CN118198677A

CN118198677A - Electrode assembly, manufacturing method thereof, battery cell, battery and power utilization device

Info

Publication number: CN118198677A
Application number: CN202410160635.1A
Authority: CN
Inventors: 吴翔; 张小畏; 温裕乾
Original assignee: Contemporary Amperex Technology Co Ltd
Current assignee: Contemporary Amperex Technology Co Ltd
Priority date: 2024-02-04
Filing date: 2024-02-04
Publication date: 2024-06-14

Abstract

The application provides an electrode assembly and a manufacturing method thereof, a battery cell, a battery and an electric device. In the above structure, since the first end face of the first current collector end portion is covered with the first insulating member, the first insulating member can cover the burrs at the first end face, so that the risk that the burrs pierce the separator of the electrode assembly is reduced, the possibility of short circuit inside the battery is reduced, and the reliability of the battery is improved.

Description

Electrode assembly, manufacturing method thereof, battery cell, battery and power utilization device

Technical Field

The present application relates to the field of battery technologies, and in particular, to an electrode assembly, a method for manufacturing the same, a battery cell, a battery, and an electric device.

Background

The battery has the advantages of high specific energy, high power density and the like, and is widely used in electronic equipment and vehicles, such as mobile phones, notebook computers, battery cars, electric automobiles, electric airplanes, electric ships, electric tools and the like.

With the continuous expansion of the application range of batteries, the requirements of people on the reliability of the batteries are also increasing. How to improve the reliability of batteries is becoming increasingly interesting to those skilled in the art.

Disclosure of Invention

In view of the above, the present application provides an electrode assembly, which is advantageous in improving the reliability of a battery, a method of manufacturing the same, a battery cell, a battery, and an electric device.

In a first aspect, the present application provides an electrode assembly comprising first and second electrode sheets of opposite polarity wound in a winding direction; the first pole piece comprises a first current collector and a first active material layer arranged on the surface of the first current collector, and the end part of the first current collector along the winding direction is provided with a first end face; the electrode assembly further includes a first insulating member connected to the first electrode tab and covering at least a portion of the first end face. In the above structure, since the first end face of the first current collector end portion is covered with the first insulating member, the first insulating member can cover the burrs at the first end face, so that the risk that the burrs pierce the separator of the electrode assembly is reduced, the possibility of short circuit inside the battery is reduced, and the reliability of the battery is improved.

According to the electrode assembly provided by some embodiments of the application, the first insulating pieces are arranged at the two ends of the first pole piece along the winding direction, so that burrs on the first end faces of the two ends of the first pole piece can be coated, the risk that the burrs pierce through the separator of the electrode assembly can be further reduced, and the reliability of the battery can be further improved.

According to the electrode assembly provided by some embodiments of the application, the first insulating member is adhered to the first active material layer or the first current collector, so that the first insulating member is firmly connected to the first pole piece and is not easy to fall off.

According to the electrode assembly provided by some embodiments of the present application, the first insulating member includes two first insulating layers disposed opposite to each other, the first insulating layers include a first connection portion and a first covering portion, the first covering portion is laminated on the first electrode sheet, and the first connection portions of the two first insulating layers are bonded to each other, so as to cover the first end surface connected between the two opposite surfaces of the first electrode sheet.

According to some embodiments of the present application, there is provided an electrode assembly, wherein the first electrode sheet has a thickness H1, the first insulating layer has a thickness H2,The electrode assembly formed by winding is facilitated to be reduced in occurrence of steps, and the possibility of cracking of the first pole piece due to step stress is reduced.

According to the electrode assembly provided by some embodiments of the application, the inner end of the first pole piece is connected with the first insulating piece, and at least part of the first pole piece is wound on the outer side of the first insulating piece, so that the first insulating piece at the inner end of the first pole piece can be wound on the center of the electrode assembly, the first insulating piece can play a supporting role on the electrode assembly, and the electrode assembly is beneficial to reducing the possibility of collapse.

According to the electrode assembly provided by some embodiments of the application, the length of the first insulating piece at the inner end of the first pole piece, extending out of the first pole piece along the direction opposite to the winding direction, is A1, and A1 is more than or equal to 0.5mm and less than or equal to 120mm.

According to some embodiments of the present application, the second electrode sheet includes a second current collector and a second active material layer disposed on a surface of the second current collector, and an end portion of the second current collector along a winding direction has a second end surface; the electrode assembly further comprises a second insulating part, wherein the second insulating part is connected to the second pole piece and covers at least part of the second end face, so that burrs of the second end face, which are covered by the second insulating part, the possibility that the burrs pierce the isolating part is reduced, and the risk of short circuit of the battery cell is reduced.

According to the electrode assembly provided by some embodiments of the application, the elastic modulus of the first insulating piece is larger than that of the first pole piece, and the elastic modulus of the second insulating piece is larger than that of the second pole piece, so that the first insulating piece connected with the inner end of the first pole piece can be better supported at the center of the electrode assembly, the second insulating piece connected with the inner end of the second pole piece can be better supported at the center of the electrode assembly, and the possibility of collapse of the electrode assembly is reduced.

According to some embodiments of the present application, the first electrode sheet is an anode electrode sheet, the second electrode sheet is a cathode electrode sheet, and the first insulating member extends from the second insulating member in a direction opposite to a winding direction, so that the first insulating member connected to the anode electrode sheet can be longer than the second insulating member at a center of the electrode assembly and wound into the center of the electrode assembly.

According to the electrode assembly provided by some embodiments of the application, in the thickness direction of the first pole piece, the thickness of the first insulating piece is H3, the thickness of the second insulating piece is F3, and H3 is greater than F3, so that the first insulating piece wound at the inner end of the first pole piece in the center of the electrode assembly can provide larger supporting force, and the effect of reducing collapse is improved.

According to the electrode assembly provided by some embodiments of the application, in the direction opposite to the winding direction, the first insulating member is located on the inner side of the second insulating member, so that the first insulating member is integrally located on the inner side of the second insulating member, the anode pole piece can extend out of the cathode pole piece in the winding direction, and the first insulating member connected to the inner end of the first pole piece can be wound on the center of the electrode assembly better, so that the electrode assembly can play a role in supporting better.

According to the electrode assembly provided by some embodiments of the application, the elastic modulus of the first insulating piece is larger than that of the second insulating piece, so that the first insulating piece connected with the inner end of the first pole piece can provide larger elastic restoring force to support at the center of the electrode assembly after being wound, and the first insulating piece can reduce the collapse possibility of the electrode assembly better.

According to the electrode assembly provided by some embodiments of the application, the second insulating pieces are arranged at the two ends of the second pole piece along the winding direction, so that burrs on the second end surfaces of the two ends of the second pole piece can be covered, the risk that the burrs pierce through the separator of the electrode assembly can be further reduced, and the reliability of the battery can be further improved.

According to the electrode assembly provided by some embodiments of the application, the length of the second insulating part at the inner end of the second pole piece, which extends out of the second pole piece, is B1, the length of the second insulating part at the outer end of the second pole piece, which extends out of the second pole piece, is B4, and B1 is greater than B4, so that the second insulating part has a good supporting effect and waste is reduced.

According to some embodiments of the present application, an electrode assembly is provided, which has a cylindrical structure.

According to the electrode assembly provided by some embodiments of the present application, the first electrode tab further includes a first tab connected to the first current collector, and the first tab includes a rubbing area, where the rubbing area is spaced from the first insulating member, so that the rubbing area is separated from the first insulating member, and the first insulating member does not affect connection between the rubbing area and the current collecting disc.

In a second aspect, the present application provides a battery cell, which includes a housing and at least one electrode assembly provided in any one of the above aspects, and is accommodated in the housing.

In a third aspect, the present application provides a battery, which includes the battery cell provided in the above technical solution.

In a fourth aspect, the present application provides an electric device, which includes the battery provided by the above technical solution, where the battery is used to provide electric energy.

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

Providing a plurality of first pole pieces and insulating pieces, wherein the first pole pieces comprise a first current collector and a first active material layer arranged on the surface of the first current collector, and the end part of the first current collector along the length direction of the first current collector is provided with a first end face;

connecting two adjacent first pole pieces through an insulating piece, wherein the insulating piece covers at least part of the first end face;

Winding a first pole piece and an insulating member in a length direction of a first current collector;

and cutting the insulating piece between two adjacent first pole pieces to enable the two ends of the first pole pieces in the winding direction to form first insulating pieces, wherein at least part of the first end face is covered by the first insulating pieces.

The technical scheme provided by the embodiment of the disclosure at least brings the following beneficial effects:

the application provides an electrode assembly, which comprises a first pole piece, a second pole piece and a first insulating piece, wherein the polarities of the first pole piece and the second pole piece are opposite, the first pole piece and the second pole piece are wound along a winding direction, the first pole piece comprises a first current collector and a first active material layer arranged on the surface of the first current collector, the end part of the first current collector along the winding direction is provided with a first end face, and the first insulating piece is connected to the first pole piece and covers at least part of the first end face. In the above structure, since the first end face of the first current collector end portion is covered with the first insulating member, the first insulating member can cover the burrs at the first end face, so that the risk that the burrs pierce the separator of the electrode assembly is reduced, the possibility of short circuit inside the battery is reduced, and the reliability of the battery is improved.

The foregoing description is only an overview of the present application, and is intended to be implemented in accordance with the teachings of the present application in order that the same may be more clearly understood and to make the same and other objects, features and advantages of the present application more readily apparent.

Drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the application. Also, like reference numerals are used to designate like parts throughout the figures.

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

FIG. 2 is a split view of a battery provided in some embodiments of the present application;

fig. 3 is a split view of a battery module according to some embodiments of the present application;

fig. 4 is a cross-sectional view of a battery cell according to some embodiments of the present application;

fig. 5 is a cross-sectional view of an electrode assembly in a battery cell according to some embodiments of the present application;

FIG. 6 is a cross-sectional view of a first pole piece provided in some embodiments of the present application;

FIG. 7 is a cross-sectional view of a first insulator and a first pole piece according to some embodiments of the present application after attachment;

FIG. 8 is a cross-sectional view of a second pole piece provided in some embodiments of the present application;

FIG. 9 is a cross-sectional view of a second insulator and second pole piece according to some embodiments of the present application after attachment;

FIG. 10 is a top view of a first pole piece at a first end face provided in some embodiments of the present application;

fig. 11 is a top view of a first pole piece at a first end face provided in further embodiments of the present application.

In the drawings:

1. A vehicle; 2. a battery; 3. a controller; 4. a motor; 5. a case; 5a, a first box body part; 5b, a second box body part; 5c, an accommodating space; 6. a battery module; 7. a battery cell; 20. a housing; 30. an electrode assembly; 301. a first pole piece; 3011. a first current collector; 30111. a first end face; 3012. a first active material layer; 3013. a first tab; 30131. rubbing the area; 302. a second pole piece; 3021. a second current collector; 30211. a second end face; 3022. a second active material layer; 303. a first insulating member; 3031. a first insulating layer; 30311. a first connection portion; 30312. a first cover; 304. a second insulating member; 3041. a second insulating layer; 30411. a second connecting portion; 30412. a second cover; 305. a spacer; x, winding direction.

Detailed Description

Embodiments of the technical scheme of the present application will be described in detail below with reference to the accompanying drawings. The following examples are only for more clearly illustrating the technical aspects of the present application, and thus are merely examples, and are not intended to limit the scope of the present application.

It should be noted that unless otherwise indicated, technical or scientific terms used in the embodiments of the present application should be given the ordinary meanings as understood by those skilled in the art to which the embodiments of the present application belong.

In the description of the embodiments of the present application, the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are merely for convenience in describing the embodiments of the present application and simplify the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the embodiments of the present application.

Furthermore, the technical terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. In the description of the embodiments of the present application, the meaning of "plurality" is two or more (including two) unless otherwise specifically defined.

In the description of the embodiments of the present application, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured" and the like are to be construed broadly and may be, for example, fixedly connected, detachably connected, or integrally formed; or may be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the embodiments of the present application will be understood by those of ordinary skill in the art according to specific circumstances.

In the description of embodiments of the application, unless expressly specified and limited otherwise, a first feature "up" or "down" on a second feature may be that the first and second features are in direct contact, or that the first and second features are in indirect contact via an intervening medium. Moreover, a first feature being "above," "over" and "on" a second feature may be a first feature being directly above or obliquely above the second feature, or simply indicating that the first feature is level higher than the second feature. The first feature being "under", "below" and "beneath" the second feature may be the first feature being directly under or obliquely below the second feature, or simply indicating that the first feature is less level than the second feature.

Currently, the more widely the battery is used in view of the development of market situation. The battery is widely used not only in energy storage power supply systems such as hydraulic power, thermal power, wind power and solar power stations, but also in electric vehicles such as electric bicycles, electric motorcycles and electric automobiles.

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.

In the embodiment of the application, the battery cell can be a secondary battery, and the secondary battery refers to a battery cell which can activate the active material in a charging mode to continue to use after the battery cell discharges.

The battery cells may include, but are not limited to, lithium ion battery cells, sodium lithium ion battery cells, lithium metal battery cells, sodium metal battery cells, lithium sulfur battery cells, magnesium ion battery cells, nickel hydrogen battery cells, nickel cadmium battery cells, lead storage battery cells, and the like.

As examples, the battery cell may be a cylindrical battery cell, a prismatic battery cell, or other shaped battery cell, including a square-case battery cell, a blade-shaped battery cell, a polygonal-prismatic battery, such as a hexagonal-prismatic battery, or the like.

In some embodiments, the battery may be a battery module, and when there are a plurality of battery cells, the plurality of battery cells are arranged and fixed to form one battery module.

In some embodiments, the battery may be a battery pack including a case and a battery cell, the battery cell or battery module being housed in the case.

In some embodiments, the tank may be part of the chassis structure of the vehicle. For example, a portion of the tank may become at least a portion of the floor of the vehicle, or a portion of the tank may become at least a portion of the cross member and the side member of the vehicle.

In some embodiments, the battery may be an energy storage device. The energy storage device comprises an energy storage container, an energy storage electric cabinet and the like.

The battery cell generally includes an electrode assembly and a case, in which the electrode assembly is received. The electrode assembly includes a cathode, an anode, and a separator. During the charge and discharge of the battery cell, active ions (e.g., lithium ions) are intercalated and deintercalated between the cathode and the anode. The separator is arranged between the cathode and the anode, so that the risk of cathode and anode short circuit can be reduced, and active ions can pass through.

The case is used to encapsulate the electrode assembly, the electrolyte, and the like. The shell can be a steel shell, an aluminum shell, a plastic shell (such as polypropylene), a composite metal shell (such as a copper-aluminum composite shell), an aluminum-plastic film or the like.

In some embodiments, the cathode may be a cathode sheet, and the cathode sheet may include a cathode current collector and a cathode active material layer disposed on at least one surface of the cathode current collector. The anode may be an anode tab, and the anode tab may include an anode current collector and an anode active material layer disposed on at least one surface of the anode current collector.

In the preparation of a pole piece (cathode or anode) it is often necessary to cut (e.g., a pole piece slitting process or a tab die cutting process) to the desired size and shape. However, after being cut, the current collector is prone to burrs at the cut location; in the process of charging and discharging the battery cell, burrs may puncture the separator and conduct the anode and the cathode, so that the risk of short circuit is caused, and the reliability of the battery cell is affected.

In view of the above, the embodiment of the application provides a technical scheme that an insulating piece is arranged on a pole piece to cover the end face of a current collector, which is easy to generate burrs, so that the risk that the burrs conduct cathodes and anodes is reduced, and the reliability of a battery cell is improved.

The electrode assembly described in the embodiments of the present application is applicable to a battery cell, a battery, and an electric device using the battery.

The battery disclosed by the embodiment of the application can be used for an electric device using the battery as a power supply or various energy storage systems using the battery as an energy storage element. The power device may be, but is not limited to, a cell phone, tablet, notebook computer, electric toy, electric tool, battery car, electric car, ship, spacecraft, etc. Among them, the electric toy may include fixed or mobile electric toys, such as game machines, electric car toys, electric ship toys, electric plane toys, and the like, and the spacecraft may include planes, rockets, space planes, and spacecraft, and the like.

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 1 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 2 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) housed in the case 5. The battery cell may be the smallest unit constituting the battery 2.

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 cover, and the second housing part 5b may also be referred to as a lower housing part 5.

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.

The plurality of battery cells may be directly disposed in the case 5 to form the battery 10, or may be a plurality of battery cells may be first formed into the battery module 6, and then the plurality of battery modules 6 may be disposed in the case 5 to form the battery 10.

Fig. 3 is an exploded view of a battery module 6 according to some embodiments of the present application.

As shown in fig. 3, in some embodiments, 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 an integral battery module 6, and are accommodated in the case 5.

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.

The battery cells 7 may be cylindrical battery cells 7, prismatic battery cells 7, or battery cells 7 of other shapes.

As shown in fig. 4, in some embodiments, the battery cell 7 includes a housing 20 and an electrode assembly 30. The electrode assembly 30 is accommodated in the case 20. Wherein the electrode assembly 30 is a cylindrical winding structure.

The housing 20 may be of various shapes and sizes, such as rectangular parallelepiped, hexagonal prism, etc. Specifically, the shape of the case 20 may be determined according to the specific shape and size of the electrode assembly 30. The material of the housing 20 may be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc.

The electrode assembly 30 is a component in which electrochemical reactions occur in the battery cells 7. One or more electrode assemblies 30 may be contained within the housing 20.

Some embodiments of the present application provide an electrode assembly 30, as shown in fig. 5, the electrode assembly 30 including first and second electrode sheets 301 and 302 having opposite polarities, the first and second electrode sheets 301 and 302 being wound in a winding direction X; as shown in fig. 6, the first electrode sheet 301 includes a first current collector 3011 and a first active material layer 3012 provided on a surface of the first current collector 3011, and an end of the first current collector 3011 in the winding direction X has a first end face 30111; the electrode assembly 30 further includes a first insulator 303, the first insulator 303 being connected to the first pole piece 301 and covering at least a portion of the first end face 30111.

The first electrode sheet 301 and the second electrode sheet 302 are two electrode sheets with opposite electrode characteristics, one of which is an anode electrode sheet and the other of which is a cathode electrode sheet. The first and second electrode sheets 301 and 302 are wound in the winding direction X, so that the electrode assembly 30 is in a wound structure.

The first current collector 3011 may be a structure having conductive capability, which may be formed by disposing a conductive material on an insulating substrate. Illustratively, the conductive material on the first current collector 3011 may include a metallic material including aluminum, aluminum alloy, nickel alloy, titanium alloy, silver alloy, or the like. The first active material layer 3012 may be a structural layer containing a polar active material.

In some examples, the first electrode sheet 301 may be an anode electrode sheet, the second electrode sheet 302 may be a cathode electrode sheet, and the first active material layer 3012 includes an anode active material, which may be an anode active material for the battery cell 7 as known in the art. As an example, the anode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, lithium titanate, and the like. The silicon-based material may be at least one selected from elemental silicon, silicon oxygen compounds, silicon carbon composites, silicon nitrogen composites, and silicon alloys. The tin-based material may be at least one selected from elemental tin, tin oxide, and tin alloys. However, the present application is not limited to these materials, and other conventional materials that can be used as the anode active material of the battery 2 may be used. These anode active materials may be used alone or in combination of two or more.

The first active material layer 3012 may be formed by coating an anode active material on the surface of the first current collector 3011 through a coating process.

The first end face 30111 may be a surface of an end of the first current collector 3011 in the winding direction X, which may be formed by cutting during the pole piece preparation process. For example, the first end face 30111 may intersect the first current collector 3011 first active material coated surface.

The first insulating member 303 may be a member having insulating properties, and by attaching the first insulating member 303 to the first pole piece 301 such that the first insulating member 303 covers at least a portion of the first end face 30111, burrs at the portion of the first end face 30111 covered by the first insulating member 303 are covered by the first insulating member 303, the possibility that the burrs pierce the separator 305 is reduced, and the risk of short-circuiting the battery cells 7 is reduced.

Illustratively, the first insulator 303 may be an insulating structure having an opening into which an end of the first current collector 3011 having the first end face 30111 is inserted to encase the first end face 30111; the first insulating member 303 may be formed by curing an insulating adhesive, and the insulating adhesive is adhered to the first end face 30111 to cover the first end face 30111; the first insulating member 303 may also be formed by adhering an insulating tape to the end of the first current collector 3011 having the first end 30111 and cladding the first end 30111.

In the above structure, since the first end face 30111 of the end of the first current collector 3011 is covered with the first insulating member 303, the first insulating member 303 can cover burrs at the first end face 30111, the risk of the burrs penetrating the separator 305 of the electrode assembly 30 can be reduced, the possibility of occurrence of short circuits inside the battery 2 can be reduced, and the reliability of the battery 2 can be advantageously improved.

In some embodiments, the first pole piece 301 is provided with a first insulating member 303 at both ends in the winding direction X.

By arranging the first insulating members 303 at both ends of the first pole piece 301 along the winding direction X, the first end surfaces 30111 at both ends of the first pole piece 301 along the winding direction X are at least partially covered by the first insulating members 303, so that burrs on the first end surfaces 30111 at both ends of the first pole piece 301 can be covered, the risk that the burrs pierce through the separator 305 of the electrode assembly 30 can be further reduced, and the reliability of the battery 2 can be further improved.

In some embodiments, the first insulator 303 is bonded to the first active material layer 3012 or the first current collector 3011.

By bonding the first insulating member 303 to the first active material layer 3012 or the first current collector 3011 of the first electrode tab 301, the first insulating member 303 is firmly connected to the first electrode tab 301, and is not easily detached. The first insulator 303 may be adhered to the first active material layer 3012 or the first current collector 3011 by an adhesive material such as glue.

In some embodiments, the first insulating member 303 is adhered to the first active material layer 3012, so that the first insulating member 303 and the first pole piece 301 have a larger adhesion area by adhering the first insulating member 303 to the surface of the first active material layer 3012, which is beneficial to improving the connection firmness of the first insulating member 303 on the first pole piece 301.

In some embodiments, the first insulating member 303 includes two first insulating layers 3031 disposed opposite to each other, the first insulating layers 3031 include a first connection portion 30311 and a first cover portion 30312, the first cover portion 30312 is laminated on the first pole piece 301, and the first connection portions 30311 of the two first insulating layers 3031 are adhered to each other.

The first insulating layer 3031 may be a part of the structure constituting the first insulating member 303, and the two first insulating layers 3031 are disposed opposite to each other and connected to two opposite surfaces of the end portion of the first electrode sheet 301, respectively, for covering the first end face 30111.

As shown in fig. 7, the first insulating layer 3031 includes a first connection portion 30311 and a first cover portion 30312 connected to each other, and the first connection portion 30311 and the first cover portion 30312 are sequentially disposed in the winding direction X. The first covering portion 30312 is configured to be connected to the first pole piece 301, and the first connecting portion 30311 is configured to be connected to the first connecting portion 30311 of the other first insulating layer 3031 so as to cover an end portion of the first pole piece 301 where the first end face 30111 is located.

The first covering portions 30312 of the two first insulating members 303 are adhered to the two opposite surfaces of the first electrode sheet 301, and are respectively laminated on both sides of the first electrode sheet 301, so that the first connection portions 30311 of the two first insulating layers 3031 are adhered to each other, thereby coating the first end face 30111 connected between the two opposite surfaces of the first electrode sheet 301.

Illustratively, the first insulating layer 3031 may be an insulating tape, where a portion of the insulating tape is adhered to the surface of the first pole piece 301, and another portion is adhered to another insulating tape in a relatively adhesive manner.

In some embodiments, the first pole piece 301 has a thickness H1, the first insulating layer 3031 has a thickness H2,

By setting the thickness of the first pole piece 301 to H1, the thickness of the first insulating layer 3031 is set to H2, andThe thickness of the first connection part 30311 in the two first insulating layers 3031 after being bonded is smaller than or equal to the thickness of the first pole piece 301, which is favorable for reducing the occurrence of steps of the electrode assembly 30 formed by winding and reducing the possibility of cracks of the first pole piece 301 due to step stress.

In some embodiments, a first insulator 303 is connected to the inner end of the first pole piece 301, and at least a portion of the first pole piece 301 is wound outside the first insulator 303.

By attaching the first insulating member 303 to the inner end of the first electrode sheet 301 and winding at least part of the first electrode sheet 301 around the outer side of the first insulating member 303, the first insulating member 303 of the inner end of the first electrode sheet 301 can be wound around the center of the electrode assembly 30, so that the first insulating member 303 can support the electrode assembly 30, which is advantageous in reducing the possibility of collapse of the electrode assembly 30.

In some embodiments, the first insulator 303 at the inner end of the first pole piece 301 extends beyond the first pole piece 301 by a length A1,0.5mm < A1 < 120mm, in the opposite direction to the winding direction X.

The length A1 of the first insulating member 303 of the inner end of the first pole piece 301 protruding out of the first pole piece 301 is the length of the first connection portion 30311 in the opposite direction to the winding direction X. By setting the range of the length A1 of the first insulating member 303 connected to the inner end of the first pole piece 301 extending out of the first pole piece 301 in the opposite direction to the winding direction X to be 0.5mm < A1 < 120mm, the first insulating member 303 connected to the inner end of the first pole piece 301 can form a winding core with good supporting ability, the center of the electrode assembly 30 can be better supported, and the first insulating member 303 connected to the inner end of the first pole piece 301 can better prevent collapse of the electrode assembly 30.

In some embodiments, 1 mm.ltoreq.a1.ltoreq.100 mm, so that the first insulating member 303 connected to the inner end of the first pole piece 301 can not only support the center of the electrode assembly 30 well, but also reduce the amount of the first insulating member 303 and reduce waste.

In some embodiments, as shown in fig. 8, the second pole piece 302 includes a second current collector 3021 and a second active material layer 3022 disposed on a surface of the second current collector 3021, and an end of the second current collector 3021 in the winding direction X has a second end surface 30211; the electrode assembly 30 further includes a second insulator 304, the second insulator 304 being connected to the second pole piece 302 and covering at least a portion of the second end face 30211.

The second electrode sheet 302 is a cathode electrode sheet, and the second current collector 3021 included in the second electrode sheet 302 may be a structure having an electrically conductive capability, which may be formed by disposing an electrically conductive material on an insulating substrate. Illustratively, the conductive material on the second current collector 3021 may include a metal material including aluminum, an aluminum alloy, nickel, a nickel alloy, titanium, a titanium alloy, silver, a silver alloy, or the like.

The second active material layer 3022 may be a structural layer containing a cathode active material that may include at least one of the following materials: lithium-containing phosphates, lithium transition metal oxides, and their respective modified compounds. However, the present application is not limited to these materials, and other conventional materials that can be used as cathode active materials of the battery 2 may be used. These cathode active materials may be used alone or in combination of two or more. Examples of the lithium-containing phosphate may include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO ₄ (which may also be referred to simply as LFP)), a composite of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnPO ₄), a composite of lithium manganese phosphate and carbon, lithium manganese phosphate, and a composite of lithium manganese phosphate and carbon. Examples of lithium transition metal oxides may include, but are not limited to, at least one of lithium cobalt oxide (e.g., liCoO ₂), lithium nickel oxide (e.g., liNiO ₂), lithium manganese oxide (e.g., liMnO ₂、LiMn₂O₄), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (e.g., liNi _1/3Co_1/3Mn_1/3O₂ (which may also be abbreviated as NCM ₃₃₃)、LiNi_0.5Co_0.2Mn_0.3O₂ (which may also be abbreviated as NCM ₅₂₃)、LiNi_0.5Co_0.25Mn_0.25O₂ (which may also be abbreviated as NCM ₂₁₁)、LiNi_0.6Co_0.2Mn_0.2O₂ (which may also be abbreviated as NCM ₆₂₂)、LiNi_0.8Co_0.1Mn_0.1O₂ (which may also be abbreviated as NCM ₈₁₁)), lithium nickel cobalt aluminum oxide (e.g., liNi _0.80Co_0.15Al_0.05O₂), modified compounds thereof, and the like.

The second end surface 30211 may be a surface of an end of the second current collector 3021 in the winding direction X, which may be formed by cutting during the pole piece manufacturing process. For example, the second end surface 30211 may intersect the second current collector 3021 second active material coated surface.

The second insulator 304 may be a member having insulating properties, and by attaching the second insulator 304 to the second pole piece 302 such that the second insulator 304 covers at least a portion of the second end surface 30211, burrs at the portion of the second end surface 30211 covered by the second insulator 304 are covered by the second insulator 304, the possibility that the burrs puncture the separator 305 is reduced, and the risk of shorting the battery cells 7 is reduced.

Illustratively, the second insulator 304 may be an insulating structure having an opening, and the end of the second current collector 3021 having the second end surface 30211 is inserted into the opening to cover the second end surface 30211; the second insulating member 304 may be formed by curing an insulating adhesive, where the insulating adhesive adheres to the second end surface 30211 to cover the second end surface 30211; the second insulator 304 may also be formed by adhering an insulating tape to the end of the second current collector 3021 having the second end surface 30211 and cladding the second end surface 30211.

A spacer 305 for isolating the first and second pole pieces 301 and 302 arranged in a stacked manner is provided between the first and second pole pieces 301 and 302, which are arranged in a stacked manner between the adjacent first and second pole pieces 301 and 302. For example, the separator 305 may be a separator film, and any known porous separator film having good chemical and mechanical stability may be used for the separator film in the embodiments of the present application.

As an example, the main material of the separator may be at least one selected from glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramic. The separator may be a single-layer film or a multilayer composite film. When the separator is a multilayer composite film, the materials of the respective layers may be the same or different. The separator 305 may be a single component located between the first pole piece 301 and the second pole piece 302, or may be attached to the surfaces of the first pole piece 301 and the second pole piece 302.

In some embodiments, the separator 305 may also be a solid state electrolyte. The solid electrolyte is disposed between the first and second pole pieces 301, 302, and serves to both transport ions and isolate the first and second pole pieces 301, 302.

In some embodiments, the modulus of elasticity of the first insulator 303 is greater than the modulus of elasticity of the first pole piece 301, and the modulus of elasticity of the second insulator 304 is greater than the modulus of elasticity of the second pole piece 302.

By configuring the modulus of elasticity of the first insulating member 303 to be greater than the modulus of elasticity of the first pole piece 301, and configuring the modulus of elasticity of the second insulating member 304 to be greater than the modulus of elasticity of the second pole piece 302, the first insulating member 303 connected to the inner end of the first pole piece 301 can be better supported at the center of the electrode assembly 30, so that the second insulating member 304 connected to the inner end of the second pole piece 302 can be better supported at the center of the electrode assembly 30, which is advantageous in reducing the possibility of collapse of the electrode assembly 30.

For example, the modulus of elasticity for the first insulating member 303 and the second insulating member 304 may be young's modulus, which may be obtained by measurement according to the national standard GB/T1447-2005, and a specific measurement method thereof may be performed with reference to the national standard GB/T1447-2005, which will not be described herein.

In some embodiments, the first pole piece 301 is an anode pole piece, the second pole piece 302 is a cathode pole piece, and the first insulating member 303 protrudes from the second insulating member 304 in the direction opposite to the winding direction X.

Since the anode electrode sheet is generally protruded from the cathode electrode sheet in the winding direction X in the electrode assembly 30 of the cylindrical winding structure. By configuring the first electrode sheet 301 as an anode electrode sheet, configuring the second electrode sheet 302 as a cathode electrode sheet, and extending the first insulating member 303 from the second insulating member 304 in the opposite direction to the winding direction X, the first insulating member 303 connected to the anode electrode sheet can be longer at the center of the electrode assembly 30 than the second insulating member 304 and wound into the center of the electrode assembly 30.

In some embodiments, in the thickness direction of the first pole piece 301, the thickness of the first insulating member 303 is H3, and the thickness of the second insulating member 304 is F3, H3 > F3.

By configuring the thickness H3 of the first insulating member 303 to be greater than the thickness of the second insulating member F3 in the thickness direction of the first electrode sheet 301, the first insulating member 303 wound around the inner end of the first electrode sheet 301 at the center of the electrode assembly 30 can provide a greater supporting force, which is advantageous in improving the collapse reduction effect.

In some embodiments, the first insulator 303 is located inside the second insulator 304 in the opposite direction to the winding direction X.

By arranging the first insulating member 303 on the inner side of the second insulating member 304 in the opposite direction to the winding direction X, the first insulating member 303 is located on the inner side of the second insulating member 304, so that the anode pole piece can extend out of the cathode pole piece in the winding direction X, and the first insulating member 303 connected to the inner end of the first pole piece 301 can be better wound on the center of the electrode assembly 30, thereby better supporting.

In some embodiments, the modulus of elasticity of the first insulator 303 is greater than the modulus of elasticity of the second insulator 304.

By configuring the elastic modulus of the first insulating member 303 to be greater than that of the second insulating member 304, the first insulating member 303, which is connected to the inner end of the first electrode sheet 301, can provide a greater elastic restoring force to support at the center of the electrode assembly 30 after winding, so that the first insulating member 303 can better reduce the possibility of collapse of the electrode assembly 30.

In some embodiments, the second pole piece 302 is provided with a second insulator 304 at both ends in the winding direction X.

By arranging the second insulating members 304 at both ends of the second electrode sheet 302 along the winding direction X, the second end surfaces 30211 of both ends of the second electrode sheet 302 along the winding direction X are at least partially covered by the second insulating members 304, so that burrs on the second end surfaces 30211 of both ends of the second electrode sheet 302 can be covered, the risk that the burrs pierce through the separator 305 of the electrode assembly 30 can be further reduced, and further improvement of the reliability of the battery 2 is facilitated.

In some embodiments, the second insulator 304 at the inner end of the second pole piece 302 extends beyond the second pole piece 302 by a length B1, and the second insulator 304 at the outer end of the second pole piece 302 extends beyond the second pole piece 302 by a length B4, B1 > B4.

By setting the length of the second insulating member 304 of the inner end of the second pole piece 302 protruding out of the second pole piece 302 to B1, setting the length of the second insulating member 304 of the outer end of the second pole piece 302 protruding out of the second pole piece 302 to B4, and making B1 > B4, it is possible to reduce waste while making the second insulating member 304 have a good supporting effect.

In some embodiments, the second insulating member 304 includes two second insulating layers 3041 disposed opposite to each other, the second insulating layers 3041 including second connection portions 3041 and second cover portions 30112, the second cover portions 30112 being laminated on the second pole piece 302, the second connection portions 3041 of the two second insulating layers 3041 being bonded to each other.

As shown in fig. 9, the second insulating layer 3041 includes a second connection portion 3041 and a second cover portion 30112 connected to each other, the second connection portion 3041 and the second cover portion 30112 being sequentially disposed along the winding direction X. The second covering portion 30112 is configured to be connected to the second pole piece 302, and the second connecting portion 3041 is configured to be connected to a second connecting portion 3041 of another second insulating layer 3041 so as to cover an end portion of the second pole piece 302 where the second end surface 30211 is located.

The second covering portions 30112 of the two second insulating members 304 are adhered to two opposite surfaces of the second pole piece 302, and are respectively stacked on two sides of the second pole piece 302, so that the second connecting portions 3041 of the two second insulating layers 3041 are adhered to each other, and the second end surface 30211 connected between the two opposite surfaces of the second pole piece 302 is covered.

The length B1 of the second insulating member 304 extending from the inner end of the second pole piece 302 to the second pole piece 302 is the length of the second connecting portion 3041 of the inner end of the second pole piece 302 in the opposite direction to the winding direction X. The length B4 of the second insulating member 304 extending out of the outer end of the second pole piece 302 from the second pole piece 302 is the length of the second connecting portion 3041 of the outer end of the second pole piece 302 in the winding direction X.

In some embodiments, the length B1 of the second insulating member 304 extending from the inner end of the second pole piece 302 (the length of the second connecting portion 3041 of the inner end of the second pole piece 302 in the opposite direction to the winding direction X) of the second pole piece 302 is configured to be 0.5 mm+.b1+.120 mm. By configuring the range of the length B1 of the second insulating member 304 extending from the inner end of the second electrode plate 302 to be 0.5mm less than or equal to B1 less than or equal to 120mm, the second insulating member 304 extending from the inner end of the second electrode plate 302 can extend into the center of the electrode assembly 30 by a sufficient length, which is beneficial to improving the supporting effect of the second insulating member 304 on the electrode assembly 30 without wasting too much. In some embodiments, the extent to which the second insulator 304 at the inner end of the second pole piece 302 extends beyond the length B1 of the second pole piece 302 is configured to be 1 mm.ltoreq.B1.ltoreq.100 mm, so that the second insulator 304 at the inner end of the second pole piece 302 does not become excessively long while better supporting the electrode assembly 30.

In some embodiments, the length B4 of the second insulating member 304 of the outer end of the second pole piece 302 (the length of the second connecting portion 3041 of the outer end of the second pole piece 302 in the winding direction X) that extends out of the second pole piece 302 is configured to be 0.5 mm+.b4+.10mm. By configuring the range of the length B4 of the second insulating member 304 extending out of the second pole piece 302 from the outer end of the second pole piece 302 to be 0.5 mm+.b4+.10mm, the second insulating member 304 at the outer end of the second pole piece 302 can cover the second end surface 30211 at the outer end of the second pole piece 302 and reduce the waste of the second insulating member 304. In some embodiments, the extent to which the second insulator 304 at the outer end of the second pole piece 302 extends beyond the length B4 of the second pole piece 302 is configured to be 1 mm+.B4+.6mm, such that the second insulator 304 at the outer end of the second pole piece 302 can both cover the second end face 30211 at the outer end of the second pole piece 302 and reduce wastage of the second insulator 304.

The second insulating layer 3041 may be an insulating tape, and two parts of the insulating tape are adhered to the surface of the second electrode sheet 302, and the other parts are adhered to another insulating tape.

In some embodiments, in the winding direction X, the length of the first covering portion 30312 at the inner end of the first pole piece 301 is A2, and the length of the second covering portion 30112 at the inner end of the second pole piece 302 is B2, B2 < A2.

The length A2 of the first covering portion 30312 at the inner end of the first pole piece 301 is the length of the portion of the first insulating member 303 at the inner end of the first pole piece 301 covered on the first pole piece 301 along the winding direction X, and the length B2 of the second covering portion 30112 at the inner end of the second pole piece 302 is the length of the portion of the second insulating member 304 at the inner end of the second pole piece 302 covered on the second pole piece 302 along the winding direction X. By making B2 < A2, the area of the second insulating member 304 at the inner end of the second pole piece 302 covering the second pole piece 302 can be reduced, which is advantageous in reducing the capacity loss caused by providing the second insulating member 304.

Illustratively, the length A2 of the first covering portion 30312 at the inner end of the first pole piece 301 is configured to range from 0.5mm < A2 < 120mm. By configuring the range of the length A2 of the first covering portion 30312 at the inner end of the first pole piece 301 to be 0.5mm less than or equal to a2 less than or equal to 120mm, the first insulating member 303 at the inner end of the first pole piece 301 and the first pole piece 301 have enough bonding areas, and meanwhile, the waste of the first pole piece 301 caused by overlarge bonding areas is not easy to occur, so that the first insulating member 303 can be firmly bonded to the first pole piece 301 through the first covering portion 30312, and the functional area of the first pole piece 301 is not wasted. In some embodiments, the length A2 of the first covering portion 30312 of the inner end of the first pole piece 301 is configured to be 1 mm. Ltoreq.A2. Ltoreq.100 mm, so that the first insulating member 303 is firmly adhered to the first pole piece 301 without wasting the area of the first pole piece 301.

The length B2 of the second covering portion 30112 at the inner end of the second pole piece 302 is set to be 0.5 mm.ltoreq.b2.ltoreq.10 mm. By configuring the range of the length B2 of the second covering portion 30112 at the inner end of the second pole piece 302 to be 0.5 mm+.b2+.10mm, the second insulating member 304 at the inner end of the second pole piece 302 has a sufficient bonding area with the second pole piece 302 while also being able to reduce the covering of the second pole piece 302, so that the second insulating member 304 can be firmly bonded to the second pole piece 302 through the second covering portion 30112 without excessively covering the second pole piece 302. In some embodiments, the length B2 of the second cover 30112 at the inner end of the second pole piece 302 is configured to range from 1mm < B2 > < 6mm, so that the second insulator 304 is firmly bonded to the second pole piece 302 without wasting the area of the second pole piece 302.

Illustratively, the length A3 of the first covering portion 30312 at the outer end of the first pole piece 301 is configured to range from 0.5 mm. Ltoreq.A3. Ltoreq.120 mm. By configuring the range of the length A3 of the first covering portion 30312 at the outer end of the first pole piece 301 to be 0.5mm less than or equal to a3 less than or equal to 120mm, the first insulating member 303 at the outer end of the first pole piece 301 has a sufficient bonding area with the first pole piece 301, and meanwhile, the waste of the first pole piece 301 caused by the overlarge bonding area is not easy, so that the first insulating member 303 can be firmly bonded to the first pole piece 301 through the first covering portion 30312, and the functional area of the first pole piece 301 is not wasted. In some embodiments, the length A3 of the first covering portion 30312 at the outer end of the first pole piece 301 is configured to be 1 mm. Ltoreq.A3. Ltoreq.100 mm, so that the first insulating member 303 is firmly adhered to the first pole piece 301 without wasting the area of the first pole piece 301.

Illustratively, the length A4 of the first connection portion 30311 at the outer end of the first pole piece 301 is configured to range 0.5mm < A4 < 120mm. By configuring the range of the length A4 of the first connection portion 30311 of the outer end of the first pole piece 301 to be 0.5 mm+.a4+.120mm, the first connection portion 30311 of the outer end of the first pole piece 301 can cover the first end face 30111 of the outer end of the first pole piece 301 while also reducing the waste of the first insulating member 303. In some embodiments, the length A4 of the first connection portion 30311 at the outer end of the first pole piece 301 is configured to range 1 mm. Ltoreq.A4. Ltoreq.100 mm such that the first connection portion 30311 at the outer end of the first pole piece 301 both covers the first end face 30111 at the outer end of the first pole piece 301 and reduces wastage of the first insulating member 303.

In some embodiments, the electrode assembly 30 is a cylindrical structure.

The cylindrical structure formed by the arrangement of the electrode assembly 30 may be formed by winding the first and second electrode sheets 301 and 302 and the separator 305 in the electrode assembly 30 in the winding direction X after being laminated.

In some embodiments, the first pole piece 301 further includes a first tab 3013 connected to the first current collector 3011, the first tab 3013 including a flattened area 30131, the flattened area 30131 being spaced apart from the first insulator 303.

The first tab 3013 may be a portion of the first current collector 3011 where the first active material layer 3012 is not disposed on a surface, and may be used to connect with other components in the battery cell 7.

The first tab 3013 is subjected to a rubbing treatment to obtain a rubbing region 30131, so that the end of the electrode assembly 30 in the direction perpendicular to the winding direction X can be flattened, the possibility of occurrence of a sharp corner structure can be reduced, current collecting disc welding is conveniently performed at the end of the electrode assembly 30 in the direction perpendicular to the winding direction X, and welding quality is ensured.

The arrangement of the rubbing area 30131 and the first insulating member 303 at a distance may mean that the rubbing area 30131 of the first tab 3013 is not provided with the first insulating member 303, so that the rubbing area 30131 is separated from the first insulating member 303, and the first insulating member 303 does not affect the connection between the rubbing area 30131 and the current collecting disc.

In some embodiments, as shown in fig. 10, the first insulating member 303 may protrude from the side of the first electrode sheet 301 where the first tab 3013 is disposed to the surface of the first tab 3013 in a direction perpendicular to the winding direction X, so that the first insulating member 303 can cover a larger area of the first end face 30111, which is advantageous in covering more burrs on the first end face 30111, which is advantageous in further reducing the risk of burrs penetrating the separator 305 of the electrode assembly 30.

Illustratively, the first insulating member 303 extends beyond the first active material layer 3012 by a length G1, G1. Ltoreq.4 mm in a direction perpendicular to the winding direction X, so that the first insulating member 303 can better avoid the flattened area 30131 of the first tab 3013.

As shown in fig. 11, the first insulating member 303 may not extend from the side of the first pole piece 301 where the first tab 3013 is provided, so that the first insulating member 303 can better avoid the rubbing area 30131 of the first tab 3013, and is not easy to affect and change the structure of the first tab 3013. In some embodiments, the length of the first insulator 303 from the edge of the first active material layer 3012 is G2, G2. Ltoreq.4 mm, such that the first insulator 303 is able to cover a larger area of the first end face 30111, facilitating covering more burrs on the first end face 30111, facilitating further reducing the risk of burrs penetrating the separator 305 of the electrode assembly 30.

In some embodiments, the first insulating member 303 may protrude from the side of the first pole piece 301 remote from the first tab 3013 in a direction perpendicular to the winding direction X by a first active material layer 3012, so that the first insulating member 303 can better cover the first end face 30111, advantageously covering more burrs on the first end face 30111, advantageously further reducing the risk of burrs penetrating the separator 305 of the electrode assembly 30. Illustratively, the first insulating member 303 extends from the side of the first pole piece 301 away from the first tab 3013 to form a first active material layer 3012 with a thickness I1, I1 being less than or equal to 4mm, which is advantageous in reducing the amount of the first insulating member 303 and reducing the waste of materials.

Illustratively, the first insulating member 303 may also not protrude from a side of the first pole piece 301 remote from the first tab 3013 in a direction perpendicular to the winding direction X, where the length of the first insulating member 303 from the edge of the first active material layer 3012 is I, i+.4 mm, so that the first insulating member 303 can cover a larger area of the first end face 30111, facilitating covering more burrs on the first end face 30111, facilitating further reducing the risk of burrs penetrating the separator 305 of the electrode assembly 30.

Some embodiments of the present application further provide a battery cell 7, where the battery cell 7 includes a housing 20 and at least one electrode assembly 30 provided in the foregoing technical solution, and the electrode assembly 30 is accommodated in the housing 20. Since the battery cell 7 includes the electrode assembly 30 provided in the above-described technical scheme, the battery cell 7 has good reliability.

Some embodiments of the present application further provide a battery 2, where the battery 2 includes the battery cell 7 provided by the above technical solution. Since the battery 2 includes the battery cell 7 provided by the above-described technical solution, the battery 2 has good reliability.

Some embodiments of the present application further provide an electric device, where the electric device includes the battery 2 provided by the above technical solution, and the battery 2 is used for providing electric energy. The powered device may be any of the aforementioned devices or systems employing the battery 2.

Some embodiments of the present application also provide a method of manufacturing an electrode assembly 30, the method of manufacturing the electrode assembly 30 including the steps of:

s1, providing a plurality of first electrode sheets 301 and insulating members, wherein the first electrode sheets 301 include a first current collector 3011 and a first active material layer 3012 provided on a surface of the first current collector 3011, and the end of the first current collector 3011 in the longitudinal direction thereof has a first end face 30111.

The first electrode sheet 301 may be provided as the first electrode sheet 301 in the foregoing embodiment, which includes a first current collector 3011 and a first active material layer 3012 disposed on a surface of the first current collector 3011, each first electrode sheet 301 being configured to form one electrode assembly 30, and an end portion of the first current collector 3011 in the first electrode sheet 301 along its own length direction having a first end face 30111. The insulator may be an insulating structure for connecting the two first pole pieces 301.

Step S1 can provide a material for manufacturing the electrode assembly 30, facilitating the subsequent processing to manufacture the electrode assembly 30.

S2, connecting two adjacent first pole pieces 301 through an insulating piece, wherein the insulating piece covers at least part of the first end face 30111.

Through step S2, a plurality of first pole pieces 301 are sequentially connected along the length direction of the first pole pieces 301 to form a long strip structure. Wherein, two adjacent first pole pieces 301 are connected through the insulating part, and the insulating part coats at least part of the first end face 30111 of the first current collector 3011, so that the insulating part coats at least part burrs of the first end face 30111, and the possibility of puncturing the separator 305 after winding the electrode assembly 30 is reduced.

S3, winding the first electrode sheet 301 and the insulator in the longitudinal direction of the first current collector 3011.

The long ribbon structure including the plurality of first pole pieces 301 and the insulating member is wound to form a cylindrical winding structure through step S2.

S4, cutting insulation pieces between two adjacent first pole pieces 301, so that the first pole pieces 301 form first insulation pieces 303 at two ends of the winding direction X, and the first insulation pieces 303 cover at least part of the first end face 30111.

After one first pole piece 301 is wound to form a winding structure, the insulating member between the first pole piece 301 and the adjacent first pole piece 301 is cut off at the middle, so that the insulating member is divided into first insulating members 303 connected to two ends of the adjacent first pole pieces 301 in the winding direction X, and at least part of the first end face 30111 is covered by the first insulating members 303.

According to some embodiments of the present application, there is provided an electrode assembly 30, the electrode assembly 30 including a first electrode sheet 301, a second electrode sheet 302, a separator 305, a first insulating member 303, and a second insulating member 304, the first electrode sheet 301, the second electrode sheet 302, and the separator 305 being stacked, the separator 305 being disposed between the first electrode sheet 301 and the second electrode sheet 302, the first electrode sheet 301 including a first current collector 3011 and a first active material layer 3012 disposed on a surface of the first current collector 3011, an end of the first current collector 3011 in a winding direction X having a first end face 30111, the first insulating member 303 being connected to the first electrode sheet 301 and covering at least a portion of the first end face 30111; the second electrode sheet 302 includes a second current collector 3021 and a second active material layer 3022 disposed on a surface of the second current collector 3021, an end portion of the second current collector 3021 in the winding direction X has a second end surface 30211, and the second insulating member 304 is connected to the second electrode sheet 302 and covers at least a portion of the second end surface 30211. Wherein, the inner end of the first pole piece 301 is connected with a first insulating piece 303, and at least part of the first pole piece 301 is wound on the outer side of the first insulating piece 303. In the above structure, since the first end face 30111 of the end of the first current collector 3011 is covered with the first insulating member 303, the first insulating member 303 can cover burrs at the first end face 30111, reducing the risk of the burrs penetrating the separator 305 of the electrode assembly 30, reducing the possibility of short circuits occurring inside the battery 2, and contributing to the improvement of the reliability of the battery 2.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present application, and not for limiting the same; 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 scheme described in the foregoing embodiments can be modified or some or all of the technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the application, and are intended to be included within the scope of the appended claims and description. In particular, the technical features mentioned in the respective embodiments may be combined in any manner as long as there is no structural conflict. The present application is not limited to the specific embodiments disclosed herein, but encompasses all technical solutions falling within the scope of the claims.

Claims

1. An electrode assembly comprising first and second electrode sheets of opposite polarity, the first and second electrode sheets being wound in a winding direction;

The first pole piece comprises a first current collector and a first active material layer arranged on the surface of the first current collector, and the end part of the first current collector along the winding direction is provided with a first end face;

the electrode assembly further includes a first insulating member connected to the first electrode tab and covering at least a portion of the first end face.

2. The electrode assembly according to claim 1, wherein both ends of the first electrode sheet in the winding direction are provided with the first insulating member.

3. The electrode assembly of claim 1, wherein the first insulating member is bonded to the first active material layer or the first current collector.

4. The electrode assembly of claim 1, wherein the first insulating member comprises two oppositely disposed first insulating layers, the first insulating layers comprising a first connecting portion and a first covering portion, the first covering portion being laminated to the first electrode sheet, the first connecting portions of the two first insulating layers being bonded to each other.

5. The electrode assembly of claim 4 wherein the first electrode sheet has a thickness H1 and the first insulating layer has a thickness H2,

6. The electrode assembly of claim 1, wherein the first insulating member is connected to an inner end of the first pole piece, and at least a portion of the first pole piece is wound on an outer side of the first insulating member.

7. The electrode assembly of claim 6, wherein the first insulator at the inner end of the first pole piece extends beyond the first pole piece by a length A1,0.5mm ∈a1 ∈120mm, in a direction opposite to the winding direction.

8. The electrode assembly according to any one of claims 1 to7, wherein the second electrode sheet includes a second current collector and a second active material layer provided on a surface of the second current collector, an end portion of the second current collector in the winding direction having a second end face; the electrode assembly further includes a second insulator connected to the second pole piece and covering at least a portion of the second end face.

9. The electrode assembly of claim 8, wherein the first insulator has a modulus of elasticity that is greater than a modulus of elasticity of the first pole piece and the second insulator has a modulus of elasticity that is greater than a modulus of elasticity of the second pole piece.

10. The electrode assembly of claim 8, wherein the first electrode sheet is an anode electrode sheet and the second electrode sheet is a cathode electrode sheet, and wherein the first insulator extends beyond the second insulator in a direction opposite the winding direction.

11. The electrode assembly of claim 10, wherein the first insulating member has a thickness H3 and the second insulating member has a thickness F3, H3 > F3, in a thickness direction of the first electrode sheet.

12. The electrode assembly of claim 10, wherein the first insulator is located inside the second insulator in a direction opposite to the winding direction.

13. The electrode assembly of claim 10, wherein the first insulating member has a modulus of elasticity greater than the modulus of elasticity of the second insulating member.

14. The electrode assembly according to claim 10, wherein both ends of the second electrode sheet in the winding direction are provided with the second insulating member.

15. The electrode assembly of claim 14, wherein the second insulator of the inner end of the second pole piece extends beyond the second pole piece by a length B1, and the second insulator of the outer end of the second pole piece extends beyond the second pole piece by a length B4, B1 > B4.

16. The electrode assembly of claim 1, wherein the electrode assembly is a cylindrical structure.

17. The electrode assembly of claim 1, wherein the first pole piece further comprises a first tab connected to the first current collector, the first tab comprising a flattened region, the flattened region being spaced apart from the first insulator.

18. A battery cell, comprising:

a housing;

at least one electrode assembly according to any one of claims 1 to 17, accommodated in the case.

19. A battery comprising the battery cell of claim 18.

20. An electrical device comprising a battery as claimed in claim 19 for providing electrical energy.

21. A method of manufacturing an electrode assembly, comprising:

Providing a plurality of first pole pieces and insulating pieces, wherein each first pole piece comprises a first current collector and a first active material layer arranged on the surface of the first current collector, and the end part of the first current collector along the length direction of the first current collector is provided with a first end face;

connecting two adjacent first pole pieces through the insulating piece, wherein the insulating piece covers at least part of the first end face;

Winding the first pole piece and the insulating member in a length direction of the first current collector;

cutting the insulating pieces between two adjacent first pole pieces to enable the two ends of the first pole pieces in the winding direction to form first insulating pieces, wherein the first insulating pieces cover at least part of the first end face.