulating tape 60 to bond the main body 231, solder mark 233 and electrode drainage structure 50, it is easy to gather and bond the stacked electrode tabs 232 layers together.

[0109] In some embodiments, the protective layer 40 is made of the same material as the insulating tape 60.

[0110] Both the protective layer 40 and the insulating tape 60 can be made of materials such as polypropylene, polyimide, and fluororubber.

[0111] In the above solution, by using the same material for the protective layer 40 and the insulating tape 60, it is easier to obtain raw materials and reduce costs.

[0112] Figure 10 This is a schematic diagram of the tab structure of some other embodiments of this application.

[0113] like Figure 10 As shown, in some embodiments, the distance D between the edge of the protective layer 40 and the solder mark 233 is greater than or equal to 0.5 mm and less than or equal to 2 mm.

[0114] The distance D between the edge of the protective layer 40 and the solder mark 233 can be any value between 0.5mm and 2mm. For example, the distance D between the edge of the protective layer 40 and the solder mark 233 can be 0.5mm, 0.7mm, 0.9mm, 1mm, 1.5mm, 1.7mm or 2mm.

[0115] In the above solution, by limiting the distance between the edge of the protective layer 40 and the solder mark 233 to a suitable range, the cracking rate during welding of the tab 232 can be further reduced.

[0116] In some embodiments, the distance D between the edge of the protective layer 40 and the solder mark 233 is less than or equal to 1 mm.

[0117] The distance D between the edge of the protective layer 40 and the solder mark 233 can be any value between 0.5mm and 1mm. For example, the distance D between the edge of the protective layer 40 and the solder mark 233 can be 0.5mm, 0.6mm, 0.7mm, 0.8mm or 1mm.

[0118] In the above solution, by further reducing the distance between the edge of the protective layer 40 and the solder mark 233, the area of ​​the solder mark 233 can be guaranteed to a certain extent, thereby improving the welding reliability.

[0119] Figure 11 This is a cross-sectional schematic diagram of the protective layer in some embodiments of this application.

[0120] like Figure 11 As shown, in some embodiments, the protective layer 40 includes a protective base film 42 and an adhesive layer 43. The adhesive layer 43 is bonded to the side of the tab 232 opposite to the electrode drain structure 50, and the protective base film 42 is disposed on the side of the adhesive layer 43 opposite to the tab 232.

[0121] The adhesive layer 43 is attached to one side of the electrode guide structure 50, such as the side of the adapter 51, with an adhesive side. The protective base film 42 is located on the side facing the welding head 70.

[0122] In the above scheme, by using the combination of adhesive layer 43 and protective base film 42, the connection between protective layer 40 and tab 232 can be facilitated.

[0123] In some embodiments, the thickness H1 of the adhesive layer 43 is less than or equal to 0.3 mm.

[0124] The thickness H1 of the adhesive layer 43 can be any value less than or equal to 0.3 mm. For example, the thickness H1 of the adhesive layer 43 can be 0.1 mm, 0.15 mm, 0.2 mm, 0.25 mm or 0.3 mm.

[0125] In the above scheme, by setting the thickness H1 of the adhesive layer 43 to less than or equal to 0.3 mm, the space occupied by the adhesive layer 43 on the battery cell 20 can be reduced, and the space utilization rate of the battery cell 20 can be improved.

[0126] In some embodiments, the thickness H1 of the adhesive layer 43 is greater than or equal to 0.002 mm and less than or equal to 0.005 mm.

[0127] The thickness H1 of the adhesive layer 43 can be any value between 0.002 and 0.3 mm. For example, the thickness H1 of the adhesive layer 43 can be 0.002 mm, 0.005 mm, 0.01 mm, 0.015 mm, or 0.05 mm.

[0128] In the above solution, by further limiting the thickness range of the adhesive layer 43, not only can the bonding effect of the adhesive layer 43 be guaranteed to a certain extent, but the space occupied by the adhesive layer 43 on the battery cell 20 can also be further reduced.

[0129] In some embodiments, the thickness H2 of the protective base film 42 is greater than or equal to 0.005 mm.

[0130] The thickness H2 of the protective base film 42 can be any value greater than or equal to 0.005 mm. For example, the thickness H2 of the protective base film 42 can be 0.005 mm, 0.008 mm, 0.01 mm, 0.05 mm, or 0.1 mm.

[0131] In the above scheme, by setting the thickness H2 of the protective base film 42 to be greater than or equal to 0.005 mm, the protective base film 42 can guarantee the protective effect of the tab 232 to a certain extent.

[0132] In some embodiments, the thickness H2 of the protective base film 42 is greater than or equal to 0.01 mm and less than or equal to 0.2 mm.

[0133] The thickness H2 of the protective base film 42 can be any value between 0.01 and 0.2. For example, the thickness H2 of the protective base film 42 can be 0.01 mm, 0.03 mm, 0.06 mm, 0.08 mm, 0.12 mm, 0.15 mm, 0.17 mm, 0.19 mm, or 0.2 mm.

[0134] In the above scheme, by further limiting the thickness range of the protective base film 42, it is possible not only to ensure the protective effect of the protective base film 42 on the tab 232 to a certain extent, but also to reduce the space occupied by the protective base film 42 on the battery cell 20.

[0135] Secondly, embodiments of this application also provide a battery device 100, including a battery cell 20 of any of the above embodiments.

[0136] Thirdly, embodiments of this application also provide an electrical device, including the aforementioned battery device 100, which is used to provide electrical energy.

[0137] According to some embodiments of this application, this application provides a battery cell 20, which includes a housing 24, an electrode assembly 23, and a protective layer 40. The housing 24 is provided with an electrode current-guiding structure 50. The electrode assembly 23 is disposed inside the housing 24 and includes a main body 231 and a tab 232 extending from the end of the main body 231. The tab 232 is welded to the electrode current-guiding structure 50, and a solder mark 233 is formed on the side of the tab 232 away from the electrode current-guiding structure 50. The electrode current-guiding structure 50 is used to conduct current between the electrode assembly 23 and a component located outside the housing 24. The protective layer 40 is disposed on the side of the tab 232 away from the electrode current-guiding structure 50, and the protective layer 40 is provided with a through hole 41 for exposing the solder mark 233. The through hole 41 is circumferentially arranged around the edge of the solder mark 233.

[0138] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0139] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features. However, these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A battery cell, characterized in that, include: The outer casing is equipped with an electrode drainage structure; An electrode assembly is disposed inside the housing. The electrode assembly includes a main body and a tab extending from an end of the main body. The tab is welded to the electrode current-guiding structure and a solder mark is formed on the side of the tab away from the electrode current-guiding structure. The electrode current-guiding structure is used to conduct current between the electrode assembly and a component located outside the housing. A protective layer is disposed on the side of the tab opposite to the electrode drain structure, and the protective layer is provided with vias for exposing the solder print.

2. The battery cell according to claim 1, characterized in that, The vias are arranged circumferentially around the edge of the solder mark.

3. The battery cell according to claim 1, characterized in that, The electrode tab includes a connecting end and a free end. The connecting end is connected to the main body, and the free end is disposed away from the main body. The protective layer extends to the connecting end of the electrode tab.

4. The battery cell according to claim 3, characterized in that, The protective layer extends to the free end of the tab.

5. The battery cell according to claim 3, characterized in that, The electrode tab also includes two oppositely arranged sides, the two ends of which are respectively connected to the connecting end and the free end, and the protective layer extends to the two sides of the electrode tab.

6. The battery cell according to claim 1, characterized in that, The battery cell also includes insulating tape, which is disposed on the side of the protective layer away from the electrode lead-in structure and covers the solder mark.

7. The battery cell according to claim 6, characterized in that, The insulating tape is bonded to the main body, the solder mark, and the electrode drainage structure, respectively.

8. The battery cell according to claim 6, characterized in that, The protective layer is made of the same material as the insulating tape.

9. The battery cell according to claim 1, characterized in that, The distance between the edge of the protective layer and the solder mark is greater than or equal to 0.5 mm and less than or equal to 2 mm.

10. The battery cell according to claim 9, characterized in that, The distance between the edge of the protective layer and the solder mark is less than or equal to 1 mm.

11. The battery cell according to claim 1, characterized in that, The protective layer includes a protective base film and an adhesive layer. The adhesive layer is bonded to the side of the tab opposite to the electrode drainage structure, and the protective base film is disposed on the side of the adhesive layer opposite to the tab.

12. The battery cell according to claim 11, characterized in that, The thickness of the adhesive layer is less than or equal to 0.3 mm.

13. The battery cell according to claim 12, characterized in that, The thickness of the adhesive layer is greater than or equal to 0.002 mm and less than or equal to 0.005 mm.

14. The battery cell according to claim 11, characterized in that, The thickness of the protective base film is greater than or equal to 0.005 mm.

15. The battery cell according to claim 14, characterized in that, The thickness of the protective base film is greater than or equal to 0.01 mm and less than or equal to 0.2 mm.

16. A battery device, characterized in that, Includes the battery cell according to any one of claims 1-15.

17. An electrical appliance, characterized in that, Includes the battery device according to claim 16, the battery device being used to provide electrical energy.

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