Battery cells, batteries, and electrical devices

Abstract

The present application provides a battery cell, a battery, and an electrical device. The battery cell includes: a first electrode assembly and a second electrode assembly, the first electrode assembly includes a first pole lug, and the second electrode assembly includes a second pole lug; the first pole lug and the second pole lug are stacked, and at least part of the first pole lug and the second pole lug are connected in the stacking area of ​​the first pole lug and the second pole lug. The first pole lug and the second pole lug are at least partially stacked, so that the electrode terminal of the battery cell can be connected to the first pole lug and the second pole lug at the stacking position of the first pole lug and the second pole lug at the same time, which can simplify the mutual connection between the first pole lug, the second pole lug and the electrode terminal.

Description

Technical Field

[0001] The present application relates to the field of batteries, and in particular to a battery cell, a battery, and an electrical device. Background Art

[0002] Energy conservation and emission reduction are the key to the sustainable development of the automobile industry. Electric vehicles have become an important part of the sustainable development of the automobile industry due to their advantages of energy conservation and environmental protection. For electric vehicles, battery technology is an important factor related to their development.

[0003] In order to increase the electric capacity, a plurality of electrode assemblies are usually provided in a battery cell. When a plurality of electrode assemblies are provided in a battery cell, there is a problem that the number of connection times is large when the tabs of the electrode assemblies are connected to the electrode terminals. Utility Model Content

[0004] In view of the above problems, the present application provides a battery cell, a battery, and an electrical device, which can simplify the interconnection between the tabs and the electrode terminals in the battery cell.

[0005] In a first aspect, the present application provides a battery cell, comprising: a first electrode assembly and a second electrode assembly, the first electrode assembly comprising a first pole lug, the second electrode assembly comprising a second pole lug; the first pole lug and the second pole lug are stacked, and at least part of the first pole lug and the second pole lug are connected in the stacking area of ​​the first pole lug and the second pole lug.

[0006] In the technical solution of the embodiment of the present application, the first electrode assembly includes a first pole ear, the second electrode assembly includes a second pole ear, and the first pole ear and the second pole ear are at least partially stacked, so that the first pole ear and the second pole ear can be connected to other components of the battery cell in their stacking area, which can simplify and reduce the number of connections between the first pole ear, the second pole ear and other components. The first pole ear and the second pole ear are connected to each other in the stacking area of ​​the first pole ear and the second pole ear, so that the pole ears of multiple electrode assemblies are more stably connected to each other.

[0007] In some embodiments, the first pole tab and the second pole tab are connected in the stacking region by a first welding zone. In these embodiments, by providing the first welding zone, the first pole tab and the second pole tab can be welded and connected to each other in the first welding zone, which can improve the stability of the connection between the first pole tab and the second pole tab.

[0008] In some embodiments, the present invention further comprises: an electrode terminal, wherein the first welding zone is connected to the electrode terminal via a second welding zone. In these embodiments, by providing the second welding zone, the first welding zone connecting the first pole tab and the second pole tab can be mutually welded and connected to the electrode terminal via the second welding zone, thereby improving the stability of the connection between the electrode terminal and the first pole tab and the second pole tab.

[0009] In some embodiments, the area of ​​the first welding zone is larger than that of the second welding zone. The larger area of ​​the first welding zone facilitates the connection of the electrode terminal with the first pole tab and the second pole tab in the first welding zone, and can improve the connection strength between the electrode terminal and the first pole tab and the second pole tab.

[0010] In some embodiments, the second welding zone is located within the first welding zone, and the second welding zone is arranged near the middle of the first welding zone. In these embodiments, the second welding zone is located within the first welding zone, that is, the electrode terminal is connected to the first pole tab and the second pole tab in the first welding zone, which can improve the stability of the relative position between the electrode terminal and the first pole tab and the second pole tab. Compared with forming the second welding zone at the edge of the first welding zone, the second welding zone is arranged near the middle of the first welding zone, which can further improve the connection strength between the electrode terminal and the first pole tab and the second pole tab.

[0011] In some embodiments, the first fusion zone is formed by at least one of ultrasonic welding and resistance welding. That is, the first electrode tab and the second electrode tab are connected to each other in the stacking area by at least one of ultrasonic welding and resistance welding to form the first fusion zone, which can improve the connection strength between the first electrode tab and the second electrode tab.

[0012] In some embodiments, the second fusion zone is formed by laser welding, that is, the electrode terminal is connected to the first fusion zone by laser welding to form the second fusion zone, which can improve the connection strength between the electrode terminal and the first and second tabs.

[0013] In some embodiments, the first pole tab includes a plurality of first sub-pole tabs, the second pole tab includes a plurality of second sub-pole tabs, and the first pole tab is located on one side of the second pole tab. That is, the plurality of first sub-pole tabs are located on one side of the plurality of second sub-pole tabs, so that the mutual stacking operation of the first pole tab and the second pole tab is simpler, and the manufacturing efficiency of the battery cell can be improved.

[0014] In some embodiments, the first pole tab includes a plurality of first sub-pole tabs, the second pole tab includes a plurality of second sub-pole tabs, and the first sub-pole tabs and the second sub-pole tabs are interlaced and overlapped. In these embodiments, the plurality of first sub-pole tabs and the plurality of second sub-pole tabs are interlaced and overlapped, which can improve the stability of the connection between the first pole tab and the second pole tab.

[0015] In some embodiments, an end cap is further included, and the electrode terminal is arranged on the end cap. In the direction in which the two electrode assemblies are arranged side by side, the size d of the stacking area of ​​the first pole tab and the second pole tab satisfies: 5mm≤d≤D / 2, where D is the width of the end cap. When the size of the stacking area of ​​the first pole tab and the second pole tab satisfies the above relationship, it can improve the instability of the connection between the first pole tab and the second pole tab due to the stacking area of ​​the first pole tab and the second pole tab being too small; it can also improve the size of the space occupied by the first pole tab and the second pole tab due to the stacking area of ​​the first pole tab and the second pole tab being too large.

[0016] In some embodiments, the first electrode assembly includes an electrode body, the first pole ear extends from the first end face of the electrode body, the first pole ear includes a top edge on the side away from the electrode body and two side edges connected to the top edge and the first end face, and at least one side edge is inclined toward the other side edge. In these optional embodiments, the width of the first pole ear gradually decreases on the path where the first pole ear extends out of the electrode body, and the width of the free end of the first pole ear away from the electrode body is small, which can improve the pole ear flanging problem caused by the folding of the free end of the first pole ear.

[0017] In some embodiments, the angle between at least one side edge and the first end face is a, and the complementary angle q of a is greater than or equal to 4 degrees. This can improve the problem that the free end of the first pole tab away from the electrode body is large due to the small inclination of the side edge, and the first pole tab is easy to bend.

[0018] In some embodiments, the complementary angle q between at least one side edge and the first end surface satisfies the following relationship:

[0019] q≤arctan[W0 / (4h-2d)]

[0020] Wherein, W0 is the width of the connection position between the first pole ear and the first end face, h is the length of the first pole ear extending from the electrode body, and d is the extension dimension of the stacking region of the first pole ear and the second pole ear in the direction in which the first electrode assembly and the second electrode assembly are arranged side by side. This can improve the problem that the first pole ear is too small in size due to the excessive inclination of the side edge affects the current capacity of the first pole ear.

[0021] In some embodiments, the first electrode tab and the second electrode tab have the same polarity, so that the electrode terminal connected to the first electrode tab and the second electrode tab can be a positive electrode terminal or a negative electrode terminal.

[0022] In a second aspect, an embodiment of the present application further provides a battery, comprising a battery cell according to any one of the above-mentioned embodiments of the first aspect.

[0023] In a third aspect, an embodiment of the present application further provides an electrical device, comprising a battery cell according to any one of the above-mentioned embodiments of the first aspect, wherein the battery cell is used to provide electrical energy.

[0024] In a fourth aspect, the present application also provides a method for manufacturing a battery cell, comprising:

[0025] Providing a first electrode assembly and a second electrode assembly, the first electrode assembly comprising a first electrode tab, and the second electrode assembly comprising a second electrode tab;

[0026] Laying at least a portion of the first electrode tab and the second electrode tab on top of each other;

[0027] The first electrode tab and the second electrode tab are connected in a stacking region of the first electrode tab and the second electrode tab.

[0028] In the manufacturing method provided in the embodiment of the present application, the first pole tab and the second pole tab are firstly at least partially stacked, so that the first pole tab and the second pole tab can be connected to other components of the battery cell at the same time in the stacking area thereof, which can simplify and reduce the number of connections between the first pole tab, the second pole tab and other components. Then, the first pole tab and the second pole tab are further connected to each other in the stacking area of ​​the first pole tab and the second pole tab, so that the pole tabs of the multiple electrode assemblies are more stably connected to each other.

[0029] In some embodiments, the first electrode tab includes a plurality of first sub-electrode tabs, and the second electrode tab includes a plurality of second sub-electrode tabs.

[0030] Before the step of stacking the first electrode tab and the second electrode tab on each other:

[0031] Performing a pre-welding process on the plurality of first sub-electrode tabs to form a first sub-welding region, so that the plurality of first sub-electrode tabs are connected to each other in the first sub-welding region;

[0032] The plurality of second sub-electrode tabs are pre-welded to form a second sub-welding region, so that the plurality of second sub-electrode tabs are connected to each other in the second sub-welding region.

[0033] In these embodiments, the first pole lug and the second pole lug are pre-welded respectively, so that the first sub-pole lugs of the plurality of first pole lugs can be connected to each other in the first sub-welding area, and the second sub-pole lugs of the plurality of second pole lugs can be connected to each other in the second sub-welding area. The interconnected first sub-pole lugs and the interconnected second sub-pole lugs facilitate the operation of stacking the first pole lug and the second pole lug on each other according to polarity, which can improve the manufacturing efficiency of the battery cell. In some embodiments, in the step of "connecting the first pole lug and the second pole lug in the stacking area of ​​the first pole lug and the second pole lug",

[0034] The first sub-welding zone is overlapped with the second sub-welding zone and welded to form a first welded zone.

[0035] In these embodiments, since multiple first sub-electrode tabs are connected in the first sub-welding zone, multiple second sub-electrode tabs are connected in the second sub-welding zone, the first sub-welding zone and the second sub-welding zone are welded to form the first welding zone, which can improve the connection strength between the first electrode tab and the second electrode tab.

[0036] In some embodiments, the first pole tab includes a plurality of first sub-pole tabs, and the second pole tab includes a plurality of second sub-pole tabs, and the step of “connecting the first pole tab and the second pole tab in the stacking region of the first pole tab and the second pole tab” includes:

[0037] The stacked regions of the first electrode tab and the second electrode tab are welded to form a first welded region.

[0038] In these embodiments, after the first pole lug and the second pole lug are stacked, the first pole lug and the second pole lug are welded in the stacking area to form a first welding zone. On the one hand, the number of welding times of the first pole lug and the second pole lug can be reduced, thereby improving the manufacturing efficiency of the battery cell; on the other hand, the first welding zone can also improve the connection strength between the first pole lug and the second pole lug.

[0039] In some embodiments, after the step of connecting the first electrode tab and the second electrode tab at the stacking region of the first electrode tab and the second electrode tab, the method further includes:

[0040] The first welding area and the electrode terminal are welded to form a second welding area.

[0041] In these embodiments, the first welding area and the electrode terminal are welded so that the electrode terminal can be connected to the first pole tab and the second pole tab at the same time. Compared with the solution in which the first pole tab and the second pole tab are welded to the electrode terminal separately, the number of welding times can be reduced and the manufacturing efficiency of the battery cell can be improved. The formed second welding area can also improve the connection strength between the first pole tab, the second pole tab and the electrode terminal.

[0042] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Also, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0044] Figure 1 is a structural schematic diagram of a vehicle provided by an embodiment of the present application;

[0045] Figure 2 is a schematic diagram of the structure of a battery pack provided in one embodiment of the present application;

[0046] Figure 3 is an axonometric diagram of a battery cell provided in one embodiment of the present application;

[0047] Figure 4 is a schematic diagram of the exploded structure of a battery cell provided in one embodiment of the present application;

[0048] Figure 5 is an axonometric diagram of a battery cell 40 provided in an embodiment of the present application during the manufacturing process;

[0049] Figure 6 is a top view of a battery cell 40 provided in an embodiment of the present application during the manufacturing process;

[0050] Figure 7 In one example Figure 6 Sectional view at AA in the middle;

[0051] Figure 8 yes Figure 7 A schematic diagram of the local enlarged structure at position I in the middle;

[0052] Fig. 9 In another example Figure 6 Sectional view at AA in the middle;

[0053] Fig.10 yes Fig. 9 A schematic diagram of the local enlarged structure at II in the middle;

[0054] Fig.11 is a top view of a battery cell 40 provided in another embodiment of the present application during the manufacturing process;

[0055] Fig.12 It is a schematic diagram of a manufacturing method of a battery cell provided in an embodiment of the present application;

[0056] Fig.13 It is a flow chart of a certain step in a method for manufacturing a battery cell provided in an embodiment of the present application.

[0057] The reference numerals in the specific implementation manner are as follows:

[0058] 1. Vehicle; 10. Battery; 11. Controller; 12. Motor;

[0059] 20. Battery module;

[0060] 30. Box body; 301. First box body portion; 302. Second box body portion;

[0061] 40. Battery cells;

[0062] 100, first electrode assembly; 110, first electrode tab; 110a, first sub-electrode tab; 111, top edge; 112, side edge; 120, electrode body;

[0063] 200, second electrode assembly; 210, second electrode tab; 210a, second sub-electrode tab;

[0064] 310, stacking area; 320, first welding area;

[0065] 400, end cap; 410, electrode terminal;

[0066] 500, second welding zone;

[0067] 600, housing; 610, opening;

[0068] X, first direction; Y, second direction; Z, third direction. DETAILED DESCRIPTION

[0069] The following embodiments of the technical solution of the present application will be described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0070] It should be noted that, unless otherwise specified, the technical terms or scientific terms used in the embodiments of the present application should have the common meanings understood by technicians in the field to which the embodiments of the present application belong.

[0071] In the description of the embodiments of the present application, the orientations or positional relationships indicated by technical terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", and "circumferential" are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the embodiments of the present application.

[0072] In addition, the technical terms "first", "second", etc. are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0073] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0074] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0075] At present, from the perspective of market development, the application of power batteries is becoming more and more extensive. Power batteries are not only used in energy storage power systems such as hydropower, thermal power, wind power and solar power stations, but also widely used in electric vehicles such as electric bicycles, electric motorcycles, electric cars, as well as military equipment and aerospace and other fields. With the continuous expansion of the application field of power batteries, the market demand is also constantly expanding.

[0076] In the present application, the battery cell may include a lithium-ion secondary battery cell, a lithium-ion primary battery cell, a lithium-sulfur battery cell, a sodium-lithium-ion battery cell, a sodium-ion battery cell or a magnesium-ion battery cell, etc., and the embodiments of the present application do not limit this. The battery cell may be cylindrical, flat, rectangular or other shapes, etc., and the embodiments of the present application do not limit this.

[0077] The battery mentioned in the embodiments of the present application refers to a single physical module including one or more battery cells to provide higher voltage and capacity. For example, the battery mentioned in the present application may include a battery module or a battery pack. The battery generally includes a box for encapsulating one or more battery cells. The box can prevent liquid or other foreign matter from affecting the charging or discharging of the battery cells.

[0078] A battery cell includes an electrode assembly and an electrolyte. The electrode assembly includes a positive electrode sheet, a negative electrode sheet and a separator. A battery cell mainly works by the movement of metal ions between the positive electrode sheet and the negative electrode sheet. The positive electrode sheet includes a positive current collector and a positive active material layer. The positive active material layer is coated on the surface of the positive current collector. The positive current collector includes a positive current collector and a positive electrode ear connected to the positive current collector. The positive current collector is coated with a positive active material layer, and the positive electrode ear is not coated with a positive active material layer. Taking a lithium-ion battery as an example, the material of the positive current collector can be aluminum, and the positive active material layer includes a positive active material. The positive active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium or lithium manganese oxide, etc. The negative electrode sheet includes a negative current collector and a negative active material layer, and the negative active material layer is coated on the surface of the negative current collector; the negative current collector includes a negative current collector and a negative electrode tab connected to the negative current collector, and the negative current collector is coated with the negative active material layer, and the negative electrode tab is not coated with the negative active material layer. The material of the negative current collector can be copper, and the negative active material layer includes a negative active material, and the negative active material can be carbon or silicon, etc. The material of the separator can be PP (polypropylene, polypropylene) or PE (polyethylene, polyethylene), etc.

[0079] The inventors of the present invention have noticed that in a battery cell, the battery cell includes a shell, an electrode assembly located in the shell, and a top cover plate covering the shell opening, the electrode assembly includes a tab, and the top cover plate is provided with an electrode terminal. In order to solve the problem of too long overcurrent path caused by welding the tab to the electrode terminal through the adapter, and too high temperature rise caused by current overcurrent, the battery cell will adopt a non-adapter design, that is, the tab of the electrode assembly is directly connected to the electrode terminal.

[0080] In the related art, in order to increase the capacity of a battery cell, two or more electrode assemblies are usually provided in the same battery cell. When the tabs of the two or more electrode assemblies are connected to the same electrode terminal, there is a problem of many welding times.

[0081] In order to solve the above technical problems, the applicant has found that before welding the electrode tabs to the electrode terminals, the electrode tabs of two or more electrode assemblies can be connected to each other as a whole, and then the two or more connected electrode tabs can be welded to the electrode terminals, which can solve the problem of multiple electrode welding times.

[0082] Based on the above considerations, in order to solve the problem of many welding times when connecting the electrode terminal and the pole ear in the battery cell, the inventor has designed a battery cell, a battery, an electrical device and a manufacturing method of the battery cell after in-depth research. In such a battery cell, the battery cell includes a first electrode assembly and a second electrode assembly, the first electrode assembly includes a first pole ear, the second electrode assembly includes a second pole ear, at least part of the first pole ear and the second pole ear are stacked on each other, and the first pole ear and the second pole ear are connected to each other in their stacking area.

[0083] The technical solutions described in the embodiments of the present application are applicable to batteries and electrical devices using batteries.

[0084] The electrical device may be a vehicle, a mobile phone, a portable device, a laptop computer, a ship, a spacecraft, an electric toy, an electric tool, and the like. The vehicle may be a fuel vehicle, a gas vehicle, or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle, or an extended-range vehicle, and the like; the spacecraft may include an airplane, a rocket, a space shuttle, and a spacecraft, and the like; the electric toy may include a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, and an electric airplane toy, and the like; the electric tool may include a metal cutting electric tool, a grinding electric tool, an assembly electric tool, and an electric tool for railways, such as an electric drill, an electric grinder, an electric wrench, an electric screwdriver, an electric hammer, an impact drill, a concrete vibrator, and an electric planer, and the like. The embodiments of the present application do not impose any special restrictions on the above-mentioned electrical devices.

[0085] It should be understood that the technical solutions described in the embodiments of the present application are not limited to the batteries and electrical equipment described above, but can also be applied to all batteries including a box and electrical equipment using the battery. However, for the sake of simplicity, the following embodiments are described using electric vehicles as an example.

[0086] Please refer to Figure 1 , Figure 1 A schematic diagram of the structure of a vehicle 1 provided for some embodiments of the present application. The vehicle 1 may be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery 10 is provided inside the vehicle 1, and the battery 10 may be provided at the bottom, the head or the tail of the vehicle 1. The battery 10 may be used to power the vehicle 1, for example, the battery 10 may be used as an operating power source for the vehicle 1. The vehicle 1 may also include a controller 11 and a motor 12, and the controller 11 is used to control the battery 10 to power the motor 12, for example, for the starting, navigation and working power requirements of the vehicle 1 during driving.

[0087] In some embodiments of the present application, the battery 10 can be used not only as an operating power source for the vehicle 1 , but also as a driving power source for the vehicle 1 , replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1 .

[0088] In order to meet different power requirements, the battery 10 may include a plurality of battery cells, which refers to the smallest unit that constitutes a battery module or a battery pack. A plurality of battery cells can be connected in series and / or in parallel via electrode terminals for use in various applications. The battery mentioned in the present application includes a battery module or a battery pack. Among them, a plurality of battery cells can be connected in series, in parallel, or in mixed connection, where mixed connection refers to a mixture of series and parallel connection. In the embodiment of the present application, a plurality of battery cells can directly constitute a battery pack, or they can first constitute a battery module 20, and the battery module 20 can then constitute a battery pack.

[0089] Figure 2 A schematic structural diagram of a battery 10 according to an embodiment of the present application is shown.

[0090] like Figure 2 As shown, the battery 10 includes a case 30 and a battery cell 40 , and the battery cell 40 is accommodated in the case 30 .

[0091] The box 30 can be a simple three-dimensional structure such as a single cuboid, cylinder or sphere, or a complex three-dimensional structure composed of simple three-dimensional structures such as cuboids, cylinders or spheres, which is not limited in the present embodiment. The box 30 can be made of alloy materials such as aluminum alloy, iron alloy, polymer materials such as polycarbonate, polyisocyanurate foam plastic, or composite materials such as glass fiber and epoxy resin, which is not limited in the present embodiment.

[0092] The box 30 is used to accommodate the battery cell 40, and the box 30 can be a variety of structures. In some embodiments, the box 30 may include a first box portion 301 and a second box portion 302, the first box portion 301 and the second box portion 302 cover each other, and the first box portion 301 and the second box portion 302 jointly define a storage space for accommodating the battery cell 40. The second box portion 302 may be a hollow structure with one end open, the first box portion 301 is a plate-like structure, and the first box portion 301 covers the open side of the second box portion 302 to form a box 30 with a storage space; the first box portion 301 and the second box portion 302 may also be a hollow structure with one side open, and the open side of the first box portion 301 covers the open side of the second box portion 302 to form a box 30 with a storage space. Of course, the first box portion 301 and the second box portion 302 may be in a variety of shapes, such as a cylinder, a cuboid, etc.

[0093] In order to improve the sealing performance after the first box body 301 and the second box body 302 are connected, a sealing member, such as a sealant, a sealing ring, etc., may also be provided between the first box body 301 and the second box body 302 .

[0094] Assuming that the first box body portion 301 covers the top of the second box body portion 302 , the first box body portion 301 can also be referred to as an upper box cover, and the second box body portion 302 can also be referred to as a lower box body 30 .

[0095] In the battery 10, there can be one or more battery cells 40. If there are more than one battery cell 40, the battery cells 40 can be connected in series, in parallel, or in a mixed connection. A mixed connection means that the battery cells 40 are both connected in series and in parallel. The battery cells 40 can be directly connected in series, in parallel, or in a mixed connection, and then the whole formed by the battery cells 40 is accommodated in the box 30; of course, the battery modules 20 can also be formed by connecting the battery cells 40 in series, in parallel, or in a mixed connection, and then the battery modules 20 are connected in series, in parallel, or in a mixed connection to form a whole, and then accommodated in the box 30.

[0096] Please continue to participate Figure 2 In some embodiments, there are multiple battery cells 40, and the multiple battery cells 40 are first connected in series, in parallel, or in mixed series to form a battery module 20. The multiple battery modules 20 are then connected in series, in parallel, or in mixed series to form a whole, and are accommodated in the box 30.

[0097] The multiple battery cells 40 in the battery module 20 can be electrically connected through a busbar component to achieve parallel connection, series connection, or mixed connection of the multiple battery cells 40 in the battery module 20 .

[0098] In the present application, the battery cell 40 may include a lithium-ion battery cell 40, a sodium-ion battery cell 40, or a magnesium-ion battery cell 40, etc., and the embodiments of the present application do not limit this. The battery cell 40 may be cylindrical, flat, rectangular, or in other shapes, etc., and the embodiments of the present application do not limit this. The battery cell 40 is generally divided into three types according to the packaging method: cylindrical battery cells 40, square battery cells 40, and soft-pack battery cells 40, and the embodiments of the present application do not limit this. However, for the sake of simplicity, the following embodiments are all described using square battery cells 40 as an example.

[0099] Figure 3 An axonometric view of a battery cell 40 provided in some embodiments of the present application, Figure 4 A schematic diagram of the exploded structure of a battery cell 40 provided in some embodiments of the present application.

[0100] like Figure 3 and Figure 4 As shown, the battery cell 40 includes a first electrode assembly 100 and a second electrode assembly 200, the first electrode assembly 100 includes a first pole ear 110, and the second electrode assembly 200 includes a second pole ear 210; the first pole ear 110 and the second pole ear 210 are stacked, and at least part of the first pole ear 110 and the second pole ear 210 are connected in the stacking area 310 of the first pole ear 110 and the second pole ear 210.

[0101] The battery cell 40 further includes a shell 600 and an end cap 400 covering an opening 610 of the shell 600. The shell 600 and the end cap 400 together form the outer shell of the battery cell 40. The first electrode assembly 100 and the second electrode assembly 200 are located in the outer shell of the battery cell 40.

[0102] The end cap 400 refers to a component that covers the opening 610 of the shell 600 to isolate the internal environment of the battery cell 40 from the external environment. Without limitation, the shape of the end cap 400 can be adapted to the shape of the shell 600 to match the shell 600. Optionally, the end cap 400 can be made of a material with a certain hardness and strength (such as aluminum alloy), so that the end cap 400 is not easily deformed when squeezed and collided, so that the battery cell 40 can have a higher structural strength and the safety performance can also be improved. Functional components such as electrode terminals 410 can be provided on the end cap 400. The electrode terminal 410 can be used to electrically connect to the electrode assembly 100 for outputting or inputting electrical energy of the battery cell 40. In some embodiments, the end cap 400 can also be provided with a pressure relief mechanism for releasing the internal pressure when the internal pressure or temperature of the battery cell 40 reaches a threshold. The material of the end cap 400 can also be a variety of materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiment of the present application does not impose any special restrictions on this. In some embodiments, a partition may be provided inside the end cap 400 to isolate the electrical connection components in the housing 600 from the end cap 400 to reduce the risk of short circuit. For example, the partition 200 may be made of plastic, rubber, or the like.

[0103] At least one of the first electrode assembly 100 and the second electrode assembly 200 is mainly formed by winding a pole sheet with an active material and a separator, and the pole sheet includes a positive pole sheet and a negative pole sheet. The electrode assembly 100 is a component in the battery cell 40 where an electrochemical reaction occurs. One or more electrode assemblies 100 may be included in the housing 600. The first electrode assembly 100 and / or the second electrode assembly 200 include an electrode body 120, and the portions of the positive and negative pole sheets coated with active materials are wound to form the electrode body 120. The first pole ear 110 and / or the second pole ear 210 include a positive pole ear and a negative pole ear, and the portions of the positive and negative pole sheets that are connected without active materials each constitute a positive pole ear and a negative pole ear, and the positive pole ear and the negative pole ear may be located together at one end of the electrode body 120 or at both ends of the electrode body 120.

[0104] The shell 600 is a component used to cooperate with the end cap 400 to form the internal environment of the battery cell 40, wherein the formed internal environment can be used to accommodate the electrode assembly 100, the electrolyte (not shown in the figure) and other components. The shell 600 and the end cap 400 can be independent components, and an opening 610 can be set on the shell 600, and the end cap 400 is covered with the opening 610 at the opening 610 to form the internal environment of the battery cell 40. Without limitation, the end cap 400 and the shell 600 can also be integrated. Specifically, the end cap 400 and the shell 600 can form a common connection surface before other components are put into the shell, and when the interior of the shell 600 needs to be encapsulated, the end cap 400 is covered with the shell 600. The shell 600 can be of various shapes and sizes, such as a rectangular parallelepiped, a cylindrical shape, a hexagonal prism, etc. Specifically, the shape of the shell 600 can be determined according to the specific shape and size of the electrode assembly 100. The shell 600 can be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiment of the present application does not impose any special restrictions on this.

[0105] Optionally, an insulating member may be provided on the side of the end cap 400 facing the electrode assembly, that is, the insulating member may be provided between the end cap 400 and the electrode body 120. In other embodiments, the insulating member may also be provided between the inner wall surface of the housing 600 and the electrode body 120. There are many ways to set the material of the insulating member, and the insulating member may be made of insulating materials such as rubber and plastic. The insulating member is made of rubber so that the insulating member has appropriate elasticity, which better improves the force concentration of the electrode body 120.

[0106] The first electrode tab 110 and the second electrode tab 210 are connected in the stacking region 310 of the first electrode tab 110 and the second electrode tab 210 . This may be that the first electrode tab 110 and the second electrode tab 210 are connected to each other before the electrode terminal 410 is connected, or the first electrode tab 110 and the second electrode tab 210 are connected to each other during the step of connecting the electrode terminal 410 .

[0107] In the technical solution of the embodiment of the present application, the first electrode assembly 100 includes a first pole ear 110, the second electrode assembly 200 includes a second pole ear 210, and the first pole ear 110 and the second pole ear 210 are at least partially stacked, so that the first pole ear 110 and the second pole ear 210 can be connected to other components of the battery cell 10 in their stacking area 310. For example, the electrode terminal 410 can connect the pole ears of more than two electrode assemblies in the same step, which can simplify the mutual connection between the first pole ear 110, the second pole ear 210 and the electrode terminal 410.

[0108] In addition, the first pole tab 110 and the second pole tab 210 are also connected to each other in the stacking region 310 of the first pole tab 110 and the second pole tab 210, so that the pole tabs of the plurality of electrode assemblies are more stably connected to each other. When the electrode terminal 410 connects the first pole tab 110 and the second pole tab 210 through the stacking region 310, the stability of the connection between the electrode terminal 410 and the first pole tab 110 and the second pole tab 210 can also be improved.

[0109] See also Figures 3 to 5 , Figure 5 It is an axonometric diagram of the battery cell 40 provided in the embodiment of the present application during the manufacturing process.

[0110] According to some embodiments of the present application, Figures 3 to 5 As shown, the first electrode tab 110 and the second electrode tab 210 are connected in the stacking region 310 via a first weld zone 320 .

[0111] Optionally, the area of ​​the first welding zone 320 is smaller than the area of ​​the stacking region 310 , and the first welding zone 320 is within the stacking region 310 .

[0112] There are many ways to set the first welding zone 320. For example, before the first electrode tab 110 and the second electrode tab 210 are stacked, the first electrode tab 110 is pre-welded to form a first pre-welding zone, the second electrode tab 210 is pre-welded to form a second pre-welding zone, and the first pre-welding zone and the second pre-welding zone are stacked to form the first welding zone 320. Alternatively, after the first electrode tab 110 and the second electrode tab 210 are stacked, the first electrode tab 110 and the second electrode tab 210 are pre-welded to form the first welding zone 320.

[0113] In these optional embodiments, by providing the first welding zone 320 , the first electrode tab 110 and the second electrode tab 210 can be welded and connected to each other in the first welding zone 320 , thereby improving the stability of the connection between the first electrode tab 110 and the second electrode tab 210 .

[0114] According to some embodiments of this application, please continue to refer to Figures 3 to 5 As described above, the battery cell 40 further includes an electrode terminal 410 , and the first welding region 320 is connected to the electrode terminal 410 via the second welding region 500 .

[0115] The second welding area 500 may be a welding area formed when the first welding area 320 and the electrode terminal 410 are connected by welding or the like, or the second welding area 500 may be an area where the first welding area 320 and the electrode terminal 410 are connected to each other.

[0116] In these optional embodiments, by setting the second welding zone 500, the first welding zone 320 connecting the first pole tab 110 and the second pole tab 210 can be welded and connected to the electrode terminal 410 through the second welding zone 500, thereby improving the stability of the connection between the electrode terminal 410 and the first pole tab 110 and the second pole tab 210.

[0117] According to some embodiments of this application, please continue to refer to Figures 3 to 5 , the area of ​​the first welding zone 320 is greater than the area of ​​the second welding zone 500 .

[0118] The first welding zone 320 and the second welding zone 500 may have various shapes, for example, the first welding zone 320 may be circular, polygonal, elliptical or irregular in shape. The second welding zone 500 may also be circular, polygonal, elliptical or irregular in shape.

[0119] Optionally, when the extension dimension of the first welding zone 320 in the first direction X is greater than its own extension dimension in the second direction Y, the extension dimension of the second welding zone 500 in the first direction X is also greater than its own extension dimension in the second direction Y, so that the second welding zone 500 is conveniently disposed within the first welding zone 320. Optionally, the first electrode assembly 100 and the second electrode assembly 200 are disposed side by side along the second direction Y.

[0120] Optionally, when the first electrode tab 110 and the second electrode tab 210 are trapezoidal, the stacking region 310 of the first electrode tab 110 and the second electrode tab 210 may be hexagonal, and the shape of the first welding zone 320 may be hexagonal. The shape of the second welding zone 500 may be waist-shaped.

[0121] In these optional embodiments, the area of ​​the first welding zone 320 is relatively large, which facilitates the electrode terminal 410 to be connected to the first pole tab 110 and the second pole tab 210 in the first welding zone 320 , thereby improving the connection strength between the electrode terminal 410 and the first pole tab 110 and the second pole tab 210 .

[0122] According to some embodiments of this application, please continue to refer to Figures 3 to 5 The second welding zone 500 is located within the first welding zone 320 , and the second welding zone 500 is arranged close to the middle of the first welding zone 320 .

[0123] Optionally, the second welding zone 500 may be disposed close to the middle of the first welding zone 320 in the first direction X and / or the second direction Y.

[0124] In these optional embodiments, the second welding zone 500 is located within the first welding zone 320, that is, the electrode terminal 410 is connected to the first pole tab 110 and the second pole tab 210 in the first welding zone 320, which can improve the stability of the relative position between the electrode terminal 410 and the first pole tab 110 and the second pole tab 210. Compared with forming the second welding zone 500 at the edge of the first welding zone 320, the second welding zone 500 is arranged close to the middle of the first welding zone 320, which can further improve the connection strength between the electrode terminal 410 and the first pole tab 110 and the second pole tab 210.

[0125] According to some embodiments of the present application, the first welding zone 320 is formed by at least one of ultrasonic welding and resistance welding.

[0126] In these optional embodiments, the first electrode tab 110 and the second electrode tab 210 are connected to each other in the stacking area 310 by at least one of ultrasonic welding and resistance welding to form a first fusion zone 320 , which can improve the connection strength between the first electrode tab 110 and the second electrode tab 210 .

[0127] According to some embodiments of the present application, the second welding zone 500 is formed by laser welding. That is, the electrode terminal 410 is connected to the first welding zone 320 by laser welding to form the second welding zone 500, which can improve the connection strength between the electrode terminal 410 and the first and second tabs 110 and 210.

[0128] See also Figures 6 to 10 , Figure 6 is a top view of a battery cell 40 provided in an embodiment of the present application during the manufacturing process; Figure 7 In one example Figure 6 The cross-sectional view at AA in the middle. Figure 8 yes Figure 7 A schematic diagram of the local enlarged structure at position I in the middle; Fig. 9 In another example Figure 6 The cross-sectional view at AA in the middle. Fig.10 yes Fig. 9 Schematic diagram of the local enlarged structure at II in the middle.

[0129] According to some embodiments of the present application, Figures 6 to 10 As shown, the first pole tab 110 includes a plurality of first sub-pole tabs 110a, and the second pole tab 210 includes a plurality of second sub-pole tabs 210a. Figure 7 and Figure 8 As shown, the first pole tab 110 is located on one side of the second pole tab 210. That is, the first sub-pole tabs 110a are located on one side of the second sub-pole tabs 210a, making the mutual stacking operation of the first pole tab 110 and the second pole tab 210 easier and improving the manufacturing efficiency of the battery cell 40.

[0130] When the first pole tab 110 includes a plurality of first sub-pole tabs 110a, and the second pole tab 210 includes a plurality of second sub-pole tabs 210a, before the first pole tab 110 and the second pole tab 210 are stacked, the first pole tab 110 may be pre-welded so that the plurality of first sub-pole tabs 110a of the first pole tab 110 are connected to each other, and the second pole tab 210 may be pre-welded so that the plurality of second sub-pole tabs 210a of the second pole tab 210 are connected to each other. Then, the first pole tab 110 and the second pole tab 210 after the pre-welding treatment are stacked on each other, and the stacking area 310 is ultrasonically welded, resistively welded, etc. to form the first fusion zone 320. Finally, the first fusion zone 320 is connected to the electrode terminal 410 by laser welding to form the second fusion zone 500.

[0131] Alternatively, in other embodiments, before the first pole tab 110 and the second pole tab 210 are stacked, the first pole tab 110 and the second pole tab 210 may not be pre-welded, and after the first pole tab 110 and the second pole tab 210 are stacked, the stacking region 310 is ultrasonically welded, resistively welded, etc. to form the first fusion zone 320. Finally, the first fusion zone 320 is connected to the electrode terminal 410 by laser welding to form the second fusion zone 500.

[0132] According to some embodiments of the present application, Fig. 9 and Fig.10 As shown, the first pole tab 110 includes a plurality of first sub-pole tabs 110 a , and the second pole tab 210 includes a plurality of second sub-pole tabs 210 a . The first sub-pole tabs 110 a and the second sub-pole tabs 210 a are alternately overlapped.

[0133] In these optional embodiments, the plurality of first sub-electrode tabs 110 a and the plurality of second sub-electrode tabs 210 a are alternately stacked, which can improve the stability of the connection between the first electrode tab 110 and the second electrode tab 210 .

[0134] The first sub-pole lugs 110a and the second sub-pole lugs 210a are interlaced and overlapped with each other, which means that at least one first sub-pole lug 110a is located between two adjacent second sub-pole lugs 210a, and / or at least one second sub-pole lug 210a is located between two adjacent first sub-pole lugs 110a. Optionally, a second sub-pole lug 210a is disposed between any two adjacent first sub-pole lugs 110a, so that the first sub-pole lug 110a and the second sub-pole lug 210a are fully interlaced, further improving the stability of the connection between the first pole lug 110 and the second pole lug 210.

[0135] According to some embodiments of the present application, Figures 3 to 10As shown, as described above, the battery cell 40 also includes an end cover 400, and the electrode terminal 410 is arranged on the end cover 400. In the side-by-side arrangement direction of the two electrode assemblies (i.e., the second direction Y), the size d of the stacking area 310 of the first pole ear 110 and the second pole ear 210 satisfies: 5mm≤d≤D / 2, where D is the width of the end cover 400.

[0136] D is the width of the end cap 400 in the direction in which the two electrode assemblies are arranged side by side.

[0137] In these optional embodiments, when the size of the stacking area 310 of the first pole lug 110 and the second pole lug 210 satisfies the above relationship, it can improve the unstable connection between the first pole lug 110 and the second pole lug 210 due to the stacking area 310 of the first pole lug 110 and the second pole lug 210 being too small; it can also improve the stacking area 310 of the first pole lug 110 and the second pole lug 210 being too large, which increases the size of the space occupied by the first pole lug 110 and the second pole lug 210.

[0138] According to some embodiments of the present application, Fig.11 As shown, the first electrode assembly 100 includes an electrode body 120, and a first electrode ear 110 extends from a first end surface of the electrode body 120. The first electrode ear 110 includes a top edge 111 on a side away from the electrode body 120 and two side edges 112 connected to the top edge 111 and the first end surface, and at least one side edge 112 is inclined toward the other side edge 112.

[0139] Optionally, the two side edges 112 of the first electrode tab 110 are arranged obliquely in a direction approaching each other, that is, the shape of the first electrode tab 110 is a trapezoid.

[0140] In these optional embodiments, the width of the first pole ear 110 gradually decreases on the path where the first pole ear 110 extends out of the electrode body 120, and the width of the free end of the first pole ear 110 away from the electrode body 120 is smaller, which can improve the pole ear flange problem caused by the folding of the free end of the first pole ear 110.

[0141] In other embodiments, the second electrode assembly 200 may also include the above-mentioned electrode body 120, the second electrode ear 210 extends from the first end face of the electrode body 120, the second electrode ear 210 includes a top edge 111 on the side away from the electrode body 120 and two side edges 112 connected to the top edge 111 and the first end face, and at least one side edge 112 is inclined toward the other side edge 112.

[0142] In these optional embodiments, the width of the second pole lug 210 gradually decreases on the path where the second pole lug 210 extends out of the electrode body 120, and the width of the free end of the second pole lug 210 away from the electrode body 120 is smaller, which can improve the pole lug flanging problem caused by the folding of the free end of the second pole lug 210.

[0143] According to some embodiments of the present application, Fig.11 As shown, the angle between at least one side edge 112 and the first end surface is a, and the complementary angle q of a is greater than or equal to 4 degrees.

[0144] In these optional embodiments, when the complementary angle q of a satisfies the above relationship, the problem that the free end of the first pole tab 110 away from the electrode body 120 is larger due to the small inclination of the side edge 112 and the first pole tab 110 is easy to bend over can be improved.

[0145] According to some embodiments of the present application, Fig.11 As shown, the complementary angle q between at least one side edge 112 and the first end surface satisfies the following relationship:

[0146] q≤arctan[W0 / (4h-2d)]

[0147] Among them, W0 is the width of the connection position between the first electrode tab 110 and the first end face, h is the length of the first electrode tab 110 extending from the electrode body 120, and d is the extension dimension of the stacking area 310 of the first electrode tab 110 and the second electrode tab 210 in the side-by-side direction of the first electrode assembly 100 and the second electrode assembly 200.

[0148] In these optional embodiments, when the complementary angle q of a satisfies the above relationship, the problem that the size of the first pole tab 110 is too small due to the excessive inclination of the side edge 112 affects the current carrying capacity of the first pole tab 110 can be improved.

[0149] In some embodiments, the first electrode tab 110 and the second electrode tab 210 have the same polarity, so that the electrode terminal 410 connected to the first electrode tab 110 and the second electrode tab 210 can be a positive electrode terminal 410 or a negative electrode terminal 410 .

[0150] The first electrode tab 110 and the second electrode tab 210 may both be positive electrode tabs, or the first electrode tab 110 and the second electrode tab 210 may both be negative electrode tabs.

[0151] According to some embodiments of the present application, the present application further provides a battery, comprising the battery cell 40 described in any of the above schemes.

[0152] According to some embodiments of the present application, the present application further provides an electrical device, comprising the battery cell 40 described in any of the above schemes, and the battery cell 40 is used to provide electrical energy to the electrical device.

[0153] The electrical device may be any of the aforementioned devices or systems using the battery cell 40 .

[0154] According to some embodiments of the present application, the present application further provides a method for manufacturing a battery cell 40. The battery cell 40 is the battery cell 40 in any of the above embodiments. Figures 3 to 11 , and see Fig.12 The manufacturing method of the battery cell 40 provided in the embodiment of the present application includes:

[0155] Step S01 : providing a first electrode assembly 100 and a second electrode assembly 200 , wherein the first electrode assembly 100 includes a first electrode tab 110 , and the second electrode assembly 200 includes a second electrode tab 210 .

[0156] Step S02: stacking at least a portion of the first electrode tab 110 and the second electrode tab 210 on each other.

[0157] Step S03 : connecting the first electrode tab 110 and the second electrode tab 210 in the stacking region 310 of the first electrode tab 110 and the second electrode tab 210 .

[0158] In the manufacturing method of the battery cell 40 provided in the embodiment of the present application, firstly, a first electrode assembly 100 and a second electrode assembly 200 are provided, so that the battery cell 40 includes more than two electrode assemblies, which can improve the capacity of the battery cell 40. Then, at least part of the first electrode tab 110 of the first electrode assembly 100 and the second electrode tab 210 of the second electrode assembly 200 are stacked on each other through step S02. Finally, in step S03, the first electrode tab 110 and the second electrode tab 210 are connected in the connection area. After the first electrode tab 110 and the second electrode tab 210 are connected, the connected first electrode tab 110 and the second electrode tab 210 can be directly connected to the electrode terminal 410 of the battery cell 40. Compared with the first electrode tab 110 and the second electrode tab 210 being connected to the electrode terminal 410 respectively, the connection process of the first electrode tab 110, the second electrode tab 210 and the electrode terminal 410 can be simplified, the number of welding times can be reduced, and the manufacturing efficiency of the battery cell 40 can be improved.

[0159] According to some embodiments of the present application, the first pole tab 110 includes a plurality of first sub-pole tabs 110a, and the second pole tab 210 includes a plurality of second sub-pole tabs 210a. Fig.13 As shown, before step S02, the following steps may also be included:

[0160] Step S021 : performing a pre-welding process on the plurality of first sub-electrode tabs 110 a to form a first sub-welding region, so that the plurality of first sub-electrode tabs 110 a are connected to each other in the first sub-welding region.

[0161] Step S022: performing a pre-welding process on the plurality of second sub-electrode tabs 210 a to form a second sub-welding region, so that the plurality of second sub-electrode tabs 210 a are connected to each other in the second sub-welding region.

[0162] The order of step S021 and step S022 is not limited.

[0163] In these optional embodiments, before step S02, the plurality of first sub-pole tabs 110a and the plurality of second sub-pole tabs 210a are pre-welded respectively through step S021 and step S022. Then, in step S02, the plurality of first sub-pole tabs 110a are already connected to each other, and the plurality of second sub-pole tabs 210a are also connected to each other, so as to facilitate the stacking operation of the first pole tabs 110 and the second pole tabs 210.

[0164] According to some embodiments of the present application, in step S03: the first sub-welding area is overlapped with the second sub-welding area and the first sub-welding area and the second sub-welding area are welded to form a first welding area 320. That is, the first welding area 320 is formed in the area where the first sub-electrode tab 110a is connected to each other and the area where the second sub-electrode tab 210a is connected to each other, which can improve the stability of the connection between the first electrode tab 110 and the second electrode tab 210.

[0165] According to some embodiments of the present application, the first pole tab 110 includes a plurality of first sub-pole tabs 110a, and the second pole tab 210 includes a plurality of second sub-pole tabs 210a, then in step S03: the stacking region 310 of the first pole tab 110 and the second pole tab 210 is welded to form a first welding region 320. That is, after the first pole tab 110 and the second pole tab 210 are stacked, the first pole tab 110 and the second pole tab 210 are connected to each other to form the first welding region 320, and there is no need to pre-weld the first pole tab 110 and the second pole tab 210, which can simplify the manufacturing process of the battery cell 40 and improve the manufacturing efficiency of the battery cell 40.

[0166] According to some embodiments of the present application, after step S03, the step further includes: welding the first welding area 320 and the electrode terminal 410 to form a second welding area 500. That is, the electrode terminal 410 is connected to the first pole tab 110 and the second pole tab 210 in the area where the first pole tab 110 and the second pole tab 210 are connected to each other, and there is no need to connect the first pole tab 110 and the electrode terminal 410, and the second pole tab 210 and the electrode terminal 410 respectively, which can simplify the manufacturing process of the battery cell 40 and ensure the stability of the relative positions of the first pole tab 110, the second pole tab 210 and the electrode terminal 410.

[0167] like Figures 3 to 11As shown, the battery cell 40 includes a first electrode assembly 100 and a second electrode assembly 200, the first electrode assembly 100 includes a first pole lug 110, and the second electrode assembly 200 includes a second pole lug 210; the first pole lug 110 and the second pole lug 210 are stacked, and at least part of the first pole lug 110 and the second pole lug 210 are connected in the stacking area 310 of the first pole lug 110 and the second pole lug 210. The first pole lug 110 and the second pole lug 210 are connected in the stacking area 310 through the first welding area 320. The battery cell 40 also includes an electrode terminal 410, and the first welding area 320 is connected to the electrode terminal 410 through the second welding area 500. The area of ​​the first welding area 320 is greater than that of the second welding area 500, and the second welding area 500 is located within the first welding area 320, and the second welding area 500 is arranged near the middle of the first welding area 320. The battery cell 40 further includes an end cap 400 , and the electrode terminal 410 is disposed on the end cap 400 . In the side-by-side arrangement direction of the two electrode assemblies, the size d of the stacking region 310 of the first electrode tab 110 and the second electrode tab 210 satisfies: 5 mm≤d≤D / 2, where D is the width of the end cap 400 . The first electrode assembly 100 includes an electrode body 120, and a first electrode tab 110 extends from a first end face of the electrode body 120. The first electrode tab 110 includes a top edge 111 on a side away from the electrode body 120 and two side edges 112 connected to the top edge 111 and the first end face. The angle between at least one side edge 112 and the first end face is a, and the complementary angle q of a is greater than or equal to 4 degrees and less than or equal to arctan[W0 / (4h-2d)], W0 is the width of the connection position between the first electrode tab 110 and the first end face, h is the length of the first electrode tab 110 extending from the electrode body 120, and d is the extension dimension of the stacking region 310 of the first electrode tab 110 and the second electrode tab 210 in the direction in which the first electrode assembly 100 and the second electrode assembly 200 are arranged side by side.

[0168] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A battery cell, comprising: A first electrode assembly and a second electrode assembly, wherein the first electrode assembly includes a first electrode tab and the second electrode assembly includes a second electrode tab; At least a portion of the first electrode tab and the second electrode tab are stacked, and the first electrode tab and the second electrode tab are connected in a stacking region of the first electrode tab and the second electrode tab.

2. The battery cell according to claim 1, wherein: The first electrode tab and the second electrode tab are connected in the stacking region via a first weld zone.

3. The battery cell according to claim 2, wherein: Also includes: The electrode terminal, the first welding area is connected to the electrode terminal through the second welding area.

4. The battery cell according to claim 3, wherein: The area of ​​the first welding zone is greater than the area of ​​the second welding zone.

5. The battery cell according to claim 4, wherein: The second welding zone is located within the first welding zone, and the second welding zone is arranged close to the middle of the first welding zone.

6. The battery cell according to claim 3, wherein: The first fusion zone is formed by at least one of ultrasonic welding and resistance welding; And / or, the second fusion zone is formed by laser welding.

7. The battery cell according to claim 2, wherein: The first pole lug includes a plurality of first sub-pole lugs, the second pole lug includes a plurality of second sub-pole lugs, the first pole lug is located on one side of the second pole lug, or the first sub-pole lug and the second sub-pole lug are staggered and overlapped with each other.

8. The battery cell according to claim 1, wherein: It also includes an end cover, the electrode terminal is arranged on the end cover, and in the side-by-side arrangement direction of the two electrode assemblies, the size d of the stacking area of ​​the first electrode tab and the second electrode tab satisfies: 5mm≤d≤D / 2, where D is the width of the end cover.

9. The battery cell according to claim 1, wherein: The first electrode assembly includes an electrode body, the first electrode ear extends from a first end surface of the electrode body, the first electrode ear includes a top edge facing away from the electrode body and two side edges connected to the top edge and the first end surface, and at least one of the side edges is inclined toward the other side edge.

10. The battery cell according to claim 9, wherein: An angle between at least one of the side edges and the first end face is a, and a complementary angle q of a is greater than or equal to 4 degrees.

11. The battery cell according to claim 9, wherein: The complementary angle q between at least one of the side edges and the first end surface satisfies the following relationship: q≤arctan[W0 / (4h-2d)] Among them, W0 is the width of the connection position between the first pole ear and the first end face, h is the length of the first pole ear extending from the electrode body, and d is the extension dimension of the stacking area of ​​the first pole ear and the second pole ear in the direction in which the first electrode assembly and the second electrode assembly are arranged side by side.

12. The battery cell according to any one of claims 1 to 11, wherein: The first electrode tab and the second electrode tab have the same polarity.

13. A battery, characterized in that: A battery cell comprising the battery cell according to any one of claims 1 to 12.

14. An electrical device, characterized in that: The battery cell comprises the battery cell according to any one of claims 1 to 12, wherein the battery cell is used to provide electrical energy.

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