Battery cells, battery packs and electrical devices

Abstract

This application discloses a battery cell, a battery device, and a power-consuming device. The battery cell includes a casing, electrode terminals, an electrode assembly, and an adapter plate. The electrode assembly is provided with tabs, each tab comprising multiple tab layers. The tab layers are bent in a first direction, and adjacent tab layers are stacked in a second direction to form a bent structure. The adapter plate has a protrusion on the side facing the electrode terminals, which is fixedly connected to the electrode terminals and forms a gap between the electrode terminals and the electrode assembly. A first portion of the bent structure is fixedly connected to the side of the adapter plate facing the electrode assembly, and a second portion of the bent structure is fixedly connected to the side of the adapter plate facing the electrode terminals. According to the battery cell of this application, the length of the tabs can be shortened, and the adapter plate is less prone to deformation or cracking during welding, thereby giving the battery cell higher reliability, better battery cycle performance, and better safety.

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] In related technologies, the electrical connection between the battery cell tabs and terminals is usually achieved through indirect connection using adapters or direct welding without adapters. However, when using indirect connection with adapters, the adapters are prone to deformation or cracking during welding, which can easily lead to increased contact resistance and consequently reduce battery cycle performance and safety. When using direct welding without adapters, the tabs are longer, and the tab length increases with the cell thickness. Longer tabs are prone to plastic deformation or folding during die-cutting, winding, or gathering, which can also reduce battery cycle performance and safety. Utility Model Content

[0003] This application aims to at least solve one of the technical problems existing in the prior art. To this end, one object of this application is to provide a battery cell, and a battery device and an electrical device comprising the battery cell, wherein the battery cell can effectively shorten the length of the tabs, and the adapter is not easily deformed or cracked during welding, thereby enabling the battery cell to have high reliability, as well as good battery cycle performance and safety.

[0004] In a first aspect, embodiments of this application provide a battery cell, the battery cell comprising: a housing, the housing including a first wall portion; an electrode terminal disposed on the first wall portion; an electrode assembly, the electrode assembly having a tab on the side facing the electrode terminal; the tab comprising a plurality of tab layers, the tab layers being bent toward a first direction, and adjacent tab layers being stacked in a second direction to form a bent structure, wherein the first direction and the second direction are perpendicular to each other, and the second direction is the thickness direction of the first wall portion; an adapter piece, the adapter piece being disposed between the electrode terminal and the tab, the adapter piece having a protrusion on the side facing the electrode terminal, the protrusion being fixedly connected to the electrode terminal and used to construct a gap space between the electrode terminal and the electrode assembly, the bent structure having a first portion and a second portion, the first portion being fixedly connected to the side of the adapter piece facing the electrode assembly, and the second portion being fixedly connected to the side of the adapter piece facing the electrode terminal.

[0005] In the above-mentioned technical methods, the tab can be formed into a bent structure by smoothing it out, and the bent structure is fixedly connected to the adapter piece. This can effectively reduce the extension length of the tab layer, making it less prone to plastic deformation or folding during die-cutting, winding, or gathering, thereby improving the reliability of the tab layer. The bent structure can be fixedly connected to both sides of the adapter piece at the same time, which can improve the connection reliability between the bent structure and the adapter piece. The adapter piece can be provided with a protrusion, and the protrusion is fixedly connected to the electrode terminal, making the adapter piece less prone to deformation or cracking. This can effectively improve the reliability of the battery cell, giving the battery cell better battery cycle performance and safety.

[0006] In some embodiments, the plurality of tab layers of the second portion are welded.

[0007] In the above-mentioned technical method, after the tab layer is formed into a bent structure through a smoothing process, multiple tab layers in the second part located outside the adapter piece can be fixedly connected into a whole by welding. Thus, the operation difficulty can be reduced when the second part is folded and fixed to the adapter piece.

[0008] In some embodiments, the number N of the tab layers in the second part satisfies: 1≤N≤60.

[0009] In the above technical approach, by satisfying the condition of the number of layers of the tab layer in the second part, the structural strength and connection strength of the second part can be improved, and the reliability of the bending structure can be ensured while reducing the extension length of the tab layer.

[0010] In some embodiments, along the second direction, the length L1 of the tab layer when it is not bent satisfies: 10mm≤L1≤30mm.

[0011] In the above technical method, by satisfying the above conditions, the extension length of the tab layer is shortened, so that the tab layer is less likely to undergo plastic deformation or folding during die cutting, winding or gathering.

[0012] In some embodiments, the electrode terminal has a recess on the side away from the adapter plate, and the recess is opposite to the protrusion.

[0013] In the above-mentioned technical methods, the battery cells can be welded to the electrode terminals and protrusions by through welding, and by constructing concave portions, the thickness of the welding position of the electrode terminals can be reduced, thereby reducing the welding difficulty.

[0014] In some embodiments, along the second direction, the height H of the protrusion satisfies: 0.5mm ≤ H ≤ 1mm.

[0015] In the above-mentioned technical method, by making the height of the protrusion meet the above conditions, the adapter piece is less likely to deform or crack when the protrusion is welded to the electrode terminal. In addition, the gap space can be constructed better, so that the second part of the bent structure can be folded into the gap space.

[0016] In some embodiments, along the second direction, the thickness of the adapter piece satisfies T: 0.4mm ≤ T ≤ 0.8mm.

[0017] In the above-mentioned technical methods, by meeting the above conditions, the adapter piece can have better structural strength, improve the reliability of the adapter piece, and make the adapter piece less prone to deformation or cracking during welding, thereby better ensuring the battery cycle performance and safety.

[0018] In some embodiments, the adapter piece is provided with at least one reinforcing rib, which extends along a third direction. When there are multiple reinforcing ribs, the multiple reinforcing ribs are symmetrically arranged on both sides of the protrusion in the first direction, and the third direction is perpendicular to the first direction and the second direction, respectively.

[0019] In the above-mentioned technical methods, the reinforcing ribs can effectively improve the structural strength of the adapter plate, making it less prone to deformation or cracking during welding.

[0020] In some embodiments, the projected shape of the protrusion is a circle, an ellipse, or a rectangle in a projection plane perpendicular to the second direction.

[0021] In the above-mentioned technical method, the protrusion can be set with different shapes according to actual needs, so that the protrusion can be welded to the electrode terminal better.

[0022] In some embodiments, the multiple weld seams of the adapter piece and the electrode tab extend along a first direction, and the length L2 of each weld seam satisfies: 8mm≤L2≤15mm.

[0023] In the above technical method, by ensuring that the length L2 of each weld segment meets the above conditions, the adapter plate can dissipate heat better during each welding, making it less likely for the adapter plate to accumulate heat locally, thereby reducing the possibility of deformation of the adapter plate during welding.

[0024] In some embodiments, the protrusion is configured as a strip extending along the first direction.

[0025] In the above-mentioned technical method, by making the protrusion strip-shaped, the structural strength of the adapter piece can be improved, and the deformation of the adapter piece during welding can be suppressed.

[0026] In some embodiments, the adapter piece is an integrally formed stamped part.

[0027] In the above-mentioned technical methods, the integrally molded adapter piece can have better structural strength.

[0028] In some embodiments, the adapter plate and the electrode terminal, and the adapter plate and the bent structure are respectively laser-through welded.

[0029] In the above-mentioned technical methods, the use of laser penetration welding makes it less prone to cracking of the tab layer, which can improve the battery cycle performance and safety.

[0030] Secondly, embodiments of this application provide a battery device comprising: a battery cell according to the first aspect of this application.

[0031] In the above-described technical approach, by incorporating battery cells as described in the above embodiments, the electrical cycle performance and safety of the battery device can be significantly improved.

[0032] Thirdly, embodiments of this application provide an electrical device that includes a battery device according to the second aspect of this application.

[0033] In the above-described technical approach, by incorporating the battery device described in the above embodiments, the power consumption performance and safety of the power-consuming device can be significantly improved.

[0034] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0035] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0036] Figure 1 The electrical device provided in some embodiments of this application is a structural schematic diagram of a vehicle.

[0037] Figure 2 Exploded views of the structure of a battery cell provided in some embodiments of this application.

[0038] Figure 3 A partial cross-sectional view of a battery cell provided in some embodiments of this application.

[0039] Figure 4 for Figure 3 A magnified view of region A in the middle.

[0040] Figure 5 This is a schematic diagram of the electrode assembly when the tab layer is not bent, as provided in some embodiments of this application.

[0041] Figure 6 This is a schematic diagram of the structure of the adapter piece of the first embodiment provided for some embodiments of this application.

[0042] Figure 7 This is a schematic diagram of the structure of the adapter piece of the second embodiment provided in some embodiments of this application.

[0043] Figure 8 This is a schematic diagram of the structure of the adapter piece of the third embodiment provided in some embodiments of this application.

[0044] Figure label:

[0045] 1000, Vehicle; 100, Battery unit; 200, Controller; 300, Motor;

[0046] 10. Battery cells;

[0047] 1. Shell; 11. Top cover; 111. First wall portion; 12. Shell body;

[0048] 2. Electrode terminal; 21. Recess;

[0049] 3. Electrode assembly; 31. Tab; 311. Tab layer; 30. Bending structure; 301. First part; 302. Second part;

[0050] 4. Adapter plate; 41. Protrusion; 42. Reinforcing rib;

[0051] X, first direction; Y, second direction; Z, third direction. Detailed Implementation

[0052] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0053] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0054] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0055] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0056] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0057] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two).

[0058] In the description of the embodiments of this application, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0059] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0060] The battery apparatus 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 one or more battery cells, and when there are multiple battery cells, they are connected in series, parallel, or mixed connections via a busbar.

[0061] 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 together to form a single module. As an example, a battery module can be formed by bundling multiple battery cells together with cable ties.

[0062] In some embodiments, the battery device may be a battery pack, which includes a housing and one or more individual battery cells housed within the housing.

[0063] 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.

[0064] As an example, battery cell assemblies can also be housed in a housing by directly fixing multiple battery cells to the housing.

[0065] As an example, the enclosure may include a first enclosure and a second enclosure. The first enclosure and the second enclosure are fastened together to form a closed space inside the enclosure to house the individual battery cells. Here, "closed" refers to covering or closing, and can be either sealed or unsealed. The first enclosure may be a top cover or a bottom plate.

[0066] As an example, the enclosure may include a top cover, a frame, and a bottom plate. The top cover and bottom plate are connected to the frame, creating an enclosed space inside the enclosure to house the individual battery cells.

[0067] As an example, the housing can be part of the vehicle's chassis structure. For instance, the housing's roof can be at least part of the vehicle's floor, or the housing's frame can be at least part of the vehicle's crossbeams and longitudinal beams.

[0068] In some embodiments, the battery device refers to an energy storage device, which includes a housing with a door on at least one side. Energy storage devices include energy storage containers, energy storage cabinets, etc.

[0069] The battery cells mentioned in the embodiments of this application may include lithium-ion secondary batteries, lithium-ion primary batteries, lithium-sulfur batteries, sodium-lithium-ion batteries, sodium-ion batteries, or magnesium-ion batteries, etc., and the embodiments of this application are not limited to these. Battery cells may be cylindrical, flat, cuboid, or other shapes, etc., and the embodiments of this application are not limited to these shapes either. Battery cells are generally classified into three types according to their packaging method: cylindrical battery cells, square battery cells, and pouch battery cells, and the embodiments of this application are not limited to these types either.

[0070] For example, a single battery cell typically includes a housing, a cell assembly, and an electrolyte. The housing is used to house the cell assembly and the electrolyte, and the housing has at least one positive electrode post and at least one negative electrode post. The cell assembly includes one or more electrode assemblies, which are formed by stacking or winding positive electrode sheets, negative electrode sheets, and separators.

[0071] The positive electrode generally includes a positive current collector and a positive active material layer. The positive active material layer is directly or indirectly coated on the positive current collector. The positive current collector without the positive active material layer protrudes from the positive current collector with the positive active material layer. The positive current collector without the positive active material layer serves as a positive electrode tab. Multiple positive electrode tabs are stacked together and form an electrical connection with the positive electrode post. For example, the multiple stacked positive electrode tabs can be directly soldered to the positive electrode post to form an electrical connection; or, the battery cell assembly can also include a positive electrode adapter piece. The multiple stacked positive electrode tabs are soldered to one end of the positive electrode adapter piece, and the other end of the positive electrode adapter piece is soldered to the positive electrode post, so that the positive electrode tabs and the positive electrode post form an electrical connection.

[0072] The negative electrode generally includes a negative current collector and a negative active material layer. The negative active material layer is directly or indirectly coated on the negative current collector. The negative current collector without the negative active material layer protrudes from the negative current collector with the negative active material layer. The negative current collector without the negative active material layer serves as a negative electrode tab. Multiple negative electrode tabs are stacked together and form an electrical connection with the negative electrode post. For example, the stacked negative electrode tabs can be directly welded to the negative electrode post to form an electrical connection; alternatively, the battery cell assembly may also include a negative electrode adapter piece. The stacked negative electrode tabs are welded to one end of the negative electrode adapter piece, and the other end of the negative electrode adapter piece is welded to the negative electrode post, so that the negative electrode tabs and the negative electrode post form an electrical connection. The material of the separator is not limited; for example, it can be polypropylene or polyethylene.

[0073] Meanwhile, individual battery cells primarily function by the movement of metal ions between the positive and negative electrode plates. Taking lithium-ion batteries as an example, the positive electrode current collector can be made of aluminum, and the positive electrode active material layer can be made of lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide, etc. The negative electrode current collector can be made of copper, and the negative electrode active material layer can be made of carbon or silicon, etc. During charging and discharging, Li+ ions repeatedly insert and extract between the two electrodes: during charging, Li+ ions extract from the positive electrode, pass through the electrolyte, and insert into the negative electrode, leaving the negative electrode in a lithium-rich state; the reverse occurs during discharging.

[0074] The technical solutions described in the embodiments of this application are applicable to various electrical devices that use battery cells and battery devices, such as mobile phones, portable devices, laptops, electric vehicles, electric toys, power tools, vehicles, ships and spacecraft, etc. For example, spacecraft include airplanes, rockets, space shuttles and spacecraft.

[0075] In related technologies, the electrical connection between the battery cell tabs and terminals is usually achieved through indirect connection using adapters or direct welding without adapters. However, when using indirect connection with adapters, the adapters are prone to deformation or cracking during welding, which can easily lead to increased contact resistance and consequently reduce battery cycle performance and safety. When using direct welding without adapters, the tabs are longer, and the tab length increases with the cell thickness. Longer tabs are prone to plastic deformation or folding during die-cutting, winding, or gathering, which can also reduce battery cycle performance and safety.

[0076] Based on the above considerations, in order to improve the cycle performance and safety of battery cells, the applicant, after in-depth research, designed a battery cell in which the tabs can be formed into a bent structure by smoothing, and the bent structure is fixedly connected to the adapter plate. This can effectively reduce the extension length of the tab layer, making the tab layer less prone to plastic deformation or folding during die-cutting, winding, or gathering, thereby improving the reliability of the tab layer. The bent structure can be fixedly connected to both sides of the adapter plate at the same time, which can improve the connection reliability between the bent structure and the adapter plate. The adapter plate can be provided with a protrusion, and the protrusion is fixedly connected to the electrode terminal, making the adapter plate less prone to deformation or cracking, which can effectively improve the reliability of the battery cell, giving the battery cell better battery cycle performance and safety.

[0077] For ease of explanation, the following embodiments use a vehicle 1000 as an example to describe in detail the structure of the electrical device, battery device 100 and battery cell 10 of this application.

[0078] Please refer to Figure 1 , Figure 1This application provides a schematic diagram of the structure of an electrical device for a vehicle 1000, as shown in some embodiments. 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. The vehicle 1000 is equipped with a battery device 100, which can be located at the bottom, front, or rear of the vehicle 1000. The battery device 100 can be used to supply power to the vehicle 1000; for example, it 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 controls the battery device 100 to supply power to the motor 300, for example, to meet the power requirements of the vehicle 1000 during starting, navigation, and driving. 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, replacing or partially replacing gasoline or natural gas to provide driving power to the vehicle 1000.

[0079] The following is for reference. Figures 2-8 A battery cell 10 according to an embodiment of the first aspect of this application is described.

[0080] Please refer to Figures 2-4 , Figure 2 This is an exploded view of the structure of a battery cell 10 provided in some embodiments of this application. Figure 3 This is a partial cross-sectional view of a battery cell 10 provided in some embodiments of this application. Figure 4 for Figure 3 A magnified view of region A in the middle.

[0081] According to an embodiment of this application, the battery cell 10 includes a housing 1, electrode terminals 2, electrode assembly 3, and adapter plate 4. The housing 1 includes a first wall portion 111, the electrode terminals 2 are disposed on the first wall portion 111, and the electrode assembly 3 has a tab 31 on the side facing the first wall portion 111. The tab 31 includes a plurality of tab layers 311, the tab layers 311 are bent toward a first direction X, and adjacent tab layers 311 are stacked in a second direction Y to form a bent structure 30, wherein the first direction X and the second direction Y are perpendicular to each other, and the second direction Y... Along the thickness direction of the first wall portion 111, the adapter piece 4 is disposed between the electrode terminal 2 and the tab 31. The side of the adapter piece 4 facing the electrode terminal 2 is provided with a protrusion 41, which is fixedly connected to the electrode terminal 2 and is used to create a gap space between the electrode terminal 2 and the electrode assembly 3. The bending structure 30 has a first part 301 and a second part 302. The first part 301 is fixedly connected to the side of the adapter piece 4 facing the electrode assembly 3, and the second part 302 is fixedly connected to the side of the adapter piece 4 facing the electrode terminal 2.

[0082] It should be noted that, taking the cell 10 as a cuboid cell as an example, the casing 1 may have six walls. For the convenience of describing this application, the wall with the electrode terminals 2 is referred to as the first wall 111.

[0083] Exemplarily, the housing 1 may include a housing body 12 and a top cover 11. The top cover 11 includes a first wall portion 111, which has an electrode post hole. The electrode terminal 2 may include an electrode post and an insulating member. The electrode post may pass through the electrode post hole, and the insulating member is disposed between the first wall portion 111 and the electrode post. In addition, the electrode post may be a one-piece molded part or may be composed of two parts fixedly connected. This example is only for the purpose of understanding the solution of this application and should not be construed as a limitation of this application. That is, the first wall portion 111 may be any side wall of the housing 1.

[0084] For example, the tab 31 in the above example is a general term. In other words, the electrode assembly 3 can be formed by stacking positive electrode plates, negative electrode plates and separator films. Each positive electrode plate has a positive electrode tab 31, and each negative electrode plate has a negative electrode tab 31. Taking the positive electrode tab 31 as an example, multiple positive electrode tabs 31 can be located at one end of the electrode assembly 3. The sum of multiple positive electrode tabs 31 can be called the tab 31 of the electrode assembly 3. In addition, the sum of multiple negative electrode tabs 31 can also be called the tab 31 of the electrode assembly 3.

[0085] Furthermore, regarding the tab layer 311, as can be seen from the above example, the tab 31 located at the end of the electrode assembly 3 can be gathered by a smoothing process. Therefore, the tab layer 311 is only for the convenience of defining each protruding positive tab 31. Here, the smoothing process refers to bending and flattening multiple tab layers 311 in the same direction, so that the surface of the bent structure 30 formed by multiple tab layers 311 is relatively flat, thereby facilitating fixed connection with the adapter piece 4.

[0086] Furthermore, in the above-described features of this application, adjacent tab layers 311 are stacked in the thickness direction of the first wall portion 111 to form a bent structure 30. That is, when the tab layers 311 are smoothed, not all tab layers 311 are simultaneously stacked in the thickness direction of the first wall portion 111; only a few adjacent tab layers 311 are stacked in the thickness direction of the first wall portion 111. This effectively reduces the length of the protruding tab layers 311, making it less prone to plastic deformation or folding during die-cutting, winding, or gathering, thereby improving the reliability of the tab layers 311. Additionally, for ease of description, the thickness direction will be used to refer directly to the thickness direction of the first wall portion 111, and will not be elaborated further below.

[0087] Furthermore, by smoothing out the tab layer 311, multiple tab layers 311 can be gathered together and better fixedly connected to the adapter piece 4. The fixed connection method can be welding, and for ease of description in the following application, welding will be used directly to refer to it, and this application will not elaborate on it.

[0088] In this example, the adapter piece 4 can be provided with a protrusion 41. The protrusion 41 can improve the structural strength of the adapter piece 4. Furthermore, the adapter piece 4 is welded to the electrode terminal 2 through the protrusion 41. During the welding process, the protrusion 41 is not prone to deformation or cracking. Moreover, even if the protrusion 41 is deformed or cracked, the structure of the adapter piece 4 is not prone to deformation or cracking. This also makes the welding between the adapter piece 4 and the electrode terminal 2 less likely to interfere with the welding structure between the adapter piece 4 and the bending structure 30, thereby improving the reliability of the battery cell 10 and giving the battery cell 10 better battery cycle performance and safety.

[0089] Furthermore, when the adapter plate 4 is provided with a protrusion 41 and abuts against the electrode terminal 2 through the protrusion 41, a gap space is formed on the outer periphery of the protrusion 41, that is, between the adapter plate 4 and the electrode terminal 2. When the tab layer 311 is flattened to form a bent structure 30, part of the bent structure 30 will extend beyond the adapter plate 4. At this time, this part of the bent structure 30 can be folded towards the gap space and then fixed to the side of the adapter plate 4 facing the electrode terminal 2. In this way, the space occupied by the flattened tab layer 311 can be reduced by utilizing the gap space. Moreover, the bent structure 30 is welded to both sides of the adapter plate 4, which can better improve the connection strength between the bent structure 30 and the adapter plate 4, thereby improving the connection reliability between the bent structure 30 and the adapter plate 4.

[0090] In addition, it can be understood that the tab 31 of this application is not directly welded to the electrode terminal 2, but is welded to the electrode terminal 2 through the adapter piece 4. After the extension length of the tab 31 is shortened, the tab 31 is flattened to form a bending structure 30, and then welded to the adapter piece 4 through the bending structure 30. When the electrode assembly 3 expands during operation, the bending structure 30 between the electrode assembly 3 and the adapter piece 4 can be well buffered, so that even if the extension length of the tab 31 is shortened, it is not easy to break during the electric cycle of the electrode assembly 3, which can improve the reliability of the battery cell 10.

[0091] In the above-mentioned technical method, the tab 31 can be formed into a bent structure 30 by smoothing, and the bent structure 30 is fixedly connected to the adapter piece 4. This can effectively reduce the extension length of the tab layer 311, making the tab layer 311 less prone to plastic deformation or folding during die-cutting, winding or gathering, thereby improving the reliability of the tab layer 311. The bent structure 30 can be fixedly connected to both sides of the adapter piece 4 at the same time, which can improve the connection reliability between the bent structure 30 and the adapter piece 4. The adapter piece 4 can be provided with a protrusion 41, and the protrusion 41 is fixedly connected to the electrode terminal 2, making the adapter piece 4 less prone to deformation or cracking, which can effectively improve the reliability of the battery cell 10, so that the battery cell 10 has better battery cycle performance and safety.

[0092] In some embodiments of this application, the multiple tab layers 311 of the second portion 302 are welded.

[0093] like Figure 3 As shown, the bending structure 30 has a first part 301 and a second part 302. In the projection plane perpendicular to the second direction Y, the projection of the first part 301 is located within the projection of the adapter piece 4, and the projection of the second part 302 is located outside the projection of the adapter piece 4. After welding, the second part 302 is folded over and fixed to the side of the adapter piece 4 away from the electrode assembly 3.

[0094] In other words, after the tab layer 311 is formed into a bent structure 30 through a smoothing process, the multiple tab layers 311 of the second part 302 located outside the adapter piece 4 can be fixedly connected into a whole by welding. Thus, the operation difficulty can be reduced when the second part 302 is folded and fixed with the adapter piece 4.

[0095] In some embodiments of this application, the number N of the tab layers 311 in the second portion 302 satisfies: 1 ≤ N ≤ 60. When the tab layers 311 are smoothed, the number of tab layers 311 in the second portion 302 can represent the number of tab layers 311 continuously stacked in a predetermined region of the bending structure 30. Furthermore, it should be noted that the length of each tab layer 311 can be equal; therefore, when multiple tab layers 311 are bent in the same direction, the ends of each tab layer 311 will not overlap in the thickness direction.

[0096] For example, the number N of the tab layer 311 of the second part 302 can be 1 or greater than 1. Alternatively, the number N of the tab layer 311 of the second part 302 can be greater than or equal to 3. By ensuring that the number of tab layers 311 of the second part 302 meets the above conditions, the second part 302 has a sufficient number of layers, thereby having sufficient structural strength and thickness. This makes it less likely that the tab layer 311 will be welded through when the second part 302 is welded into a whole, and also less likely that the second part 302 will be welded through when it is welded to the adapter piece 4, which can help improve the welding quality.

[0097] Preferably, the number N of the tab layer 311 in the second part 302 can satisfy: 30≤N≤60.

[0098] In addition, the number N of the tab layer 311 in the second part 302 can reflect the relationship between the extension length of the tab layer 311 and the thickness of the electrode (e.g., positive electrode or negative electrode). That is, by constraining the number of tab layers 311 in the second part 302, the extension length of the tab layer 311 can be better constrained, so that the reliability of the bending structure 30 is guaranteed while reducing the extension length of the tab layer 311.

[0099] For example, the number of layers N of the tab layer 311 in the second part 302 can be 3, 4, or 5, and this application does not limit this.

[0100] For example, each tab layer 311 can be bent as follows: Figure 3 The arc shape shown.

[0101] In the above technical approach, by satisfying the condition of the number of layers of the tab layer 311 in the second part 302, the structural strength and connection strength of the second part 302 can be improved, and the reliability of the bending structure 30 can be guaranteed while reducing the extension length of the tab layer 311.

[0102] Please refer to Figure 5 , Figure 5 This is a schematic diagram of the structure of the electrode assembly 3 when the tab layer 311 is not bent, as provided in some embodiments of this application.

[0103] In some embodiments of this application, along the second direction Y, the length L1 of the tab layer 311 when it is not bent satisfies: 10mm≤L1≤30mm.

[0104] The length L1 of the tab layer 311 represents the length of the tab layer 311 before the smoothing process after the positive electrode, negative electrode, and separator are stacked or wound to form the electrode assembly 3. Compared with related technologies, the extension length of the tab 31 is generally more than 45mm, while the extension length of the tab layer 311 in this application can be between 10mm and 30mm, which shortens the extension length of the tab layer 311 and makes it less prone to plastic deformation or folding during die-cutting, winding, or gathering.

[0105] For example, the length L1 can be 10mm, 15mm, 16mm, 17mm, 18mm, 19mm, 20mm, 21mm, 22mm, 23mm, 24mm, 25mm, or 30mm.

[0106] In the above technical method, by satisfying the above conditions, the extension length of the tab layer 311 is shortened, so that the tab layer 311 is not prone to plastic deformation or folding during die cutting, winding or gathering.

[0107] In some embodiments of this application, such as Figure 3 and Figure 4 As shown, a recess 21 is provided on the side of the electrode terminal 2 away from the adapter plate 4. The recess 21 is opposite to the protrusion 41. The battery cell 10 is welded to the electrode terminal 2 and the protrusion 41 through the recess 21.

[0108] For example, the opening of the recess 21 gradually increases in the direction away from the protrusion 41, which can facilitate the welding equipment to approach the bottom surface of the recess 21 or facilitate the welding head of the welding equipment to extend into the recess 21.

[0109] For example, in a projection plane perpendicular to the thickness direction, the projected area of ​​the concave portion 21 is greater than the projected area of ​​the convex portion 41.

[0110] In the above-mentioned technical method, the battery cell 10 can be welded to the electrode terminal 2 and the protrusion 41 by through welding. By constructing the concave portion 21, the thickness of the welding position of the electrode terminal 2 can be reduced, thereby reducing the welding difficulty.

[0111] In some embodiments of this application, such as Figure 3 and Figure 4 As shown, along the second direction Y, the height H of the protrusion 41 satisfies: 0.5mm≤H≤1mm.

[0112] In the above-mentioned technical method, by making the height of the protrusion 41 meet the above conditions, the adapter piece 4 is not easily deformed or cracked when the protrusion 41 is welded to the electrode terminal 2. In addition, the gap space can be constructed better, so that the second part 302 of the bending structure 30 can be folded into the gap space.

[0113] For example, the height H of the protrusion 41 can be 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, or 1mm.

[0114] In some embodiments of this application, such as Figure 3 and Figure 4 As shown, along the second direction Y, the thickness of the adapter piece 4 satisfies T: 0.4mm≤T≤0.8mm.

[0115] In the above technical approach, by meeting the above conditions, the adapter piece 4 can have better structural strength, which can improve the reliability of the adapter piece 4 and make the adapter piece 4 less prone to deformation or cracking during welding, thereby better ensuring the battery cycle performance and safety.

[0116] Please refer to Figure 6 , Figure 6 This is a schematic diagram of the structure of the adapter piece 4 of the first embodiment provided in some embodiments of this application.

[0117] In some embodiments of this application, the adapter piece 4 is provided with at least one reinforcing rib 42, which extends along the third direction Z. When there are multiple reinforcing ribs 42, the multiple reinforcing ribs 42 are symmetrically arranged on both sides of the protrusion 41 in the first direction X, and the third direction Z is perpendicular to the first direction X and the second direction Y, respectively.

[0118] In the above-mentioned technical method, the reinforcing rib 42 can effectively improve the structural strength of the adapter piece 4, making the adapter piece 4 less prone to deformation or cracking during welding.

[0119] For example, four reinforcing ribs 42 can be provided, and the four reinforcing ribs 42 can be symmetrically arranged on both sides of the protrusion 41, that is, two reinforcing ribs 42 can be provided on each side of the protrusion 41. It is understood that the number of reinforcing ribs 42, the cross-sectional shape and size of the reinforcing ribs 42 can be set according to actual needs, and this application does not limit them.

[0120] Please refer to Figure 7 and Figure 8 , Figure 7 This is a schematic diagram of the structure of the adapter piece 4 of the second embodiment provided in some embodiments of this application. Figure 8 This is a schematic diagram of the structure of the adapter piece 4 of the third embodiment provided in some embodiments of this application.

[0121] In some embodiments of this application, the projection shape of the protrusion 41 is a circle, an ellipse, or a rectangle in a projection plane perpendicular to the second direction Y.

[0122] In the above technical method, the protrusion 41 can be set with different shapes according to actual needs, so that the protrusion 41 can be welded to the electrode terminal 2 better.

[0123] In some embodiments of this application, the battery cell 10 is welded to the adapter 4 and the bending structure 30 from the side of the adapter 4 away from the bending structure 30. The multiple weld seams of the adapter 4 and the bending structure 30 extend along the first direction X, and the length L2 of each weld seam satisfies: 8mm≤L2≤15mm.

[0124] In other words, the adapter piece 4 and the bending structure 30 can also be welded by penetration welding, so that the weld extends along the bending direction of the tab layer 311, which makes the adapter piece 4 and the bending structure 30 have a better connection effect and can improve the connection strength between the adapter piece 4 and the bending structure 30.

[0125] Furthermore, by ensuring that the length L2 of each weld segment meets the above conditions, the adapter plate 4 can dissipate heat better during each welding process, making it less likely for the adapter plate 4 to accumulate heat locally, thereby reducing the possibility of deformation of the adapter plate 4 during welding.

[0126] For example, the length L2 of each weld segment can be 8mm, 9mm, 10mm, 11mm, 12mm, 13mm, 14mm, or 15mm.

[0127] For example, when welding the adapter piece 4 and the bending structure 30, the two sides of the adapter piece 4 can be constrained by the pressure strip, and then the middle part of the adapter piece 4 can be welded first, and then the two sides of the adapter piece 4 can be welded.

[0128] For example, multiple weld segments can be sequentially connected along the bending direction of the tab layer 311 to form a single weld. For this single weld, the middle section can be welded first to form a middle weld, and then welding can be performed at both ends of the middle weld.

[0129] In the above technical method, by ensuring that the length L2 of each weld segment meets the above conditions, the adapter plate 4 can dissipate heat better during each welding, making it less likely for the adapter plate 4 to accumulate heat locally, thereby reducing the possibility of deformation of the adapter plate 4 during welding.

[0130] In some embodiments of this application, such as Figure 8 As shown, the protrusion 41 is constructed as a strip extending along the first direction X.

[0131] For example, the length direction of the reinforcing rib 42 is perpendicular to the extension direction of the protrusion 41. Thus, the adapter piece 4 can better improve the structural strength through the cooperation of the reinforcing rib 42 and the protrusion 41, making the adapter piece 4 less prone to deformation or cracking.

[0132] Furthermore, the extension direction of the protrusion 41 is parallel to the length direction of the weld. Therefore, the protrusion 41 is less likely to affect the welding between the adapter piece 4 and the bending structure 30, and the protrusion 41 can better suppress the deformation of the adapter piece 4 during welding.

[0133] In the above-mentioned technical method, by making the protrusion 41 strip-shaped, the structural strength of the adapter piece 4 can be improved, and the deformation of the adapter piece 4 during welding can be suppressed.

[0134] In some embodiments of this application, the adapter piece 4 is a one-piece stamped part.

[0135] For example, the adapter plate 4 can be made by stamping aluminum or copper sheets, which has a simple structure and can effectively reduce production costs.

[0136] In the above-mentioned technical approach, the integrally molded adapter plate 4 can have better structural strength.

[0137] In some embodiments of this application, the adapter plate 4 and the electrode terminal 2, and the adapter plate 4 and the bent structure 30 are respectively welded by laser penetration welding. In the field of metal processing, laser penetration welding refers to using a high-power-density laser beam to form a "keyhole" effect, completely melting through stacked or butt-jointed metal plates along the thickness direction in one go, realizing a large aspect ratio weld with single-sided welding and double-sided forming. This process does not require pre-drilling or filling material, and has the advantages of small heat-affected zone, fast welding speed, small deformation, and high flexibility.

[0138] In the above-mentioned technical methods, by using laser penetration welding, the tab layer 311 is less prone to cracking, which can improve the battery cycle performance and safety.

[0139] This application also proposes a battery device 100 having the battery cell 10 of the above embodiments.

[0140] The battery device 100 according to the embodiments of this application can improve the electrical cycle performance and safety of the battery device 100 by providing the battery cell 10 of the above embodiments.

[0141] This application also proposes an electrical device having the battery device 100 of the above embodiments.

[0142] According to the embodiments of this application, by providing the battery device 100 of the above embodiments, the power consumption performance and safety of the power device can be improved.

[0143] Other configurations and operations of the battery cell 10, battery device 100, and electrical device according to embodiments of this application are known to those skilled in the art and will not be described in detail here.

[0144] In the description of this specification, references to terms such as "some embodiments," "optionally," "furthermore," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0145] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A battery cell (10) characterized by, include: The housing (1) includes a first wall portion (111); Electrode terminal (2), the electrode terminal (2) is disposed on the first wall portion (111); An electrode assembly (3) is provided with tabs (31) on the side facing the electrode terminal (2); the tabs (31) include a plurality of tab layers (311), the tab layers (311) are bent toward a first direction (X), and adjacent tab layers (311) are stacked in a second direction (Y) to form a bent structure (30), wherein the first direction (X) and the second direction (Y) are perpendicular to each other, and the second direction (Y) is the thickness direction of the first wall portion (111); The adapter (4) is disposed between the electrode terminal (2) and the tab (31). The adapter (4) has a protrusion (41) on the side facing the electrode terminal (2). The protrusion (41) is fixedly connected to the electrode terminal (2) and is used to create a gap space between the electrode terminal (2) and the electrode assembly (3). The bending structure (30) has a first part (301) and a second part (302). The first part (301) is fixedly connected to the side of the adapter (4) facing the electrode assembly (3), and the second part (302) is fixedly connected to the side of the adapter (4) facing the electrode terminal (2).

2. The battery cell (10) according to claim 1, characterized in that The plurality of tab layers (311) of the second part (302) are welded.

3. The battery cell (10) according to claim 2, characterized in that The number of layers N of the tab layer (311) in the second part (302) satisfies: 1≤N≤60.

4. The battery cell (10) according to claim 1, characterized in that, Along the second direction (Y), the length L1 of the tab layer (311) when it is not bent satisfies: 10mm≤L1≤30mm.

5. The battery cell (10) according to claim 1, characterized in that The electrode terminal (2) has a recess (21) on the side away from the adapter plate (4), and the recess (21) is opposite to the protrusion (41).

6. The battery cell (10) according to claim 1, characterized in that Along the second direction (Y), the height H of the protrusion (41) satisfies: 0.5mm≤H≤1mm.

7. The battery cell (10) according to claim 1, characterized in that Along the second direction (Y), the thickness of the adapter piece (4) satisfies T: 0.4mm≤T≤0.8mm.

8. The battery cell (10) according to claim 1, characterized in that The adapter piece (4) is provided with at least one reinforcing rib (42), which extends along a third direction (Z). When there are multiple reinforcing ribs (42), the multiple reinforcing ribs (42) are symmetrically arranged on both sides of the protrusion (41) in the first direction (X). The third direction (Z) is perpendicular to the first direction (X) and the second direction (Y) respectively.

9. The battery cell (10) according to claim 1, characterized in that In the projection plane perpendicular to the second direction (Y), the projection shape of the protrusion (41) is circular, elliptical or rectangular.

10. The battery cell (10) according to claim 1, characterized in that The multiple welds of the adapter piece (4) and the electrode tab (31) extend along the first direction (X), and the length L2 of each weld segment satisfies: 8mm≤L2≤15mm.

11. The battery cell (10) according to claim 1, characterized in that The protrusion (41) is constructed as a strip extending along the first direction (X).

12. The battery cell (10) according to claim 1, characterized in that The adapter piece (4) is a stamped part formed in one piece.

13. The battery cell (10) according to claim 1, characterized in that The adapter piece (4) and the electrode terminal (2), the adapter piece (4) and the bending structure (30) are respectively connected by laser penetration welding.

14. A battery device (100), characterized by A battery device (100) comprising the battery cell (10) according to any one of claims 1-13.

15. An electrical device, comprising: A battery device (100) comprising the battery cell (10) according to any one of claims 1-13.

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