WO2023092459A1

WO2023092459A1 - Electrode assembly, battery cell, battery, and electrical device

Info

Publication number: WO2023092459A1
Application number: PCT/CN2021/133559
Authority: WO
Inventors: 雷育永; 郭志君; 王鹏; 金海族
Original assignee: 宁德时代新能源科技股份有限公司
Priority date: 2021-11-26
Filing date: 2021-11-26
Publication date: 2023-06-01

Abstract

Embodiments of the present application provide an electrode assembly, a battery cell, a battery, and an electrical device. The electrode assembly comprises a main body portion and a plurality of first tabs led out from the main body portion, wherein the plurality of first tabs are 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 overlapping at the same time is less than the total number of the first tabs. According to the present application, the number of first tabs overlapping at the same time in the thickness direction is reduced, so as to reduce the difficulty in connecting the first tabs to other conductive structures, so that the electrode assembly can be provided with more first tabs, thereby improving the current passing capability of the electrode assembly.

Description

Electrode assembly, battery cell, battery and electrical device

technical field

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

Background technique

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

In the development of battery technology, how to improve the over-current capability is a research direction in battery technology.

Contents of the invention

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

In a first aspect, an embodiment of the present application provides an electrode assembly, including a main body and a plurality of first tabs drawn out from the main body, and the plurality of first tabs are 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 simultaneously overlapping first tabs is less than the total number of first tabs.

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

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

In the above solution, a plurality of first tabs are sequentially arranged in dislocation in the second direction, which can reduce the number of first tabs that overlap simultaneously in the thickness direction.

In some embodiments, the plurality of first tabs are displaced at an equal distance in the second direction.

The above-mentioned solution can make the overall thickness change of the plurality of first tabs more uniform, help to improve the bonding effect between the first tab and other conductive structures, and improve the connection strength between the first tab and the conductive structure.

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

The above solution can make the overall maximum thickness of the plurality of first tabs not exceed the set value H, thereby ensuring the connection strength between the first tab and other conductive structures.

In some embodiments, the thickness of the first tab is T, and the maximum number of simultaneously overlapping first tabs in the thickness direction is N, where N and T satisfy: N×T≦1mm.

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

In some embodiments, the maximum number of first tabs overlapping in the thickness direction is N, the total number of first tabs is M, and N and M satisfy: N/M≦0.8.

The above solution can reduce the maximum number of first tabs that overlap simultaneously in the thickness direction, and reduce the overall maximum thickness of a plurality of first tabs, thereby ensuring the connection strength between the first tab 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 first pole piece and the second pole piece opposite polarity. The first pole piece includes a first coating area coated with a first active material layer and a first tab led out from the first coating area. The body portion includes a first coating area.

In the above solution, since a plurality of first pole pieces are arranged independently, each first pole piece needs to be provided with a first tab to realize the derivation of electric energy. The above solution can reduce the number of first tabs that overlap in the thickness direction at the same time, so that the electrode assembly can be provided with more first tabs, and the electrode assembly can be provided with more first pole pieces, thereby improving the electrode performance. The capacity of the component.

In some embodiments, the electrode assembly includes first and second pole pieces of opposite polarity, the first and second pole pieces being 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 tabs drawn out from the first coating area. The body portion includes a first coating area.

In some embodiments, the electrode assembly includes a first pole piece and a second pole piece with opposite polarities, the first pole piece is bent continuously and includes a plurality of laminated segments and a plurality of bent segments, a plurality of laminated segments and a plurality of The second pole pieces are stacked alternately, and each bent section connects two adjacent stacked sections. Each lamination segment is provided with a first tab. The main body includes a laminated section and a bent section.

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

In the above solution, the first tab and the second tab are respectively arranged on both sides of the main body, so that more space can be provided for the first tab and the second tab, so that the first tab and the second tab have Larger size, thus improving the flow capacity of the electrode assembly.

In a second aspect, an embodiment of the present application provides a battery cell, including: a casing; the electrode assembly in any embodiment of the first aspect, accommodated in the casing; a first electrode terminal, installed in the casing and used to connect with the first pole Ear connection.

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

In a third aspect, the embodiment of the present application provides a battery, including a plurality of battery cells in the second aspect.

In a fourth aspect, an embodiment of the present application provides an electrical device, including the battery cell in the second aspect, and the battery cell is used to provide electric energy.

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

providing a first pole piece and a second pole piece;

winding or stacking the first pole piece and the second pole piece to form an electrode assembly;

Wherein, the electrode assembly includes a main body and a plurality of first tabs drawn out from the main body, and the plurality of first tabs are stacked; in the thickness direction of the first tabs, at least part of the adjacent two first tabs ground overlap; in the thickness direction, the maximum number of simultaneously overlapping first tabs is less than the total number of first tabs.

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

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

assembly means for winding or stacking the first pole piece and the second pole piece to form an electrode assembly;

Description of drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the accompanying drawings that need to be used in the embodiments of the present application. Obviously, the accompanying drawings described below are only some embodiments of the present application. Those of ordinary skill in the art can also obtain other drawings based on the accompanying drawings on the premise of not paying creative efforts.

Fig. 1 is a schematic structural diagram of a vehicle provided by some embodiments of the present application;

Fig. 2 is a schematic explosion diagram of a battery provided by some embodiments of the present application;

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

Fig. 4 is a schematic explosion diagram of a battery cell provided by some embodiments of the present application;

FIG. 5 is a perspective view of an electrode assembly provided by some embodiments of the present application;

6 is a schematic side view of the electrode assembly shown in FIG. 5;

Fig. 7 is a schematic side view of an electrode assembly provided by another embodiment of the present application;

Fig. 8 is a schematic side view of an electrode assembly provided in some other embodiments of the present application;

9 is a schematic cross-sectional view of the electrode assembly shown in FIG. 5;

Fig. 10 is a schematic structural view of the first pole piece shown in Fig. 9;

Fig. 11 is a schematic cross-sectional view of an electrode assembly provided by some embodiments of the present application;

Fig. 12 is a schematic structural diagram of the first pole piece shown in Fig. 11 in an unfolded state;

Fig. 13 is a schematic cross-sectional view of an electrode assembly provided by some embodiments of the present application;

Fig. 14 is a schematic structural diagram of the first pole piece shown in Fig. 13 in an unfolded state;

Fig. 15 is a schematic flowchart of a method for manufacturing an electrode assembly provided in some embodiments of the present application;

Fig. 16 is a schematic block diagram of an electrode assembly manufacturing system provided by some embodiments of the present application.

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

Detailed ways

In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions 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 the Claim some of the examples, not all of them. Based on the embodiments in this application, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of this application.

Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by those skilled in the technical field of this application; the terms used in this application in the description of the application are only to describe specific implementations The purpose of the example is not intended to limit the present application; the terms "comprising" and "having" and any variations thereof in the description and claims of the present application and the description of the above drawings are intended to cover non-exclusive inclusion. The terms "first", "second" and the like in the description and claims of the present application or the above drawings are used to distinguish different objects, rather than to describe a specific sequence or primary-subordinate relationship.

Reference in this application to an "embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the present application. The occurrences of this phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments.

In the description of this application, it should be noted that, unless otherwise clearly stipulated and limited, the terms "installation", "connection", "connection" and "attachment" should be understood in a broad sense, for example, it may be a fixed connection, It can also be detachably connected or integrally connected; it can be directly connected or indirectly connected through an intermediary, and it can be internal communication between two components. Those of ordinary skill in the art can understand the specific meanings of the above terms in this application according to specific situations.

The term "and/or" in this application is only an association relationship describing associated objects, which means that there may be three relationships, for example, A and/or B, which can mean: A exists alone, A and B exist simultaneously, and A and B exist alone. There are three cases of B. In addition, the character "/" in this application generally indicates that the contextual objects are an "or" relationship.

In the embodiments of the present application, "parallel" not only includes the situation of being absolutely parallel, but also includes the situation of roughly parallel in engineering conventional recognition; at the same time, "perpendicular" also includes not only the situation of being absolutely perpendicular, but also the situation of conventional engineering. Cognitive roughly vertical situations.

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 the various components in the embodiments of the application shown in the drawings, as well as the overall thickness, length and width of the integrated device, are for illustrative purposes only, and should not constitute any limitation to the application .

"Plurality" in this application refers to two or more (including two).

In the embodiments of 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 Body, etc., which are not limited in this embodiment of the present application. The battery cell can be in the form of a cylinder, a flat body, a cuboid or other shapes, which is not limited in this embodiment 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 this application may be a battery module or a battery pack. Batteries generally include a case for enclosing one or more battery cells. The box can prevent liquid or other foreign objects 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 pole piece, a negative pole piece and a separator. The electrode assembly can adopt a wound structure or a laminated structure. In the wound-type electrode assembly, the positive pole piece, the separator, and the negative pole piece are stacked in sequence and wound more than two times. In the laminated electrode assembly, a plurality of positive electrode sheets and a plurality of negative electrode sheets are alternately stacked.

A battery cell works primarily by moving metal ions between the positive and negative pole pieces. The positive electrode sheet includes a positive electrode current collector and a positive electrode active material layer, and the positive electrode active material layer is coated on the surface of the positive electrode current collector; the positive electrode current collector includes a positive electrode current collector and a positive electrode lug connected to the positive electrode current collector, and the positive electrode current collector It is coated with a positive electrode active material layer, and the positive electrode tab is not coated with a positive electrode active material layer. Taking a lithium ion battery as an example, the material of the positive electrode current collector can be aluminum, the positive electrode active material layer includes the positive electrode active material, and the positive electrode active material can be lithium cobaltate, lithium iron phosphate, ternary lithium or lithium manganate. The negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer, and the negative electrode active material layer is coated on the surface of the negative electrode current collector; the negative electrode current collector includes a negative electrode current collector and a negative electrode tab connected to the negative electrode current collector, and the negative electrode current collector The negative electrode active material layer is coated, and the negative electrode tab is not coated with the negative electrode active material layer. The material of the negative electrode current collector may be copper, the negative electrode active material layer includes the negative electrode active material, and the negative electrode active material may be carbon or silicon. The material of the spacer can be PP (polypropylene, polypropylene) or PE (polyethylene, polyethylene).

The electrode assembly draws the current through the positive tab and the negative tab. In order to ensure that large currents will not be blown, there are multiple positive tabs and stacked together, and multiple negative tabs are stacked together.

A plurality of positive tabs (or negative tabs) of the electrode assembly need to be stacked together and connected to the electrode terminal or transition member of the battery cell, so as to lead the current to the outside of the battery cell. The inventors have found that the greater the number of positive tabs, the greater the total thickness of the positive tabs, and the greater the difficulty in connecting the positive tabs to the electrode terminals; when the total thickness of the positive tabs reaches a certain value, it may It will cause poor connection between the positive tab and the electrode terminal, or even cause the positive tab and the electrode terminal to fail to connect. Therefore, the number of positive tabs will be limited, thereby affecting the flow-through capability of the electrode assembly. In particular, in the laminated electrode assembly, each positive electrode piece needs to be provided with a positive electrode tab. When the number of positive electrode tabs is limited, the number of positive electrode pieces will also be limited, which will affect the electrode assembly. capacity.

In view of this, an embodiment of the present application provides a technical solution. In this technical solution, the electrode assembly includes a main body and a plurality of first tabs drawn from the main body, and the plurality of first tabs are 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 simultaneously overlapping first tabs is less than the total number of first tabs. The embodiment of the present application reduces the number of first tabs that overlap in the thickness direction at the same time, so as to reduce the difficulty of connecting the first tabs to the electrode terminals or transition members, so that the electrode assembly can be provided with more first tabs , thereby improving the overcurrent capability of the electrode assembly. Two adjacent first tabs at least partially overlap, so that the plurality of first tabs can be in a continuous state, which can simplify the connection process between the first tabs and the electrode terminals, and improve the assembly efficiency of the battery cells.

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

Electric devices can be vehicles, mobile phones, portable devices, notebook computers, ships, spacecraft, electric toys and electric tools, and so on. Vehicles can be fuel vehicles, gas vehicles or new energy vehicles, and new energy vehicles can be pure electric vehicles, hybrid vehicles or extended-range vehicles; spacecraft include airplanes, rockets, space shuttles and spacecraft, etc.; electric toys include fixed Type or mobile electric toys, such as game consoles, electric car toys, electric boat toys and electric airplane toys, etc.; electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools and railway electric tools, for example, Electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, electric planers, and more. The embodiments of the present application do not impose special limitations on the above-mentioned electrical devices.

In the following embodiments, for the convenience of description, the electric device is taken as an example for description.

Fig. 1 is a schematic structural diagram of a vehicle provided by some embodiments of the present application.

As shown in FIG. 1 , a battery 2 is arranged inside the vehicle 1 , and the battery 2 can be arranged at the bottom, head or tail of the vehicle 1 . The battery 2 can be used for power supply of the vehicle 1 , for example, the battery 2 can be used as an operating power source of the vehicle 1 .

The vehicle 1 may also include a controller 3 and a motor 4 , the controller 3 is used to control the battery 2 to supply power to the motor 4 , for example, for the starting, navigation and working power requirements of the vehicle 1 during driving.

In some embodiments of the present application, the battery 2 can not only be used as an operating power source for the vehicle 1 , but can also be used as a driving power source for the vehicle 1 to provide driving power for the vehicle 1 instead of or partially replacing fuel oil or natural gas.

Fig. 2 is a schematic explosion diagram of a battery provided by some embodiments of the present application. As shown in FIG. 2 , the battery 2 includes 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 body 5 is used to accommodate the battery cells, and the box body 5 may have various structures. In some embodiments, the box body 5 may include a first box body part 5a and a second box body part 5b, the first box body part 5a and the second box body part 5b cover each other, the first box body part 5a and the second box body part 5a The two box parts 5b jointly define an accommodating space 5c for accommodating the battery cells. The second box body part 5b can be a hollow structure with one end open, the first box body part 5a is a plate-shaped structure, and the first box body part 5a covers the opening side of the second box body part 5b to form an accommodating space 5c The box body 5; the first box body portion 5a and the second box body portion 5b also can be a hollow structure with one side opening, and the opening side of the first box body portion 5a is covered on the opening side of the second box body portion 5b , to form a box body 5 with an accommodating space 5c. Certainly, the first box body part 5a and the second box body part 5b can be in various shapes, such as a cylinder, a cuboid, and the like.

In order to improve the airtightness after the connection of the first box body part 5a and the second box body part 5b, a sealant, such as sealant, sealing ring, etc., can also be arranged between the first box body part 5a and the second box body part 5b. .

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

In the battery 2, there may 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 parallel. The hybrid connection means that there are both series and parallel connections among the multiple battery cells. A plurality of battery cells can be directly connected in series or in parallel or mixed together, and then the whole composed of a plurality of battery cells is accommodated in the box 5; of course, it is also possible to first connect a plurality of battery cells in series or parallel or The battery modules 6 are formed by parallel connection, and multiple battery modules 6 are connected in series or in parallel or in series to form a whole, and are housed in the box body 5 .

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

In some embodiments, as shown in FIG. 3 , there are multiple battery cells 7 , and the multiple battery cells 7 are connected in series, in parallel, or in parallel to form a battery module 6 . A plurality of battery modules 6 are connected in series, in parallel or in parallel to form a whole, and accommodated in the box.

The plurality of battery cells 7 in the battery module 6 can be electrically connected through a confluence component, so as to realize parallel connection, series connection or mixed connection of the plurality of battery cells 7 in the battery module 6 .

Fig. 4 is a schematic exploded view of a battery cell provided by 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 casing 20 , and the casing 20 is used to accommodate the electrode assembly 10 .

The electrode assembly 10 is the core component for the battery cell 7 to realize the charging and discharging function, and it includes a first pole piece, a second pole piece and a spacer, the polarity of the first pole piece and the second pole piece are opposite, and the spacer is used to The first pole piece is insulated from the second pole piece. The electrode assembly 10 mainly relies on metal ions to move between the first pole piece and the second pole piece to work. 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 tab 12 and a second tab 13 extending from the main body 11 . The main body 11 is the electricity generation part of the electrode assembly 10 , and the active material inside it is used for electrochemical reaction with the electrolyte etc., so as to generate the charging and discharging process. The polarities of the first tab 12 and the second tab 13 are opposite, and are used to lead out the electric energy generated by the main body 11 .

The first tab 12 and the second tab 13 can be drawn out from the same end of the main body 11 , or can be drawn out from opposite ends of the main body 11 respectively. Exemplarily, as shown in FIG. 4 , the first tab 12 and the second tab 13 are drawn out from both ends of the main body 11 .

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

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

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

The battery cell 7 also includes a first electrode terminal 30 and a second electrode terminal 40 mounted on the casing 20, the first electrode terminal 30 is used for electrical connection with the first tab 12, and the second electrode terminal 40 is used for connecting with the second pole The ear 13 is electrically connected, and the first electrode terminal 30 and the second electrode terminal 40 are used to export the electric 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 installed on the two end caps 22 respectively.

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

In some embodiments, the first tab 12 is directly connected to the first electrode terminal 30 , so that an adapter member can be omitted, the internal structure of the battery cell 7 can be simplified, and the energy density can be increased.

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

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

In some embodiments, the second tab 13 is directly connected to the second electrode terminal 40 , so that an adapter member can be omitted, the internal structure of the battery cell 7 can be simplified, and the energy density can be increased.

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

FIG. 5 is a schematic perspective view of an electrode assembly provided by some embodiments of the present application; FIG. 6 is a schematic side view of the electrode assembly shown in FIG. 5 .

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

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

Simultaneous overlapping of the first tabs 12 in the thickness direction Z means that projections of the first tabs 12 along the thickness direction Z have overlapping regions, and it is not required that the projections of the first tabs 12 along the thickness direction Z completely overlap. The projections of the first tabs 12 refer to the projections of the first tabs 12 in the same plane perpendicular to the thickness direction Z.

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

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

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

In some embodiments, the plurality of first tabs 12 are connected to the first electrode terminal by laser welding. Specifically, during assembly, a plurality of first tabs 12 are stacked on the first electrode terminal, and then the first tab 12 and the first electrode terminal are welded by laser from the side of the first tab 12 . In this embodiment, the plurality of first tabs 12 are in a continuous state, so that the laser can move continuously to weld the plurality of first tabs 12 to the first electrode terminal, thus reducing the number of times of starting and stopping of the laser welding equipment, Therefore, the connection process between the first tab 12 and the first electrode terminal is simplified, and the assembly efficiency of the battery cell is improved.

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 arranged in a dislocation in the second direction Y, and the second direction Y is perpendicular to The first direction X and the thickness direction Z.

The main body 11 includes a first surface 11a and a second surface 11b opposite to each other along a second direction Y, and a third surface 11c and a fourth surface 11d opposite to each other 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 tabs 12, the minimum distance between the first tab 12 close to the third surface 11c and the first surface 11a in the second direction Y is greater than that of the first tab far away from the third surface 11c 12 and the minimum distance between the first surface 11a in the second direction Y.

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

In this embodiment, a plurality of first tabs 12 are sequentially arranged in dislocation in the second direction Y, which can reduce the number of first tabs 12 overlapping in the thickness direction Z at the same time.

In some embodiments, the plurality of first tabs 12 are dislocated in the second direction Y at an equal distance.

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

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

This embodiment can make the overall thickness change of a plurality of first tabs 12 more uniform, help to improve the bonding effect between the first tab 12 and other conductive structures, and improve the bonding effect between the first tab 12 and the conductive structure. connection strength.

In some embodiments, the thickness of the first tab 12 is T, the dimension of the first tab 12 along the second direction Y is L, and the misalignment of two adjacent first tabs 12 in the second direction Y For D, 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 the plate structure with a maximum thickness H to the conductive structure.

In this embodiment, the overall maximum thickness of the plurality of first tabs 12 does not exceed the set value H, so as to ensure the connection strength between the first tab 12 and other conductive structures.

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

N, T and H satisfy: N×T≦H.

Exemplarily, N×T≦0.5mm.

In this embodiment, the maximum thickness of the whole of multiple first tabs 12 is no more than 1 mm, which can reduce the power required for welding multiple first tabs 12, reduce heat generation, and reduce burns of the first tabs 12 risks of.

In some embodiments, the maximum number of first tabs 12 overlapping 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.

Exemplarily, 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 tabs 12 that overlap simultaneously in the thickness direction Z, and reduce the overall maximum thickness of a plurality of first tabs 12, thereby ensuring the connection between the first tab 12 and other conductive structures. connection strength.

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

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

Fig. 7 is a schematic side view of an electrode assembly provided by another embodiment of the present application.

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

Fig. 8 is a schematic side view of an electrode assembly provided by some other embodiments of the present application.

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

The first first tab 12 to the Kth first tab 12 are sequentially arranged in dislocation along the direction away from the first surface 11a in the second direction Y, and the Kth first tab 12 to the Mth first tab The tabs 12 are sequentially arranged in a dislocation along 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 ; 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 , and a plurality of first pole pieces 14 and a plurality of second pole pieces 15 Alternately stacked, and the polarity of the first pole piece 14 and the second pole piece 15 are opposite. The first pole piece 14 includes a first coating area 141 coated with a first active material layer and a first tab 12 drawn out from the first coating area 141 . The body portion includes a first coating area 141 .

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

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

The second pole piece 15 includes a second coating area coated with a second active material layer and a second tab led out from the second coating area.

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

The electrode assembly 10 also includes a spacer 16 insulating and isolating the first pole piece 14 and the second pole piece 15 .

The main body includes a first coating area 141 , a second coating area and a spacer 16 .

In this embodiment, since a plurality of first pole pieces 14 are provided independently, each first pole piece 14 needs to be provided with a first tab 12 to realize the derivation of electric energy. This embodiment can reduce the number of first tabs 12 overlapping in the thickness direction, so that more first tabs 12 can be provided on the electrode assembly 10, and more first poles can be provided on the electrode assembly 10. sheet 14, thereby increasing the capacity of the electrode assembly 10.

Fig. 11 is a schematic cross-sectional view of an electrode assembly provided by some embodiments of the present application; Fig. 12 is a schematic structural view of the first pole piece shown in Fig. 11 in an unfolded state.

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

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

The second pole piece 15 includes a second coating area coated with a second active material layer and a plurality of second tabs drawn out from the second coating area. The main body part 11 includes a first coating area 141 , a second coating area and a spacer 16 .

FIG. 13 is a schematic cross-sectional view of an electrode assembly provided by some embodiments of the present application; FIG. 14 is a schematic structural view of the first pole piece shown in FIG. 13 in an unfolded state.

As shown in FIGS. 13 and 14 , 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 is continuously bent and includes a plurality of laminated segments 14 a and multiple bent sections 14b, multiple stacked sections 14a and multiple second pole pieces 15 are alternately stacked, and each bent section 14b connects two adjacent stacked sections 14a. Each lamination segment 14a is provided with a first tab 12 . The main body 11 includes a laminated section 14a and a bent section 14b.

The first pole piece 14 includes a first coating area 141 coated with a first active material layer and a first tab 12 drawn out from the first coating area 141 . The first coating area 141 is bent continuously to form a laminated section 14a and a bent section 14b.

The second pole piece 15 includes a second coating area coated with a second active material layer and a second tab led out from the second coating area. The main body includes a first coating area 141 , a second coating area and a spacer 16 .

Fig. 15 is a schematic flowchart of a method for manufacturing an electrode assembly provided by some embodiments of the present application.

As shown in Figure 15, 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 piece and the second pole piece to form an electrode assembly;

It should be noted that, for the relevant structure of the electrode assembly manufactured by the above method for manufacturing the electrode assembly, reference may be made to the electrode assembly provided in the above embodiments.

As shown in Figure 16, the electrode assembly manufacturing system 90 of the embodiment of the present application includes a supply device 91 and an assembly device 92, the supply device 91 is used to provide the first pole piece and the second pole piece, and the assembly device 92 is used to use the first The pole piece and the second pole piece are wound or laminated to form an electrode assembly. The electrode assembly includes a main body and a plurality of first tabs drawn out from the main body, and the plurality of first tabs are 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 simultaneously overlapping first tabs is less than the total number of first tabs.

For the relevant structure of the electrode assembly manufactured by the above manufacturing system, reference may be made to the electrode assembly provided in the above embodiments.

It should be noted that, in the case of no conflict, the embodiments in the present application and the features in the embodiments can 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 limiting them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: it can still Modifications are made to the technical solutions described in the foregoing embodiments, or equivalent replacements are made to some of the technical features, but these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit of the technical solutions of the embodiments of the present application.

Claims

An electrode assembly, comprising a main body and a plurality of first tabs drawn out from the main body, 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 simultaneously overlapping first tabs is less than the total number of first tabs.
The electrode assembly according to claim 1, wherein a plurality of the first tabs are led out from one end of the main body along the first direction, and the plurality of first tabs are sequentially arranged in a shifted position in the second direction , the second direction is perpendicular to the first direction and the thickness direction.
The electrode assembly according to claim 2, wherein a plurality of the first tabs are displaced equidistantly in the second direction.
The electrode assembly according to claim 3, wherein the thickness of the first tab is T, the dimension of the first tab along the second direction is L, and two adjacent first poles The amount of misalignment of the ear in the second direction is D, and T, L and D satisfy:

D≥(T×L)/H;

Among them, 0.1mm≤H≤2mm.
The electrode assembly according to any one of claims 1-4, wherein the thickness of the first tab is T, and the maximum number of the first tabs simultaneously overlapping in the thickness direction is N, N and T satisfy: N×T≤1mm.
The electrode assembly according to any one of claims 1-5, wherein the maximum number of the first tabs overlapped simultaneously in the thickness direction is N, and the total number of the first tabs is M, N and M satisfy: N/M≤0.8.
The electrode assembly according to any one of claims 1-6, comprising a plurality of first pole pieces and a plurality of second pole pieces, a plurality of the first pole pieces and a plurality of the second pole pieces are alternately stacked, And the polarity of the first pole piece and the second pole piece are opposite;

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

The body portion includes the first coating area.
The electrode assembly according to any one of claims 1-6, comprising a first pole piece and a second pole piece with opposite polarities, the first pole piece and the second pole piece being 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 tabs drawn from the first coating area;

The body portion includes the first coating area.
The electrode assembly according to any one of claims 1-6, comprising a first pole piece and a second pole piece with opposite polarities, the first pole piece is bent continuously and includes a plurality of laminated segments and a plurality of bends segments, a plurality of the stacked segments and a plurality of the second pole pieces are alternately stacked, and each of the bent segments connects two adjacent stacked segments;

Each of the lamination segments is provided with the first tab;

The main body part includes the laminated section and the bent section.
The electrode assembly according to any one of claims 1-9, further comprising a second tab, the first tab and the second tab are drawn out from both ends of the main body respectively.
A battery cell, comprising:

shell;

The electrode assembly according to any one of claims 1-10, housed in the casing;

The first electrode terminal is installed on the housing and used for electrical connection with the first tab.
The battery cell according to claim 11, wherein the first tab is directly connected to the first electrode terminal.
A battery comprising a plurality of battery cells according to claim 11 or 12.
An electric device, comprising the battery cell according to claim 11 or 12, the battery cell is used to provide electric energy.
A method of manufacturing an electrode assembly, comprising:

providing a first pole piece and a second pole piece;

winding or stacking the first pole piece and the second pole piece to form an electrode assembly;

Wherein, the electrode assembly includes a main body and a plurality of first tabs drawn out from the main body, and the plurality of first tabs are stacked; in the thickness direction of the first tabs, adjacent Two first tabs are at least partially overlapped; in the thickness direction, the maximum number of overlapping first tabs at the same time is less than the total number of first tabs.
A manufacturing system for an electrode assembly, comprising:

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

an assembly device for winding or stacking the first pole piece and the second pole piece to form an electrode assembly;

Wherein, the electrode assembly includes a main body and a plurality of first tabs drawn out from the main body, and the plurality of first tabs are stacked; in the thickness direction of the first tabs, adjacent Two first tabs are at least partially overlapped; in the thickness direction, the maximum number of overlapping first tabs at the same time is less than the total number of first tabs.