Battery monomer, battery and electric device

Abstract

The utility model relates to the field of batteries, and provides a battery monomer, a battery and a power utilization device. The battery monomer comprises an electrode assembly, and the electrode assembly comprises a diaphragm and two pole pieces with opposite polarities. The pole piece comprises a current collector, an active material layer and a tab, the active material layer is arranged on at least one surface of the current collector, and the tab is welded with the edge of the current collector. And a reinforcing structure is arranged on the tab. Based on the structure, although the tabs are pulled by the current collector in the processing process of the pole piece, especially in the period that the current collector is pressed, the tabs can resist the pulling force due to the fact that the strength and the ductility of the tabs are enhanced by the reinforcing structures, so that the risks of wrinkling, warping and the like of the tabs caused by pulling of the current collector can be reduced, and the reliability of the pole piece is improved. The risk of production problems such as collapse, folding to a membrane area, internal short circuit and folding of the tab can be reduced, the production yield and production efficiency of the pole piece, the electrode assembly and the battery monomer can be improved, and the use reliability of the battery monomer in the life cycle can be improved.

Description

Technical Field

[0001] This application belongs to the technical field of batteries, and particularly relates to a battery cell, a battery, and an electrical device. Background Art

[0002] The electrode assembly is a component in the battery cell where electrochemical reactions occur. The electrode assembly includes two polar plates with opposite polarities, and a separator that separates the two polar plates. In some cases, the polar plate includes a current collector, an active material layer disposed on the surface of the current collector, and a tab welded to the current collector at the edge of the current collector. The area of the current collector where the active material layer is provided is the film area. However, during the processing of the polar plate, especially during the period when the current collector is pressed, the tab is easily pulled by the current collector and appears wrinkled, warped, etc., resulting in production problems and safety problems such as the tab being easily collapsed, folded into the film area and causing internal short circuit, flipping, etc. Summary of the Utility Model

[0003] Embodiments of this application provide a battery cell, a battery, and an electrical device, aiming to solve the problem that during the processing of the polar plate, the tab is easily pulled by the current collector and appears wrinkled, warped, etc., resulting in situations such as the tab being easily collapsed, folded into the film area and causing internal short circuit, flipping, etc.

[0004] To achieve the above object, the technical solution adopted in the embodiments of this application is:

[0005] In a first aspect, a battery cell is provided. The battery cell includes an electrode assembly, and the electrode assembly includes a separator and two polar plates with opposite polarities;

[0006] The polar plate includes a current collector, an active material layer, and a tab. The active material layer is disposed on at least one surface of the current collector, and the tab is welded to the edge of the current collector;

[0007] A strengthening structure is provided on the tab.

[0008] For the battery cell provided by the embodiments of this application, by providing a strengthening structure on the tab of the polar plate, the strength and ductility of the tab are strengthened via the strengthening structure. Based on this, during the processing of the polar plate, especially during the period when the current collector is pressed (for example, during the cold pressing process in the film area, or during the rolling process in the welding area), although the tab will also be pulled by the current collector, because the strengthening structure strengthens the strength and ductility of the tab, the tab can counteract the pulling force, thereby reducing the risk of the tab appearing wrinkled, warped, etc. due to the pulling of the current collector, reducing the risk of production problems and safety problems such as the tab being collapsed, folded into the film area and causing internal short circuit, flipping, etc., improving the production yield, production excellence rate and production efficiency of the polar plate, the electrode assembly and the battery cell, and improving the use reliability of the battery cell during its life cycle.

[0009] In some embodiments, the reinforcing structure is formed by the tab protruding towards one side in its own thickness direction.

[0010] By adopting the above solution, without increasing the material amount of the tab, it is convenient, fast and reliable to locally press the tab into a reinforcing structure. Based on this, the processing convenience and efficiency of forming the reinforcing structure on the tab can be improved, the strengthening effect of the protruding reinforcing structure on the strength and ductility of the tab can be enhanced, the material amount of the tab can be reduced, and the cost can be lowered.

[0011] In some embodiments, there are multiple reinforcing structures, and the multiple reinforcing structures are arranged at intervals along the length direction of the tab.

[0012] By adopting the above solution, by arranging multiple reinforcing structures at intervals along the length direction of the tab, the layout of the reinforcing structures can be optimized, so that the multiple reinforcing structures can comprehensively cover the length direction of the tab, and the multiple reinforcing structures can reliably strengthen the tab at multiple sites along the length direction of the tab. Thus, based on the distributed strengthening method, the strength and ductility of the tab can be enhanced. Therefore, during the processing of the electrode sheet, especially during the period when the current collector is compressed and extends along the length direction of the tab, the tab can be made to better resist the pulling force generated by the extension of the current collector on the tab, thereby reducing the risks of production problems and safety problems such as the tab wrinkling, warping, collapsing, folding into the film area and causing internal short circuit, flipping, etc.

[0013] In some embodiments, along the length direction of the tab, the distance between two adjacent reinforcing structures is d1, and 1 mm (millimeter) ≤ d1 ≤ 50 mm.

[0014] By adopting the above solution, the distance between two adjacent reinforcing structures can be optimized, and the distribution of the multiple reinforcing structures in the length direction of the tab can be optimized. Based on this, the strengthening effects of the multiple reinforcing structures on the strength and ductility of the tab can be balanced and optimized.

[0015] In some embodiments, the reinforcing structure includes reinforcing bumps.

[0016] By adopting the above solution, by making the reinforcing structure include dot-shaped reinforcing bumps, it is convenient to directly provide additional strength and ductility at the key stress points or potential deformation areas of the tab via the reinforcing bumps. Based on this, the tab can be locally strengthened efficiently, and it is convenient for the tab to accurately cope with the stress concentration problem in a specific area. Thus, during the processing of the electrode sheet, especially during the period when the current collector is compressed, the tab can be made to effectively resist the pulling force generated by the current collector on it, thereby reducing the risks of production problems and safety problems such as the tab wrinkling, warping, collapsing, folding into the film area and causing internal short circuit, flipping, etc.

[0017] In some embodiments, the strengthening structure includes a plurality of strengthening bumps arranged at intervals along the width direction of the tab.

[0018] By adopting the above solution, by making the strengthening structure include a plurality of strengthening bumps arranged at intervals along the width direction of the tab, it is convenient to distribute a plurality of local strengthening points in the width direction of the tab, so as to promote the uniform distribution of the strengthening effect, and enable the plurality of strengthening bumps to better cope with different stress conditions of the tab in the width direction, thereby effectively enhancing the strength and ductility of the tab, effectively enhancing the tensile strength of the tab, and effectively reducing the risks of wrinkling, warping, collapse, folding into the film area and causing internal short circuit, folding, etc. of the tab during the processing of the electrode sheet.

[0019] In some embodiments, the area of the strengthening bump is S, and 0.1 mm² ≤ S ≤ 250 mm².

[0020] By adopting the above solution, the area S of the strengthening bump can be set appropriately. Based on this, on the one hand, it can enable the strengthening bump to provide an appropriate strengthening effect, and enable the strengthening bump to accurately strengthen the key area of the tab, thereby improving the strength and ductility of the tab in the key area and improving the tensile strength of the tab. On the other hand, without sacrificing the performance of the tab, the material cost and processing cost of the strengthening bump can be reduced, and the weight increase and production cost of the tab can be reduced.

[0021] In some embodiments, the strengthening structure includes a strengthening rib, and the strengthening rib extends along the width direction of the tab.

[0022] By adopting the above solution, by making the strengthening structure include strip-shaped or linear strengthening ribs and making the strengthening rib extend along the width direction of the tab, it is convenient to linearly enhance the strength and ductility of the tab directly along the width direction via the strengthening rib. Based on this, the strength and ductility of the tab can be effectively enhanced, the tensile strength of the tab can be effectively enhanced, and the risks of wrinkling, warping, collapse, folding into the film area and causing internal short circuit, folding, etc. of the tab during the processing of the electrode sheet can be effectively reduced.

[0023] In some embodiments, at least one strengthening bump is provided on the strengthening rib.

[0024] By adopting the above - mentioned solution, on the basis of the previous embodiment, that is, on the basis of linearly enhancing the strength and ductility of the tab through the reinforcing rib along the width direction of the tab, by providing reinforcing bumps on the reinforcing rib, additional strength and ductility can be provided to the local area (i.e., the key stress point) of the reinforcing rib via the reinforcing bumps. Based on this, the reinforcing rib and the reinforcing bumps forming the local strengthening points can be combined to jointly enhance the strength and ductility of the tab, and jointly enhance the tensile and tearing resistance of the tab, thereby significantly reducing the risks of the tab wrinkling, warping, collapsing, folding into the film area and causing internal short - circuit, flipping, etc. during the processing of the electrode sheet.

[0025] In some embodiments, the area where the tab is welded to the current collector is the welding area, the area where the tab is provided with the strengthening structure is the strengthening area, the strengthening area and the welding area are arranged at intervals, and the tab forms a first spacer area between the strengthening area and the welding area.

[0026] By adopting the above - mentioned solution, it is convenient to separate the strengthening area and the welding area via the first spacer area to avoid the overlap between the strengthening area and the welding area. Based on this, during the processing of the electrode sheet, the risk of the welding area being secondarily compressed due to the processing and forming of the strengthening structure in the strengthening area can be reduced, the risk of the welding area cracking and generating metal particles due to secondary compression can be reduced, the risk of the metal particles generated by the cracking of the welding area entering the film area and causing internal short - circuit can be reduced, the risk of the metal particles detaching from the welding area resulting in a reduction in the current - carrying area, a deterioration in the current - carrying capacity, and an increase in the temperature rise of the welding area can be reduced, and the service performance and reliability of the battery cell can be improved.

[0027] In some embodiments, the dimension of the first spacer area along the width direction of the tab is d2, and 0.1mm ≤ d2 ≤ 50mm.

[0028] By adopting the above - mentioned solution, the dimension d2 of the first spacer area along the width direction of the tab can be set appropriately. Based on this, on the one hand, it can promote a certain distance between the strengthening area and the welding area, and reduce the risk of the welding area cracking during the processing and forming of the strengthening structure in the strengthening area. On the other hand, it can prevent the dimension d2 of the first spacer area along the width direction of the tab from being too large, promote a certain strength at the root of the tab close to the current collector, and reduce the risk of the root of the tab being bent.

[0029] In some embodiments, the current collector includes a support layer and a conductive layer provided on at least one surface of the support layer.

[0030] By adopting the above scheme, the current collector can be a composite current collector composed of a support layer and a conductive layer. Based on this, the current collector can have a thinner conductive layer and a support layer with a smaller density, thereby significantly improving the weight energy density of the battery cell compared with the traditional metal current collector. Moreover, since the current collector has a thinner conductive layer, in the case of abnormal conditions such as nail penetration, the generated metal burrs will be smaller; and since the current collector has a support layer with a smaller density, in the case of abnormal conditions such as nail penetration, the short-circuit resistance is larger than that of the traditional metal current collector; therefore, the nail penetration safety performance of the battery cell can be improved, and the reliability of the battery cell under abnormal conditions such as nail penetration can be improved.

[0031] In some embodiments, the area of the current collector where the active material layer is provided is the film area, the area where the current collector is welded to the tab is the welding area, and the current collector is provided with an extension area between the film area and the welding area.

[0032] By adopting the above scheme, it is convenient to separate the film area and the welding area via the extension area to avoid the overlap of the film area and the welding area. Based on this, during the processing of the electrode sheet, the risk of local multiple compressions in the welding area caused by the overlap of the welding area and the film area can be reduced, the risk of cracking in the welding area due to multiple compressions and generating metal particles can be reduced, the risk of internal short circuit caused by the metal particles generated by the cracking in the welding area entering the film area can be reduced, the risk of the metal particles in the welding area detaching and causing the reduction of the current-carrying area, the deterioration of the current-carrying capacity, and the increase of the temperature rise in the welding area can be reduced, and the service performance and reliability of the battery cell can be improved.

[0033] In some embodiments, an insulating layer is provided on the surface of the extension area.

[0034] By adopting the above scheme, by providing an insulating layer on the surface of the extension area, on the one hand, the mechanical strength and hardness of the extension area can be improved, the risk of bending and deformation of the extension area can be reduced, and the risk of damage to the conductive layer at the extension area affecting the welding quality of the welding area can be reduced, thereby being beneficial to improving the welding quality of the welding area and reducing the generation of metal particles. On the other hand, during the processing of the electrode sheet, especially in the case where the electrode sheet generates edge burrs and metal particles due to processes such as slitting and die-cutting, the extension area can be insulated and protected via the insulating layer, thereby reducing the risk of internal short circuit caused by edge burrs and metal particles in the extension area, and improving the service performance and reliability of the battery cell.

[0035] In some embodiments, a second spacer area is provided between the extension area and the welding area.

[0036] By adopting the above solution, on the basis of the previous embodiment, a second spacer is provided between the extension area and the welding area to separate the extension area and the welding area via the second spacer, thereby avoiding the overlap (i.e., partial coincidence) between the extension area and the welding area. Based on this, during the process of pole piece processing, especially during the welding process and the rolling process in the welding area, the risk of cracking of the insulating layer on the surface of the extension area due to stress is reduced, so that the functions of strengthening and insulating protection of the insulating layer on the extension area can be maintained.

[0037] In a second aspect, a battery is provided, and the battery includes the battery cell provided in the embodiment of the present application.

[0038] By adopting the above solution, the battery can optimize the production yield, performance and use reliability of the battery by applying the battery cell provided in the embodiment of the present application.

[0039] In a third aspect, an electrical device is provided, and the electrical device includes the battery provided in the embodiment of the present application, or the battery cell provided in the embodiment of the present application.

[0040] By adopting the above solution, the electrical device can optimize the production yield, performance and use reliability of the electrical device by applying the battery or the battery cell provided in the embodiment of the present application. Description of the Drawings

[0041] In order to clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0042] Figure 1 It is a schematic structural diagram of a vehicle provided in some embodiments of the present application;

[0043] Figure 2 It is an exploded schematic diagram of a battery provided in some embodiments of the present application;

[0044] Figure 3 It is an exploded schematic diagram of a battery cell provided in some embodiments of the present application;

[0045] Figure 4 It is a schematic structural diagram of an electrode assembly provided in some embodiments of the present application;

[0046] Figure 5 It is a schematic cross-sectional structure diagram of a pole piece provided in some embodiments of the present application, wherein an active material layer and a tab are provided on one side of the current collector of the pole piece;

[0047] Figure 6Schematic cross-sectional structure diagram of the electrode tab provided for some other embodiments of the present application. Among them, active material layers and electrode tabs are respectively arranged on opposite sides of the current collector of the electrode tab, and the electrode tabs on opposite sides of the current collector will overlap each other after the rolling process in the welding area;

[0048] Figure 7 Schematic top view structure diagram of the electrode tab provided for some embodiments of the present application. Among them, the strengthening structure includes strengthening bumps;

[0049] Figure 8 Schematic top view structure diagram of the electrode tab provided for some other embodiments of the present application. Among them, the strengthening structure includes strengthening bumps, the current collector is provided with an extension area and a second spacing area, and an insulating layer is provided on the surface of the current collector in the extension area;

[0050] Figure 9 Schematic top view structure diagram of the electrode tab provided for some other embodiments of the present application. Among them, the strengthening structure includes strengthening ribs;

[0051] Figure 10 Schematic top view structure diagram of the electrode tab provided for some other embodiments of the present application. Among them, the strengthening structure includes strengthening ribs, the current collector is provided with an extension area and a second spacing area, and an insulating layer is provided on the surface of the current collector in the extension area;

[0052] Figure 11 Schematic top view structure diagram of the electrode tab provided for some other embodiments of the present application. Among them, the strengthening structure includes strengthening ribs and strengthening bumps;

[0053] Figure 12 Schematic top view structure diagram of the electrode tab provided for some other embodiments of the present application. Among them, the strengthening structure includes strengthening ribs and strengthening bumps, the current collector is provided with an extension area and a second spacing area, and an insulating layer is provided on the surface of the current collector in the extension area;

[0054] Figure 13 Schematic cross-sectional structure diagram of the electrode tab provided for some other embodiments of the present application. Among them, an active material layer, an insulating layer and an electrode tab are arranged on one side of the current collector of the electrode tab;

[0055] Figure 14 Schematic cross-sectional structure diagram of the electrode tab provided for some other embodiments of the present application. Among them, active material layers, insulating layers and electrode tabs are respectively arranged on opposite sides of the current collector of the electrode tab, and the electrode tabs on opposite sides of the current collector will overlap each other after the rolling process in the welding area.

[0056] Among them, each reference numeral in the figure:

[0057] 1 - Battery, 2 - Controller, 3 - Motor; 100 - Battery unit, 200 - Box body, 201 - First part, 202 - Second part; 10 - Battery cell, 11 - Outer shell, 111 - Housing, 112 - End cover; 12 - Electrode assembly; 13 - Insulating part; 14 - Electrode terminal, 14a - Positive electrode terminal, 14b - Negative electrode terminal; 15 - Adapter, 15a - Positive electrode adapter, 15b - Negative electrode adapter; 16 - Pressure relief mechanism; 121 - Electrode tab, 121a - Positive electrode tab, 121b - Negative electrode tab, 122 - Separator, 123 - Electrode body; 1211 - Tab ear, 1211a - Positive tab ear, 1211b - Negative tab ear, 1212 - Current collector, 12121 - Support layer, 12122 - Conductive layer, 1213 - Active material layer, 1214 - Reinforcing structure, 12141 - Reinforcing bump, 12142 - Reinforcing rib, 1215 - Insulating layer, d1 - Spacing between two adjacent reinforcing structures along the length direction of the tab ear, d2 - Dimension of the first spacer along the width direction of the tab ear, A - Welding area, B - Reinforcing area, C - First spacer, D - Membrane area, E - Extension area, F - Second spacer, z - Thickness direction of the tab ear, x - Length direction of the tab ear, y - Width direction of the tab ear. Detailed implementation mode

[0058] In order to make the technical problems, technical solutions and beneficial effects to be solved by this application clear and understandable, the following describes this application in detail with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not used to limit this application.

[0059] In the description of this application, it should be understood that the orientation or positional relationship indicated by the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing this application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to this application.

[0060] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of these features. In the description of this application, "a plurality" means two or more unless otherwise specifically defined.

[0061] In this application, unless otherwise clearly defined and limited, terms such as "installation", "connection", "linkage", "fixation" shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral body; it may be a mechanical connection or an electrical connection; it may be a direct connection or an indirect connection through an intermediate medium, and it may be the communication inside two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0062] A battery cell is the smallest unit for storing and outputting electric energy. The battery cell includes an electrode assembly, which is the component in the battery cell where an electrochemical reaction occurs. The electrode assembly includes two polar plates with opposite polarities and a separator that separates the two polar plates.

[0063] In some cases, the polar plate includes a current collector, an active material layer disposed on at least one surface of the current collector, and a tab electrically connected to the current collector. The tab is welded to the current collector at the edge of the current collector. Among them, the area of the current collector where the active material layer is provided is the membrane area, and the area where the current collector is welded to the tab is the welding area. During the processing of the polar plate, a cold pressing process is performed on the membrane area, and a rolling process is performed on the welding area.

[0064] However, since the strength and elongation rate of the tab are different from those of the current collector, during the cold pressing process of the membrane area, the membrane area will extend along its length direction, while the tab does not extend. Similarly, during the rolling process of the welding area, the welding area will extend along its length direction, while the tab does not extend. Based on this, it will cause the tab to be pulled by the current collector and appear wrinkled, warped and other phenomena, resulting in production problems and safety problems such as the tab (especially the wide tab) being prone to collapse, folding to the membrane area and causing internal short circuit, folding, etc., resulting in a poor production yield of the polar plate.

[0065] Therefore, some embodiments of this application provide a battery cell, which strengthens the strength and ductility of the tab through a strengthening structure provided on the tab of the polar plate. Based on this, during the processing of the polar plate, especially during the period when the current collector is pressed (for example, during the cold pressing process of the membrane area, or during the rolling process of the welding area), although the tab will also be pulled by the current collector, because the strengthening structure strengthens the strength and ductility of the tab, the tab can resist the pulling force, thereby reducing the risk of the tab being wrinkled, warped and other phenomena due to the pulling of the current collector, reducing the risk of production problems and safety problems such as the tab collapsing, folding to the membrane area and causing internal short circuit, folding, etc., improving the production yield, production excellent rate and production efficiency of the polar plate, electrode assembly and battery cell, and improving the use reliability of the battery cell during its life cycle.

[0066] The battery cells disclosed in the embodiments of the present application may be lithium-ion secondary battery cells, lithium-sulfur battery cells, sodium-lithium-ion battery cells, sodium-ion battery cells, magnesium-ion battery cells, etc. The battery cells may be in the shape of a cylinder, a flat body, a cuboid, or other shapes, etc. The battery cells may adopt different packaging methods to form cylindrical battery cells, square battery cells, soft-pack battery cells, etc.

[0067] The battery cells disclosed in the embodiments of the present application can be used independently or in combination with other battery cells to form a modular battery that can provide higher voltage and capacity, such as a battery module, a battery pack, or a battery unit.

[0068] The battery cells and batteries disclosed in the embodiments of the present application can be used in electrical devices that use the battery cells and batteries as power sources, or in various energy storage systems that use the battery cells and batteries as energy storage elements. The electrical devices may be, but are not limited to, vehicles, mobile phones, portable devices, laptop computers, ships, spacecraft, electric toys, and power tools, etc. The vehicle may be a fuel vehicle, a gas vehicle, or a new energy vehicle. The new energy vehicle may be a pure electric vehicle, a hybrid vehicle, or an extended-range vehicle, etc. The spacecraft includes airplanes, rockets, space shuttles, and spaceships, etc. The electric toys include stationary or mobile electric toys, such as game consoles, electric vehicle toys, electric ship toys, and electric airplane toys, etc. The power tools include metal-cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact electric drills, concrete vibrators, and electric planers, etc.

[0069] To illustrate the technical solutions provided in the present application, the following will be described in detail with reference to specific drawings and embodiments, taking "the electrical device is a vehicle" as an example.

[0070] Please refer to Figure 1 , Figure 1 which is a schematic structural diagram of a vehicle provided in some embodiments of the present application. The vehicle may be a fuel vehicle, a gas vehicle, or a new energy vehicle. The new energy vehicle may be a pure electric vehicle, a hybrid vehicle, or an extended-range vehicle, etc. A battery 1 is provided inside the vehicle. The battery 1 may be provided at the bottom, the head, or the tail of the vehicle. The battery 1 is used to supply power to the vehicle. For example, the battery 1 may be used as the operating power source of the vehicle. The vehicle may further include a controller 2 and a motor 3. The controller 2 is used to control the battery 1 to supply power to the motor 3, for example, to meet the working power requirements during the start, navigation, and driving of the vehicle.

[0071] In some embodiments of the present application, the battery 1 can not only be used as the operating power source of the vehicle, but also be used as the driving power source of the vehicle, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle.

[0072] Please refer toFigure 2 , Figure 2 Exploded schematic view of battery 1 provided for some embodiments of the present application. Battery 1 includes battery cell 100 and housing 200, and battery cell 100 is accommodated in housing 200. Among them, housing 200 is used to provide an accommodation space for battery cell 100, and housing 200 can adopt various structures. In some embodiments, housing 200 may include a first part 201 and a second part 202. The first part 201 and the second part 202 cover each other, and the first part 201 and the second part 202 jointly define an accommodation space for accommodating battery cell 100. The second part 202 may be a hollow structure with one end open, and the first part 201 may be a plate-like structure. The first part 201 covers the open side of the second part 202 so that the first part 201 and the second part 202 jointly define an accommodation space; the first part 201 and the second part 202 may also both be hollow structures with one side open, and the open side of the first part 201 covers the open side of the second part 202. Of course, the housing 200 formed by the first part 201 and the second part 202 can be of various shapes, such as a cylinder, a cuboid, etc.

[0073] In battery 1, there may be at least two battery cells 100, and at least two battery cells 100 may be connected in series, in parallel, or in a mixed connection. A mixed connection means that there are both series and parallel connections among at least two battery cells 100.

[0074] Specifically, battery cell 100 may be a battery cell 10 (as shown in Figure 3 ). At least two battery cells 10 may be directly connected in series, in parallel, or in a mixed connection together, and then the whole formed by at least two battery cells 10 is accommodated in housing 200. Among them, battery cell 10 may be a lithium-ion secondary battery cell, a lithium-sulfur battery cell, a sodium-lithium-ion battery cell, a sodium-ion battery cell, a magnesium-ion battery cell, etc. Battery cell 10 may be in the shape of a cylinder, a flat body, a cuboid, or other shapes, etc. Battery cell 10 may adopt different packaging methods to form a cylindrical battery cell, a square battery cell, a soft-pack battery cell, etc.

[0075] Alternatively, battery cell 100 may be a battery module or a battery pack. At least two battery cells 10 may first be connected in series, in parallel, or in a mixed connection to form a modular structure, that is, a battery module or a battery pack; at least two battery modules or battery packs are then connected in series, in parallel, or in a mixed connection to form a whole and are accommodated in housing 200.

[0076] Of course, battery 1 may further include other structures. For example, battery 1 may further include a busbar component (not shown in the figure) for realizing the electrical connection between at least two battery cells 100.

[0077] Of course, in some embodiments, the battery 1 may not include the box body 200, but at least two battery cells 10 are electrically connected and formed into a whole through necessary fixing structures and then assembled into an electrical device.

[0078] See also Figure 3 , Figure 4 , Figure 3 This is a schematic diagram of an exploded view of a battery cell 10 provided in some embodiments of the present application. Figure 4 A schematic diagram of the structure of an electrode assembly 12 provided in some embodiments of the present application. A battery cell 10 is the smallest unit for storing and outputting electrical energy. The battery cell 10 includes a housing 11, an electrode assembly 12, an insulating member 13, an electrode terminal 14, a switching member 15, a pressure relief mechanism 16, an electrolyte (not shown in the figure), and other components.

[0079] The outer shell 11 is a component that isolates the internal environment of the battery cell 10 from the external environment. The outer shell 11 may include a shell 111 and an end cover 112. The end cover 112 is a component that covers the opening of the shell 111 to isolate the internal environment of the battery cell 10 from the external environment. In some embodiments, the shape of the end cover 112 can be adapted to the shape of the shell 111 to match the shell 111. In some embodiments, the end cover 112 can be made of a material with a certain hardness and strength, so that the end cover 112 is not easily deformed when squeezed and collided, so that the battery cell 10 can have a higher structural strength and the safety performance can also be improved. Among them, the material of the end cover 112 can be diversified, and the end cover 112 can be made of copper, iron, aluminum, stainless steel, aluminum alloy, plastic and other materials.

[0080] The shell 111 is a component used to cooperate with the end cap 112 to form the internal environment of the battery cell 10. The internal environment formed by the shell 111 and the end cap 112 can be used to accommodate the electrode assembly 12, the insulating member 13, the electrolyte and other components. In some embodiments, the shell 111 and the end cap 112 can be independent components, and an opening can be set on the shell 111, and the end cap 112 is made to cover the opening at the opening to form the internal environment of the battery cell 10. In some embodiments, the end cap 112 and the shell 111 can also be integrated. Specifically, the end cap 112 and the shell 111 can form a common connection surface before other components are put into the shell. When it is necessary to encapsulate the interior of the shell 111, the end cap 112 is made to cover the shell 111. Among them, the shell 111 can be of various shapes and sizes, such as a cuboid, a cylinder, a hexagonal prism, etc. The shape of the shell 111 can be determined according to the shape and size of the electrode assembly 12. The material of the housing 111 can be varied, and the housing 111 can be made of copper, iron, aluminum, stainless steel, aluminum alloy, plastic, and other materials.

[0081] The electrode assembly 12 is a component in the battery cell 10 where electrochemical reactions occur. The housing 11 may include one or at least two electrode assemblies 12. The electrode assembly 12 includes two polar plates 121 with opposite polarities and a separator 122. The two polar plates 121 with opposite polarities are respectively the positive electrode plate 121a and the negative electrode plate 121b, and the separator 122 separates the positive electrode plate 121a and the negative electrode plate 121b. The positive electrode plate 121a, the separator 122, and the negative electrode plate 121b can be processed into the electrode assembly 12 by winding, laminating, or other methods. In the electrode assembly 12, the parts of the positive electrode plate 121a and the negative electrode plate 121b with active materials constitute the electrode body 123 of the electrode assembly 12, and the parts of the positive electrode plate 121a and the negative electrode plate 121b without active materials respectively constitute the electrode tabs 1211. The electrode tabs 1211 are the current transmission ends of the electrode assembly 12 and are used to transmit current. The electrode tab 1211 of the positive electrode plate 121a is the positive electrode tab 1211a, and the electrode tab 1211 of the negative electrode plate 121b is the negative electrode tab 1211b. The positive electrode tab 1211a and the negative electrode tab 1211b can be located at one end of the electrode body 123 together or at both ends of the electrode body 123 respectively.

[0082] The electrolyte is a liquid that infiltrates the electrode assembly 12. The battery cell 10 mainly operates by the movement of active ions between the positive electrode plate 121a and the negative electrode plate 121b. When the battery cell 10 is charged, active ions are generated on the positive electrode plate 121a. The active ions provided by the positive electrode plate 121a can penetrate the pores of the separator 122, move through the electrolyte to the negative electrode plate 121b, and be embedded in the negative active material of the negative electrode plate 121b. Conversely, when the battery cell 10 is discharged, the active ions embedded in the negative active material of the negative electrode plate 121b escape. The active ions escaping from the negative electrode plate 121b can penetrate the pores of the separator 122, move through the electrolyte to the positive electrode plate 121a, and be embedded in the positive active material of the positive electrode plate 121a. Among them, the active ions can be lithium ions, sodium ions, and so on.

[0083] The electrode terminals 14 are components that are electrically connected to the electrode assembly 12 and are used to output or input electrical energy. The electrode terminals 14 include a positive electrode terminal 14a and a negative electrode terminal 14b. The positive electrode terminal 14a is electrically connected to the positive electrode tab 1211a of the electrode assembly 12. The negative electrode terminal 14b is electrically connected to the negative electrode tab 1211b of the electrode assembly 12. The electrode terminals 14 can be installed on the housing 11 and have a stable installation position and installation state relative to the housing 11. In some embodiments, the electrode terminals 14 can be installed on the housing 11 by flanging and riveting.

[0084] The adapter 15 is a current collecting member electrically connected between the tab 1211 of the electrode assembly 12 and the corresponding electrode terminal 14. The adapter 15 can also be referred to as an adapter connection member, a current collecting plate, a transfer sheet, etc. The adapter 15 has electrical conductivity and is made of a conductive material. The material of the adapter 15 can include aluminum, aluminum alloy, copper, copper alloy, copper-aluminum alloy, etc. The adapter 15 includes a positive adapter 15a and a negative adapter 15b. The positive tab 1211a of the electrode assembly 12 can be electrically connected to the positive electrode terminal 14a through the positive adapter 15a, and the negative tab 1211b of the electrode assembly 12 can be electrically connected to the negative electrode terminal 14b through the negative adapter 15b to form a current loop. In some embodiments, the adapter 15 can be connected to the tab 1211 of the electrode assembly 12 by means of welding, abutting, etc. The adapter 15 can be connected to the electrode terminal 14 by means of welding, abutting, etc. Among them, the shape of the adapter 15 can be diversified, such as square, circular, irregular, etc.

[0085] The insulating member 13 is a component with insulating properties. The insulating member 13 is disposed inside the housing 11, especially between the electrode assembly 12 and the wall portion (such as the end cap 112) of the housing 11 having the electrode terminal 14. On the basis that the tab 1211 of the electrode assembly 12 and the corresponding electrode terminal 14 can achieve electrical connection, the insulating member 13 can be used to insulate and isolate the electrode assembly 12 and the wall portion of the housing 11 having the electrode terminal 14 to reduce the risk of short circuit, current leakage and other phenomena. In addition, the insulating member 13 can also be fixed to the wall portion of the housing 11 having the electrode terminal 14 and abut against the electrode assembly 12 to fill the gap between the electrode assembly 12 and this wall portion of the housing 11, and tightly fix the electrode assembly 12, so as to prevent the electrode assembly 12 from moving or shaking relative to each other during the use of the battery cell 10, which is beneficial to maintaining the structural integrity of the battery cell 10 and reducing the risk of loosening or deformation of the electrode assembly 12.

[0086] In some embodiments, a pressure relief mechanism 16 can also be provided on the housing 11. The pressure relief mechanism 16 can be used to release the internal pressure when the internal pressure (or temperature) of the battery cell 10 reaches a threshold value. Among them, the pressure relief mechanism 16 can be disposed on the end cap 112 or on any wall portion of the housing 111.

[0087] Please refer to Figure 3 、 Figure 4 , some embodiments of the present application provide a battery cell 10. The battery cell 10 includes an electrode assembly 12, and the electrode assembly 12 includes a separator 122 and two polar plates 121 with opposite polarities. Please refer to Figure 5 、 Figure 6, the electrode tab 121 includes a current collector 1212, an active material layer 1213, and an electrode ear 1211. The active material layer 1213 is disposed on at least one surface of the current collector 1212, and the electrode ear 1211 is welded to the edge of the current collector 1212. Please refer to Figure 7 , Figure 8 , a strengthening structure 1214 is provided on the electrode ear 1211.

[0088] It should be noted that the electrode assembly 12 is a component in the battery cell 10 where an electrochemical reaction occurs. The battery cell 10 may be provided with one or at least two electrode assemblies 12. The electrode assembly 12 may be accommodated in the housing 11 of the battery cell 10.

[0089] The electrode assembly 12 includes two electrode tabs 121 with opposite polarities (i.e., a positive electrode tab 121a and a negative electrode tab 121b) and a separator 122. The separator 122 separates the positive electrode tab 121a and the negative electrode tab 121b. The positive electrode tab 121a, the separator 122, and the negative electrode tab 121b can be processed into the electrode assembly 12 by winding, laminating, or other methods. That is, the electrode assembly 12 can be a wound electrode assembly 12, a laminated electrode assembly 12, or an electrode assembly 12 in other forms.

[0090] In addition, other relevant descriptions of the electrode assembly 12 can be referred to in the previous text and will not be repeated here.

[0091] It should also be noted that the electrode tab 121 includes a current collector 1212, an active material layer 1213, and an electrode ear 1211.

[0092] The current collector 1212 is a structure for collecting current. In the case where the electrode tab 121 is a positive electrode tab 121a, the current collector 1212 is a positive current collector, and the material of the positive current collector can be aluminum, etc. In the case where the electrode tab 121 is a negative electrode tab 121b, the current collector 1212 is a negative current collector, and the material of the negative current collector can be copper, etc.

[0093] The active material layer 1213 is a layered structure made of active material. The active material layer 1213 can be disposed on one surface of the current collector 1212 along its thickness direction (as Figure 5 shown), or can be disposed on opposite two surfaces of the current collector 1212 along its thickness direction (as Figure 6As shown). The active material layer 1213 can be formed on the surface of the current collector 1212 by, but not limited to, coating. When the electrode sheet 121 is the positive electrode sheet 121a, the active material layer 1213 is the positive electrode active material layer, and the positive electrode active material of the positive electrode active layer can be lithium cobaltate, lithium iron phosphate, ternary lithium, lithium manganate, and so on. When the electrode sheet 121 is the negative electrode sheet 121b, the active material layer 1213 is the negative electrode active material layer, and the negative electrode active material of the negative electrode active layer can be graphite, carbon, silicon, and so on.

[0094] The tab 1211 is the current transmission end of the electrode assembly 12 for transmitting current. The tab 1211 is welded to the current collector 1212 at the edge of the current collector 1212 so that the tab 1211 is electrically connected to the current collector 1212. As Figure 5 shown, in some embodiments, the tab 1211 can be disposed on one side of the current collector 1212 along its thickness direction. As Figure 6 shown, in some other embodiments, the tab 1211 can also be disposed on opposite sides of the current collector 1212 along its thickness direction. In this case, the tabs 1211 on opposite sides of the current collector 1212 will overlap each other during the rolling process in the welding area A. The welding area A is the area where the current collector 1212 and the tab 1211 are welded together.

[0095] When the electrode sheet 121 is the positive electrode sheet 121a, the tab 1211 is the positive electrode tab 1211a. When the electrode sheet 121 is the negative electrode sheet 121b, the tab 1211 is the negative electrode tab 1211b. The welding method can be, but not limited to, roll welding and so on.

[0096] It should also be noted that a strengthening structure 1214 is provided on the tab 1211. The strengthening structure 1214 can be formed based on the tab 1211 itself (i.e., formed without adding materials), or can be formed on the tab 1211 by adding materials. The strengthening structure 1214 is used to strengthen the strength and ductility of the tab 1211.

[0097] In summary, for the battery cell 10 provided by the embodiment of the present application, a strengthening structure 1214 is arranged on the tab 1211 of the electrode tab 121 to strengthen the strength and ductility of the tab 1211 via the strengthening structure 1214. Based on this, during the processing of the electrode tab 121, especially during the period when the current collector 1212 is pressed (for example, during the cold pressing process in the membrane area D (i.e., the area where the active material layer 1213 is provided on the current collector 1212), or for another example, during the rolling process in the welding area A), although the tab 1211 is also pulled by the current collector 1212, because the strengthening structure 1214 strengthens the strength and ductility of the tab 1211, the tab 1211 can resist the pulling force, thereby reducing the risk of wrinkles, warping and other phenomena of the tab 1211 caused by the pulling of the current collector 1212, reducing the risk of production problems and safety problems such as collapse, folding to the membrane area D and causing internal short circuit, folding back, etc. of the tab 1211, improving the production yield, production excellence rate and production efficiency of the electrode tab 121, the electrode assembly 12 and the battery cell 10, and improving the use reliability of the battery cell 10 during its life cycle.

[0098] Please refer to Figure 7 、 Figure 8 , in some embodiments of the present application, the strengthening structure 1214 is formed by protruding from the tab 1211 toward one side in the thickness direction z of itself.

[0099] It should be noted that a part of the tab 1211 can protrude toward one side in the thickness direction z of the tab 1211 to form the strengthening structure 1214. For example, a part of the tab 1211 can be pressed into the strengthening structure 1214 by means of rolling, stamping or the like.

[0100] By adopting the above solution, on the basis of not increasing the material amount of the tab 1211, a part of the tab 1211 can be conveniently, quickly and reliably pressed into the strengthening structure 1214. Based on this, the processing convenience and processing efficiency of forming the strengthening structure 1214 on the tab 1211 can be improved, the strengthening effect of the protruding strengthening structure 1214 on the strength and ductility of the tab 1211 can be improved, the material amount of the tab 1211 can be reduced, and the cost can be lowered.

[0101] Of course, in other embodiments, the strengthening structure 1214 can be formed on the tab 1211 by adding materials.

[0102] Please refer to Figure 6 、 Figure 7 、 Figure 8 , in some embodiments of the present application, a plurality of strengthening structures 1214 are provided, and the plurality of strengthening structures 1214 are arranged at intervals along the length direction x of the tab 1211.

[0103] It should be noted that the number of the reinforcing structures 1214 provided on the tab 1211 is at least two. On the tab 1211, multiple reinforcing structures 1214 may be evenly spaced along the length direction x of the tab 1211, or may be unevenly spaced.

[0104] By adopting the above solution, by arranging multiple reinforcing structures 1214 spaced along the length direction x of the tab 1211 on the tab 1211, the layout of the reinforcing structures 1214 can be optimized, so that multiple reinforcing structures 1214 can more comprehensively cover the length direction x of the tab 1211, and multiple reinforcing structures 1214 can reliably strengthen the tab 1211 at multiple sites along the length direction x of the tab 1211. Thus, based on the distributed strengthening method, the strength and ductility of the tab 1211 can be strengthened and improved. Therefore, during the processing of the electrode tab 121, especially during the period when the current collector 1212 is compressed and extends along the length direction x of the tab 1211, the tab 1211 can be made to better resist the pulling force generated by the extension of the current collector 1212 on the tab 1211, thereby reducing the risks of production problems and safety problems such as wrinkling, warping, collapse, folding to the membrane area D and causing internal short circuit, and folding of the tab 1211.

[0105] Of course, in other embodiments, one reinforcing structure 1214 may be provided. In other embodiments, multiple reinforcing structures 1214 may be provided, but multiple reinforcing structures 1214 may be spaced along other directions (for example, the width direction y of the tab 1211, or any direction that is inclined to both the length direction x and the width direction y of the tab 1211).

[0106] Please refer to Figure 7 、 Figure 8 , in some embodiments of the present application, along the length direction x of the tab 1211, the distance between two adjacent reinforcing structures 1214 is d1, and 1 mm ≤ d1 ≤ 50 mm.

[0107] It should be noted that the distance d1 between two adjacent reinforcing structures 1214 along the length direction x of the tab 1211 is greater than or equal to 1 mm and less than or equal to 50 mm. For example, d1 may be, but is not limited to, 1 mm, 5 mm, 10 mm, 15 mm, 20 mm, 25 mm, 30 mm, 35 mm, 40 mm, 45 mm, 50 mm, and so on.

[0108] By adopting the above solution, the distance between two adjacent reinforcing structures 1214 can be optimized, and the distribution of multiple reinforcing structures 1214 in the length direction x of the tab 1211 can be optimized. Based on this, the strengthening effects of multiple reinforcing structures 1214 on the strength and ductility of the tab 1211 can be balanced and optimized.

[0109] Please refer to Figure 6 and Figure 7 and Figure 8 , in some embodiments of the present application, the strengthening structure 1214 includes strengthening bumps 12141.

[0110] It should be noted that the strengthening bumps 12141 are dot-shaped, and the shape of the strengthening bumps 12141 can be, but is not limited to, circular, rectangular, etc.

[0111] By adopting the above solution, by making the strengthening structure 1214 include dot-shaped strengthening bumps 12141, it is convenient to directly provide additional strength and ductility at the key stress points or potential deformation areas of the tab 1211 via the strengthening bumps 12141. Based on this, local strengthening of the tab 1211 can be efficiently carried out, and it is convenient for the tab 1211 to accurately cope with the stress concentration problem in a specific area. Thus, during the processing of the electrode tab 121, especially during the period when the current collector 1212 is pressed, it can be promoted that the tab 1211 can effectively resist the pulling force generated by the current collector 1212 on it, thereby reducing the risk of production problems and safety problems such as wrinkling, warping, collapse, folding to the film area D and causing internal short circuit, folding, etc. of the tab 1211.

[0112] Please refer to Figure 6 and Figure 7 and Figure 8 , in some embodiments of the present application, the strengthening structure 1214 includes a plurality of strengthening bumps 12141 arranged at intervals along the width direction y of the tab 1211.

[0113] It should be noted that the strengthening structure 1214 includes a plurality of strengthening bumps 12141. In the strengthening structure 1214, the plurality of strengthening bumps 12141 can be arranged at equal intervals or unequal intervals along the width direction y of the tab 1211. Among them, the width direction y of the tab 1211 is perpendicular to the length direction x of the tab 1211.

[0114] By adopting the above solution, by making the strengthening structure 1214 include a plurality of strengthening bumps 12141 arranged at intervals along the width direction y of the tab 1211, it is convenient to distribute a plurality of local strengthening points in the width direction y of the tab 1211 to promote the uniform distribution of the strengthening effect, so that the plurality of strengthening bumps 12141 can better cope with different stress conditions of the tab 1211 in the width direction y, thereby effectively enhancing the strength and ductility of the tab 1211, effectively enhancing the tensile strength of the tab 1211, and effectively reducing the risk of phenomena such as wrinkling, warping, collapse, folding to the film area D and causing internal short circuit, folding, etc. of the tab 1211 during the processing of the electrode tab 121.

[0115] This embodiment is particularly suitable for being combined with the embodiment in which "a plurality of reinforcing structures 1214 are provided, and the plurality of reinforcing structures 1214 are arranged at intervals along the length direction x of the tab 1211". With such an arrangement, it is convenient to comprehensively utilize each reinforcing bump 12141 to provide a balanced and reliable strengthening effect on each region of the tab 1211 along the length direction x of the tab 1211 and the width direction y perpendicular to the length direction x, and it can promote the tab 1211 to better resist the pulling force generated by the current collector 1212 on the tab 1211 along the length direction x of the tab 1211.

[0116] Of course, in other embodiments, in the reinforcing structure 1214, the plurality of reinforcing bumps 12141 may be arranged at intervals along a direction inclined to the width direction y of the tab 1211.

[0117] Please refer to Figure 7 、 Figure 8 In some embodiments of the present application, the area of the reinforcing bump 12141 is S, and 0.1 mm2 ≤ S ≤ 250 mm2.

[0118] It should be noted that the shape of the reinforcing bump 12141 may be, but is not limited to, circular, rectangular, etc. The area S of the reinforcing bump 12141 is greater than or equal to 0.1 mm2 and less than or equal to 250 mm2. For example, the area S of the reinforcing bump 12141 may be, but is not limited to, 0.1 mm2, 1 mm2, 10 mm2, 20 mm2, 30 mm2, 40 mm2, 50 mm2, 60 mm2, 70 mm2, 80 mm2, 90 mm2, 100 mm2, 110 mm2, 120 mm2, 130 mm2, 140 mm2, 150 mm2, 160 mm2, 170 mm2, 180 mm2, 190 mm2, 200 mm2, 210 mm2, 220 mm2, 230 mm2, 240 mm2, 250 mm2, and so on.

[0119] By adopting the above scheme, the area S of the reinforcing bump 12141 can be set appropriately. Based on this, on the one hand, it can promote the reinforcing bump 12141 to provide an appropriate strengthening effect, and can promote the reinforcing bump 12141 to accurately strengthen the key area of the tab 1211, thereby improving the strength and ductility of the tab 1211 in the key area and improving the tensile resistance ability of the tab 1211. On the other hand, without sacrificing the performance of the tab 1211, the material cost and processing cost of the reinforcing bump 12141 can be reduced, and the weight increase and production cost of the tab 1211 can be reduced.

[0120] Please refer to Figure 6 、 Figure 9 、 Figure 10, in some embodiments of the present application, the reinforcing structure 1214 includes reinforcing ribs 12142, and the reinforcing ribs 12142 extend along the width direction y of the tab 1211.

[0121] It should be noted that the reinforcing ribs 12142 are strip-shaped or linear, and the reinforcing ribs 12142 extend along the width direction y of the tab 1211. The cross-sectional shape of the reinforcing ribs 12142 perpendicular to the width direction y of the tab 1211 can be, but is not limited to, a rectangle, a trapezoid, etc.

[0122] By adopting the above solution, by making the reinforcing structure 1214 include strip-shaped or linear reinforcing ribs 12142 and making the reinforcing ribs 12142 extend along the width direction y of the tab 1211, it is convenient to linearly enhance the strength and ductility of the tab 1211 directly along the width direction y of the tab 1211 via the reinforcing ribs 12142. Based on this, the strength and ductility of the tab 1211 can be effectively enhanced, the tensile strength of the tab 1211 can be effectively enhanced, and the risks of wrinkling, warping, collapse, folding to the film area D and causing internal short circuit, folding, etc. of the tab 1211 during the processing of the electrode tab 121 can be effectively reduced.

[0123] This embodiment is particularly suitable for being combined with the embodiment in which "a plurality of reinforcing structures 1214 are provided, and the plurality of reinforcing structures 1214 are arranged at intervals along the length direction x of the tab 1211". With this arrangement, it is convenient to comprehensively utilize each reinforcing rib 12142 to provide a balanced and reliable strengthening effect on each area of the tab 1211 along the length direction x of the tab 1211 and the width direction y perpendicular to the length direction x, and can prompt the tab 1211 to better resist the pulling force generated by the current collector 1212 on the tab 1211 along the length direction x of the tab 1211.

[0124] Of course, in other embodiments, in the reinforcing structure 1214, the reinforcing ribs 12142 may extend in a direction inclined to the width direction y of the tab 1211.

[0125] Please refer to Figure 6 、 Figure 11 、 Figure 12 , in some embodiments of the present application, at least one reinforcing bump 12141 is provided on the reinforcing rib 12142.

[0126] It should be noted that, on the basis of the previous embodiment, at least one reinforcing bump 12141 may be provided on the reinforcing rib 12142. In the case where a plurality of reinforcing bumps 12141 are provided on the reinforcing rib 12142, the plurality of reinforcing bumps 12141 may be arranged at intervals along the extending direction of the reinforcing rib 12142, that is, the plurality of reinforcing bumps 12141 may be arranged at intervals along the width direction y of the tab 1211 on the reinforcing rib 12142.

[0127] Among them, the reinforcing bumps 12141 are in a dot shape, and the shape of the reinforcing bumps 12141 can be, but is not limited to, circular, rectangular, etc.

[0128] Among them, the area of the reinforcing bumps 12141 can be set as required. In some embodiments, the area S of the reinforcing bumps 12141 is greater than or equal to 0.1 mm2 and less than or equal to 250 mm2.

[0129] By adopting the above solution, on the basis of the previous embodiment, that is, on the basis of linearly enhancing the strength and ductility of the tab 1211 along the width direction y of the tab 1211 through the reinforcing rib 12142, by providing the reinforcing bumps 12141 on the reinforcing rib 12142, additional strength and ductility can be provided to the local area (i.e., the key stress point) of the reinforcing rib 12142 through the reinforcing bumps 12141. Based on this, the reinforcing rib 12142 and the reinforcing bumps 12141 forming local strengthening points can jointly enhance the strength and ductility of the tab 1211, jointly enhance the tensile resistance ability of the tab 1211, so as to greatly reduce the risks of wrinkling, warping, collapse, folding to the film area D and causing internal short circuit, folding, etc. of the tab 1211 during the processing of the electrode tab 121.

[0130] Of course, in other embodiments, the reinforcing bumps 12141 may not be provided on the reinforcing rib 12142.

[0131] Please refer to Figure 6 , Figure 11 , Figure 12 , in some embodiments of the present application, the area where the tab 1211 is welded to the current collector 1212 is the welding area A, the area where the tab 1211 is provided with the reinforcing structure 1214 is the reinforcing area B, the reinforcing area B and the welding area A are arranged at intervals, and the tab 1211 forms a first interval area C between the reinforcing area B and the welding area A.

[0132] It should be noted that the welding area A is the area where the current collector 1212 and the tab 1211 are welded to each other, and the welding area A can be die-cut into a required shape (for example, Figure 11 the shape of the welding area A shown is different from Figure 12 the shape of the welding area A shown). The reinforcing area B is the area where the tab 1211 is provided with the reinforcing structure 1214. The first interval area C is the area of the tab 1211 provided between the reinforcing area B and the welding area A, that is, the reinforcing area B and the welding area A are arranged at intervals through the first interval area C, that is, the first interval area C separates the reinforcing area B and the welding area A. The first interval area C is neither provided with the reinforcing structure 1214 nor participates in the welding.

[0133] During the processing of the electrode tab 121, usually, the welding operation between the current collector 1212 and the tab 1211 is first performed, and then the operation of processing and forming the reinforcing structure 1214 in the reinforcing area B of the tab 1211 is carried out. Therefore, by adopting the above solution, it is convenient to separate the reinforcing area B and the welding area A via the first spacer C to avoid the overlap (i.e., partial coincidence) between the reinforcing area B and the welding area A. Based on this, during the processing of the electrode tab 121, the risk of the welding area A being secondarily compressed due to the processing and forming of the reinforcing structure 1214 in the reinforcing area B can be reduced, the risk of the welding area A cracking and generating metal particles due to secondary compression can be reduced, the risk of the metal particles generated by the cracking of the welding area A entering the membrane area D (i.e., the area where the current collector 1212 is provided with the active material layer 1213) and causing an internal short circuit can be reduced, the risk of the metal particles breaking away from the welding area A and resulting in a reduction in the current-carrying area, a deterioration in the current-carrying capacity, and an increase in the temperature rise of the welding area A can be reduced, and the service performance and service reliability of the battery cell 10 (such as Figure 3 as shown) can be improved.

[0134] Please refer to Figure 11 and Figure 12 . In some embodiments of the present application, the dimension of the first spacer C in the width direction y of the tab 1211 is d2, and 0.1 mm ≤ d2 ≤ 50 mm.

[0135] It should be noted that along the width direction y of the tab 1211, the reinforcing area B and the welding area A are spaced apart by the first spacer C. In this case, the dimension d2 of the first spacer C in the width direction y of the tab 1211 is greater than or equal to 0.1 mm and less than or equal to 50 mm. For example, d2 can be, but is not limited to, 0.1 mm, 0.5 mm, 1 mm, 5 mm, 10 mm, 15 mm, 20 mm, 25 mm, 30 mm, 35 mm, 40 mm, 45 mm, 50 mm, etc.

[0136] By adopting the above solution, the dimension d2 of the first spacer C in the width direction y of the tab 1211 can be set appropriately. Based on this, on the one hand, it can promote a certain distance between the reinforcing area B and the welding area A, and reduce the risk of cracking of the welding area A during the processing and forming of the reinforcing structure 1214 in the reinforcing area B. On the other hand, it can prevent the dimension d2 of the first spacer C in the width direction y of the tab 1211 from being too large, promote a certain strength of the root of the tab 1211 close to the current collector 1212, and reduce the risk of bending of the root of the tab 1211.

[0137] Please refer to Figure 5 and Figure 6 and Figure 13 and Figure 14, in some embodiments of the present application, the current collector 1212 includes a support layer 12121 and a conductive layer 12122 provided on at least one surface of the support layer 12121.

[0138] It should be noted that in this embodiment, the current collector 1212 is a composite current collector, that is, it is composed of at least two materials compounded. Structurally, the current collector 1212 includes a support layer 12121 and a conductive layer 12122. As Figure 5 , Figure 13 shown, in some embodiments, the conductive layer 12122 can be provided on one surface of the support layer 12121 along its own thickness direction. As Figure 6 , Figure 14 shown, in some other embodiments, the conductive layer 12122 can be provided on opposite two surfaces of the support layer 12121 along its own thickness direction.

[0139] Among them, the support layer 12121 is a layered structure in the current collector 1212 that plays a supporting role and a protecting role for the conductive layer 12122. The support layer 12121 can adopt an organic polymer material or a polymer composite material, so that the density of the support layer 12121 is less than the density of the conductive layer 12122, thereby significantly improving the weight energy density of the battery cell 10 (such as Figure 3 shown).

[0140] Among them, the conductive layer 12122 is a layered structure in the current collector 1212 that plays a conductive role and a current collecting role. The material of the conductive layer 12122 can be but is not limited to metal conductive materials (such as aluminum, copper, nickel, titanium, silver, nickel-copper alloy, aluminum-zirconium alloy), carbon-based conductive materials (such as graphite, acetylene black, graphene, carbon nanotubes), etc. The conductive layer 12122 can be formed on the support layer 12121 by but is not limited to mechanical rolling, bonding, chemical vapor deposition, electroless plating, electroplating and other methods.

[0141] The thickness of the conductive layer 12122 can be much smaller than the thickness of conventional metal current collectors such as aluminum foil or copper foil (the thickness of the commonly used aluminum foil metal current collector is usually 12 μm (micrometers), the thickness of the commonly used copper foil metal current collector is usually 8 μm, and the thickness of the conductive layer 12122 can be made 30 nm (nanometers) to 2 μm), thereby significantly improving the mass energy density and volume energy density of the battery cell 10 compared with conventional metal current collectors.

[0142] By adopting the above solution, the current collector 1212 can be a composite current collector formed by a support layer 12121 and a conductive layer 12122. Based on this, the current collector 1212 can have a thinner conductive layer 12122 and a support layer 12121 with a smaller density, so that the weight energy density of the battery cell 10 can be significantly improved compared with the traditional metal current collector. Moreover, since the current collector 1212 has a thinner conductive layer 12122, the metal burrs generated in abnormal situations such as nail penetration will be smaller; and since the current collector 1212 has a support layer 12121 with a smaller density, the short-circuit resistance is larger than that of the traditional metal current collector in abnormal situations such as nail penetration; therefore, the nail penetration safety performance of the battery cell 10 can be improved, and the reliability of the battery cell 10 in abnormal situations such as nail penetration can be improved.

[0143] Moreover, since the composite current collector and the tab 1211 are separately formed and then welded, the strength and elongation rate of the composite current collector will be significantly different from those of the tab 1211. The electrode sheet 121 using the composite current collector is more likely to have the technical problems proposed in this application. Therefore, some of the above embodiments of this application are more applicable to the electrode sheet 121 and the battery cell 10 that "adopt a composite current collector".

[0144] In particular, since the thickness of the conductive layer 12122 is relatively thin, the strength and toughness of the welding area A are relatively weak, and the welding area A of the composite current collector is more likely to crack under the condition of secondary compression. Therefore, the above embodiments related to the "first spacer C" are more applicable to the electrode sheet 121 and the battery cell 10 that "adopt a composite current collector".

[0145] Of course, in other embodiments, the current collector 1212 can be a metal current collector.

[0146] Please refer to Figure 3 、 Figure 13 、 Figure 14 , in some embodiments of this application, the area of the current collector 1212 where the active material layer 1213 is provided is the film area D, the area where the current collector 1212 is welded to the tab 1211 is the welding area A, and the current collector 1212 is provided with an extension area E between the film area D and the welding area A.

[0147] It should be noted that the film area D is the area of the current collector 1212 where the active material layer 1213 is provided. The welding area A is the area where the current collector 1212 and the tab 1211 are welded to each other, and the welding area A can be die-cut into the required shape and size. The extension area E is the area of the current collector 1212 provided between the film area D and the welding area A. The extension area E is neither provided with the active material layer 1213 nor participates in the welding, and belongs to the transition area between the film area D and the welding area A.

[0148] By adopting the above solution, it is convenient to separate the film region D and the welding region A via the extension region E to avoid the overlap (i.e., partial coincidence) between the film region D and the welding region A. Based on this, during the processing of the electrode tab 121, the risk of local multiple compressions of the welding region A (such as cold pressing of the film region D and roll pressing of the welding region A) caused by the overlap between the welding region A and the film region D can be reduced. The risk of the welding region A cracking and generating metal particles due to multiple compressions can be reduced. The risk of internal short circuit caused by the metal particles generated by the cracking of the welding region A entering the film region D can be reduced. The risk of the metal particles of the welding region A detaching and resulting in a reduction in the current-carrying area, a deterioration in the current-carrying capacity, and an increase in the temperature rise of the welding region A can be reduced. The service performance and service reliability of the battery cell 10 can be improved.

[0149] Please refer to Figure 13 、 Figure 14 In some embodiments of the present application, an insulating layer 1215 is provided on the surface of the extension region E.

[0150] It should be noted that, as Figure 13 shown, in some embodiments, an insulating layer 1215 is provided on one surface of the extension region E along its thickness direction. As Figure 14 shown, in some other embodiments, insulating layers 1215 are provided on opposite two surfaces of the extension region E along its thickness direction. The insulating layer 1215 is made of an insulating material and has insulating properties. The insulating layer 1215 can be an organic insulating layer or an inorganic insulating layer.

[0151] By adopting the above solution, by providing the insulating layer 1215 on the surface of the extension region E, on the one hand, the mechanical strength and hardness of the extension region E can be improved, the risk of bending and deformation of the extension region E can be reduced, and the risk of damage to the conductive layer 12122 at the extension region E affecting the welding quality of the welding region A can be reduced, thereby facilitating the improvement of the welding quality of the welding region A and reducing the generation of metal particles. On the other hand, during the processing of the electrode tab 121, especially in the case where the electrode tab 121 generates edge burrs and metal particles due to processes such as slitting and die cutting, the extension region E can be insulated and protected via the insulating layer 1215, thereby reducing the risk of internal short circuit caused by edge burrs and metal particles, etc. to the extension region E, and improving the service performance and service reliability of the battery cell 10.

[0152] Please refer to Figure 13 、 Figure 14 In some embodiments of the present application, a second spacer region F is provided between the extension region E and the welding region A.

[0153] It should be noted that, based on the previous embodiment, a second spacer F is provided between the extension region E and the welding region A. That is, the second spacer F is the region between the extension region E and the welding region A, which means that the extension region E and the welding region A are spaced apart by the second spacer F, that is, the second spacer F separates the extension region E and the welding region A. Neither an insulating layer 1215 is provided in the second spacer F nor does it participate in the welding.

[0154] By adopting the above solution, based on the previous embodiment, by providing a second spacer F between the extension region E and the welding region A, the extension region E and the welding region A can be separated by the second spacer F, thereby avoiding the overlap (i.e., partial coincidence) between the extension region E and the welding region A. Based on this, during the processing of the electrode tab 121, especially during the welding process and the rolling process in the welding region A, the risk of the insulating layer 1215 on the surface of the extension region E cracking due to stress can be reduced, so that the utility of the insulating layer 1215 for strengthening and insulating protection of the extension region E can be maintained.

[0155] Please refer to Figure 3 、 Figure 4 、 Figure 12 、 Figure 14 ,Combining some of the above embodiments, the embodiments of the present application hereby provide a specific example of the battery cell 10. The battery cell 10 includes an electrode assembly 12, and the electrode assembly 12 includes a separator 122 and two electrode tabs 121 with opposite polarities. The electrode tab 121 includes a current collector 1212, an active material layer 1213, and an electrode ear 1211. The current collector 1212 is a composite current collector. The current collector 1212 includes a support layer 12121 and conductive layers 12122 provided on the two opposite surfaces of the support layer 12121.

[0156] The active material layer 1213 is provided on the two opposite surfaces of the current collector 1212, and the region of the current collector 1212 where the active material layer 1213 is provided is the film region D. The electrode ear 1211 is welded to the edge of the current collector 1212, and the region where the current collector 1212 is welded to the electrode ear 1211 is the welding region A. The current collector 1212 is provided with an extension region E between the film region D and the welding region A.

[0157] The tab 1211 is provided with a strengthening structure 1214. The strengthening structure 1214 is formed by protruding from the tab 1211 towards one side in the z direction of its own thickness. There are multiple strengthening structures 1214, and the multiple strengthening structures 1214 are arranged at intervals along the length direction x of the tab 1211. Along the length direction x of the tab 1211, the distance between two adjacent strengthening structures 1214 is d1, and 1 mm ≤ d1 ≤ 50 mm. The strengthening structure 1214 includes a reinforcing rib 12142 and multiple strengthening bumps 12141 provided on the reinforcing rib 12142. The reinforcing rib 12142 extends along the width direction y of the tab 1211. The multiple strengthening bumps 12141 are arranged at intervals along the extending direction of the reinforcing rib 12142. The area of the strengthening bump 12141 is S, and 0.1 mm² ≤ S ≤ 250 mm². Based on this, the strength and ductility of the tab 1211 can be strengthened via the strengthening structure 1214. Thus, during the processing of the electrode tab 121, especially during the period when the current collector 1212 is pressed (for example, during the cold pressing process in the film area D, or during the rolling process in the welding area A), although the tab 1211 will also be pulled by the current collector 1212, because the strengthening structure 1214 strengthens the strength and ductility of the tab 1211, the tab 1211 can resist the pulling force, thereby reducing the risk of the tab 1211 wrinkling, warping, etc. due to the pulling of the current collector 1212, reducing the risk of production problems and safety problems such as the tab 1211 collapsing, folding into the film area D and causing internal short circuits, flipping, etc., improving the production yield, production excellence rate and production efficiency of the electrode tab 121, the electrode assembly 12 and the battery cell 10, and improving the use reliability of the battery cell 10 during its life cycle.

[0158] The area of the tab 1211 where the strengthening structure 1214 is provided is the strengthening area B. The strengthening area B is arranged at intervals with the welding area A, and the tab 1211 forms a first interval area C between the strengthening area B and the welding area A. The dimension of the first interval area C in the width direction y of the tab 1211 is d2, and 0.1 mm ≤ d2 ≤ 50 mm. Based on this, the strengthening area B and the welding area A can be separated via the first interval area C to avoid the overlapping of the strengthening area B and the welding area A. Thus, during the processing of the electrode tab 121, the risk of the welding area A being secondarily pressed due to the processing and forming of the strengthening structure 1214 in the strengthening area B can be reduced, the risk of the welding area A cracking and generating metal particles due to the secondary pressing can be reduced, the risk of the metal particles generated by the cracking of the welding area A entering the film area D and causing internal short circuits can be reduced, the risk of the metal particles of the welding area A detaching and resulting in the reduction of the current-carrying area, the deterioration of the current-carrying capacity and the increase of the temperature rise in the welding area A can be reduced, and the use performance and use reliability of the battery cell 10 can be improved.

[0159] The surface of the extension region E is provided with an insulating layer 1215, and a second spacer region F is provided between the extension region E and the welding region A. Based on this, the mechanical strength and hardness of the extension region E can be improved via the insulating layer 1215, the risk of bending and deformation of the extension region E can be reduced, the risk that the conductive layer 12122 at the extension region E is damaged and affects the welding quality of the welding region A can be reduced, thereby being beneficial to improving the welding quality of the welding region A and reducing the generation of metal particles. Moreover, during the processing of the electrode sheet 121, especially when the electrode sheet 121 generates edge burrs and metal particles due to processes such as slitting and die-cutting, the extension region E can be insulated and protected via the insulating layer 1215, thereby reducing the risk of internal short circuit of the extension region E caused by edge burrs and metal particles, and improving the service performance and reliability of the battery cell 10. Moreover, during the processing of the electrode sheet 121, especially during the welding process and the rolling process of the welding region A, the extension region E and the welding region A can be separated via the second spacer region F to reduce the risk that the insulating layer 1215 on the surface of the extension region E cracks due to stress, thereby maintaining the functions of the insulating layer 1215 for strengthening and insulating protection of the extension region E.

[0160] Please refer to Figure 1 、 Figure 3 , some embodiments of the present application provide a battery 1, and the battery 1 includes the battery cell 10 provided by the embodiments of the present application.

[0161] By adopting the above solution, the battery 1 can optimize the production yield, performance and reliability of use of the battery 1 by applying the battery cell 10 provided by the embodiments of the present application.

[0162] Please refer to Figure 1 、 Figure 3 , some embodiments of the present application provide an electrical device, and the electrical device includes the battery 1 provided by the embodiments of the present application, or the battery cell 10 provided by the embodiments of the present application.

[0163] By adopting the above solution, the electrical device can optimize the production yield, performance and reliability of use of the electrical device by applying the battery 1 or the battery cell 10 provided by the embodiments of the present application.

[0164] The above are only the preferred embodiments of the present application and are not intended to limit the present application. Any modification, equivalent replacement or improvement made within the spirit and principle of the present application shall be included within the protection scope of the present application.

Claims

1. A battery cell, characterized in that, The battery cell includes an electrode assembly, and the electrode assembly includes a separator and two current collectors with opposite polarities; The current collector includes a current collector body, an active material layer, and a tab, the active material layer is disposed on at least one surface of the current collector body, and the tab is welded to the edge of the current collector body; The tab is provided with a strengthening structure.

2. The battery cell according to claim 1, wherein The strengthening structure is formed by protruding from the tab towards one side in its thickness direction.

3. The battery cell according to claim 1, characterized in that, There are multiple strengthening structures, and the multiple strengthening structures are arranged at intervals along the length direction of the tab.

4. The battery cell according to claim 3, wherein, Along the length direction of the tab, the distance between two adjacent strengthening structures is d1, and 1mm ≤ d1 ≤ 50mm.

5. The battery cell according to claim 1, characterized in that, The strengthening structure includes strengthening bumps.

6. The battery cell according to claim 5, characterized in that, The strengthening structure includes multiple strengthening bumps arranged at intervals along the width direction of the tab.

7. The battery cell according to claim 5, wherein, The area of the reinforcing bump is S, 0.1mm 2 ≤ S ≤ 250mm 2 .

8. The battery cell according to claim 1, characterized in that, The strengthening structure includes a strengthening rib, and the strengthening rib extends along the width direction of the tab.

9. The battery cell according to claim 8, wherein, At least one strengthening bump is provided on the strengthening rib.

10. The battery cell according to any one of claims 1-9, characterized in that, The area where the tab is welded to the current collector body is the welding area, the area where the tab is provided with the strengthening structure is the strengthening area, the strengthening area and the welding area are spaced apart, and the tab forms a first spacing area between the strengthening area and the welding area.

11. The battery cell according to claim 10, characterized in that, The dimension of the first spacing area in the width direction of the tab is d2, and 0.1mm ≤ d2 ≤ 50mm.

12. The battery cell according to any one of claims 1-9, characterized in that, The current collector body includes a support layer, and a conductive layer disposed on at least one surface of the support layer.

13. The battery cell according to any one of claims 1-9, characterized in that, The area of the current collector body where the active material layer is disposed is the film area, the area where the current collector body is welded to the tab is the welding area, and the current collector body is provided with an extension area between the film area and the welding area.

14. The battery cell according to claim 13, wherein An insulating layer is provided on the surface of the extension area.

15. The battery cell according to claim 14, wherein A second spacing area is provided between the extension area and the welding area.

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

17. An electrical device, characterized in that, The electrical device includes the battery according to claim 16, or the battery cell according to any one of claims 1-15.

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