CN221508426U - Electrode assembly, battery cell, battery and electrical device - Google Patents

Abstract

The embodiment of the application provides an electrode assembly, a battery cell, a battery and an electric device. The electrode assembly includes a main body portion and a plurality of first tabs extending from the main body portion, the plurality of first tabs being stacked. In the thickness direction of the first tabs, two adjacent first tabs at least partially overlap. In the thickness direction, the maximum number of first tabs that overlap simultaneously is smaller than the total number of first tabs. The application reduces the number of the first tabs which are overlapped at the same time in the thickness direction, so as to reduce the difficulty of connecting the first tabs to other conductive structures, and enable the electrode assembly to be provided with more first tabs, thereby improving the overcurrent capacity of the electrode assembly.

Description

Electrode assembly, battery cell, battery and electrical device

Technical Field

The present application relates to the technical field of batteries, and more particularly, to an electrode assembly, a battery cell, a battery, and an electrical device.

Background Art

Battery cells are widely used in electronic devices, such as mobile phones, laptop computers, electric vehicles, electric cars, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes, and electric tools, etc. Battery cells can include nickel-cadmium battery cells, nickel-hydrogen battery cells, lithium-ion battery cells, and secondary alkaline zinc-manganese battery cells, etc.

In the development of battery technology, how to improve the current carrying capacity is a research direction in battery technology.

Summary of the invention

The present application provides an electrode assembly and a manufacturing method and system thereof, a battery cell, a battery and an electrical device, which can improve the current carrying capacity.

In a first aspect, an embodiment of the present application provides an electrode assembly, comprising a main body and a plurality of first pole tabs extending from the main body, wherein the plurality of first pole tabs are stacked. In the thickness direction of the first pole tabs, two adjacent first pole tabs at least partially overlap. In the thickness direction, the maximum number of first pole tabs that overlap simultaneously is less than the total number of first pole tabs.

The above scheme reduces the number of first pole tabs that overlap simultaneously in the thickness direction, so as to reduce the difficulty of connecting the first pole tabs to other conductive structures, so that the electrode assembly can be provided with more first pole tabs, thereby improving the current carrying capacity of the electrode assembly. Two adjacent first pole tabs overlap at least partially, so that multiple first pole tabs can be in a continuous state, which can simplify the connection process between the first pole tabs and the conductive structure and improve the assembly efficiency of the battery cell.

In some embodiments, a plurality of first pole tabs are led out from one end of the main body along a first direction, and the plurality of first pole tabs are arranged in a staggered manner in a second direction, and the second direction is perpendicular to the first direction and the thickness direction.

In the above solution, the plurality of first electrode tabs are arranged in a staggered manner in the second direction, so that the number of first electrode tabs that overlap simultaneously in the thickness direction can be reduced.

In some embodiments, the plurality of first tabs are staggered at equal distances in the second direction.

The above solution can make the overall thickness variation of the plurality of first electrode tabs more uniform, which helps to improve the lamination effect between the first electrode tab and other conductive structures and enhance the connection strength between the first electrode tab and the conductive structure.

In some embodiments, the thickness of the first pole tab is T, the dimension of the first pole tab along the second direction is L, the offset of two adjacent first pole tabs in the second direction is D, and T, L and D satisfy: D≥(T×L)/H; wherein 0.1mm≤H≤2mm.

The above solution can ensure that the maximum thickness of the whole formed by the plurality of first electrode tabs does not exceed the set value H, thereby ensuring the connection strength between the first electrode tabs and other conductive structures.

In some embodiments, the thickness of the first electrode tab is T, the maximum number of first electrode tabs that overlap simultaneously in the thickness direction is N, and N and T satisfy: N×T≤1 mm.

The above solution can make the maximum thickness of the whole formed by the multiple first pole ears not exceed 1 mm, which can reduce the power required for welding the multiple first pole ears, reduce heat generation, and reduce the risk of burning the first pole ears.

In some embodiments, the maximum number of first electrode tabs that overlap simultaneously in the thickness direction is N, the total number of first electrode tabs is M, and N and M satisfy: N/M≤0.8.

The above solution can reduce the maximum number of first electrode tabs that overlap simultaneously in the thickness direction, and reduce the maximum thickness of the whole formed by multiple first electrode tabs, thereby ensuring the connection strength between the first electrode tabs and other conductive structures.

In some embodiments, the electrode assembly includes a plurality of first pole pieces and a plurality of second pole pieces, the plurality of first pole pieces and the plurality of second pole pieces are alternately stacked, and the polarities of the first pole pieces and the second pole pieces are opposite. The first pole piece includes a first coating area coated with a first active material layer and a first pole ear led out from the first coating area. The main body includes the first coating area.

In the above scheme, since multiple first pole pieces are independently provided, each first pole piece needs to be provided with a first pole ear to realize the extraction of electric energy. The above scheme can reduce the number of first pole ears that overlap simultaneously in the thickness direction, so that the electrode assembly can be provided with more first pole ears, and thus the electrode assembly can be provided with more first pole pieces, thereby increasing the capacity of the electrode assembly.

In some embodiments, the electrode assembly includes a first pole piece and a second pole piece with opposite polarities, and the first pole piece and the second pole piece are wound along a winding axis. The first pole piece includes a first coating area coated with a first active material layer and a plurality of first pole tabs extending from the first coating area. The main body includes the first coating area.

In some embodiments, the electrode assembly includes a first electrode sheet and a second electrode sheet with opposite polarities, the first electrode sheet is continuously bent and includes a plurality of stacked sections and a plurality of bent sections, the plurality of stacked sections and the plurality of second electrode sheets are alternately stacked, and each bent section connects two adjacent stacked sections. Each stacked section is provided with a first electrode ear. The main body includes a stacked section and a bent section.

In some embodiments, the electrode assembly further includes a second electrode tab, and the first electrode tab and the second electrode tab are respectively led out from two ends of the main body.

The above scheme arranges the first pole ear and the second pole ear on both sides of the main body respectively, which can provide more space for the first pole ear and the second pole ear, so that the first pole ear and the second pole ear have a larger size, thereby improving the current flow capacity of the electrode assembly.

In a second aspect, an embodiment of the present application provides a battery cell, comprising: a housing; an electrode assembly according to any embodiment of the first aspect, housed in the housing; and a first electrode terminal, mounted on the housing and used to be electrically connected to the first electrode tab.

In some embodiments, the first electrode tab is directly connected to the first electrode terminal, which can omit the traditional transition component, simplify the structure of the battery cell, and improve the energy density of the battery cell.

In a third aspect, an embodiment of the present application provides a battery comprising a plurality of battery cells according to the second aspect.

In a fourth aspect, an embodiment of the present application provides an electrical device, comprising the battery cell of the second aspect, wherein the battery cell is used to provide electrical energy.

In a fifth aspect, an embodiment of the present application provides a method for manufacturing an electrode assembly, comprising:

Providing a first pole piece and a second pole piece;

Winding or stacking the first electrode sheet and the second electrode sheet to form an electrode assembly;

The electrode assembly includes a main body and a plurality of first pole ears extending from the main body, wherein the plurality of first pole ears are stacked; in the thickness direction of the first pole ears, two adjacent first pole ears at least partially overlap; in the thickness direction, the maximum number of first pole ears overlapping at the same time is less than the total number of first pole ears.

In a sixth aspect, an embodiment of the present application provides a manufacturing system for an electrode assembly, comprising:

providing a device for providing a first pole piece and a second pole piece;

An assembling device, used for winding or stacking the first pole sheet and the second pole sheet to form an electrode assembly;

The electrode assembly includes a main body and a plurality of first pole ears extending from the main body, wherein the plurality of first pole ears are stacked; in the thickness direction of the first pole ears, two adjacent first pole ears at least partially overlap; in the thickness direction, the maximum number of first pole ears overlapping at the same time is less than the total number of first pole ears.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the drawings without creative work.

FIG1 is a schematic diagram of the structure of a vehicle provided in some embodiments of the present application;

FIG2 is an exploded schematic diagram of a battery provided in some embodiments of the present application;

FIG3 is a schematic structural diagram of the battery module shown in FIG2 ;

FIG4 is an exploded schematic diagram of a battery cell provided in some embodiments of the present application;

FIG5 is a perspective schematic diagram of an electrode assembly provided in some embodiments of the present application;

FIG6 is a schematic side view of the electrode assembly shown in FIG5 ;

FIG7 is a side view schematic diagram of an electrode assembly provided in some other embodiments of the present application;

FIG8 is a side view schematic diagram of an electrode assembly provided in some other embodiments of the present application;

FIG9 is a schematic cross-sectional view of the electrode assembly shown in FIG5 ;

FIG10 is a schematic structural diagram of the first pole piece shown in FIG9 ;

FIG11 is a cross-sectional schematic diagram of an electrode assembly provided in some embodiments of the present application;

FIG12 is a schematic structural diagram of the first pole piece shown in FIG11 in an unfolded state;

FIG13 is a cross-sectional schematic diagram of an electrode assembly provided in some embodiments of the present application;

FIG14 is a schematic structural diagram of the first pole piece shown in FIG13 in an unfolded state;

FIG. 15 is a schematic flow chart of a method for manufacturing an electrode assembly according to some embodiments of the present application;

FIG. 16 is a schematic block diagram of a system for manufacturing an electrode assembly according to some embodiments of the present application.

In the drawings, the drawings are not drawn to scale.

DETAILED DESCRIPTION

In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as those commonly understood by technicians in the technical field of this application; the terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned drawings and any variations thereof are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary and secondary relationship.

Reference to "embodiment" in this application means that a particular feature, structure or characteristic described in conjunction with the embodiment may be included in at least one embodiment of the present application. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments.

In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "attached" 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 direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

The term "and/or" in this application is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and/or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character "/" in this application generally indicates that the associated objects before and after are in an "or" relationship.

In the embodiments of the present application, "parallel" includes not only the absolutely parallel situation, but also the roughly parallel situation conventionally recognized in engineering; at the same time, "vertical" includes not only the absolutely vertical situation, but also the roughly vertical situation conventionally recognized in engineering.

In the embodiments of the present application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width and other dimensions of various components in the embodiments of the present application shown in the drawings, as well as the overall thickness, length, width and other dimensions of the integrated device are only exemplary descriptions and should not constitute any limitation to the present application.

The term "plurality" used in the present application refers to two or more (including two).

In the embodiments of the present application, the battery cells may include lithium-ion secondary battery cells, lithium-ion primary battery cells, lithium-sulfur battery cells, sodium-lithium-ion battery cells, sodium-ion battery cells or magnesium-ion battery cells, etc., which are not limited in the embodiments of the present application. The battery cells may be cylindrical, flat, cuboid or other shapes, which are not limited in the embodiments of the present application.

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 be 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.

The battery cell includes an electrode assembly and an electrolyte, and the electrode assembly includes a positive electrode sheet, a negative electrode sheet and a separator. The electrode assembly can adopt a wound structure or a laminated structure. In a wound electrode assembly, the positive electrode sheet, the separator and the negative electrode sheet are stacked in sequence and wound more than two times. In a laminated electrode assembly, multiple positive electrode sheets and multiple negative electrode sheets are alternately stacked.

Battery cells mainly rely on the movement of metal ions between the positive electrode sheet and the negative electrode sheet to work. The positive electrode sheet includes a positive current collector and a positive active material layer, and 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 tab connected to the positive current collector, the positive current collector is coated with a positive active material layer, and the positive electrode tab is not coated with the positive active material layer. Taking lithium-ion batteries as an example, the material of the positive current collector can be aluminum, and the positive active material layer includes a positive active material, and 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, the negative current collector is coated with a negative active material layer, and the negative electrode tab is not coated with a negative active material layer. The negative electrode current collector may be made of copper, the negative electrode active material layer includes a negative electrode active material, and the negative electrode active material may be carbon or silicon, etc. The separator may be made of PP (polypropylene) or PE (polyethylene), etc.

The electrode assembly draws out the current through the positive electrode tab and the negative electrode tab. In order to ensure that a large current can pass without melting, the positive electrode tabs are multiple and stacked together, and the negative electrode tabs are multiple and stacked together.

The multiple positive pole ears (or negative pole ears) of the electrode assembly need to be stacked together and connected to the electrode terminal or the adapter member of the battery cell to lead the current to the outside of the battery cell. The inventor found that the more positive pole ears there are, the greater the total thickness of the positive pole ears, and the greater the difficulty of connecting the positive pole ears to the electrode terminals; when the total thickness of the positive pole ears reaches a certain value, it may cause the positive pole ears to be poorly connected to the electrode terminals, and even cause the positive pole ears to be unable to connect to the electrode terminals. Therefore, the number of positive pole ears will be limited, thereby affecting the current capacity of the electrode assembly. In particular, in a laminated electrode assembly, each positive pole sheet needs to be provided with a positive pole ear. When the number of positive pole ears is limited, the number of positive pole sheets will also be limited, which will affect the capacity of the electrode assembly.

In view of this, an embodiment of the present application provides a technical solution, in which an electrode assembly includes a main body and a plurality of first pole ears extending from the main body, and the plurality of first pole ears are stacked. In the thickness direction of the first pole ears, two adjacent first pole ears at least partially overlap. In the thickness direction, the maximum number of first pole ears that overlap simultaneously is less than the total number of first pole ears. An embodiment of the present application reduces the number of first pole ears that overlap simultaneously in the thickness direction to reduce the difficulty of connecting the first pole ears to the electrode terminal or the transition member, so that the electrode assembly can be provided with more first pole ears, thereby improving the current carrying capacity of the electrode assembly. Two adjacent first pole ears at least partially overlap, so that the plurality of first pole ears can be in a continuous state, which can simplify the connection process between the first pole ears and the electrode terminal and improve the assembly efficiency of the battery cell.

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

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 includes an airplane, a rocket, a space shuttle, and a spacecraft, and the like; the electric toy includes 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 includes 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.

For the convenience of description, the following embodiments are described by taking the electric device as a vehicle as an example.

FIG1 is a schematic diagram of the structure of a vehicle provided in some embodiments of the present application.

As shown in FIG1 , a battery 2 is disposed inside the vehicle 1, and the battery 2 may be disposed at the bottom, head, or tail of the vehicle 1. The battery 2 may be used to power the vehicle 1, for example, the battery 2 may be used as an operating power source for the vehicle 1.

The vehicle 1 may further include a controller 3 and a motor 4 , wherein the controller 3 is used to control the battery 2 to supply power to the motor 4 , for example, to meet the power requirements of starting, navigating, and driving the vehicle 1 .

In some embodiments of the present application, the battery 2 can not only serve as an operating power source for the vehicle 1, but also serve 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.

Fig. 2 is an exploded schematic diagram of a battery provided in some embodiments of the present application. As shown in Fig. 2 , the battery 2 comprises a box body 5 and a battery cell (not shown in Fig. 2 ), and the battery cell is accommodated in the box body 5 .

The box 5 is used to accommodate the battery cells, and the box 5 can be of various structures. In some embodiments, the box 5 can include a first box portion 5a and a second box portion 5b, the first box portion 5a and the second box portion 5b cover each other, and the first box portion 5a and the second box portion 5b jointly define a storage space 5c for accommodating the battery cells. The second box portion 5b can be a hollow structure with one end open, the first box portion 5a is a plate-like structure, and the first box portion 5a covers the open side of the second box portion 5b to form a box 5 with a storage space 5c; the first box portion 5a and the second box portion 5b can also be hollow structures with one side open, and the open side of the first box portion 5a covers the open side of the second box portion 5b to form a box 5 with a storage space 5c. Of course, the first box portion 5a and the second box portion 5b can be of various shapes, such as a cylinder, a cuboid, etc.

In order to improve the sealing performance after the first box body part 5a and the second box body part 5b are connected, a sealing member, such as a sealant, a sealing ring, etc., may also be provided between the first box body part 5a and the second box body part 5b.

Assuming that the first box body portion 5a covers the top of the second box body portion 5b, the first box body portion 5a can also be called an upper box cover, and the second box body portion 5b can also be called a lower box.

In the battery 2, there can be one or more battery cells. If there are multiple battery cells, the multiple battery cells can be connected in series, in parallel, or in mixed connection. Mixed connection means that the multiple battery cells are both connected in series and in parallel. The multiple battery cells can be directly connected in series, in parallel, or in mixed connection, and then the whole formed by the multiple battery cells is accommodated in the box 5; of course, multiple battery cells can also be connected in series, in parallel, or in mixed connection to form a battery module 6, and the multiple battery modules 6 are then connected in series, in parallel, or in mixed connection to form a whole, and accommodated in the box 5.

FIG. 3 is a schematic structural diagram of the battery module shown in FIG. 2 .

In some embodiments, as shown in FIG3 , there are multiple battery cells 7, and the multiple battery cells 7 are first connected in series, in parallel, or in mixed connection to form a battery module 6. The multiple battery modules 6 are then connected in series, in parallel, or in mixed connection to form a whole, and are accommodated in a box.

The multiple battery cells 7 in the battery module 6 can be electrically connected through a busbar component to achieve parallel connection, series connection or mixed connection of the multiple battery cells 7 in the battery module 6 .

FIG. 4 is a schematic diagram of an explosion of a battery cell provided in some embodiments of the present application.

As shown in FIG. 4 , the battery cell 7 of the embodiment of the present application includes an electrode assembly 10 and a housing 20 , and the housing 20 is used to accommodate the electrode assembly 10 .

The electrode assembly 10 is a core component for realizing the charge and discharge functions of the battery cell 7, and includes a first pole piece, a second pole piece, and a separator. The first pole piece and the second pole piece have opposite polarities, and the separator is used to insulate and isolate the first pole piece and the second pole piece. The electrode assembly 10 mainly works by moving metal ions between the first pole piece and the second pole piece. One of the first pole piece and the second pole piece is a positive pole piece, and the other of the first pole piece and the second pole piece is a negative pole piece.

From the appearance of the electrode assembly 10, the electrode assembly 10 includes a main body 11 and a first pole ear 12 and a second pole ear 13 led out from the main body 11. The main body 11 is the electricity generating part of the electrode assembly 10, and the active material inside it is used to react electrochemically with the electrolyte, etc. to generate a charge and discharge process. The first pole ear 12 and the second pole ear 13 have opposite polarities and are used to lead out the electric energy generated by the main body 11.

The first electrode tab 12 and the second electrode tab 13 may be led out from the same end of the main body 11, or may be led out from opposite ends of the main body 11. For example, as shown in FIG4 , the first electrode tab 12 and the second electrode tab 13 are led out from opposite ends of the main body 11.

In the battery cell 7 , there may be one or more electrode assemblies 10 .

The housing 20 is a hollow structure, and a cavity for accommodating the electrode assembly 10 and the electrolyte is formed inside the housing 20. The housing 20 can be in various shapes, such as a cylinder, a cuboid, etc. The shape of the housing 20 can be determined according to the specific shape of the electrode assembly 10. For example, if the electrode assembly 10 is a cylindrical structure, a cylindrical housing can be selected; if the electrode assembly 10 is a cuboid structure, a cuboid housing can be selected.

In some embodiments, the housing 20 includes a shell 21 and an end cap 22, the shell 21 is a hollow structure with an opening, and the end cap 22 covers the opening of the shell 21 and forms a sealed connection to form a receiving chamber for accommodating the electrode assembly 10 and the electrolyte. In some examples, the shell 21 is a hollow structure with an opening on one side, and the end cap 22 is one and covers the opening of the shell 21. In other examples, the shell 21 is a hollow structure with openings on both sides, and there are two end caps 22, and the two end caps 22 cover the two openings of the shell 21 respectively.

The battery cell 7 also includes a first electrode terminal 30 and a second electrode terminal 40 installed on the outer shell 20. The first electrode terminal 30 is used to be electrically connected to the first pole ear 12, and the second electrode terminal 40 is used to be electrically connected to the second pole ear 13. The first electrode terminal 30 and the second electrode terminal 40 are used to conduct electrical energy in the electrode assembly 10 to the outside of the battery cell 7.

In some embodiments, the first electrode terminal 30 and the second electrode terminal 40 are mounted on the end cap 22. In some examples, the battery cell 7 includes two end caps 22, and the first electrode terminal 30 and the second electrode terminal 40 are mounted on the two end caps 22, respectively.

The first electrode terminal 30 may be directly connected to the first electrode tab 12 , or may be indirectly connected to the first electrode tab 12 through other transition components.

In some embodiments, the first electrode tab 12 is directly connected to the first electrode terminal 30 , which can omit the transition component, simplify the internal structure of the battery cell 7 , and improve the energy density.

The first electrode terminal 30 can be connected to the first electrode tab 12 by welding, clamping, bonding or other methods. In some embodiments, the first electrode tab 12 is welded to the first electrode terminal 30 .

The second electrode terminal 40 may be directly connected to the second electrode tab 13 , or may be indirectly connected to the second electrode tab 13 through other transition components.

In some embodiments, the second electrode tab 13 is directly connected to the second electrode terminal 40 , which can omit the transition component, simplify the internal structure of the battery cell 7 , and improve the energy density.

The second electrode terminal 40 can be connected to the second electrode tab 13 by welding, clamping, bonding or other methods. In some embodiments, the second electrode tab 13 is welded to the second electrode terminal 40.

FIG5 is a three-dimensional schematic diagram of an electrode assembly provided in some embodiments of the present application; FIG6 is a side schematic diagram of the electrode assembly shown in FIG5 .

As shown in FIGS. 5 and 6 , the electrode assembly 10 of the embodiment of the present application includes a main body 11 and a plurality of first pole tabs 12 extending from the main body 11, and the plurality of first pole tabs 12 are stacked. In the thickness direction Z of the first pole tabs 12, two adjacent first pole tabs 12 at least partially overlap. In the thickness direction Z, the maximum number of first pole tabs 12 that overlap simultaneously is less than the total number of first pole tabs 12.

In this embodiment, any two adjacent first pole tabs 12 at least partially overlap in the thickness direction Z. In some examples, any two adjacent first pole tabs 12 are staggered so that the two adjacent first pole tabs 12 only partially overlap in the thickness direction Z. In other examples, in some first pole tabs 12, any two adjacent first pole tabs 12 are staggered so that the two adjacent first pole tabs 12 only partially overlap in the thickness direction Z; in other first pole tabs 12, any two adjacent first pole tabs 12 completely overlap in the thickness direction Z.

The simultaneous overlap of the first pole tabs 12 in the thickness direction Z means that there is an overlapping area of the projections of the first pole tabs 12 along the thickness direction Z, and it is not required that the projections of the first pole tabs 12 along the thickness direction Z completely overlap. The projections of the first pole tabs 12 refer to the projections of the first pole tabs 12 in the same plane perpendicular to the thickness direction Z.

The projections of all the first electrode tabs 12 in a plane perpendicular to the thickness direction Z are continuous.

The embodiment of the present application reduces the number of first pole tabs 12 that overlap simultaneously in the thickness direction Z, so as to reduce the difficulty of connecting the first pole tabs 12 to other conductive structures (such as first electrode terminals or transition components), so that the electrode assembly 10 can be provided with more first pole tabs 12, thereby improving the current carrying capacity of the electrode assembly 10. Two adjacent first pole tabs 12 overlap at least partially, so that the plurality of first pole tabs 12 can be in a continuous state, which can simplify the connection process between the first pole tabs 12 and the conductive structure and improve the assembly efficiency of the battery cell.

In some embodiments, the first electrode tab 12 is directly connected to the first electrode terminal, which can omit the traditional transition component, simplify the structure of the battery cell, and improve the energy density of the battery cell.

In some embodiments, the plurality of first pole tabs 12 are connected to the first electrode terminal by laser welding. Specifically, during assembly, the plurality of first pole tabs 12 are first stacked on the first electrode terminal, and then the first pole tab 12 and the first electrode terminal are welded by laser from the side of the first pole tab 12. In this embodiment, the plurality of first pole tabs 12 are in a continuous state, so that the laser can be moved continuously to weld the plurality of first pole tabs 12 to the first electrode terminal, thereby reducing the number of starts and stops of the laser welding equipment, thereby simplifying the connection process of the first pole tab 12 and the first electrode terminal, and improving the assembly efficiency of the battery cell.

In some embodiments, a plurality of first tabs 12 are led out from one end of the main body 11 along the first direction X, and the plurality of first tabs 12 are sequentially staggered in a second direction Y, and the second direction Y is perpendicular to the first direction X and the thickness direction Z.

The body portion 11 includes a first surface 11a and a second surface 11b disposed oppositely along a second direction Y, and a third surface 11c and a fourth surface 11d disposed oppositely along a third direction perpendicular to the second direction Y. Exemplarily, the third direction is parallel to the thickness direction Z.

Among any two adjacent first electrode tabs 12 , the minimum distance between the first electrode tab 12 close to the third surface 11 c and the first surface 11 a in the second direction Y is greater than the minimum distance between the first electrode tab 12 away from the third surface 11 c and the first surface 11 a in the second direction Y.

In this embodiment, the plurality of first electrode tabs 12 may have the same size in the second direction Y, or may have different sizes.

In this embodiment, the plurality of first electrode tabs 12 are sequentially arranged in a staggered manner in the second direction Y, so that the number of first electrode tabs 12 that overlap simultaneously in the thickness direction Z can be reduced.

In some embodiments, the plurality of first electrode tabs 12 are staggered in the second direction Y at equal distances.

The offset amount of two adjacent first electrode tabs 12 in the second direction Y is D. The distance between the ends of two adjacent first electrode tabs 12 facing the first surface 11 a in the second direction Y is the offset amount D.

In this embodiment, the misalignment amount of any two adjacent first tabs 12 in the second direction Y is D. D is a set constant value. Of course, due to process errors, the value of D is allowed to fluctuate within a certain range.

This embodiment can make the thickness of the whole structure formed by the plurality of first electrode tabs 12 more uniform, which helps to improve the lamination effect between the first electrode tab 12 and other conductive structures and enhance the connection strength between the first electrode tab 12 and the conductive structure.

In some embodiments, the thickness of the first pole tab 12 is T, the dimension of the first pole tab 12 along the second direction Y is L, the offset of two adjacent first pole tabs 12 in the second direction Y is D, and T, L and D satisfy: D≥(T×L)/H; wherein 0.1mm≤H≤2mm.

The value of H is determined based on the welding capability of the welding equipment. Under the premise of ensuring the connection strength, the welding equipment can weld a plate-like structure with a maximum thickness of H to the conductive structure.

In this embodiment, the maximum thickness of the whole formed by the plurality of first electrode tabs 12 does not exceed the set value H, thereby ensuring the connection strength between the first electrode tabs 12 and other conductive structures.

In some embodiments, the thickness of the first electrode tab 12 is T, the maximum number of first electrode tabs 12 overlapping simultaneously in the thickness direction Z is N, and N and T satisfy: N×T≤1 mm. N is a positive integer greater than 1.

N, T and H satisfy: N×T≤H.

Exemplarily, N×T≤0.5 mm.

This embodiment can make the maximum thickness of the whole formed by the multiple first pole tabs 12 not exceed 1 mm, which can reduce the power required for welding the multiple first pole tabs 12, reduce heat generation, and reduce the risk of the first pole tabs 12 being burned.

In some embodiments, the maximum number of first tabs 12 overlapping simultaneously in the thickness direction Z is N, the total number of first tabs 12 is M, and N and M satisfy: N/M≤0.8. Both N and M are positive integers greater than 1.

Illustratively, the value of N/M may be 0.2, 0.4, 0.6 or 0.8.

This embodiment can reduce the maximum number of first electrode tabs 12 that overlap simultaneously in the thickness direction Z, and reduce the maximum thickness of the entire structure formed by the plurality of first electrode tabs 12 , thereby ensuring the connection strength between the first electrode tabs 12 and other conductive structures.

In some embodiments, the electrode assembly 10 further includes a second electrode tab 13 , and the first electrode tab 12 and the second electrode tab 13 are respectively led out from two ends of the main body 11 .

In this embodiment, the first pole tab 12 and the second pole tab 13 are respectively arranged on both sides of the main body 11, so that more space can be provided for the first pole tab 12 and the second pole tab 13, so that the first pole tab 12 and the second pole tab 13 have a larger size, thereby improving the current flow capacity of the electrode assembly 10.

FIG. 7 is a schematic side view of an electrode assembly provided in some other embodiments of the present application.

As shown in FIG. 7 , in some embodiments, in some first pole tabs 12 , any two adjacent first pole tabs 12 are staggered so that the two adjacent first pole tabs 12 only partially overlap in the thickness direction Z; in other first pole tabs 12 , any two adjacent first pole tabs 12 completely overlap in the thickness direction Z.

FIG8 is a schematic side view of an electrode assembly provided in some other embodiments of the present application.

As shown in FIG. 8 , in some embodiments, along the direction from the third surface 11 c to the fourth surface 11 d , the M first pole tabs 12 are respectively defined as a first first pole tab 12 , a second first pole tab 12 , . . . the Mth first pole tab 12 .

The first first pole tab 12 to the Kth first pole tab 12 are sequentially staggered in the direction away from the first surface 11a in the second direction Y, and the Kth first pole tab 12 to the Mth first pole tab 12 are sequentially staggered in the direction facing the first surface 11a in the second direction Y. K is a positive integer greater than 1 and less than M.

FIG. 9 is a schematic cross-sectional view of the electrode assembly shown in FIG. 5 ; and FIG. 10 is a schematic structural view of the first pole piece shown in FIG. 9 .

As shown in FIGS. 9 and 10 , in some embodiments, the electrode assembly 10 includes a plurality of first pole pieces 14 and a plurality of second pole pieces 15, which are alternately stacked, and the polarities of the first pole pieces 14 and the second pole pieces 15 are opposite. The first pole piece 14 includes a first coating area 141 coated with a first active material layer and a first pole ear 12 led out from the first coating area 141. The main body includes the first coating area 141.

The electrode assembly 10 of this embodiment is a laminated electrode assembly. The first electrode sheet 14 and the second electrode sheet 15 are both flat plate structures, and the stacking direction of the first electrode sheet 14 and the second electrode sheet 15 is parallel to the thickness direction of the first electrode sheet 14 and the thickness direction of the second electrode sheet 15 .

The first electrode sheet 14 includes a first current collector and a first active material layer, the first active material layer is coated on the surface of the first current collector; the first current collector includes a first current collecting portion and a first electrode tab 12 connected to the first current collecting portion, the first current collecting portion is coated with the first active material layer, and the first electrode tab 12 is not coated with the first active material layer. The first coating area 141 includes the first current collecting portion and the first active material layer coated on the first current collecting portion.

The second electrode sheet 15 includes a second coating region coated with a second active material layer and a second electrode tab extending from the second coating region.

Specifically, the second pole piece 15 includes a second current collector and a second active material layer, the second active material layer is coated on the surface of the second current collector; the second current collector includes a second current collecting portion and a second pole ear connected to the second current collecting portion, the second current collecting portion is coated with the second active material layer, and the second pole ear is not coated with the second active material layer. The second coating area includes the second current collecting portion and the second active material layer coated on the second current collecting portion.

The electrode assembly 10 further includes an isolation member 16 for insulating and isolating the first electrode sheet 14 from the second electrode sheet 15 .

The main body portion includes a first coating region 141 , a second coating region, and an isolation member 16 .

In this embodiment, since a plurality of first pole pieces 14 are independently provided, each first pole piece 14 needs to be provided with a first pole ear 12 to achieve the extraction of electric energy. This embodiment can reduce the number of first pole ears 12 that overlap simultaneously in the thickness direction, so that the electrode assembly 10 can be provided with more first pole ears 12, and thus the electrode assembly 10 can be provided with more first pole pieces 14, thereby increasing the capacity of the electrode assembly 10.

FIG11 is a schematic cross-sectional view of an electrode assembly provided in some embodiments of the present application; FIG12 is a schematic structural view of the first electrode piece shown in FIG11 in an unfolded state.

As shown in Figures 11 and 12, in some embodiments, the electrode assembly 10 includes a first pole piece 14 and a second pole piece 15 with opposite polarities, and the first pole piece 14 and the second pole piece 15 are wound along a winding axis. The first pole piece 14 includes a first coating area 141 coated with a first active material layer and a plurality of first pole tabs 12 led out from the first coating area 141. The main body includes the first coating area 141.

The electrode assembly 10 of this embodiment is a wound electrode assembly. The first pole piece 14 and the second pole piece 15 are both strip-shaped structures and are wound more than two times along the winding axis. Exemplarily, the electrode assembly 10 is a flat structure.

The second electrode sheet 15 includes a second coating region coated with a second active material layer and a plurality of second electrode tabs extending from the second coating region. The main body 11 includes a first coating region 141 , a second coating region and a separator 16 .

FIG13 is a schematic cross-sectional view of an electrode assembly provided in some embodiments of the present application; FIG14 is a schematic structural view of the first electrode piece shown in FIG13 in an unfolded state.

As shown in FIG. 13 and FIG. 14, in some embodiments, the electrode assembly 10 includes a first electrode sheet 14 and a second electrode sheet 15 with opposite polarities, the first electrode sheet 14 is continuously bent and includes a plurality of stacked segments 14a and a plurality of bent segments 14b, the plurality of stacked segments 14a and the plurality of second electrode sheets 15 are alternately stacked, and each bent segment 14b connects two adjacent stacked segments 14a. Each stacked segment 14a is provided with a first electrode ear 12. The main body 11 includes a stacked segment 14a and a bent segment 14b.

The first electrode sheet 14 includes a first coating area 141 coated with a first active material layer and a first electrode tab 12 extending from the first coating area 141. The first coating area 141 is continuously bent to form a stacking section 14a and a bending section 14b.

The second electrode sheet 15 includes a second coating area coated with a second active material layer and a second electrode tab extending from the second coating area. The main body includes a first coating area 141 , a second coating area and a separator 16 .

FIG. 15 is a schematic flow chart of a method for manufacturing an electrode assembly provided in some embodiments of the present application.

As shown in FIG15 , the manufacturing method of the electrode assembly of the embodiment of the present application includes:

S100, providing a first pole piece and a second pole piece;

S200, winding or stacking the first pole sheet and the second pole sheet to form an electrode assembly;

The electrode assembly includes a main body and a plurality of first pole ears extending from the main body, wherein the plurality of first pole ears are stacked; in the thickness direction of the first pole ears, two adjacent first pole ears at least partially overlap; in the thickness direction, the maximum number of first pole ears overlapping at the same time is less than the total number of first pole ears.

It should be noted that the relevant structure of the electrode assembly manufactured by the above-mentioned electrode assembly manufacturing method can refer to the electrode assembly provided in the above-mentioned embodiments.

FIG. 16 is a schematic block diagram of a system for manufacturing an electrode assembly according to some embodiments of the present application.

As shown in FIG16 , the manufacturing system 90 of the electrode assembly of the embodiment of the present application includes a providing device 91 and an assembling device 92, wherein the providing device 91 is used to provide a first pole piece and a second pole piece, and the assembling device 92 is used to wind or stack the first pole piece and the second pole piece to form an electrode assembly. The electrode assembly includes a main body and a plurality of first pole ears extending from the main body, wherein the plurality of first pole ears are stacked; in the thickness direction of the first pole ears, two adjacent first pole ears at least partially overlap; in the thickness direction, the maximum number of first pole ears overlapping at the same time is less than the total number of first pole ears.

The relevant structure of the electrode assembly manufactured by the above-mentioned manufacturing system can refer to the electrode assembly provided in the above-mentioned embodiments.

It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application may be combined with each other.

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 it. 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 make equivalent replacements for some of the technical features therein, but these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit of the technical solutions of the embodiments of the present application.

Claims (13)

1. A battery cell, comprising:

A housing;

An electrode assembly accommodated in the case, the electrode assembly including a main body portion and a plurality of first tabs drawn out from the main body portion, the plurality of first tabs being stacked; in the thickness direction of the first tabs, two adjacent first tabs at least partially overlap; the maximum number of the first tabs overlapped simultaneously is smaller than the total number of the first tabs in the thickness direction;

And a first electrode terminal mounted to the case and electrically connected to the first tab.

2. The battery cell according to claim 1, wherein a plurality of the first tabs are led out from one end of the main body portion in a first direction, the plurality of the first tabs are sequentially arranged in a staggered manner in a second direction, and the second direction is perpendicular to the first direction and the thickness direction.

3. The battery cell of claim 2, wherein a plurality of the first tabs are equidistantly offset in the second direction.

4. The battery cell of claim 3, wherein the thickness of the first tab is T, the dimension of the first tab in the second direction is L, the misalignment amounts of two adjacent first tabs in the second direction are D, T, L, and D satisfy:

D≥(T×L)/H；

Wherein H is more than or equal to 0.1mm and less than or equal to 2mm.

5. The battery cell according to claim 1, wherein the thickness of the first tab is T, and the maximum number of first tabs that overlap simultaneously in the thickness direction is N, and T satisfy: n x T is less than or equal to 1mm.

6. The battery cell according to claim 1, wherein the maximum number of the first tabs that overlap simultaneously in the thickness direction is N, the total number of the first tabs is M, N and M satisfy: N/M is less than or equal to 0.8.

7. The battery cell of any one of claims 1-6, wherein the electrode assembly comprises a plurality of first electrode sheets and a plurality of second electrode sheets, the plurality of first electrode sheets and the plurality of second electrode sheets are alternately stacked, and the polarities of the first electrode sheets and the second electrode sheets are opposite;

The first pole piece comprises a first coating area coated with a first active material layer and the first pole lug led out from the first coating area;

The body portion includes the first coating region.

8. The battery cell of any one of claims 1-6, wherein the electrode assembly comprises first and second electrode sheets of opposite polarity wound along a winding axis;

The first pole piece comprises a first coating area coated with a first active material layer and a plurality of first pole lugs led out from the first coating area;

The body portion includes the first coating region.

9. The battery cell according to any one of claims 1-6, wherein the electrode assembly comprises first and second electrode sheets of opposite polarity, the first electrode sheet being continuously bent and comprising a plurality of stacked segments and a plurality of bent segments, the plurality of stacked segments and the plurality of second electrode sheets being alternately stacked, each of the bent segments connecting two adjacent stacked segments;

each lamination section is provided with the first tab;

the body portion includes the lamination section and the bending section.

10. The battery cell of claim 1, wherein the electrode assembly further comprises a second tab, the first tab and the second tab being respectively led from both ends of the body portion.

11. The battery cell of claim 1, wherein the first tab is directly connected to the first electrode terminal.

12. A battery comprising a plurality of cells according to any one of claims 1-11.

13. An electrical device comprising a battery cell according to any one of claims 1-11 for providing electrical energy.