CN221508426U

CN221508426U - Electrode assembly, battery cell, battery and electricity utilization device

Info

Publication number: CN221508426U
Application number: CN202190000990.2U
Authority: CN
Inventors: 雷育永; 郭志君; 王鹏; 金海族
Original assignee: Contemporary Amperex Technology Co Ltd
Current assignee: Contemporary Amperex Technology Co Ltd
Priority date: 2021-11-26
Filing date: 2021-11-26
Publication date: 2024-08-09
Anticipated expiration: 2031-11-26
Also published as: WO2023092459A1

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 electricity utilization device

Technical Field

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

Background

Battery cells are widely used in electronic devices such as cellular phones, notebook computers, battery cars, electric vehicles, electric airplanes, electric ships, electric toy vehicles, electric toy ships, electric toy airplanes, electric tools, and the like. The battery cells may include cadmium-nickel battery cells, hydrogen-nickel 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 overcurrent capability is one research direction in battery technology.

Disclosure of Invention

The application provides an electrode assembly, a manufacturing method and a manufacturing system thereof, a battery cell, a battery and an electric device, which can improve overcurrent capability.

In a first aspect, an embodiment of the present application provides an electrode assembly including a main body portion and a plurality of first tabs led 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. In the thickness direction, the maximum number of first tabs that overlap simultaneously is smaller than the total number of first tabs.

According to the scheme, the number of the first tabs which are overlapped simultaneously in the thickness direction is reduced, so that the difficulty in connecting the first tabs to other conductive structures is reduced, more first tabs can be arranged on the electrode assembly, and the overcurrent capacity of the electrode assembly is improved. The adjacent two first tabs are at least partially overlapped, so that a plurality of first tabs are in a continuous state, the connection process of the first tabs and the conductive structure can be simplified, and the assembly efficiency of the battery cell is improved.

In some embodiments, the 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 staggered manner in a second direction, wherein the second direction is perpendicular to the first direction and the thickness direction.

In the scheme, the first tabs are sequentially staggered in the second direction, so that the number of the first tabs which are overlapped in the thickness direction at the same time can be reduced.

In some embodiments, the plurality of first tabs are equidistantly offset in the second direction.

The thickness change of the whole formed by the first tabs is more uniform, so that the bonding effect of the first tabs and other conductive structures is improved, and the connection strength of the first tabs and the conductive structures is improved.

In some embodiments, 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 is more than or equal to (T multiplied by L)/H; wherein H is more than or equal to 0.1mm and less than or equal to 2mm.

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

In some embodiments, 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.

According to the scheme, the maximum thickness of the whole formed by the plurality of first lugs is not more than 1mm, so that the power required by welding the plurality of first lugs can be reduced, heat generation is reduced, and the risk of burning the first lugs is reduced.

In some embodiments, the maximum number of first tabs that overlap simultaneously in the thickness direction is N, and the total number of first tabs is M, N, and M satisfy: N/M is less than or equal to 0.8.

According to the scheme, the maximum number of the first tabs which are overlapped simultaneously in the thickness direction can be reduced, and the overall maximum thickness formed by a plurality of first tabs is reduced, so that the connection strength of the first tabs and other conductive structures is ensured.

In some embodiments, the electrode assembly includes 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 being alternately stacked, and the polarities of the first electrode sheets and the second electrode sheets being opposite. The first pole piece comprises 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 coated region.

In the above scheme, since the plurality of first pole pieces are independently arranged, each first pole piece needs to be provided with a first tab so as to realize the export of electric energy. According to the scheme, the number of the first tabs overlapped simultaneously in the thickness direction can be reduced, so that more first tabs can be arranged on the electrode assembly, more first pole pieces can be arranged on the electrode assembly, and the capacity of the electrode assembly is improved.

In some embodiments, the electrode assembly includes first and second pole pieces 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 a first coated region.

In some embodiments, the electrode assembly includes first and second electrode sheets of opposite polarity, the first electrode sheet being continuously bent and including a plurality of lamination segments and a plurality of bending segments, the plurality of lamination segments and the plurality of second electrode sheets being alternately laminated, each bending segment connecting two adjacent lamination segments. Each lamination section is provided with a first tab. The body portion includes a lamination section and a bending section.

In some embodiments, the electrode assembly further includes a second tab, the first tab and the second tab being respectively led from both ends of the body portion.

According to the scheme, the first tab and the second tab are respectively arranged on two sides of the main body part, so that more space can be provided for the first tab and the second tab, the first tab and the second tab have larger sizes, and the overcurrent capacity of the electrode assembly is improved.

In a second aspect, an embodiment of the present application provides a battery cell, including: a housing; the electrode assembly of any of the embodiments of the first aspect, housed within a casing; and a first electrode terminal mounted to the case and electrically connected to the first tab.

In some embodiments, the first tab is directly connected to the first electrode terminal, so that a conventional switching member can be omitted, the structure of the battery cell can be simplified, and the energy density of the battery cell can be improved.

In a third aspect, embodiments of the present application provide a battery comprising a plurality of the battery cells of the second aspect.

In a fourth aspect, an embodiment of the present application provides an electrical device, including the battery cell of the second aspect, where the battery cell is configured to provide electrical energy.

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

Providing a first pole piece and a second pole piece;

winding or laminating the first and second electrode sheets to form an electrode assembly;

The electrode assembly comprises a main body part and a plurality of first tabs led out from the main body part, wherein the 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 that overlap simultaneously is smaller than the total number of first tabs.

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

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

An assembly device for winding or laminating the first and second electrode sheets to form an electrode assembly;

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments of the present application will be briefly described below, and it is obvious that the drawings described below are only some embodiments of the present application, and other drawings may be obtained according to the drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic illustration of a vehicle according to some embodiments of the present application;

Fig. 2 is an exploded view of a battery according to some embodiments of the present application;

fig. 3 is a schematic view of the structure of the battery module shown in fig. 2;

Fig. 4 is an exploded view of a battery cell according to some embodiments of the present application;

fig. 5 is a perspective view of an electrode assembly according to some embodiments of the present application;

FIG. 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 according to further embodiments of the present application;

FIG. 8 is a schematic side view of an electrode assembly according to further embodiments of the present application;

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

FIG. 10 is a schematic view of the first pole piece of FIG. 9;

FIG. 11 is a schematic cross-sectional view of an electrode assembly provided in some embodiments of the application;

FIG. 12 is a schematic view of the first pole piece of FIG. 11 in an expanded state;

FIG. 13 is a schematic cross-sectional view of an electrode assembly provided in some embodiments of the application;

FIG. 14 is a schematic view of the first pole piece of FIG. 13 in an expanded state;

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

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

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

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present application more apparent, the technical solutions of the embodiments of the present application will be clearly described below with reference to the accompanying drawings in the embodiments of the present application, and it is apparent that the described embodiments are some embodiments of the present application, but not all embodiments of the present application. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application; the terms "comprising" and "having" and any variations thereof in the description of the application and the claims and the description of the drawings above are intended to cover a non-exclusive inclusion. The terms first, second and the like in the description and in the claims or in the above-described figures, are used for distinguishing between different objects and not necessarily for describing a particular sequential or chronological order.

Reference in the specification to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearances of such phrases 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 the present application, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "attached" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art according to the specific circumstances.

The term "and/or" in the present application is merely an association relation describing the association object, and indicates that three kinds of relations may exist, for example, a and/or B may indicate: a exists alone, A and B exist together, and B exists alone. In the present application, the character "/" generally indicates that the front and rear related objects are an or relationship.

In embodiments of the present application, "parallel" includes not only the case of absolute parallelism, but also the case of substantially parallelism that is conventionally recognized in engineering; meanwhile, "vertical" includes not only the case of absolute vertical but also the case of substantially vertical as conventionally recognized in engineering.

In the embodiments of the present application, the same reference numerals denote the same components, and detailed descriptions of the same components are omitted in different embodiments for the sake of brevity. It should be understood that the thickness, length, width, etc. dimensions of the various components in the embodiments of the application shown in the drawings, as well as the overall thickness, length, width, etc. dimensions of the integrated device, are merely illustrative and should not be construed as limiting the application in any way.

The term "plurality" as used herein refers to two or more (including two).

In the embodiment 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, which is not limited in the embodiment of the present application. The battery cell may be in a cylindrical shape, a flat shape, a rectangular parallelepiped shape, or other shapes, which is not limited in this embodiment of the application.

Reference to a battery in accordance with an embodiment of the present application refers to a single physical module that includes one or more battery cells to provide higher voltage and capacity. For example, the battery referred to in the present application may be a battery module or a battery pack, or the like. The battery generally includes a case for enclosing one or more battery cells. The case body can prevent liquid or other foreign matters from affecting the charge or discharge of the battery cells.

The battery cell comprises an electrode assembly and electrolyte, wherein the electrode assembly comprises a positive electrode plate, a negative electrode plate and a separator. The electrode assembly may adopt a roll-to-roll structure or a lamination structure. In the wound electrode assembly, the positive electrode sheet, the separator, and the negative electrode sheet are sequentially stacked and wound for two or more turns. In the laminated electrode assembly, a plurality of positive electrode tabs and a plurality of negative electrode tabs are alternately laminated.

The battery cell mainly relies on metal ions to move between the positive pole piece and the negative pole piece to work. The positive electrode plate comprises 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 current collector comprises a positive current collecting part and a positive lug connected to the positive current collecting part, wherein the positive current collecting part is coated with a positive active material layer, and the positive lug is not coated with the positive active material layer. Taking a lithium ion battery as an example, the material of the positive electrode current collector may be aluminum, the positive electrode active material layer includes a positive electrode active material, and the positive electrode active material may be lithium cobaltate, lithium iron phosphate, ternary lithium, lithium manganate or the like. The negative electrode plate comprises 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 comprises a negative electrode current collecting part and a negative electrode tab connected to the negative electrode current collecting part, wherein the negative electrode current collecting part is coated with a negative electrode active material layer, and the negative electrode tab is not coated with the negative electrode active material layer. The material of the anode current collector may be copper, the anode active material layer includes an anode active material, and the anode active material may be carbon or silicon, or the like. The material of the separator may be PP (polypropylene) or PE (polyethylene), etc.

The electrode assembly leads out current through the positive electrode lugs and the negative electrode lugs, and in order to ensure that the current does not fuse when passing through large current, the positive electrode lugs are multiple and stacked together, and the negative electrode lugs are multiple and stacked together.

A plurality of positive electrode tabs (or negative electrode tabs) of the electrode assembly are required to be stacked together and connected to electrode terminals or switching members of the battery cells to draw current to the outside of the battery cells. The inventor finds that the more the number of the positive electrode lugs is, the larger the total thickness of the positive electrode lugs is, and the more difficult the positive electrode lugs are to be connected with the electrode terminals is; when the total thickness of the positive electrode tab reaches a certain value, the connection between the positive electrode tab and the electrode terminal may be poor, and even the connection between the positive electrode tab and the electrode terminal may not be possible. Therefore, the number of positive electrode tabs may be limited, thereby affecting the overcurrent capability of the electrode assembly. In particular, in a laminated electrode assembly, each positive electrode tab needs to be provided with a positive electrode tab, and when the number of positive electrode tabs is limited, the number of positive electrode tabs is also limited, which affects 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 portion and a plurality of first tabs led 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. In the thickness direction, the maximum number of first tabs that overlap simultaneously is smaller than the total number of first tabs. The embodiment of 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 the electrode terminal or the switching component, and enable the electrode assembly to be provided with more first tabs, thereby improving the overcurrent capacity of the electrode assembly. The adjacent two first tabs are at least partially overlapped, so that a plurality of first tabs are in a continuous state, the connection process of the first tabs and the electrode terminals can be simplified, and the assembly efficiency of the battery cell is improved.

The technical scheme described by the embodiment of the application is suitable for the battery and the power utilization device using the battery.

The electric device may be a vehicle, a mobile phone, a portable device, a notebook computer, a ship, a spacecraft, an electric toy, an electric tool, or the like. The vehicle can be a fuel oil vehicle, a fuel gas vehicle or a new energy vehicle, and the new energy vehicle can be a pure electric vehicle, a hybrid electric vehicle or a range-extended vehicle; spacecraft including airplanes, rockets, space planes, spacecraft, and the like; the electric toy includes fixed or mobile electric toys, such as a game machine, an electric car toy, an electric ship toy, and an electric airplane toy; power tools include metal cutting power tools, grinding power tools, assembly power tools, and railroad power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete shakers, and electric planers, among others. The embodiment of the application does not limit the electric device in particular.

For convenience of explanation, the following examples will be described taking an electric device as an example of a vehicle.

Fig. 1 is a schematic structural diagram of a vehicle according to some embodiments of the present application.

As shown in fig. 1, the interior of the vehicle 1 is provided with a battery 2, and the battery 2 may be provided at the bottom or at the head or at the tail of the vehicle 1. The battery 2 may be used for power supply of the vehicle 1, for example, the battery 2 may serve as an operating power source of the vehicle 1.

The vehicle 1 may further comprise a controller 3 and a motor 4, the controller 3 being arranged to control the battery 2 to power the motor 4, for example for operating power requirements during start-up, navigation and driving of the vehicle 1.

In some embodiments of the application, the battery 2 may not only serve as an operating power source for the vehicle 1, but also as a driving power source for the vehicle 1, instead of or in part instead of fuel oil or natural gas, to provide driving power for the vehicle 1.

Fig. 2 is an exploded view of a battery according to some embodiments of the present application. As shown in fig. 2, the battery 2 includes a case 5 and a battery cell (not shown in fig. 2) housed in the case 5.

The case 5 is used to accommodate the battery cells, and the case 5 may have various structures. In some embodiments, the case 5 may include a first case portion 5a and a second case portion 5b, the first case portion 5a and the second case portion 5b being overlapped with each other, the first case portion 5a and the second case portion 5b together defining an accommodating space 5c for accommodating the battery cell. The second case portion 5b may be a hollow structure having one end opened, the first case portion 5a is a plate-like structure, and the first case portion 5a is covered on the opening side of the second case portion 5b to form a case 5 having an accommodation space 5 c; the first housing part 5a and the second housing part 5b may each be a hollow structure having one side opened, and the opening side of the first housing part 5a is closed to the opening side of the second housing part 5b to form the housing 5 having the accommodation space 5c. Of course, the first and second case portions 5a and 5b may be of various shapes, such as a cylinder, a rectangular parallelepiped, or the like.

In order to improve the sealing property after the first casing part 5a and the second casing part 5b are connected, a sealing member, such as a sealant, a seal ring, or the like, may be provided between the first casing part 5a and the second casing part 5 b.

Assuming that the first housing part 5a is covered on top of the second housing part 5b, the first housing part 5a may also be referred to as an upper case cover, and the second housing part 5b may also be referred to as a lower case.

In the battery 2, the number of battery cells may be one or more. If the number of the battery cells is multiple, the multiple battery cells can be connected in series or in parallel or in series-parallel connection, and the series-parallel connection means that the multiple battery cells are connected in series or in parallel. The plurality of battery monomers can be directly connected in series or in parallel or in series-parallel, and then the whole formed by the plurality of battery monomers is accommodated in the box body 5; of course, a plurality of battery units may be connected in series or parallel or in series to form the battery module 6, and then the plurality of battery modules 6 may be connected in series or parallel or in series to form a whole and be accommodated in the case 5.

Fig. 3 is a schematic view of the structure of the battery module shown in fig. 2.

In some embodiments, as shown in fig. 3, the battery cells 7 are plural, and the plural battery cells 7 are first connected in series or parallel or series-parallel to form the battery module 6. The plurality of battery modules 6 are connected in series, in parallel or in series-parallel to form a whole, and are accommodated in a case.

The plurality of battery cells 7 in the battery module 6 may be electrically connected through a bus bar member to realize parallel connection or series-parallel connection of the plurality of battery cells 7 in the battery module 6.

Fig. 4 is an exploded view of a battery cell according to 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 case 20, the case 20 being for accommodating 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 comprises a first pole piece, a second pole piece and a separator, wherein the polarities of the first pole piece and the second pole piece are opposite, and the separator is used for insulating and isolating the first pole piece and the second pole piece. The electrode assembly 10 operates primarily by virtue of metal ions moving between the first and second electrode sheets. One of the first pole piece and the second pole piece is a positive pole piece, and the other one of the first pole piece and the second pole piece is a negative pole piece.

From the external shape of the electrode assembly 10, the electrode assembly 10 includes a main body portion 11, and first and second tabs 12 and 13 led out from the main body portion 11. The main body 11 is an electricity generating portion of the electrode assembly 10, and an active material therein is used to electrochemically react with an electrolyte or the like to generate a charge-discharge process. The polarities of the first tab 12 and the second tab 13 are opposite, and are used for guiding out the electric energy generated by the main body 11.

The first tab 12 and the second 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. Illustratively, as shown in fig. 4, the first tab 12 and the second tab 13 are led out from both ends of the main body 11, respectively.

In the battery cell 7, the number of the electrode assemblies 10 may be one or a plurality.

The case 20 has a hollow structure, and an accommodating chamber for accommodating the electrode assembly 10 and the electrolyte is formed therein. The housing 20 may be of various shapes, such as a cylinder, a rectangular parallelepiped, etc. The shape of the case 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 housing may be used; if the electrode assembly 10 has a rectangular parallelepiped structure, a rectangular parallelepiped housing may be selected.

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

The battery cell 7 further includes a first electrode terminal 30 and a second electrode terminal 40 mounted to the case 20, the first electrode terminal 30 being configured to be electrically connected to the first tab 12, the second electrode terminal 40 being configured to be electrically connected to the second tab 13, the first electrode terminal 30 and the second electrode terminal 40 being configured 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 to 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 to 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 another switching member.

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

The first electrode terminal 30 may be welded, snapped, glued or otherwise connected to the first tab 12. 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 electrode tab 13, or may be indirectly connected to the second electrode tab 13 via another switching member.

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

The second electrode terminal 40 may be welded, snapped, adhered or otherwise connected to the second tab 13. In some embodiments, the second electrode tab 13 is welded to the second electrode terminal 40.

Fig. 5 is a perspective view of an electrode assembly according to some embodiments of the present application; fig. 6 is a side view of the electrode assembly shown in fig. 5.

As shown in fig. 5 and 6, the electrode assembly 10 of the embodiment of the present application includes a main body portion 11 and a plurality of first tabs 12 drawn out from the main body portion 11, the plurality of first tabs 12 being 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 first tabs 12 that overlap simultaneously is smaller than the total number of first tabs 12.

In the present embodiment, any adjacent two of the first tabs 12 at least partially overlap in the thickness direction Z. In some examples, any adjacent two of the first tabs 12 are offset such that the adjacent two first tabs 12 only partially overlap in the thickness direction Z. In other examples, in some of the first tabs 12, any adjacent two of the first tabs 12 are offset so that the adjacent two first tabs 12 only partially overlap in the thickness direction Z; in other first tabs 12, any adjacent two first tabs 12 are entirely overlapped in the thickness direction Z.

The simultaneous overlapping of the first tabs 12 in the thickness direction Z means that there is an overlapping region of the projections of the first tabs 12 in the thickness direction Z, and it is not required that the projections of the first tabs 12 in the thickness direction Z overlap entirely. The projection of the first tabs 12 refers to the projection of the first tabs 12 in the same plane perpendicular to the thickness direction Z.

All projections of the first tabs 12 in a plane perpendicular to the thickness direction Z are in a continuous state.

The embodiment of the present application reduces the number of the first tabs 12 overlapped at the same time in the thickness direction Z to reduce the difficulty of connecting the first tabs 12 to other conductive structures (e.g., the first electrode terminal or the switching member), so that the electrode assembly 10 can be provided with more first tabs 12, thereby improving the overcurrent capability of the electrode assembly 10. The adjacent two first tabs 12 are at least partially overlapped, so that a plurality of first tabs 12 can be in a continuous state, the connection process of the first tabs 12 and the conductive structure can be simplified, and the assembly efficiency of the battery cell can be improved.

In some embodiments, the first tab 12 is directly connected to the first electrode terminal, so that a conventional switching member can be omitted, the structure of the battery cell can be simplified, and the energy density of the battery cell can be improved.

In some embodiments, the plurality of first tabs 12 are connected to the first electrode terminal by laser welding. Specifically, at the time of assembly, a plurality of first tabs 12 are stacked on the first electrode terminal, and then the first tabs 12 and the first electrode terminal are laser welded from the first tab 12 side. In this embodiment, the plurality of first tabs 12 are in a continuous state, so that the laser can continuously move to weld the plurality of first tabs 12 to the first electrode terminal, so that the start-stop times of the laser welding device are reduced, the connection process of the first tabs 12 and the first electrode terminal is simplified, and the assembly efficiency of the battery cell is improved.

In some embodiments, the 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 arranged in a staggered manner in sequence in the second direction Y, which is perpendicular to the first direction X and the thickness direction Z.

The main body portion 11 includes a first surface 11a and a second surface 11b that are disposed opposite each other in a second direction Y, and a third surface 11c and a fourth surface 11d that are disposed opposite each other in a third direction that is perpendicular to the second direction Y. Illustratively, the third direction is parallel to the thickness direction Z.

In any two adjacent first tabs 12, the minimum distance between the first tab 12 near the third surface 11c and the first surface 11a in the second direction Y is greater than the minimum distance between the first tab 12 far from the third surface 11c and the first surface 11a in the second direction Y.

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

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

In some embodiments, the plurality of first tabs 12 are equidistantly offset in the second direction Y.

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

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

The thickness variation of the whole formed by the plurality of first tabs 12 can be more uniform, which is helpful for improving the bonding effect of the first tabs 12 and other conductive structures and improving the connection strength of the first tabs 12 and the conductive structures.

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, the misalignment amounts of two adjacent first tabs 12 along the second direction Y are D, T, L, and D satisfy: d is more than or equal to (T multiplied by L)/H; wherein H is more than or equal to 0.1mm and less than or equal to 2mm.

The value of H is determined based on the welding capabilities of the welding device. The soldering apparatus is capable of soldering a plate-like structure having a maximum thickness H to the conductive structure on the premise of ensuring the connection strength.

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

In some embodiments, the thickness of the first tab 12 is T, and the maximum number of first tabs 12 that overlap simultaneously in the thickness direction Z is N, and T satisfy: n x T is less than or equal to 1mm. N is a positive integer greater than 1.

N, T and H satisfy: n x T is less than or equal to H.

Illustratively, nxT is less than or equal to 0.5mm.

The maximum thickness of the whole formed by the plurality of first tabs 12 can be not more than 1mm, so that the power required for welding the plurality of first tabs 12 can be reduced, the heat generation is reduced, and the risk of burning the first tabs 12 is reduced.

In some embodiments, the maximum number of first tabs 12 that overlap simultaneously in the thickness direction Z is N, and the total number of first tabs 12 is M, N, and M satisfy: N/M is less than or equal to 0.8.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.

The present embodiment can reduce the maximum number of first tabs 12 that overlap simultaneously in the thickness direction Z, and reduce the maximum thickness of the whole formed by a plurality of first tabs 12, thereby ensuring the connection strength of the first tabs 12 with other conductive structures.

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

In this embodiment, the first tab 12 and the second tab 13 are respectively disposed on two 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 larger dimensions, and the overcurrent capability of the electrode assembly 10 is improved.

Fig. 7 is a schematic side view of an electrode assembly according to further embodiments of the present application.

As shown in fig. 7, in some embodiments, in some first tabs 12, any adjacent two first tabs 12 are disposed in a staggered manner, so that the adjacent two first tabs 12 only partially overlap in the thickness direction Z; in other first tabs 12, any adjacent two first tabs 12 are entirely overlapped in the thickness direction Z.

Fig. 8 is a schematic side view of an electrode assembly according to still other embodiments of the present application.

As shown in fig. 8, in some embodiments, along the direction of the third surface 11c toward the fourth surface 11d, the M first tabs 12 are respectively defined as the first tab 12, the second first tab 12 … … and the M first tab 12.

The first tab 12 to the kth first tab 12 are sequentially staggered in the second direction Y along a direction away from the first surface 11a, and the kth first tab 12 to the mth first tab 12 are sequentially staggered in the second direction Y along a direction facing the first surface 11 a. 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 fig. 9 and 10, in some embodiments, the electrode assembly 10 includes a plurality of first electrode sheets 14 and a plurality of second electrode sheets 15, the plurality of first electrode sheets 14 and the plurality of second electrode sheets 15 are alternately stacked, and polarities of the first electrode sheets 14 and the second electrode sheets 15 are opposite. The first pole piece 14 includes a first coating region 141 coated with a first active material layer and a first tab 12 drawn from the first coating region 141. The body portion includes a first coated region 141.

The electrode assembly 10 of the present embodiment is a laminated electrode assembly. The first pole piece 14 and the second pole piece 15 are both of a flat plate structure, 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 comprises 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 collecting portion coated with a first active material layer and a first tab 12 connected to the first current collecting portion, the first tab 12 not being coated with the first active material layer. The first coating region 141 includes a first current collecting portion and a first active material layer coated on the first current collecting portion.

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

Specifically, the second electrode sheet 15 includes a second current collector and a second active material layer coated on a surface of the second current collector; the second current collector includes a second current collecting portion coated with a second active material layer and a second tab connected to the second current collecting portion, the second tab not being coated with the second active material layer. The second coating region includes a second current collecting portion and a second active material layer coated on the second current collecting portion.

The electrode assembly 10 further includes a separator 16 that insulates the first and second electrode sheets 14 and 15.

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

In this embodiment, since the plurality of first pole pieces 14 are independently disposed, each first pole piece 14 needs to be provided with a first tab 12 to achieve the export of electric energy. The present embodiment can reduce the number of first tabs 12 that overlap simultaneously in the thickness direction, so that the electrode assembly 10 can be provided with more first tabs 12, that is, the electrode assembly 10 can be provided with more first electrode tabs 14, thereby improving the capacity of the electrode assembly 10.

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

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

The electrode assembly 10 of the present embodiment is a rolled electrode assembly. The first pole piece 14 and the second pole piece 15 are both in a belt-like structure and are wound for more than two turns along the winding axis. Illustratively, the electrode assembly 10 is a flat-like structure.

The second tab 15 includes a second coating region coated with a second active material layer and a plurality of second tabs led out from the second coating region. The main body 11 includes a first coating region 141, a second coating region, and a spacer 16.

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

As shown in fig. 13 and 14, in some embodiments, the electrode assembly 10 includes first and second electrode sheets 14 and 15 having opposite polarities, the first electrode sheet 14 being continuously bent and including a plurality of lamination sections 14a and a plurality of bending sections 14b, the plurality of lamination sections 14a and the plurality of second electrode sheets 15 being alternately laminated, each bending section 14b connecting two adjacent lamination sections 14a. Each lamination segment 14a is provided with a first tab 12. The main body 11 includes a lamination section 14a and a bending section 14b.

The first pole piece 14 includes a first coating region 141 coated with a first active material layer and a first tab 12 drawn from the first coating region 141. The first coating region 141 is continuously folded and forms the lamination section 14a and the folded section 14b.

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

Fig. 15 is a flowchart illustrating a method for manufacturing an electrode assembly according to some embodiments of the present application.

As shown in fig. 15, the manufacturing method of the electrode assembly according to the embodiment of the present application includes:

s100, providing a first pole piece and a second pole piece;

S200, winding or laminating the first pole piece and the second pole piece to form an electrode assembly;

The relevant structure of the electrode assembly manufactured by the manufacturing method of the electrode assembly can be referred to the electrode assembly provided in the above embodiments.

As shown in fig. 16, the manufacturing system 90 of the electrode assembly according to the embodiment of the present application includes a providing device 91 for providing the first and second electrode sheets, and an assembling device 92 for winding or laminating the first and second electrode sheets to form the electrode assembly. The electrode assembly comprises a main body part and a plurality of first tabs led out from the main body part, wherein the 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 that overlap simultaneously is smaller than the total number of first tabs.

The related structure of the electrode assembly manufactured by the above-described manufacturing system can be seen from the electrode assemblies provided in the above-described embodiments.

It should be noted that, without conflict, the embodiments of the present application and features of the embodiments may be combined with each other.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present application, and are not limiting; although the application has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may be modified or some technical features may be replaced equivalently, 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

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.