CN111261826B

CN111261826B - Electrode assembly, battery using same and electric device

Info

Publication number: CN111261826B
Application number: CN202010218101.1A
Authority: CN
Inventors: 王佳伟; 江行国; 徐炎; 李�瑞
Original assignee: Ningde Amperex Technology Ltd
Current assignee: Ningde Amperex Technology Ltd
Priority date: 2020-03-25
Filing date: 2020-03-25
Publication date: 2023-01-10
Anticipated expiration: 2040-03-25
Also published as: CN111261826A

Abstract

An electrode assembly comprises a first pole piece, wherein the first pole piece comprises a first current collector, the first current collector comprises a first area, a second area and a third area, the second area and the third area are formed by extending the first area to two different directions, the boundary line of the first area and the second area is a first boundary line, and the boundary line of the first area and the third area is a second boundary line; a first active layer disposed on the first current collector surface; an open region extending through the electrode assembly; the partition area is connected with the opening area, the surface of the first pole piece positioned in the partition area is not provided with the first active layer, and at least part of the first area is positioned in the partition area and is overlapped. The application also provides a battery and an electric device applying the electrode assembly.

Description

Electrode assembly, battery using same and electric device

Technical Field

The present application relates to the field of energy storage technologies, and in particular, to an electrode assembly, a battery using the electrode assembly, and an electric device using the electrode assembly.

Background

The soft package battery is a polymer battery packaged by an aluminum-plastic film, is usually a lithium polymer battery, is mostly used for electric devices such as mobile phones and tablet computers, and is gradually valued along with the development of the electronic industry. The existing special-shaped batteries, such as L-shaped batteries, have relatively weak relative strength due to the fact that the external dimension of the pole piece is suddenly changed at some places, which causes stress concentration at the position. Moreover, when the battery is impacted, the positions are easy to break after being impacted, and more fragments are generated at the broken positions to further cause short-circuit combustion of the battery.

To address this problem, the prior art generally employs two approaches to improve: (1) The heat dissipation is accelerated, and a local combustion failure mode caused by the fact that the heat of the battery is concentrated and cannot be quickly released is avoided; (2) reducing the fracture fragments reduces the risk of shorting. To solution (1) accelerate the heat dissipation often need improve battery heat radiation structure, can make whole cost rise, though this scheme can avoid breaking the back and take place violent burning as far as possible, can not reduce the battery and receive the risk that takes place the short circuit after the striking. For the solution (2), the pole ear of the battery is usually arranged on the same side of the notch, meanwhile, the thickness of the base material is increased, the hardness of the battery is further enhanced, and the battery forms a complete fracture when being impacted, so that the risk of secondary short circuit combustion caused by fragments is reduced; however, the increase in the thickness of the substrate increases the quality of the battery, increases the cost, and decreases the energy density of the battery.

How to solve the above problems needs to be considered by those skilled in the art.

Disclosure of Invention

In order to solve the problems of a local combustion failure mode caused by easy short circuit due to impact and the reduction of energy density due to the fact that the thickness of a base material is increased and the impact resistance is improved in the prior art, the embodiment of the application provides an electrode assembly.

An embodiment of the present application provides an electrode assembly including:

a first pole piece;

the second pole piece is stacked with the first pole piece;

an open area extending through the electrode assembly, the open area having a shape that is at least a portion of a circle;

the body region comprises a first region, a second region and a third region, the second region and the third region extend from the first region to two different directions, the boundary line of the first region and the second region is a first intersection line, the boundary line of the first region and the third region is a second intersection line, and the center of the opening region is the intersection point of the first intersection line and the second intersection line; and

first utmost point ear and second utmost point ear, first utmost point ear and second utmost point ear by the main part district outwards extends and forms, first utmost point ear and second utmost point ear respectively with two in first region, the second region and the third region are connected.

In some embodiments, the first region comprises a separation region that extends through at least a portion of the first region in a first direction parallel to the first or second pole piece, a portion of a boundary of the separation region overlapping the first or second intersection line, the first and second pole tabs being unconnected to the separation region. The electrode assembly has the advantages that the cathode tabs and the anode tabs are respectively arranged on different sides of the fragile region of the electrode assembly, when a battery or an electrochemical device containing the electrode assembly is broken under the action of external force, the broken electrode assembly parallel loop is disconnected, so that only single short circuit or point short circuit can be caused, and the risk of combustion failure caused by large heat generated by multi-loop short circuit is reduced.

In some embodiments, a portion of the boundary of the exclusion zone overlaps the first intersection line, the first tab extends outwardly from the first region, and the second tab extends outwardly from the second region.

In some embodiments, a portion of the boundary of the exclusion zone overlaps the second intersection line, the first tab extends outwardly from the first region, and the second tab extends outwardly from the third region.

In some embodiments, the separation region includes a first separation region and a second separation region, a portion of a boundary of the first separation region overlaps the first intersection line, a portion of a boundary of the second separation region overlaps the second intersection line, the first tab extends outward from the second region, and the second tab extends outward from the third region.

In some embodiments, the first pole piece includes a first current collector and a first active layer disposed on a surface of the first current collector, and the second pole piece includes a second current collector and a second active layer disposed on a surface of the second current collector.

In some embodiments, the first tab and the second tab are strip-shaped, and a reverse extension line extending from the extension direction of the first tab or the second tab to the main body region divides one of the first region, the second region and the third region connected to the first tab or the second tab into two parts with equal resistance. When the electrode assembly is broken and short-circuited, the areas on two sides of the contour line extending from the first lug or the second lug are connected in parallel and have the same resistance, and the resistance formula of the parallel circuit shows that the overall resistance of the parallel circuit is the largest, the internal resistance is the largest in the short-circuit process, the heat generated is the smallest, and the risk of combustion failure can be reduced.

In some embodiments, the first tab and the second tab are strip-shaped, and a reverse extension line extending from the extension direction of the first tab or the second tab to the main body region divides one of the first region, the second region and the third region connected to the first tab or the second tab into two parts with equal volume. When the electrode assembly as a whole has uniform resistance coefficient, the two parts with equal volume have the same resistance, and the resistance value of the whole parallel circuit is the largest according to the resistance formula of the parallel circuit, the internal resistance is the largest in the short-circuit process, the heat generated is the smallest, and the risk of combustion failure can be reduced.

In some embodiments, the electrode assembly is L-shaped, and the open region is disposed at an L-shaped corner of the electrode assembly. The circular opening area can avoid stress from concentrating at the inner folding angle of the L-shaped battery, avoid the breakage of the opening area and avoid the generation of fragments and short circuits.

A battery includes the aforementioned electrode assembly.

An electric device comprises the battery.

Compared with the prior art, this application's electrode subassembly, this electrode subassembly sets up negative pole utmost point ear and positive pole utmost point ear respectively in the different sides in the fragile region of electrode subassembly, and when the electrochemical device who includes electrode subassembly received the exogenic action and takes place the fracture, the disconnection of the electrode subassembly parallel circuit after the fracture to only can cause single short circuit or some short circuit, thereby reduce because of the risk that multiloop short circuit produced the big heat and cause combustion failure.

Drawings

Fig. 1 is a schematic cross-sectional view of an electrode assembly according to a first embodiment of the present application.

Fig. 2 is a schematic plan view of an electrode assembly according to a first embodiment of the present application.

Fig. 3 is a schematic view of an electrode assembly according to a first embodiment of the present application.

Fig. 4 is a schematic cross-sectional view of an electrode assembly according to a second embodiment of the present application.

Fig. 5 is a schematic plan view of an electrode assembly according to a second embodiment of the present application.

Fig. 6 is a schematic view of an electrode assembly according to a second embodiment of the present application.

Fig. 7 is a schematic cross-sectional view of an electrode assembly according to a third embodiment of the present application.

Fig. 8 is a schematic plan view of an electrode assembly according to a third embodiment of the present application.

Fig. 9 is a schematic view of an electrode assembly according to a third embodiment of the present application.

Fig. 10 is a schematic plan view of a battery according to a fourth embodiment of the present application.

Fig. 11 is a perspective view of an electric device according to a fifth embodiment of the present application.

Description of the main elements

Power utilization device 100

Body 101

Packaging bag 102

Battery 1

Electrode assembly

10, 20, 30, 50

First pole piece

11, 21, 31

First

current collector

110, 210, 310

First

active layers

119, 219, 319

Second pole piece

12, 22, 32

Second

current collector

120, 220, 320

Second

active layer

129, 229, 329

Open areas

13, 23, 33

Center of

circle

130, 230, 330

Partition zones

14, 24, 34

First partition zones

141, 241, 341

Second partition zones

142, 242, 342

Body regions

15, 25, 35

First region

151, 251, 351

Second region

152, 252, 352

Third region

153, 253, 353

First intersection lines

155, 255, 355

Second intersection

156, 256, 356

Isolation membranes

16, 26, 36

First tab

17, 27, 37

Second pole ear

18, 28, 38

Contour lines

19, 29, 39

The following detailed description will further illustrate the present application in conjunction with the above-described figures.

Detailed Description

The following description will refer to the accompanying drawings to more fully describe the present disclosure. There is shown in the drawings exemplary embodiments of the present application. This application may, however, be embodied in many different forms and should not be construed as limited to the exemplary embodiments set forth herein. These exemplary embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. Like reference numerals designate identical or similar components.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. Further, as used herein, the terms "comprises," "comprising," "includes" and/or "including" or "having" and/or "having," integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, regions, integers, steps, operations, elements, components, and/or groups thereof.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. Furthermore, unless otherwise explicitly defined herein, terms such as those defined in commonly used dictionaries should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and this application and will not be interpreted in an idealized or overly formal sense.

The following description of the exemplary embodiments refers to the accompanying drawings. It should be noted that the components depicted in the referenced drawings are not necessarily shown to scale; and the same or similar components will be given the same or similar reference numerals or similar terms.

Embodiments of the present application will be described in further detail below with reference to the accompanying drawings.

First embodiment

As shown in fig. 1 and 2, the present application provides an electrode assembly 10 including a first pole piece 11, a second pole piece 12, an opening region 13, a body region 15, a separator 16, a first tab 17, and a second tab 18. The first and second electrode plates 11 and 12 are stacked at intervals, a separator 16 is disposed between the first and second electrode plates 11 and 12, and the opening region 13 penetrates the electrode assembly 10.

The electrode assembly 10 includes a body region 15, and the first and second pole pieces 11 and 12 are disposed in the body region 15. The body region 15 includes a first region 151, a second region 152, and a third region 153, and the second region 152 and the third region 153 are formed by extending the first region 151 in two different directions. The boundary between the first region 151 and the second region 152 is a first boundary 155, and the boundary between the first region 151 and the third region 153 is a second boundary 156. The first region 151 is a region where the probability of occurrence of a resultant force of an external force on the electrode assembly 10 is the greatest when the electrode assembly 10 is subjected to an external force impact (e.g., an impact or a drop). In one embodiment, the first region 151 is disposed in the corner region of the L-shaped electrode assembly 10, and the second region 152 and the third region 153 are disposed in the regions of the L-shaped first pole piece 11 extending in two different directions.

In one embodiment, the electrode assembly 10 is L-shaped, the opening 13 is disposed at an L-shaped corner of the electrode assembly 10, and specifically, the opening 13 penetrates through an inner corner of the L-shaped electrode assembly 10. The shape of the opening region 13 is at least a portion of a circle, and the center 130 of the opening region 13 is the intersection of the first intersection 155 and the second intersection 156, or the perpendicular line segments of the center 130 toward the two long sides of the L-shaped electrode assembly 10 are the first intersection 155 and the second intersection 156, respectively. The boundary line of the electrode assembly 10 is a straight line passing through the center 130 of the open area 13. The opening region 13 is disposed at the inner corner of the L-shaped electrode assembly 10 to prevent the stress concentration at the inner corner from causing a chip and a short circuit. The radius of the opening region 13 is R, the width of the second region 152 in the direction along the first intersection line 155 is La, and the width of the third region 153 in the direction along the second intersection line 156 is Lb.

The first electrode plate 11 includes a first current collector 110 and a first active layer 119, and the first active layer 119 is disposed on the surface of the first current collector 110. The second electrode sheet 12 includes a second current collector 120 and a second active layer 129, and the second active layer 129 is disposed on the surface of the second current collector 120.

The first region 151 includes the blocking region 14, and the blocking region 14 is a region where the electrode assembly 10 has a high probability of breakage when impacted by an external force. The partition region 14 penetrates at least a portion of the first region 151 in a direction parallel to the first pole piece 11 or the second pole piece 12, a portion of a boundary of the partition region 14 overlaps the first intersection line 155 or the second intersection line 156, and the partition region 14 is connected to the opening region 13.

The isolation region 14 includes a first isolation region 141 and a second isolation region 142, in an embodiment, the first isolation region 141 is a region where a resultant force or a stress is concentrated at a boundary between the first region 151 and the second region 152, and the second isolation region 142 is a region where a resultant force or a stress is concentrated at a boundary between the first region 151 and the third region 153.

In one embodiment, at least a portion of the first partition 141 overlaps the first intersection line 155, the first partition 141 includes a first edge 1411 and a second edge 1412, the first edge 1411 is close to the second region 152, a set of side lengths of the first edge 1411 is [ La-2R, la ], the second edge 1412 is far from the second region 152, and a set of side lengths of the second edge 1412 is [ La-R, la + R ]. One end of the first blocking area 141 is connected to the opening area 13, and the lengths of both sides of the first blocking area 141 connected to the opening area 13 are different.

In an embodiment, at least a portion of the second partition 142 overlaps the second intersection 156, the second partition 142 includes a third edge 1421 and a fourth edge 1422, the third edge 1421 is close to the third region 153, a set of side lengths of the third edge 1421 is [ Lb-2r, lb ], the fourth edge 1422 is far from the third region 153, and a set of side lengths of the fourth edge 1422 is [ Lb-R, lb + R ]. One end of the second blocking area 142 is connected to the opening area 13, and the lengths of both sides of the second blocking area 142 connected to the opening area 13 are different.

The first tab 17 and the second tab 18 are formed by extending the main body region 15, the first tab 17 and the second tab 18 are respectively connected to two of the first region 151, the second region 152 and the third region 153, and the first tab 17 and the second tab 18 are not connected to the blocking region 14.

In one embodiment, the boundary of the first separating region 141 overlaps the first intersection line 155, the first tab 17 extends outwardly from the first region 151, and the second tab 18 extends outwardly from the third region 153. When the electrode assembly 10 is broken at the second partition area 142, the first tab 17 and the second tab 18 are respectively located in two different broken areas, and the broken electrode assembly 10 is disconnected in parallel connection with a circuit, so that only a single short circuit or a point short circuit is caused, and the risk of combustion failure caused by large heat generated by a multi-circuit short circuit is reduced.

In one embodiment, the first tab 17 and the second tab 18 are strip-shaped, and a reverse extension line extending from the extending direction of the first tab 17 or the second tab 18 to the main body region 15 divides one of the first region 151, the second region 152, or the third region 153 connected to the first tab 17 or the second tab 18 into two parts with equal resistance. Alternatively, when the electrode assembly 10 has a uniform resistivity as a whole, the reverse extension line extending in the extending direction of the first or

second tab

17 or 18 toward the body region 15 divides one of the first, second, or

third regions

151, 152, or 153 connected to the first or

second tab

17 or 18 into two parts having the same volume, and the two parts having the same volume have the same resistance. As shown in fig. 3, one end of the first tab 17 and the second tab 18 may be connected to the outer edge of the body region 15, and the plurality of contours 19 are the first tab 17 or the second tab 18 (one first tab 17 and one second tab 18 and the plurality of contours 19 are shown in a reverse extension diagram extending toward the body region 15, and each contour 19 represents the extension of at least one of the first tab 17 or the second tab 18). When the electrode assembly 10 is broken and short-circuited, the areas on both sides of the contour line 19 extended from the first tab 17 or the second tab 18 are connected in parallel and have the same resistance, and the resistance of the parallel circuit is the largest, and the heat generated by the largest internal resistance in the short-circuiting process is the smallest according to the resistance formula of the parallel circuit, so that the risk of combustion failure can be reduced.

Second embodiment

As shown in fig. 4 and 5, the present application provides an electrode assembly 20 including a first pole piece 21, a second pole piece 22, an opening region 23, a body region 25, a separator 26, a first pole tab 27, and a second pole tab 28. The first and

second pole pieces

21 and 22 are stacked at intervals, a separation film 26 is disposed between the first and

second pole pieces

21 and 22, and the opening region 23 penetrates through the electrode assembly 20.

The electrode assembly 20 includes a main body region 25, and the first and

second electrode tabs

21 and 22 are disposed in the main body region 25. The body region 25 includes a first region 251, a second region 252, and a third region 253, and the second region 252 and the third region 253 are formed by extending the first region 251 in two different directions. The boundary between the first region 251 and the second region 252 is a first boundary 255, and the boundary between the first region 251 and the third region 253 is a second boundary 256. The first region 251 is a region where the probability of the resultant force of the external force on the electrode assembly 20 is the highest when the electrode assembly 20 is impacted by the external force (e.g., impacted or dropped). In one embodiment, the first region 251 is disposed in the bevel region of the L-shaped electrode assembly 20, and the second region 252 and the third region 253 are disposed in two regions of the L-shaped first pole piece 21 extending in two different directions.

In one embodiment, the electrode assembly 20 is L-shaped, the opening 23 is disposed at an L-shaped corner of the electrode assembly 20, and specifically, the opening 23 penetrates through an inner corner of the L-shaped electrode assembly 20. The opening area 23 is at least partially circular, and the center 230 of the opening area 23 is the intersection of the first intersection 255 and the second intersection 256, or the perpendicular line segments of the center 230 toward the two long sides of the L-shaped electrode assembly 20 are the first intersection 255 and the second intersection 256, respectively. The boundary line of the electrode assembly 20 is a straight line passing through the center 230 of the open area 23. The opening 23 is disposed at the inner corner of the L-shaped electrode assembly 20 to prevent stress concentration at the inner corner from causing a chip and a short circuit. The opening region 23 has a radius R, a width La of the second region 252 along the first intersection 255, and a width Lb of the third region 253 along the second intersection 256.

The first electrode sheet 21 includes a first current collector 210 and a first active layer 219, and the first active layer 219 is disposed on the surface of the first current collector 210. The second electrode sheet 22 includes a second current collector 220 and a second active layer 229, and the second active layer 229 is disposed on a surface of the second current collector 220.

The first region 251 includes the cut-off region 24, and the cut-off region 24 is a region where the electrode assembly 20 has a high probability of breakage when impacted by an external force. The cut-off region 24 penetrates at least part of the first region 251 in a direction parallel to the first pole piece 21 or the second pole piece 22, a part of the boundary of the cut-off region 24 overlaps the first intersection 255 or the second intersection 256, and the cut-off region 24 is connected to the open region 23.

The separating region 24 includes a first separating region 241 and a second separating region 242, in an embodiment, the first separating region 241 is a region where the resultant force or the stress is concentrated at the boundary between the first region 251 and the second region 252, and the second separating region 242 is a region where the resultant force or the stress is concentrated at the boundary between the first region 251 and the third region 253.

In one embodiment, at least a portion of the first partition 241 overlaps the first intersection 255, the first partition 241 includes a first edge 2411 and a second edge 2412, the first edge 2411 is close to the second region 252, the set of side lengths of the first edge 2411 is [ La-2R, la ], the second edge 2412 is far from the second region 252, and the set of side lengths of the second edge 2412 is [ La-R, la + R ]. One end of the first blocking area 241 is connected to the opening area 23, and the lengths of both sides of the first blocking area 241 connected to the opening area 23 are different.

In one embodiment, at least a portion of the second partition region 242 overlaps the second intersection line 256, the second partition region 242 includes a third side 2421 and a fourth side 2422, the third side 2421 is close to the third region 253, the set of the side lengths of the third side 2421 is [ Lb-2r, lb ], the fourth side 2422 is far from the third region 253, and the set of the side lengths of the fourth side 2422 is [ Lb-R, lb + R ]. One end of the second partition region 242 is connected to the opening region 23, and the lengths of both sides of the second partition region 242 connected to the opening region 23 are different.

The first tab 27 and the second tab 28 are formed by extending the main body region 25, the first tab 27 and the second tab 28 are respectively connected with two of the first region 251, the second region 252 and the third region 253, and the first tab 27 and the second tab 28 are not connected with the blocking region 24.

In one embodiment, the boundary of the first cut-off region 241 overlaps the first intersection line 255, the first tab 27 extends outwardly from the first region 251, and the second tab 28 extends outwardly from the second region 252. When the electrode assembly 20 is broken at the second partition region 242, the first tab 27 and the second tab 28 are respectively located in two different breaking regions, and the broken electrode assembly 20 is disconnected in parallel connection with a circuit, so that only a single short circuit or a point short circuit is caused, and the risk of combustion failure caused by large heat generated by a multi-circuit short circuit is reduced.

In one embodiment, the first tab 27 and the second tab 28 are strip-shaped, and a reverse extension line extending in the extending direction of the first tab 27 or the second tab 28 toward the main body region 25 divides one of the first region 251, the second region 252, or the third region 253 connected with the first tab 27 or the second tab 28 into two parts with equal resistance. Alternatively, when the electrode assembly 20 has a uniform resistivity as a whole, a reverse extension line extending in the extending direction of the first or

second tab

27 or 28 toward the body region 25 divides one of the first, second, or

third regions

251, 252, or 253 connected to the first or

second tab

27 or 28 into two parts having the same volume, and the two parts having the same volume have the same resistance. As shown in fig. 6, one end of the first tab 27 and the second tab 28 may be connected to the outer edge of the body region 25, and the plurality of contour lines 29 are the first tab 27 or the second tab 28 (one first tab 27 and one second tab 28 and the plurality of contour lines 29 are shown in a reverse extension line diagram extending toward the body region 25, and each contour line 29 represents the extending manner of at least one of the first tab 27 or the second tab 28). When the electrode assembly 20 is broken and short-circuited, the areas on both sides of the contour line 29 extending from the first tab 27 or the second tab 28 are connected in parallel and have the same resistance, and the resistance of the parallel circuit is the largest as known by the parallel circuit resistance formula, and the heat generated by the largest internal resistance in the short-circuit process is the smallest, so that the risk of combustion failure can be reduced.

Third embodiment

As shown in fig. 7 and 8, the present application provides an electrode assembly 30 including a first pole piece 31, a second pole piece 32, an opening region 33, a body region 35, a separator 36, a first tab 37, and a second tab 38. The first and

second pole pieces

31 and 32 are stacked at intervals, a separator 36 is disposed between the first and

second pole pieces

31 and 32, and the opening area 33 penetrates through the electrode assembly 30.

The electrode assembly 30 includes a body region 35, and the first and

second pole pieces

31 and 32 are disposed in the body region 35. The body region 35 includes a first region 351, a second region 352, and a third region 353, and the second region 352 and the third region 353 are formed by extending the first region 351 in two different directions. The boundary between the first region 351 and the second region 352 is a first boundary 355, and the boundary between the first region 351 and the third region 353 is a second boundary 356. The first region 351 is a region where the probability of the resultant force of the external force on the electrode assembly 30 is the highest when the electrode assembly 30 is subjected to an external force impact (e.g., an impact or a drop). In one embodiment, the first region 351 is disposed in a corner region of the L-shaped electrode assembly 30, and the second region 352 and the third region 353 are disposed in two regions of the L-shaped first pole piece 31 extending in two different directions.

In one embodiment, the electrode assembly 30 is L-shaped, and the opening 33 is disposed at an L-shaped corner of the electrode assembly 30, specifically, the opening 33 penetrates through an inner corner of the L-shaped electrode assembly 30. The shape of the open area 33 is at least a portion of a circle, and the center 330 of the open area 33 is the intersection of the first intersection 355 and the second intersection 356, or the perpendicular line segments of the center 330 towards the two long sides of the L-shaped electrode assembly 30 are the first intersection 355 and the second intersection 356, respectively. The boundary line of the electrode assembly 30 is a straight line passing through the center 330 of the open area 33. The opening 33 is disposed at the inner corner of the L-shaped electrode assembly 30 to prevent the stress concentration at the inner corner from causing a chip and a short circuit. The opening area 33 has a radius R, a width La of the second area 352 in the direction along the first intersection 355, and a width Lb of the third area 353 in the direction along the second intersection 356.

The first pole piece 31 includes a first current collector 310 and a first active layer 319, and the first active layer 319 is disposed on the surface of the first current collector 310. The second electrode sheet 32 includes a second current collector 320 and a second active layer 329, and the second active layer 329 is disposed on the surface of the second current collector 320.

The first region 351 includes the cut-off region 34, and the cut-off region 34 is a region where the electrode assembly 30 has a high probability of breaking due to external force impact. The cut-off region 34 penetrates at least part of the first region 351 in a direction parallel to the first or

second pole piece

31 or 32, a part of the boundary of the cut-off region 34 overlaps the first or

second intersection line

355 or 356, and the cut-off region 34 is connected to the opening region 33.

The isolation region 34 includes a first isolation region 341 and a second isolation region 342, in an embodiment, the first isolation region 341 is a region where the resultant force or the stress is concentrated at the boundary between the first region 351 and the second region 352, and the second isolation region 342 is a region where the resultant force or the stress is concentrated at the boundary between the first region 351 and the third region 353.

In one embodiment, at least a portion of the first blocking region 341 overlaps the first intersection 355, the first blocking region 341 includes a first edge 3411 and a second edge 3412, the first edge 3411 is close to the second region 352, the set of side lengths of the first edge 3411 is [ La-2R, la ], the second edge 3412 is far from the second region 352, and the set of side lengths of the second edge 3412 is [ La-R, la + R ]. One end of the first intercepting region 341 is connected to the opening region 33, and the lengths of both sides of the first intercepting region 341 connected to the opening region 33 are different.

In one embodiment, at least a portion of the second partition area 342 overlaps the second intersection line 356, the second partition area 342 includes a third side 3421 and a fourth side 3422, the third side 3421 is close to the third area 353, a set of side lengths of the third side 3421 is [ Lb-2r, lb ], the fourth side 3422 is far from the third area 353, and a set of side lengths of the fourth side 3422 is [ Lb-R, lb + R ]. One end of the second partition region 342 is connected to the open region 33, and the lengths of both sides of the second partition region 342 connected to the open region 33 are different.

The first tab 37 and the second tab 38 are formed by extending the main body region 35 outward, the first tab 37 and the second tab 38 are connected to two of the first region 351, the second region 352, and the third region 353, respectively, and the first tab 37 and the second tab 38 are not connected to the blocking region 34.

In one embodiment, the boundary of the first cut-off region 341 overlaps the first intersection line 355, the first tab 37 extends outward from the second region 352, and the second tab 38 extends outward from the third region 353. When the electrode assembly 30 is broken from the second partition area 342, the first tab 37 and the second tab 38 are respectively located in two different breaking areas, and the broken electrode assembly 30 is disconnected in parallel loops, so that only a single short circuit or a point short circuit is caused, and the risk of combustion failure caused by large heat generated by multi-loop short circuits is reduced.

In one embodiment, the first tab 37 and the second tab 38 are strip-shaped, and a reverse extension line extending from the extension direction of the first tab 37 or the second tab 38 to the main body region 35 divides one of the first region 351, the second region 352, or the third region 353 connected to the first tab 37 or the second tab 38 into two parts with equal resistance. Alternatively, when the electrode assembly 30 has a uniform resistivity as a whole, a reverse extension line extending in the extending direction of the first or

second tab

37 or 38 toward the body region 35 divides one of the first, second, or

third regions

351, 352, 353 connected to the first or

second tab

37 or 38 into two parts having the same volume, and the two parts having the same volume have the same resistance. As shown in fig. 9, one end of the first tab 37 and the second tab 38 may be connected to the outer edge of the body region 35, and the plurality of contours 39 are the first tab 37 or the second tab 38 (one first tab 37 and one second tab 38 and the plurality of contours 39 are shown in a reverse extension line diagram extending toward the body region 35, and each contour 39 represents the extension of at least one of the first tab 37 or the second tab 38). When the electrode assembly 30 is broken and short-circuited, the regions on both sides of the contour line 39 extending from the first tab 37 or the second tab 38 are connected in parallel and have the same resistance, and the resistance of the parallel circuit is the largest, and the heat generated by the largest internal resistance during the short-circuiting process is the smallest, so that the risk of combustion failure can be reduced.

Fourth embodiment

Fig. 10 is a perspective view of a battery according to a fourth embodiment of the present application. The cell 1 includes an electrode assembly 50, the electrode assembly 50 may be wrapped by a pouch 102, the electrode assembly 50 is impregnated with an electrolyte, and the electrode assembly 50 may be any one of the electrode assemblies described in the first to third embodiments.

Fifth embodiment

Fig. 11 is a schematic perspective exploded view of an electric device 100 according to a fifth embodiment of the present application. The present application further provides an electric device 100, which includes a body 101 and a battery 1 disposed in the body 101. In fig. 11, the electric device 100 is only used as a mobile phone, but in other embodiments, the electric device 100 may also be a personal computer, a smart appliance, an industrial controller, an energy storage device, an electric tool, or the like.

Hereinbefore, specific embodiments of the present application are described with reference to the drawings. However, those skilled in the art will appreciate that various modifications and substitutions can be made to the specific embodiments of the present application without departing from the spirit and scope of the application. Such modifications and substitutions are intended to be within the scope of the present application.

Claims

1. An electrode assembly, comprising:

a first pole piece;

the second pole piece is stacked with the first pole piece;

an opening region extending through the electrode assembly, the opening region having a shape of at least a portion of a circle;

the main body area comprises a first area, a second area and a third area, the second area and the third area extend from the first area to two different directions, the boundary line of the first area and the second area is a first intersection line, the boundary line of the first area and the third area is a second intersection line, the center of a circle of the opening area is the intersection point of the first intersection line and the second intersection line, the first area comprises a partition area, and part of the boundary of the partition area is overlapped with the first intersection line or the second intersection line; and

2. The electrode assembly of claim 1, wherein the exclusion region extends through at least a portion of the first region in a direction parallel to the first or second pole piece, the first and second pole tabs not being connected to the exclusion region.

3. The electrode assembly of claim 2, wherein a portion of the boundary of the exclusion region overlaps the first intersection line, the first tab extends outwardly from the first region, and the second tab extends outwardly from the second region.

4. The electrode assembly of claim 2 wherein a portion of the boundary of the exclusion zone overlaps the second intersection line, the first tab extending outwardly from the first region, and the second tab extending outwardly from the third region.

5. The electrode assembly of claim 2, wherein the exclusion zone comprises a first exclusion zone and a second exclusion zone, a portion of a boundary of the first exclusion zone overlapping the first intersection line, a portion of a boundary of the second exclusion zone overlapping the second intersection line, the first tab extending outward from the second region, and the second tab extending outward from the third region.

6. The electrode assembly of claim 2, wherein the first pole piece comprises a first current collector and a first active layer, the first active layer disposed on a surface of the first current collector, and the second pole piece comprises a second current collector and a second active layer, the second active layer disposed on a surface of the second current collector.

7. The electrode assembly according to claim 1, wherein the first tab and the second tab have a strip shape, and a reverse extension line extending in a direction of extension of the first tab or the second tab toward the body region divides one of the first region, the second region, and the third region connected to the first tab or the second tab into two parts having equal resistance.

8. The electrode assembly according to claim 1, wherein the first tab and the second tab have a strip shape, and a reverse extension line extending in a direction in which the first tab or the second tab extends toward the body region divides one of the first region, the second region, and the third region connected to the first tab or the second tab into two parts having the same volume.

9. The electrode assembly of claim 1, wherein the electrode assembly is L-shaped, and the open area is disposed at a folded L-shaped corner of the electrode assembly.

10. A battery comprising an electrode assembly according to any one of claims 1 to 9.

11. An electric device comprising the battery of claim 10.