WO2021195924A1

WO2021195924A1 - Battery cell structure and battery

Info

Publication number: WO2021195924A1
Application number: PCT/CN2020/082308
Authority: WO
Inventors: 郭章飞; 董惠
Original assignee: 宁德新能源科技有限公司
Priority date: 2020-03-31
Filing date: 2020-03-31
Publication date: 2021-10-07
Also published as: CN113994519B; CN113994519A

Abstract

A battery cell structure (100) and a battery (300) thereof. The battery cell structure (100) comprises a first electrode assembly (110) formed by winding a first electrode plate (11) and a second electrode plate (13), and comprises a second electrode assembly (120) formed by winding a third electrode plate (21) and a fourth electrode plate (23). The battery cell structure (100) also comprises a first tab (130) electrically connected to the first electrode plate (11) and a second tab (140) electrically connected to the second electrode plate (13), said first tab (130) and said second tab (140) both passing through the first electrode assembly (110). The first tab (130) is also electrically connected to a third electrode plate (21) of the second electrode assembly (120). In the battery cell structure (100), two electrode assemblies (110, 120) having a winding structure form an irregular-shaped battery cell, and the battery cell production efficiency is thus high and the electrode plate material utilization rate is high.

Description

Cell structure and battery

Technical field

This application relates to the technical field of electrochemical devices, in particular, to a cell structure and a battery.

Background technique

With the rapid development of electronic products, their power consumption and product endurance requirements are getting higher and higher. In the design process of electronic products, after completing the layout of electronic components, the storage space left for the battery is not a rectangular parallelepiped, but an irregular shape such as an "L" shape and a "T" shape. This requires battery manufacturers Developed a special-shaped battery that matches the storage space to improve the space utilization of electronic equipment.

Currently, the industry generally adopts the lamination process to manufacture special-shaped batteries. However, the production efficiency of the lamination process is low, and the material utilization rate is low, resulting in high production costs. In addition, the special-shaped pole piece of the current lamination process cannot be directly coated. Only the rectangular pole piece can be coated first, and then the required special-shaped pole piece shape is cut out. The cut-out pole piece material can only be scrapped, and the material utilization rate Low.

Summary of the invention

This application aims to solve at least one of the technical problems existing in the prior art. To this end, one aspect of the present application is to provide a battery cell structure that forms a special-shaped battery cell by using two winding-type electrode assemblies, which has high battery production efficiency and high pole piece material utilization.

The cell structure according to the embodiment of the present application includes a first electrode assembly formed by winding a first pole piece and a second pole piece, and a second electrode assembly formed by winding a third pole piece and a fourth pole piece. The cell structure further includes a first tab electrically connected to the first pole piece and a second tab electrically connected to the second pole piece, the first tab and the second tab Both pass through the first electrode assembly; wherein, the first tab is also electrically connected to the third pole piece of the second electrode assembly.

In some embodiments, the second tab is also electrically connected to the fourth tab of the second electrode assembly.

In some embodiments, the first tab includes a first tab segment, a second tab segment, and a first bent segment between the first tab segment and the second tab segment, The first tab section is located in the first electrode assembly, the second tab section is located in the second electrode assembly, and the first bent section is located between the first electrode assembly and the first electrode assembly. Between the two electrode assemblies, the second tab includes a third tab segment, a fourth tab segment, and a second bent segment located between the third tab segment and the fourth tab segment, The third tab section is located in the first electrode assembly, the fourth tab section is located in the second electrode assembly, and the second bent section is located between the first electrode assembly and the first electrode assembly. Between two electrode assemblies.

In some embodiments, the first electrode assembly includes n wound layers, the innermost wound layer of the first electrode assembly is defined as the first wound layer of the first electrode assembly, and the first electrode The outermost wound layer of the assembly is defined as the n-th wound layer of the first electrode assembly, the second electrode assembly includes m wound layers, and the innermost wound layer of the second electrode assembly defines Is the first wound layer of the second electrode assembly, the outermost wound layer of the second electrode assembly is defined as the m-th wound layer of the second electrode assembly, and n and m are both greater than 1. Positive integer.

In some embodiments, the first tab penetrating from the first side of the first electrode assembly is electrically connected to the third pole piece of the m-th winding layer of the second electrode assembly. The second tab through the first side of the first electrode assembly is electrically connected to the fourth pole piece of the m-th winding layer of the second electrode assembly.

In some embodiments, the first tab is electrically connected to the first pole piece of the first winding layer of the first electrode assembly, and the second tab is electrically connected to the first pole piece of the first electrode assembly. 1 second pole piece of winding layer.

In some embodiments, the first tab is electrically connected to the first pole piece of the nth winding layer of the first electrode assembly, and the second tab is electrically connected to the first pole piece of the first electrode assembly. n second pole piece of winding layer.

In some embodiments, the first tab is electrically connected to the first pole piece of the i-th wound layer of the first electrode assembly, and the second tab is electrically connected to the first pole piece of the first electrode assembly. For the second pole piece of the j winding layer, i and j are both positive integers greater than 1 and less than n, and the difference between i and j is greater than or equal to a preset value.

In some embodiments, the preset value is 4 layers.

In some embodiments, the extension length of the third pole piece of the m-th winding layer of the second electrode assembly is greater than the extension length of the fourth pole piece, and the first winding layer of the second electrode assembly has an extension length The triode piece and the fourth pole piece contain empty foil regions.

In some embodiments, the cell structure further includes an isolation pad disposed between the first electrode assembly and the second electrode assembly, the isolation pad is made of a non-conductive material, and the isolation pad is provided with There are two through holes, and the first tab and the second tab pass through the two through holes.

In some embodiments, the length of the isolation pad is less than or equal to the width of the first electrode assembly, and the width of the isolation pad is less than the thickness of the first electrode assembly and the thickness of the second electrode assembly. The larger one.

In some embodiments, the thickness of the isolation pad is 10um to 2000um.

In some embodiments, there is a gap between the first electrode assembly and the second electrode assembly, and the gap is greater than or equal to the thickness of the isolation pad plus a first preset distance, and the first The preset distance is less than or equal to 2mm.

In some embodiments, insulating tape is provided on the first tab.

In some embodiments, when the first tab is electrically connected to the third pole piece by welding, the welding area of the first tab on the third pole piece satisfies the following relationship: welding area ≥The size of the current through the tab/the current-carrying capacity per unit area of the tab.

In some embodiments, there are 2 to 5 first tabs in the welding area of the third tab.

In some embodiments, the first electrode assembly and the second electrode assembly share a housing, and when the main plane of the first electrode assembly is the line of sight plane, the first electrode assembly and the second electrode assembly The electrode assembly forms an L-shaped electrode assembly shape or a T-shaped electrode assembly shape.

In some embodiments, the winding direction of the first electrode assembly and the winding direction of the second electrode assembly are parallel to each other or perpendicular to each other.

In some embodiments, the first tab and the second tab also extend from the second electrode assembly to form two connection terminals.

In some embodiments, the first tab is formed by cutting the current collector of the first pole piece, and the second tab is formed by cutting the current collector of the second pole piece.

According to the cell structure of the embodiment of the present application, by using the tabs penetrating the electrode assembly to connect two winding-type electrode assemblies to form a special-shaped cell, the production efficiency of the cell can be improved, and the pole piece material utilization rate can be improved. high.

Another aspect of the present application is to provide a battery including a cell structure. The cell structure includes a first electrode assembly formed by winding a first pole piece and a second pole piece, and a second electrode assembly formed by winding a third pole piece and a fourth pole piece. The cell structure further includes a first tab electrically connected to the first pole piece and a second tab electrically connected to the second pole piece, the first tab and the second tab Both penetrate the first side and the second side of the first electrode assembly; wherein, the first tab penetrating from the first side of the first electrode assembly is also electrically connected to the second electrode assembly The third pole piece.

According to the battery of the embodiment of the present application, two electrode assemblies with a wound structure are connected to form a special-shaped battery cell by using tabs penetrating the electrode assembly, which can improve the production efficiency of the battery cell, and the utilization rate of the electrode piece material is high.

Description of the drawings

The above and/or additional aspects and advantages of the present application will become obvious and easy to understand from the description of the embodiments in conjunction with the following drawings, in which:

Fig. 1 shows a schematic structural diagram of a cell structure according to an embodiment of the present application;

Fig. 2 shows a schematic structural diagram of a first electrode assembly according to an embodiment of the present application;

Fig. 3 shows a schematic structural diagram of a second electrode assembly according to an embodiment of the present application;

FIG. 4 shows a schematic diagram of the connection positions of the first and second tabs electrically connected to the first electrode assembly according to an embodiment of the present application;

FIG. 5 shows a schematic diagram of the connection positions of the first and second tabs electrically connected to the first electrode assembly according to another embodiment of the present application;

FIG. 6 shows a schematic diagram of the connection positions of the first and second tabs electrically connected to the first electrode assembly according to another embodiment of the present application;

FIG. 7 shows a schematic diagram of assembling the isolation pad on the first electrode assembly according to an embodiment of the present application;

Fig. 8 shows a schematic diagram of a battery cell structure to be assembled to a housing according to an embodiment of the present application;

Fig. 9 shows a B1-B1' cross-sectional view when the first electrode assembly and the second electrode assembly are arranged in a vertical winding direction according to an embodiment of the present application;

Fig. 10 shows a cross-sectional view of A1-A1' when the first electrode assembly and the second electrode assembly are arranged in a vertical winding direction according to an embodiment of the present application;

Figure 11 shows a B1-B1' cross-sectional view when the first electrode assembly and the second electrode assembly are arranged in a parallel winding direction according to an embodiment of the present application;

Fig. 12 shows a cross-sectional view of A1-A1' when the first electrode assembly and the second electrode assembly are arranged in a parallel winding direction according to an embodiment of the present application;

Fig. 13 shows a schematic diagram of the welding position of the first tab on the second electrode assembly when the first electrode assembly and the second electrode assembly are arranged in a vertical winding direction according to an embodiment of the present application;

14 shows a schematic diagram of the welding position of the second tab on the second electrode assembly when the first electrode assembly and the second electrode assembly are arranged in a vertical winding direction according to an embodiment of the present application;

15 shows a schematic diagram of the welding position of the first tab on the second electrode assembly when the first electrode assembly and the second electrode assembly are arranged in a parallel winding direction according to an embodiment of the present application;

16 shows a schematic diagram of the welding position of the second tab on the second electrode assembly when the first electrode assembly and the second electrode assembly are arranged in a parallel winding direction according to an embodiment of the present application;

FIG. 17 shows a schematic diagram of the sticking position of the first end insulating adhesive tape on the second electrode assembly when the first electrode assembly and the second electrode assembly are arranged in a vertical winding direction according to an embodiment of the present application;

18 shows a schematic diagram of the sticking position of the second end insulating adhesive tape on the second electrode assembly when the first electrode assembly and the second electrode assembly are arranged in a parallel winding direction according to an embodiment of the present application;

19A to 19C show schematic diagrams of the structure of the first tab and the second tab according to an embodiment of the present application;

FIG. 20 shows a schematic structural diagram of a cell structure according to another embodiment of the present application;

FIG. 21 shows a schematic structural diagram of a cell structure according to another embodiment of the present application;

Fig. 22 shows a schematic diagram of a battery module according to an embodiment of the present application;

Symbol description of main components:

First pole piece 11, first isolation film 12, second pole piece 13, second isolation film 14, third pole piece 21, third isolation film 22, fourth pole piece 23, fourth isolation film 24, cell Structure 100, first electrode assembly 110, first side 111, second side 112, second electrode assembly 120, first tab 130, second tab 140, isolation pad 150, through hole 151, first welding area 160 , The second welding area 161, the first insulating tape 162, the second insulating tape 163, the first ending insulating tape 170, the second ending insulating tape 171, the first bending section 130a, the first tab section 130b , The second tab section 130c, the second bending section 140a, the third tab section 140b, the fourth tab section 140c, the housing 200, and the battery 300.

Detailed ways

The embodiments of the present application are described in detail below. Examples of the embodiments are shown in the accompanying drawings, in which the same or similar reference numerals indicate the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the drawings are exemplary, and are only used to explain the present application, and should not be construed as a limitation to the present application.

The cell structure 100 according to an embodiment of the present application will be described in detail below with reference to FIGS. 1 to 21.

As shown in FIGS. 1 to 3, the cell structure 100 according to the embodiment of the present application includes a first electrode assembly 110, a second electrode assembly 120, a first tab 130 and a second tab 140. The first electrode assembly 110 is formed by winding the first pole piece 11, the first isolation film 12, the second pole piece 13, and the second isolation film 14 around the first winding core space, and the second electrode assembly 120 is formed by the third pole piece 21 , The third isolation film 22, the fourth pole piece 23, and the fourth isolation film 24 are wound around the second winding core space. The first tab 130 is electrically connected to the first pole piece 11, the second tab 140 is electrically connected to the second pole piece 13, and both the first tab 130 and the second tab 140 penetrate the first electrode assembly 110. Side 111 and second side 112. The first tab 130 penetrating from the first side 111 of the first electrode assembly 110 is also electrically connected to the third pole piece 21 of the second electrode assembly 120. In other embodiments, the first electrode assembly 110 may also be formed by winding the first pole piece 11, the first isolation film 12, and the second pole piece 13 around the first winding core space; the second electrode assembly 120 may also be formed by the first winding core space. The triode piece 21, the third isolation film 22, and the fourth pole piece 23 are wound around the second winding core space.

In some embodiments, the second tab 140 penetrating from the first side 111 of the first electrode assembly 110 is also electrically connected to the fourth pole piece 23 of the second electrode assembly 120.

In some embodiments, the first tab 130 can be electrically connected to the empty foil area of the first pole piece 11 and the empty foil area of the third pole piece 21, and the second tab 140 can be electrically connected to the second pole piece 13 The empty foil area and the empty foil area of the fourth pole piece 23. In other embodiments, the first pole piece 11, the second pole piece 13, the third pole piece 21, and the fourth pole piece 23 may also include a connection area exposed by a cleaning process, and the first pole piece 130 may also be electrically connected In the connection area of the first pole piece 11 or the connection area of the third pole piece 21, the second lug 140 may also be electrically connected to the connection area of the second pole piece 13 or the connection area of the fourth pole piece 23.

In some embodiments, the first tab 130 is preferably electrically connected to the inner surface of the empty foil area of the first pole piece 11 (the surface close to the first core space) and the inner surface of the empty foil area of the third pole piece 21 (Close to the surface of the second winding core space), the second tab 140 is preferably electrically connected to the outer surface of the empty foil area of the second pole piece 13 (the surface away from the first winding core space) and the void of the fourth pole piece 23 The outer surface of the foil zone (the surface away from the second core space). In other embodiments, the first pole piece 11, the second pole piece 13, the third pole piece 21, and the fourth pole piece 23 may also include a connection area exposed by a cleaning process, and the first pole piece 130 may also be electrically connected On the inner surface of the connection area of the first pole piece 11 (the surface close to the first winding core space), or the inner surface of the connection area of the third pole piece 21 (the surface close to the second winding core space), the second tab 140 can also be electrically connected to the outer surface of the connection area of the second pole piece 13 (the surface away from the first core space), or the outer surface of the connection area of the fourth pole piece 23 (the surface away from the second core space) ).

In some embodiments, the first tab 130 is a positive tab and the second tab 140 is a negative tab, or the first tab 130 is a negative tab and the second tab 140 is a positive tab. When the first tab 130 is a positive tab and the second tab 140 is a negative tab, the first pole piece 11 and the third pole piece 21 may be aluminum foil, and the second pole piece 13 and the fourth pole piece 23 may be copper foil . When the first tab 130 is a negative tab and the second tab 140 is a positive tab, the first pole piece 11 and the third pole piece 21 may be copper foil, and the second pole piece 13 and the fourth pole piece 23 may be aluminum foil .

In some embodiments, the first tab 130 electrically connects the first pole piece 11 and the third pole piece 21 by welding (welded on the empty foil area/connection area of the pole piece), or other connection methods (such as Conductive adhesive paste method), the first tab 130 may also be directly cut and formed from the current collector of the first pole piece 11. The second tab 140 is electrically connected to the second pole piece 13 and the fourth pole piece 23 by welding or other connection methods. The second tab 140 can also be directly cut by the current collector of the second pole piece 13. Cut to form.

In the battery cell structure 100 of the embodiment of the present application, the first electrode assembly 110 and the second electrode assembly 120 are connected to form a special-shaped battery by using tabs penetrating the first electrode assembly 110, which can improve the production efficiency of the battery, and The pole piece material has a high utilization rate.

As shown in FIG. 2, the first electrode assembly 110 includes n wound layers, the innermost wound layer of the first electrode assembly 110 is defined as the first wound layer of the first electrode assembly 110, and the The outermost wound layer is defined as the nth wound layer of the first electrode assembly 110, and n is a positive integer greater than 1, such as n=10, that is, the first electrode assembly 110 includes 10 wound layers.

As shown in FIG. 3, the second electrode assembly 120 includes m winding layers, the innermost winding layer of the second electrode assembly 120 is defined as the first winding layer of the second electrode assembly 120, and the second electrode assembly 120 The outermost wound layer of 120 is defined as the m-th wound layer of the second electrode assembly 120, and m is a positive integer greater than 1, such as m=9, that is, the second electrode assembly 120 includes 9 wound layers.

In some embodiments, the first tab 130 penetrating from the first side 111 of the first electrode assembly 110 is preferably electrically connected to the third pole piece 21 of the m-th winding layer of the second electrode assembly 120. The second tab 140 penetrating through the first side 111 of the electrode assembly 110 is preferably electrically connected to the fourth pole piece 23 of the m-th winding layer of the second electrode assembly 120.

In some embodiments, for the convenience of connecting the first tab 130 and the second tab 140 to the third pole piece 21 and the fourth pole piece 23, respectively, the third pole piece of the m-th winding layer of the second electrode assembly 120 The extension length of the pole piece 21 is preferably greater than the extension length of the fourth pole piece 23.

In some embodiments, the third pole piece 21 and the fourth pole piece 23 of the first winding layer of the second electrode assembly 120 include an empty foil area (a pole piece area where the active layer is not coated). In other embodiments, the third pole piece 21 and the fourth pole piece 23 of the first winding layer of the second electrode assembly 120 may not include the empty foil area.

In some embodiments, for the first electrode assembly 110, the first tab 130 and the second tab 140 may be electrically connected to the pole piece of the innermost winding layer, or may be electrically connected to a middle winding layer. The pole piece of the layer can also be electrically connected to the pole piece of the outermost winding layer, or it can be electrically connected to other positions obtained by the combination of the above three positions, for example, the first tab 130 is electrically connected to the innermost The second tab 140 is electrically connected to a pole piece of a winding layer in the middle. As shown in FIG. 4, the first tab 130 is electrically connected to the first pole piece 11 of the first winding layer of the first electrode assembly 110, and the second tab 140 is electrically connected to the first winding layer of the first electrode assembly 110. The second pole piece 13 of the layer. As shown in FIG. 5, the first tab 130 is electrically connected to the first pole piece 11 of the n-th winding layer of the first electrode assembly 110, and the second tab 140 is electrically connected to the n-th winding layer of the first electrode assembly 110. The second pole piece 13 of the layer. As shown in FIG. 6, the first tab 130 is electrically connected to the first pole piece 11 of the i-th winding layer of the first electrode assembly 110, and the second tab 140 is electrically connected to the j-th winding of the first electrode assembly 110. For the second pole piece 13 of the layer, i and j are both positive integers greater than 1 and less than n.

In some embodiments, the difference between i and j is preferably greater than or equal to a preset value, and the preset value can be set according to actual needs. For example, the preset value is 4 layers, that is, when the first tab 130 When the second tab 140 is electrically connected to a pole piece of a middle winding layer, the difference in the number of winding layers between the first tab 130 and the second tab 140 is greater than or equal to 4 layers. When the first tab 130 is a positive tab and the second tab 140 is a negative tab, the i-th winding layer is close to the innermost winding layer of the first electrode assembly 110, and the j-th winding layer is far away from the first electrode assembly 110 The innermost winding layer. When the first tab 130 is a negative tab and the second tab 140 is a positive tab, the i-th winding layer is far from the innermost winding layer of the first electrode assembly 110, and the j-th winding layer is close to the first electrode assembly 110 The innermost winding layer.

As shown in FIG. 7, in order to avoid contact and short circuit between the first electrode assembly 110 and the second electrode assembly 120, an isolation pad 150 can be added between the first electrode assembly 110 and the second electrode assembly 120, and the isolation pad 150 can be worn as needed. The number of tabs passed is used to open a corresponding number of through holes. As shown in FIG. 7, two through holes 151 are provided on the isolation pad 150 so that the first tab 130 and the second tab 140 can pass through the isolation pad 150. The isolation pad 150 is made of a non-conductive material. For example, the isolation pad 150 may be made of materials such as plastic or silicone. In order to obtain a better electrical isolation effect, the isolation pad 150 preferably has a certain mechanical strength and flexibility.

In some embodiments, the length of the isolation pad 150 is preferably less than or equal to the width of the first electrode assembly 110, and the width of the isolation pad 150 is preferably less than the greater of the thickness of the first electrode assembly 110 and the thickness of the second electrode assembly 120. . For example, if the thickness of the first electrode assembly 110 is greater than the thickness of the second electrode assembly 120, the width of the spacer 150 is preferably less than the thickness of the first electrode assembly 110, and if the thickness of the first electrode assembly 110 is less than that of the second electrode assembly 120 Thickness, the width of the isolation pad 150 is preferably smaller than the thickness of the second electrode assembly 120.

In some embodiments, the thickness of the isolation pad 150 is preferably 10 um to 2000 um.

In some embodiments, in order to reduce the tensile force received by the first tab 130 and the second tab 140, there is preferably a gap between the first electrode assembly 110 and the second electrode assembly 120, and the size of the gap may be equal to The thickness of the isolation pad 150 plus a first preset distance, the first preset distance is preferably less than or equal to 2 mm, for example, the size of the gap is equal to the thickness of the isolation pad 150 plus 0.5 mm.

As shown in FIG. 8, the main plane of the first electrode assembly 110 and the main plane of the second electrode assembly 120 are on the same plane. The first electrode assembly 110 and the second electrode assembly 120 share a housing 200 for assembly. The housing 200 can be assembled according to the The actual thickness of the electrode assembly 110 and the second electrode assembly 120 is designed to design the depth of the deep and shallow pits to meet the requirements of the relative position of the first electrode assembly 110 and the second electrode assembly 120 on the plane. The thickness of the first electrode assembly 110 and the second electrode assembly 120 may be the same or different. In other embodiments, if the main plane of the first electrode assembly 110 and the main plane of the second electrode assembly 120 are not on the same plane, the shape of the housing 200 can be based on the actual assembly of the first electrode assembly 110 and the second electrode assembly 120. The shape is adjusted.

In some embodiments, in order to reduce the force exerted by the tabs when the first electrode assembly 110 and the second electrode assembly 120 move relative to each other, both the first tab 130 and the second tab 140 include bending part. As shown in FIG. 9 (a cross-sectional view taken along the B1-B1' section line of FIG. 1), it is B1 when the winding direction of the first electrode assembly 110 and the winding direction of the second electrode assembly 120 are perpendicular to each other. -B1' cross-sectional view, the first tab 130 includes a first bent section 130a, a first tab section 130b, and a second tab section 130c. The first bending section 130a is located between the first tab section 130b and the second tab section 130c, the first tab section 130b is located in the first electrode assembly 110, and the second tab section 130c is located in the second electrode assembly 120 , The first bending section 130a is located between the first electrode assembly 110 and the second electrode assembly 120. As shown in FIG. 10 (a cross-sectional view taken along the A1-A1' section line of FIG. 1), it is A1 when the winding direction of the first electrode assembly 110 and the winding direction of the second electrode assembly 120 are perpendicular to each other. -A1' cross-sectional view, the second tab 140 includes a second bent section 140a, a third tab section 140b, and a fourth tab section 140c. The second bent section 140a is located between the third tab section 140b and the fourth tab section 140c, the first tab section 140b is located in the first electrode assembly 110, and the second tab section 140c is located in the second electrode assembly 120 , The second bending section 140a is located between the first electrode assembly 110 and the second electrode assembly 120.

As shown in FIG. 11 (a cross-sectional view taken along the B1-B1' section line of FIG. 1), it is B1 when the winding direction of the first electrode assembly 110 and the winding direction of the second electrode assembly 120 are parallel to each other. -B1' cross-sectional view, the first tab section 130b is located in the first electrode assembly 110, the second tab section 130c is located in the second electrode assembly 120, and the first bent section 130a is located in the first electrode assembly 110 and the second electrode assembly Between 120. As shown in FIG. 12 (a cross-sectional view taken along the A1-A1' section line of FIG. 1), it is A1 when the winding direction of the first electrode assembly 110 and the winding direction of the second electrode assembly 120 are parallel to each other. -A1' cross-sectional view, the first tab section 140b is located in the first electrode assembly 110, the second tab section 140c is located in the second electrode assembly 120, and the second bent section 140a is located in the first electrode assembly 110 and the second electrode assembly Between 120.

In some embodiments, in order to facilitate the formation of the first bending section 130a and the second bending section 140a, the connection plane of the first tab 130 on the first electrode assembly 110 and the connection plane on the second electrode assembly 120 It is preferably not on the same plane, and the height difference between the two planes is preferably greater than or equal to 2 mm. For example, when the first tab 130 is connected to the first pole piece 11 and the third pole piece 21 by welding, the welding plane of the first tab 130 on the first electrode assembly 110 and on the second electrode assembly 120 The welding planes are not on the same plane, and the height difference between the two welding planes is greater than or equal to 2mm. Similarly, the connection plane of the second tab 140 on the first electrode assembly 110 and the connection plane on the second electrode assembly 120 are preferably not on the same plane, and the height difference between the two planes is preferably greater than or equal to 2 mm. For example, when the second tab 140 is connected to the second pole piece 13 and the fourth pole piece 23 by welding, the welding plane of the second tab 140 on the first electrode assembly 110 and on the second electrode assembly 120 The welding planes are not on the same plane, and the height difference between the two welding planes is greater than or equal to 2mm.

In some embodiments, when the first tab 130 and the second tab 140 are connected to the pole pieces of the first electrode assembly 110 and the second electrode assembly 120 by welding, the first tab 130 and the second tab The welding area of 140 on the pole piece needs to meet the preset overcurrent capability, and the preset overcurrent capability can be determined according to the actual use scenario of the battery. For example, the welding area of the first tab 130 on the third pole piece 21 satisfies the following relational formula F1: welding area ≥ tab through current size/current carrying capacity per unit area of the tab, and the second tab 140 is on the fourth pole The welding area on the sheet 23 also satisfies the above-mentioned relational formula F1.

In some embodiments, when the battery is used in 3C products (collectively referred to as computer, communication, and consumer electronic products), the welding area of the first tab 130 and the second tab 140 on the pole piece may be 8 to 200 mm ² , preferably 12 to 48 mm ² .

In some embodiments, the number of welding areas between the first tab 130, the second tab 140 and the pole piece may be 2-5, preferably 3 welding areas. The distance between the edge of the welding zone and the edge of the pole piece is preferably greater than or equal to 2 mm.

As shown in FIG. 13, it is illustrated that when the winding direction of the first electrode assembly 110 and the winding direction of the second electrode assembly 120 are perpendicular to each other, the first welding area 160 of the first tab 130 on the third pole piece 21 . The first welding area 160 includes three welding areas. In order to avoid contact and short circuit between the first welding area 160 and the pole piece, the first tab 130 is welded to the third pole piece 21 and covered with a first insulating tape 162 The first welding area 160. The thickness of the first insulating tape 162 may be determined according to the actual burr level of the first tab 130, and the length of the first insulating tape 162 can preferably completely cover the length of the first tab 130 inside the second electrode assembly 120.

As shown in FIG. 14, when the winding direction of the first electrode assembly 110 and the winding direction of the second electrode assembly 120 are perpendicular to each other, the second welding area 161 of the second tab 140 on the fourth pole piece 23 is shown. . The second welding area 161 includes three welding areas. In order to avoid contact and short circuit between the second welding area 161 and the pole piece, the second tab 140 is welded to the fourth pole piece 23 and covered with a second insulating tape 163 The second welding area 161. The thickness of the second insulating tape 163 may be determined according to the actual burr level of the second tab 140, and the length of the second insulating tape 163 preferably can completely cover the length of the second tab 140 inside the second electrode assembly 120.

As shown in FIG. 15, it is illustrated that when the winding direction of the first electrode assembly 110 and the winding direction of the second electrode assembly 120 are parallel to each other, the first welding area 160 of the first tab 130 on the third pole piece 21 is shown. The first welding area 160 includes three welding areas. In order to avoid contact and short circuit between the first welding area 160 and the pole piece, after the first tab 130 is welded to the third pole piece 21, the first insulating tape 162 is also used for Cover the first welding area 160. The thickness of the first insulating tape 162 may be determined according to the actual burr level of the first tab 130, and the length of the first insulating tape 162 can preferably completely cover the length of the first tab 130 inside the second electrode assembly 120.

As shown in FIG. 16, when the winding direction of the first electrode assembly 110 and the winding direction of the second electrode assembly 120 are parallel to each other, the second welding area 161 of the second tab 140 on the fourth pole piece 23 is shown. The second welding area 161 includes three welding areas. In order to avoid contact and short circuit between the second welding area 161 and the pole piece, after the second tab 140 is welded to the fourth pole piece 23, the second insulating tape 163 is also used. Cover the second welding area 161. The thickness of the second insulating tape 163 may be determined according to the actual burr level of the second tab 140, and the length of the second insulating tape 163 preferably can completely cover the length of the second tab 140 inside the second electrode assembly 120.

In some embodiments, the outermost winding layer of the second electrode assembly 120 is further provided with a finishing insulating tape. As shown in FIG. 17, it is illustrated that when the winding direction of the first electrode assembly 110 and the winding direction of the second electrode assembly 120 are perpendicular to each other, a first finishing is provided on the outermost winding layer of the second electrode assembly 120. The insulating tape 170 can prevent the end pole pieces of the second electrode assembly 120 from contacting and short-circuiting to a certain extent, and can also play a role in fixing the tabs on the second electrode assembly 120. The first finishing insulating adhesive tape 170 preferably can completely cover the finishing pole piece of the outermost winding layer of the second electrode assembly 120. In other embodiments, the first finishing insulating tape 170 may also partially cover the finishing pole piece of the outermost winding layer of the second electrode assembly 120.

As shown in FIG. 18, it is illustrated that when the winding direction of the first electrode assembly 110 and the winding direction of the second electrode assembly 120 are parallel to each other, a second finishing insulation is provided on the outermost winding layer of the second electrode assembly 120. The adhesive tape 171 can prevent the end pole pieces of the second electrode assembly 120 from contacting and short-circuit to a certain extent, and can also play a role in fixing the tabs on the second electrode assembly 120. The second finishing insulating adhesive tape 171 preferably can completely cover the finishing pole piece of the outermost winding layer of the second electrode assembly 120. In other embodiments, the second finishing insulating tape 171 may also partially cover the finishing pole piece of the outermost winding layer of the second electrode assembly 120.

In some embodiments, the shape of the first tab 130 and the second tab 140 can be set according to actual requirements. For example, as shown in FIG. 19A, the main plane of the first electrode assembly 110 and the main plane of the second electrode assembly 120 are on the same plane, and the main plane of the first electrode assembly 110 is the line of sight plane. The shape of the tab 140 is a straight line, as shown in FIG. 19B, the main plane of the first electrode assembly 110 is also taken as the line of sight plane, and the shape of the first tab 130 and the second tab 140 are L-shaped, as shown in FIG. 19C As shown, the main plane of the first electrode assembly 110 is also taken as the line of sight plane, and the shape of the first tab 130 and the second tab 140 are T-shaped.

In some embodiments, taking the main plane of the first electrode assembly 110 as the line of sight plane, the first electrode assembly 110 and the second electrode assembly may form an L-shaped electrode assembly shape (as shown in FIG. 1) or a T-shaped electrode assembly shape ( As shown in Figure 20). In other sight planes, the first electrode assembly 110 and the second electrode assembly can form other 3D-shaped electrode assemblies.

In some embodiments, the first tab 130 and the second tab 140 can also extend from the second electrode assembly 120 to form connection terminals, as shown in FIG. 21, that is, the first electrode assembly 110 of the cell structure 100 and The second electrode assembly 120 has tabs protruding.

In addition, as shown in FIG. 22, the present application also discloses a battery 300, which includes the cell structure 100 in any of the above cases.

The cell structure 100 according to the embodiments of the present application will be described in detail below with reference to some specific embodiments. It should be understood that the following description is only an exemplary description, rather than a specific limitation to the application.

Example 1:

In this embodiment, the cell structure 100 includes a first electrode assembly 110, a second electrode assembly 120, a first tab 130, and a second tab 140. The first electrode assembly 110 is formed by winding the first pole piece 11, the first isolation film 12, the second pole piece 13, and the second isolation film 14, and the second electrode assembly 120 is formed by the third pole piece 21 and the third isolation film 22. , The fourth pole piece 23 and the fourth isolation film 24 are wound and formed. The cell structure 100 is L-shaped and the cell structure 100 is housed in the housing 200, and the winding direction of the first electrode assembly 110 and the winding direction of the second electrode assembly 120 are perpendicular to each other. The first tab 130 is electrically connected to the first pole piece 11, the second tab 140 is electrically connected to the second pole piece 13, and both the first tab 130 and the second tab 140 penetrate the first side of the first electrode assembly 110 111 and the second side 112. The first tab 130 penetrating from the first side 111 of the first electrode assembly 110 is also electrically connected to the third pole piece 21 of the m-th winding layer of the second electrode assembly 120. The second tab 140 penetrating through the first side 111 of an electrode assembly 110 is also electrically connected to the fourth pole piece 23 of the m-th winding layer of the second electrode assembly 120. An isolation pad 150 is provided between the first electrode assembly 110 and the second electrode assembly 120. The first tab 130 includes a first bending section 130a located between the first electrode assembly 110 and the second electrode assembly 120. The ear 140 includes a second bending section 140 a located between the first electrode assembly 110 and the second electrode assembly 120. The cell structure 100 is connected to the external positive and negative electrodes through the first tab 130 and the second tab 140 penetrating from the second side 112 of the first cell assembly 110.

Example 2:

In this embodiment, the cell structure 100 includes a first electrode assembly 110, a second electrode assembly 120, a first tab 130, and a second tab 140. The first electrode assembly 110 is formed by winding the first pole piece 11, the first isolation film 12, the second pole piece 13, and the second isolation film 14, and the second electrode assembly 120 is formed by the third pole piece 21 and the third isolation film 22. , The fourth pole piece 23 and the fourth isolation film 24 are wound and formed. The cell structure 100 is T-shaped and the cell structure 100 is housed in the housing 200, and the winding direction of the first electrode assembly 110 and the winding direction of the second electrode assembly 120 are parallel to each other. The first tab 130 is electrically connected to the first pole piece 11, the second tab 140 is electrically connected to the second pole piece 13, and both the first tab 130 and the second tab 140 penetrate the first side of the first electrode assembly 110 111 and the second side 112, the first tab 130 penetrating from the first side 111 of the first electrode assembly 110 is also electrically connected to the third inner pole piece 21 of the m-th winding layer of the second electrode assembly 120, from The second tab 140 penetrating through the first side 111 of the first electrode assembly 110 is also electrically connected to the fourth pole piece 23 of the m-th winding layer of the second electrode assembly 120. An isolation pad 150 is provided between the first electrode assembly 110 and the second electrode assembly 120. The first tab 130 includes a first bending section 130a located between the first electrode assembly 110 and the second electrode assembly 120. The ear 140 includes a second bending section 140 a located between the first electrode assembly 110 and the second electrode assembly 120. The cell structure 100 is connected to the external positive and negative electrodes through the first tab 130 and the second tab 140 penetrating from the second side 112 of the first cell assembly 110.

In the description of this application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", " Back", "Left", "Right", "Vertical", "Horizontal", "Top", "Bottom", "Inner", "Outer", "Clockwise", "Counterclockwise", "Axial" , "Radial", "Circumferential", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the application and simplifying the description, rather than indicating or implying the pointed device or The element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present application. In the description of this application, "plurality" means two or more.

In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "exemplary embodiments", "examples", "specific examples", or "some examples" etc. means to incorporate the implementation The specific features, structures, materials or characteristics described by the examples or examples are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above-mentioned terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics can be combined in any one or more embodiments or examples in a suitable manner.

Although the embodiments of the present application have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and modifications can be made to these embodiments without departing from the principle and purpose of the present application. The scope of the application is defined by the claims and their equivalents.

Claims

A cell structure, comprising a first electrode assembly formed by winding a first pole piece and a second pole piece, and a second electrode assembly formed by winding a third pole piece and a fourth pole piece, characterized in that:

The cell structure further includes a first tab electrically connected to the first pole piece and a second tab electrically connected to the second pole piece, the first tab and the second tab All pass through the first electrode assembly;

Wherein, the first tab is also electrically connected to the third tab of the second electrode assembly.
8. The cell structure of claim 1, wherein the second tab is also electrically connected to the fourth tab of the second electrode assembly.
The cell structure according to claim 2, wherein the first tab includes a first tab section, a second tab section, and a position between the first tab section and the second tab section. Between the first bending section, the first tab section is located in the first electrode assembly, the second tab section is located in the second electrode assembly, and the first bending section is located in the Between the first electrode assembly and the second electrode assembly, the second tab includes a third tab section, a fourth tab section, and between the third tab section and the fourth tab section Between the second bending section, the third tab section is located in the first electrode assembly, the fourth tab section is located in the second electrode assembly, and the second bending section is located in the Between the first electrode assembly and the second electrode assembly.
The cell structure of claim 2, wherein the first electrode assembly includes n winding layers, and the innermost winding layer of the first electrode assembly is defined as the The first wound layer, the outermost wound layer of the first electrode assembly is defined as the nth wound layer of the first electrode assembly, the second electrode assembly includes m wound layers, and the first electrode assembly The innermost wound layer of the two electrode assembly is defined as the first wound layer of the second electrode assembly, and the outermost wound layer of the second electrode assembly is defined as the mth roll of the second electrode assembly For the winding layer, both n and m are positive integers greater than 1.
The cell structure of claim 4, wherein the first tab penetrating from the first side of the first electrode assembly is electrically connected to the m-th winding layer of the second electrode assembly The second tab penetrating from the first side of the first electrode assembly is electrically connected to the fourth pole piece of the m-th winding layer of the second electrode assembly.
The cell structure of claim 4, wherein the first tab is electrically connected to the first pole piece of the first winding layer of the first electrode assembly, and the second tab is electrically connected to On the second pole piece of the first winding layer of the first electrode assembly.
The cell structure of claim 4, wherein the first tab is electrically connected to the first pole piece of the n-th winding layer of the first electrode assembly, and the second tab is electrically connected to On the second pole piece of the n-th wound layer of the first electrode assembly.
The cell structure of claim 4, wherein the first tab is electrically connected to the first pole piece of the i-th winding layer of the first electrode assembly, and the second tab is electrically connected to In the second pole piece of the j-th winding layer of the first electrode assembly, i and j are both positive integers greater than 1 and less than n, and the difference between i and j is greater than or equal to a preset value.
8. The cell structure of claim 8, wherein the preset value is 4 layers.
The cell structure of claim 4, wherein the extension length of the third pole piece of the m-th winding layer of the second electrode assembly is greater than the extension length of the fourth pole piece, and the second electrode The third pole piece and the fourth pole piece of the first winding layer of the assembly contain empty foil regions.
The cell structure of claim 1, wherein the cell structure further comprises an isolation pad disposed between the first electrode assembly and the second electrode assembly, and the isolation pad is made of non-conductive Made of material, the isolation pad is provided with two through holes, and the first tab and the second tab pass through the two through holes.
The cell structure of claim 11, wherein the length of the isolation pad is less than or equal to the width of the first electrode assembly, and the width of the isolation pad is less than the thickness of the first electrode assembly and the width of the first electrode assembly. The greater of the thickness of the second electrode assembly.
The cell structure according to claim 10 or 11, wherein the thickness of the isolation pad is 10um to 2000um.
The cell structure of claim 11, wherein there is a gap between the first electrode assembly and the second electrode assembly, and the gap is greater than or equal to the thickness of the isolation pad plus the first electrode assembly. The preset distance, the first preset distance is less than or equal to 2 mm.
The cell structure according to claim 1, wherein the first tab is provided with insulating tape.
The cell structure of claim 1, wherein when the first tab is electrically connected to the third pole piece by welding, the welding of the first tab on the third pole piece The area satisfies the following relational expression: welding area ≥ current through the tab/current carrying capacity per unit area of the tab.
The cell structure according to claim 1, wherein there are 2 to 5 welding areas of the first tab in the third tab.
The cell structure according to claim 1, wherein the first electrode assembly and the second electrode assembly share a housing, and when the main plane of the first electrode assembly is the line of sight plane, the first electrode assembly An electrode assembly and the second electrode assembly form an L-shaped electrode assembly shape or a T-shaped electrode assembly shape.
The cell structure according to claim 1, wherein the winding direction of the first electrode assembly and the winding direction of the second electrode assembly are parallel or perpendicular to each other.
The cell structure according to claim 1, wherein the first tab and the second tab also extend from the second electrode assembly to form two connection terminals.
The cell structure of claim 1, wherein the first tab is formed by cutting the current collector of the first pole piece, and the second tab is formed by the current collector of the second pole piece. Genre cut formation.
A battery, characterized in that the battery further comprises the cell structure according to any one of claims 1-21.