CN113994519A

CN113994519A - Battery cell structure and battery

Info

Publication number: CN113994519A
Application number: CN202080035807.2A
Authority: CN
Inventors: 郭章飞; 董惠
Original assignee: Ningde Amperex Technology Ltd
Current assignee: Ningde Amperex Technology Ltd
Priority date: 2020-03-31
Filing date: 2020-03-31
Publication date: 2022-01-28
Anticipated expiration: 2040-03-31
Also published as: CN113994519B; WO2021195924A1

Abstract

A battery cell structure (100) and a battery (300) thereof, wherein the battery cell structure (100) comprises a first electrode assembly (110) formed by winding a first pole piece (11) and a second pole piece (13), and a second electrode assembly (120) formed by winding a third pole piece (21) and a fourth pole piece (23). The battery cell structure (100) further comprises a first tab (130) electrically connected to the first pole piece (11) and a second tab (140) electrically connected to the second pole piece (13), wherein the first tab (130) and the second tab (140) both penetrate through the first electrode assembly (110); wherein the first tab (130) is also electrically connected to a third pole piece (21) of the second electrode assembly (120). The cell structure (100) is formed into the special-shaped cell by the two electrode assemblies (110, 120) with the winding type structures, the production efficiency of the cell is high, and the utilization rate of pole piece materials is high.

Description

Battery cell structure and battery

Technical Field

The present application relates to the field of electrochemical devices, and more particularly, to an electrical core structure and a battery.

Background

With the rapid development of electronic products, the power consumption and the endurance requirements of the products are higher and higher. In the design process of electronic products, after the layout of electronic components is completed, the accommodating space reserved for batteries is not a cuboid but is irregular in shape such as 'L' -shape, 'T' -shape and the like, so that battery manufacturers are required to develop special-shaped batteries matched with the accommodating space, and the space utilization rate of electronic equipment is improved.

The lamination process is currently used in the industry to manufacture shaped batteries. However, the lamination process has low production efficiency and low material utilization rate, which results in high production cost. The special-shaped pole piece of the current lamination process cannot be directly coated, only a rectangular pole piece can be coated firstly, then the required special-shaped pole piece shape is cut, the cut pole piece material can only be scrapped, and the material utilization rate is low.

Disclosure of Invention

The present application is directed to solving at least one of the problems in the prior art. Therefore, one aspect of the present application is to provide an electrical core structure, in which a special-shaped electrical core is formed by two electrode assemblies of winding type structures, and the production efficiency of the electrical core is high and the utilization rate of pole piece materials is high.

The battery cell structure comprises 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 battery cell structure further comprises a first tab electrically connected to the first pole piece and a second tab electrically connected to the second pole piece, wherein the first tab and the second tab both penetrate through the first electrode assembly; the first electrode tab is also electrically connected to a third pole piece of the second electrode assembly.

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

In some embodiments, the first tab includes a first tab section, a second tab section, and a first bending section located between the first tab section and the second tab section, the first tab section is located in the first electrode assembly, the second tab section is located in the second electrode assembly, the first bending section is located between the first electrode assembly and the second electrode assembly, the second tab includes a third tab section, a fourth tab section, and a second bending section located between the third tab section and the fourth tab 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 between the first electrode assembly and the second electrode assembly.

In some embodiments, the first electrode assembly comprises n winding layers, the innermost winding layer of the first electrode assembly is defined as the 1 st winding layer of the first electrode assembly, the outermost winding layer of the first electrode assembly is defined as the nth winding layer of the first electrode assembly, the second electrode assembly comprises m winding layers, the innermost winding layer of the second electrode assembly is defined as the 1 st winding layer of the second electrode assembly, the outermost winding layer of the second electrode assembly is defined as the mth winding layer of the second electrode assembly, and n and m are positive integers greater than 1.

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 wound layer of the second electrode assembly, and 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 wound layer of the second electrode assembly.

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

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 second pole piece of the nth winding layer of the first electrode assembly.

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

In some embodiments, the preset value is 4 layers.

In some embodiments, the third pole piece of the m-th wound layer of the second electrode assembly extends longer than the fourth pole piece, and the third pole piece and the fourth pole piece of the first wound layer of the second electrode assembly include a void foil region.

In some embodiments, the cell structure further includes a spacer disposed between the first electrode assembly and the second electrode assembly, the spacer being made of an electrically non-conductive material, two through holes being disposed on the spacer, and the first tab and the second tab passing through the two through holes.

In some embodiments, the length of the separator pad is less than or equal to the width of the first electrode assembly, the width of the separator pad being less than the greater of the thickness of the first electrode assembly and the thickness of the second electrode assembly.

In some embodiments, the thickness of the spacer is between 10um and 2000 um.

In some embodiments, the first electrode assembly and the second electrode assembly have a gap therebetween, the gap being greater than or equal to the thickness of the separator pad plus a first predetermined distance, the first predetermined distance being less than or equal to 2 mm.

In some embodiments, an insulating adhesive paper is disposed on the first tab.

In some embodiments, when the first tab is electrically connected to the third pole piece by welding, a welding area of the first tab on the third pole piece satisfies the following relation: the welding area is larger than or equal to the current passing capacity of the tab per unit area of the tab.

In some embodiments, the number of the first tab in the welding area of the third pole piece is 2-5.

In some embodiments, the first electrode assembly and the second electrode assembly share a housing, and the first electrode assembly and the second electrode assembly form an L-shaped electrode assembly shape or a T-shaped electrode assembly shape when the main plane of the first electrode assembly is taken as a viewing plane.

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 further 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 battery cell structure provided by the embodiment of the application, the electrode assemblies of the two winding type structures are connected to form the special-shaped battery cell by using the tabs penetrating through the electrode assemblies, the production efficiency of the battery cell can be improved, and the utilization rate of pole piece materials is high.

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

According to the battery provided by the embodiment of the application, the electrode assemblies of the two winding type structures are connected to form the special-shaped battery cell by using the tabs penetrating through the electrode assemblies, the production efficiency of the battery cell can be improved, and the utilization rate of pole piece materials is high.

Drawings

The above and/or additional aspects and advantages of the present application will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of 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 view of a first electrode assembly according to an embodiment of the present application;

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

fig. 4 illustrates a schematic view of a connection location of a first tab and a second tab electrically connected to a first electrode assembly according to an embodiment of the present application;

fig. 5 is a schematic view illustrating a connection position where a first tab and a second tab are electrically connected to a first electrode assembly according to another embodiment of the present application;

fig. 6 is a schematic view illustrating a connection position where a first tab and a second tab are electrically connected to a first electrode assembly according to still another embodiment of the present application;

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

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

FIG. 9 illustrates a cross-sectional view B1-B1' of a first electrode assembly aligned in a perpendicular winding direction with a second electrode assembly in accordance with an embodiment of the present application;

FIG. 10 shows a cross-sectional view A1-A1' of a first electrode assembly aligned in a perpendicular winding direction to a second electrode assembly in accordance with an embodiment of the present application;

FIG. 11 illustrates a cross-sectional view B1-B1' of a first electrode assembly aligned in a parallel winding direction with a second electrode assembly in accordance with an embodiment of the present application;

FIG. 12 shows a cross-sectional view A1-A1' of a first electrode assembly aligned in a parallel winding direction with a second electrode assembly in accordance with an embodiment of the present application;

fig. 13 is a schematic view illustrating a welding position of a first tab on a second electrode assembly when the first electrode assembly is arranged in a vertical winding direction with the second electrode assembly according to an embodiment of the present application;

fig. 14 is a schematic view illustrating a welding position of a second tab on a 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;

fig. 15 is a schematic view illustrating a welding position of a first tab on a 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. 16 is a schematic view illustrating the welding position of a second tab on a 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 is a schematic view showing a position where a first end of an insulating adhesive tape is attached to a 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;

fig. 18 is a schematic view showing a position where a second end insulating adhesive sheet is attached to a 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. 19A to 19C are schematic structural views illustrating a first tab and a second tab according to an embodiment of the present application;

fig. 20 is a schematic structural diagram illustrating a cell structure according to another embodiment of the present application;

fig. 21 is a schematic structural diagram illustrating a cell structure according to another embodiment of the present application;

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

description of the main element symbols:

the battery comprises a first pole piece 11, a first isolation film 12, a second pole piece 13, a second isolation film 14, a third pole piece 21, a third isolation film 22, a fourth pole piece 23, a fourth isolation film 24, a cell structure 100, a first electrode assembly 110, a first side 111, a second side 112, a second electrode assembly 120, a first tab 130, a second tab 140, an isolation pad 150, a through hole 151, a first welding region 160, a second welding region 161, a first adhesive tape 162, a second adhesive tape 163, a first end-to-end adhesive tape 170, a second end-to-end adhesive tape 171, a first bending section 130a, a first tab section 130b, a second tab section 130c, a second bending section 140a, a third tab section 140b, a fourth tab section 140c, a housing 200 and a battery 300.

Detailed Description

Reference will now be made in detail to embodiments of the present application, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are exemplary only for the purpose of explaining the present application and are not to be construed as limiting the present application.

A battery cell structure 100 according to an embodiment of the present application is specifically described below with reference to fig. 1 to 21.

As shown in fig. 1 to 3, the battery cell structure 100 according to the embodiment of the present disclosure 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 separator 12, the second pole piece 13, and the second separator 14 around the first winding core space, and the second electrode assembly 120 is formed by winding the third pole piece 21, the third separator 22, the fourth pole piece 23, and the fourth separator 24 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 through the first side 111 and the second side 112 of the first electrode assembly 110. The first tab 130, which penetrates through 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 separator 12 and the second pole piece 13 around the first winding space; the second electrode assembly 120 may be formed by winding the third pole piece 21, the third separator 22 and the fourth pole piece 23 around the second winding core space.

In some embodiments, a second tab 140 extending through 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 may 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 may be electrically connected to the empty foil area of the second pole piece 13 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 further include a connection area exposed by the cleaning process, the first tab 130 may be electrically connected to the connection area of the first pole piece 11 or the connection area of the third pole piece 21, and the second tab 140 may 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 region of the first pole piece 11 (the surface near the first winding core space) and the inner surface of the empty foil region of the third pole piece 21 (the surface near the second winding core space), and the second tab 140 is preferably electrically connected to the outer surface of the empty foil region of the second pole piece 13 (the surface far from the first winding core space) and the outer surface of the empty foil region of the fourth pole piece 23 (the surface far from the second winding 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 further include a connection area exposed by a cleaning process, the first tab 130 may be electrically connected to an inner surface of the connection area of the first pole piece 11 (a surface close to the first winding core space), or an inner surface of the connection area of the third pole piece 21 (a surface close to the second winding core space), and the second tab 140 may be electrically connected to an outer surface of the connection area of the second pole piece 13 (a surface far from the first winding core space), or an outer surface of the connection area of the fourth pole piece 23 (a surface far from the second winding 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 tab 11 and the third tab 21 may be aluminum foils, and the second tab 13 and the fourth tab 23 may be copper foils. When the first tab 130 is a negative tab and the second tab 140 is a positive tab, the first tab 11 and the third tab 21 may be copper foils, and the second tab 13 and the fourth tab 23 may be aluminum foils.

In some embodiments, the way of electrically connecting the first tab 130 to the first pole piece 11 and the third pole piece 21 may be welding (welding in the empty foil area/connection area of the pole pieces), or other connection ways (such as conductive adhesive bonding), and the first tab 130 may also be formed by directly cutting the current collector of the first pole piece 11. The second tab 140 may be welded or connected to the second pole piece 13 and the fourth pole piece 23, and the second tab 140 may be formed by directly cutting the current collector of the second pole piece 13.

The cell structure 100 of the embodiment of the application, the first electrode assembly 110 and the second electrode assembly 120 are connected to form the special-shaped cell by using the tabs penetrating through the first electrode assembly 110, so that the production efficiency of the cell can be improved, and the utilization rate of the pole piece material is high.

As shown in fig. 2, first electrode assembly 110 includes n wound layers, the innermost wound layer of first electrode assembly 110 is defined as the 1 st wound layer of first electrode assembly 110, the outermost wound layer of first electrode assembly 110 is defined as the nth wound layer of first electrode assembly 110, and n is a positive integer greater than 1, such as n ═ 10, that is, 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 1 st winding layer of the second electrode assembly 120, the outermost winding layer of the second electrode assembly 120 is defined as the m-th winding layer of the second electrode assembly 120, and m is a positive integer greater than 1, for example, m is 9, that is, the second electrode assembly 120 includes 9 winding 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 mth winding layer of the second electrode assembly 120, and the second tab 140 penetrating from the first side 111 of the first electrode assembly 110 is preferably electrically connected to the fourth pole piece 23 of the mth winding layer of the second electrode assembly 120.

In some embodiments, in order to connect the first tab 130 and the second tab 140 to the third pole piece 21 and the fourth pole piece 23, respectively, the extension length of the third pole piece 21 of the mth winding layer of the second electrode assembly 120 is preferably greater than the extension length of the fourth pole piece 23.

In some embodiments, the third and

fourth pole pieces

21, 23 of the first wound layer of the second electrode assembly 120 comprise empty foil regions (pole piece regions not coated with an active layer). 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 region.

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, the pole piece of the middle winding layer, the pole piece of the outermost winding layer, or other positions obtained by combining the above three positions, for example, the first tab 130 is electrically connected to the pole piece of the innermost winding layer, and the second tab 140 is electrically connected to the pole piece of the middle winding layer. As shown in fig. 4, the first tab 130 is electrically connected to the first pole piece 11 of the 1 st winding layer of the first electrode assembly 110, and the second tab 140 is electrically connected to the second pole piece 13 of the 1 st winding layer of the first electrode assembly 110. As shown in fig. 5, the first tab 130 is electrically connected to the first pole piece 11 of the nth winding layer of the first electrode assembly 110, and the second tab 140 is electrically connected to the second pole piece 13 of the nth winding layer of the first electrode assembly 110. 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, the second tab 140 is electrically connected to the second pole piece 13 of the j-th winding layer of the first electrode assembly 110, and i and j are 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 may be set according to actual requirements, for example, the preset value is 4 layers, that is, when the first tab 130 and the second tab 140 are electrically connected to a pole piece of a winding layer in the middle, the difference between the number of the winding layers electrically connected to 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 ith winding layer is close to the innermost winding layer of the first electrode assembly 110, and the jth winding layer is far from the innermost winding layer of the first electrode assembly 110. When the first tab 130 is a negative tab and the second tab 140 is a positive tab, the ith winding layer is far from the innermost winding layer of the first electrode assembly 110, and the jth winding layer is close to the innermost winding layer of the first electrode assembly 110.

As shown in fig. 7, in order to avoid short circuit between the first electrode assembly 110 and the second electrode assembly 120, a spacer 150 may be additionally disposed between the first electrode assembly 110 and the second electrode assembly 120, and the spacer 150 may be provided with a corresponding number of through holes according to the number of tabs that need to pass through. As shown in fig. 7, two through holes 151 are formed in the separator 150 so that the first tab 130 and the second tab 140 can pass through the separator 150. The isolation pad 150 is made of a non-conductive material, for example, the isolation pad 150 may be made of plastic, silicon gel, or the like. For better electrical isolation, the isolation pad 150 preferably has a certain mechanical strength and flexibility.

In some embodiments, the length of the separator 150 is preferably less than or equal to the width of the first electrode assembly 110, and the width of the separator 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 separator 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 the thickness of the second electrode assembly 120, the width of the separator 150 is preferably less than the thickness of the second electrode assembly 120.

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

In some embodiments, in order to reduce the pulling force applied to the first tab 130 and the second tab 140, a gap is preferably formed between the first electrode assembly 110 and the second electrode assembly 120, and the gap may be equal to the thickness of the isolation pad 150 plus a first predetermined distance, which is preferably less than or equal to 2mm, for example, equal to the thickness of the isolation pad 150 plus 0.5 mm.

As shown in fig. 8, the major plane of the first electrode assembly 110 and the major plane of the second electrode assembly 120 are in the same plane, the first electrode assembly 110 and the second electrode assembly 120 are assembled by sharing a casing 200, and the casing 200 can be designed with a deep and shallow pit depth according to the actual thickness of the first electrode assembly 110 and the second electrode assembly 120 to meet the requirement of the relative position of the first electrode assembly 110 and the second electrode assembly 120 on the plane. The thicknesses of the first electrode assembly 110 and the second electrode assembly 120 may be the same or different. In other embodiments, if the major plane of the first electrode assembly 110 and the major plane of the second electrode assembly 120 are not in the same plane, the shape of the case 200 may be adjusted according to the actual assembly shape of the first electrode assembly 110 and the second electrode assembly 120.

In some embodiments, in order to reduce the stress on the tabs when the first electrode assembly 110 and the second electrode assembly 120 move relative to each other, the first tab 130 and the second tab 140 each include a bent section. As shown in fig. 9 (a sectional view taken along a sectional line B1-B1 'of fig. 1), which is a sectional view B1-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, the first tab 130 includes a first bent section 130a, a first tab section 130B, and a second tab section 130 c. The first bent 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, the second tab section 130c is located in the second electrode assembly 120, and the first bent 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 cut along a cutting line a1-a1 'of fig. 1), the second tab 140 includes a second bent segment 140a, a third tab segment 140b, and a fourth tab segment 140c, which are cross-sectional views a1-a 1' 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 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, the second tab section 140c is located in the second electrode assembly 120, and the second bent section 140a is located between the first electrode assembly 110 and the second electrode assembly 120.

As shown in fig. 11 (a sectional view taken along a sectional line B1-B1 'of fig. 1), which is a sectional view B1-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, the first tab segment 130B is located in the first electrode assembly 110, the second tab segment 130c is located in the second electrode assembly 120, and the first bent segment 130a is located between the first electrode assembly 110 and the second electrode assembly 120. As shown in fig. 12 (a sectional view taken along a sectional line a1-a1 'of fig. 1), which is a sectional view a1-a 1' 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 tab segment 140b is located in the first electrode assembly 110, the second tab segment 140c is located in the second electrode assembly 120, and the second bent segment 140a is located between the first electrode assembly 110 and the second electrode assembly 120.

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

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 welding area of the first tab 130 and the second tab 140 on the pole pieces needs to satisfy a preset overcurrent capacity, which may be determined according to the actual usage scenario of the battery. For example, the welding area of the first tab 130 on the third pole piece 21 satisfies the following relation F1: the welding area is larger than or equal to the current passing capacity of the tab/unit area of the tab, and the welding area of the second tab 140 on the fourth pole piece 23 also satisfies the above relation F1.

In some embodiments, when the battery is used in a 3C product (a general term for three products, computer products, communication products, and consumer electronics products), the welding area of the first tab 130 and the second tab 140 on the pole piece may be 8-200 mm²Preferably 12 to 48mm²。

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

As shown in fig. 13, a first welding region 160 of the first tab 130 on the third pole piece 21 is illustrated 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 includes 3 welding areas, and in order to avoid short contact between the first welding area 160 and the pole pieces, after the first tab 130 is welded to the third pole piece 21, the first welding area 160 is covered with a first insulating adhesive paper 162. The thickness of the first adhesive paper 162 may be determined according to the actual burr level of the first tab 130, and the length of the first adhesive paper 162 is preferably such that it completely covers the length of the first tab 130 located inside the second electrode assembly 120.

As shown in fig. 14, a second welding region 161 of the second tab 140 on the fourth pole piece 23 is illustrated 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 includes 3 welding areas, and in order to avoid short circuit between the second welding area 161 and the pole piece, the second pole lug 140 is welded on the fourth pole piece 23, and then the second welding area 161 is covered by a second insulating adhesive paper 163. The thickness of the second insulating paste 163 may be determined according to the actual burr level of the second tab 140, and the length of the second insulating paste 163 is preferably such that it can completely cover the length of the second tab 140 located inside the second electrode assembly 120.

As shown in fig. 15, a first welding region 160 of the first tab 130 on the third pole piece 21 is illustrated 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 includes 3 welding areas, and in order to avoid short contact between the first welding area 160 and the pole pieces, the first tab 130 is welded to the third pole piece 21, and then the first welding area 160 is covered by a first insulating adhesive paper 162. The thickness of the first adhesive paper 162 may be determined according to the actual burr level of the first tab 130, and the length of the first adhesive paper 162 is preferably such that it completely covers the length of the first tab 130 located inside the second electrode assembly 120.

As shown in fig. 16, a second welding region 161 of the second tab 140 on the fourth pole piece 23 is illustrated 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 includes 3 welding areas, and in order to avoid short circuit between the second welding area 161 and the pole piece, the second pole lug 140 is welded on the fourth pole piece 23, and the second welding area 161 is covered by a second insulating adhesive 163. The thickness of the second insulating paste 163 may be determined according to the actual burr level of the second tab 140, and the length of the second insulating paste 163 is preferably such that it can completely cover the length of the second tab 140 located inside the second electrode assembly 120.

In some embodiments, a final insulating adhesive is also disposed on the outermost wound layer of the second electrode assembly 120. As shown in fig. 17, when the winding direction of the first electrode assembly 110 is perpendicular to the winding direction of the second electrode assembly 120, the first ending insulating adhesive tape 170 is disposed on the outermost winding layer of the second electrode assembly 120, so that the ending pole pieces of the second electrode assembly 120 can be prevented from short circuit by contact to some extent, and the function of fixing the tabs on the second electrode assembly 120 can also be achieved. The first terminal insulating adhesive 170 preferably completely covers the terminal pole pieces of the outermost wound layers of the second electrode assembly 120. In other embodiments, the first ending insulating adhesive 170 may also partially cover the ending pole piece of the outermost winding layer of the second electrode assembly 120.

As shown in fig. 18, 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 ending insulating adhesive paper 171 is disposed on the outermost winding layer of the second electrode assembly 120, so that the ending pole pieces of the second electrode assembly 120 can be prevented from short circuit by contact to some extent, and the function of fixing the tabs on the second electrode assembly 120 can also be achieved. The second terminal insulating paper 171 is preferably capable of completely covering the terminal pole pieces of the outermost wound layer of the second electrode assembly 120. In other embodiments, the second ending insulating adhesive 171 may also partially cover the ending pole piece of the outermost winding layer of the second electrode assembly 120.

In some embodiments, the shapes of the first tab 130 and the second tab 140 may 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 viewing plane, and the shapes of the first tab 130 and the second tab 140 are linear, as shown in fig. 19B, the main plane of the first electrode assembly 110 is also the viewing plane, and the shapes of the first tab 130 and the second tab 140 are L-shaped, as shown in fig. 19C, the main plane of the first electrode assembly 110 is also the viewing plane, and the shapes of the first tab 130 and the second tab 140 are T-shaped.

In some embodiments, 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 fig. 20) with the major plane of the first electrode assembly 110 as a line of sight plane. In other viewing planes, the first electrode assembly 110 and the second electrode assembly may constitute other 3D volumetric electrode assemblies.

In some embodiments, the first tab 130 and the second tab 140 may also protrude from the second electrode assembly 120 to form connection terminals, as shown in fig. 21, that is, tabs of both the first electrode assembly 110 and the second electrode assembly 120 of the cell structure 100 protrude.

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

The cell structure 100 according to the embodiment of the present application is described in detail below with reference to some specific embodiments. It is to be understood that the following description is illustrative only and is not intended to be in any way limiting.

Example 1:

in this embodiment, the battery 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 a first pole piece 11, a first separator 12, a second pole piece 13, and a second separator 14, and the second electrode assembly 120 is formed by winding a third pole piece 21, a third separator 22, a fourth pole piece 23, and a fourth separator 24. The cell structure 100 is L-shaped and the cell structure 100 is accommodated in the casing 200, and the winding direction of the first electrode assembly 110 is perpendicular to the winding direction of the second electrode assembly 120. 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, the first tab 130 and the second tab 140 both penetrate through the first side 111 and the second side 112 of the first electrode assembly 110, the first tab 130 penetrating from the first side 111 of the first electrode assembly 110 is further electrically connected to the third pole piece 21 of the mth winding layer of the second electrode assembly 120, and the second tab 140 penetrating from the first side 111 of the first electrode assembly 110 is further electrically connected to the fourth pole piece 23 of the mth winding layer of the second electrode assembly 120. The separator 150 is disposed between the first electrode assembly 110 and the second electrode assembly 120, the first tab 130 includes a first bent section 130a between the first electrode assembly 110 and the second electrode assembly 120, and the second tab 140 includes a second bent section 140a between the first electrode assembly 110 and the second electrode assembly 120. The cell structure 100 is connected to external positive and negative plates through a first tab 130 and a second tab 140 penetrating through the second side 112 of the first core assembly 110.

Example 2:

in this embodiment, the battery 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 a first pole piece 11, a first separator 12, a second pole piece 13, and a second separator 14, and the second electrode assembly 120 is formed by winding a third pole piece 21, a third separator 22, a fourth pole piece 23, and a fourth separator 24. The cell structure 100 is T-shaped, the cell structure 100 is accommodated in the casing 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, the first tab 130 and the second tab 140 both penetrate through the first side 111 and the second side 112 of the first electrode assembly 110, the first tab 130 penetrating from the first side 111 of the first electrode assembly 110 is further electrically connected to the third inner pole piece 21 of the mth winding layer of the second electrode assembly 120, and the second tab 140 penetrating from the first side 111 of the first electrode assembly 110 is further electrically connected to the fourth pole piece 23 of the mth winding layer of the second electrode assembly 120. The separator 150 is disposed between the first electrode assembly 110 and the second electrode assembly 120, the first tab 130 includes a first bent section 130a between the first electrode assembly 110 and the second electrode assembly 120, and the second tab 140 includes a second bent section 140a between the first electrode assembly 110 and the second electrode assembly 120. The cell structure 100 is connected to external positive and negative plates through a first tab 130 and a second tab 140 penetrating through the second side 112 of the first core assembly 110.

In the description of the present application, it is to be understood that 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," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the present application and for simplicity in description, and are not intended to indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and are therefore not to be considered limiting of the present application. In the description of the present application, "a plurality" means two or more.

In the description herein, reference to the description of the terms "one embodiment," "some embodiments," "an illustrative embodiment," "an example," "a specific example," or "some examples" or the like means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the application. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

While embodiments of the present application have been shown and described, it will be understood by those of ordinary skill in the art that: various changes, modifications, substitutions and alterations can be made to the embodiments without departing from the principles and spirit of the application, the scope of which is defined by the claims and their equivalents.

Claims

The utility model provides a battery core structure, includes the first electrode subassembly that is formed by the coiling of first pole piece and second pole piece, and the second electrode subassembly that is formed by the coiling of third pole piece and fourth pole piece which characterized in that:

the battery cell structure further comprises a first tab electrically connected to the first pole piece and a second tab electrically connected to the second pole piece, wherein the first tab and the second tab both penetrate through the first electrode assembly;

the first electrode tab is also electrically connected to a third pole piece of the second electrode assembly.
The cell structure of claim 1, wherein the second tab is further electrically connected to a fourth pole piece of the second electrode assembly.
The cell structure of claim 2, wherein the first tab comprises a first tab segment located within the first electrode assembly, a second tab segment located within the second electrode assembly, and a first bend located between the first tab segment and the second tab segment, the first bend located between the first electrode assembly and the second electrode assembly, the second tab comprises a third tab segment located within the first electrode assembly, a fourth tab segment located within the second electrode assembly, and a second bend located between the third tab segment and the fourth tab segment, the second tab segment located between the first electrode assembly and the second electrode assembly.
The cell structure of claim 2, wherein the first electrode assembly comprises n winding layers, the innermost winding layer of the first electrode assembly is defined as the 1 st winding layer of the first electrode assembly, the outermost winding layer of the first electrode assembly is defined as the nth winding layer of the first electrode assembly, the second electrode assembly comprises m winding layers, the innermost winding layer of the second electrode assembly is defined as the 1 st winding layer of the second electrode assembly, the outermost winding layer of the second electrode assembly is defined as the mth winding layer of the second electrode assembly, and 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 a third pole piece of an m-th winding layer of the second electrode assembly, and the second tab penetrating from the first side of the first electrode assembly is electrically connected to a 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 1 st winding layer of the first electrode assembly and the second tab is electrically connected to the second pole piece of the 1 st 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 nth winding layer of the first electrode assembly and the second tab is electrically connected to the second pole piece of the nth 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 ith winding layer of the first electrode assembly, the second tab is electrically connected to the second pole piece of the jth winding layer of the first electrode assembly, i and j are positive integers greater than 1 and less than n, and a difference between i and j is greater than or equal to a predetermined value.
The cell structure of claim 8, wherein the predetermined value is 4 layers.
The cell structure of claim 4, wherein the third pole piece of the m-th wound layer of the second electrode assembly extends a length greater than the fourth pole piece, and the third and fourth pole pieces of the first wound layer of the second electrode assembly comprise a void foil region.
The cell structure of claim 1, further comprising a spacer disposed between the first electrode assembly and the second electrode assembly, the spacer being made of an electrically non-conductive material, and two through holes being disposed on the spacer, and the first tab and the second tab passing through the two through holes.
The cell structure of claim 11, wherein the length of the spacer is less than or equal to the width of the first electrode assembly, and the width of the spacer is less than the greater of the thickness of the first electrode assembly and the thickness of the second electrode assembly.
The cell structure of claim 10 or 11, wherein the spacer has a thickness of 10 to 2000 um.
The cell structure of claim 11, wherein the first electrode assembly and the second electrode assembly have a gap therebetween, the gap being greater than or equal to the thickness of the spacer plus a first predetermined distance, the first predetermined distance being less than or equal to 2 mm.
The cell structure of claim 1, wherein the first tab has an adhesive paper disposed thereon.
The cell structure of claim 1, wherein when the first tab is electrically connected to the third pole piece by welding, a welding area of the first tab on the third pole piece satisfies the following relationship: the welding area is larger than or equal to the current passing capacity of the tab per unit area of the tab.
The cell structure of claim 1, wherein the number of the first tabs in the welding area of the third pole piece is 2-5.
The cell structure of claim 1, wherein the first electrode assembly and the second electrode assembly share a housing, and the first electrode assembly and the second electrode assembly form an L-shaped electrode assembly shape or a T-shaped electrode assembly shape when the major plane of the first electrode assembly is the viewing plane.
The cell structure of claim 1, wherein the winding direction of the first electrode assembly is parallel to or perpendicular to the winding direction of the second electrode assembly.
The cell structure of claim 1, wherein the first tab and the second tab further extend from the second electrode assembly to form two connection terminals.
The cell structure of claim 1, wherein the first tab is cut from a current collector of the first pole piece, and the second tab is cut from a current collector of the second pole piece.
A battery, characterized in that the battery further comprises a cell structure according to any one of claims 1-21.