WO2022021227A1

WO2022021227A1 - Electrode plate, electrochemical device and electronic device

Info

Publication number: WO2022021227A1
Application number: PCT/CN2020/105897
Authority: WO
Inventors: 金娟; 吴飞; 蔡阳声; 郭飞龙
Original assignee: 东莞新能安科技有限公司; 宁德新能源科技有限公司
Priority date: 2020-07-30
Filing date: 2020-07-30
Publication date: 2022-02-03
Also published as: CN113853709B; CN113853709A

Abstract

An electrode plate, comprising an electrode plate body and a tab. The tab is formed by extending the electrode plate body in a first direction. The tab comprises N bending portions and N+1 laminating portions which are arranged in a laminated manner, and one of the laminating portions is connected to the electrode plate body, N is a natural number greater than or equal to 1, and each bending portion is connected to two laminating portions. The electrode plate facilitates improving overcurrent capability and reducing temperature rise. The present application also provides an electrochemical device and an electronic device applying the electrode plate..

Description

Pole Pieces, Electrochemical Devices and Electronic Devices

technical field

The present application relates to the field of electrochemistry, and in particular, to a pole piece, an electrochemical device and an electronic device using the pole piece.

Background technique

Lithium-ion batteries have the advantages of large specific energy, high operating voltage, low self-discharge rate, small size, and light weight, and are widely used in the field of consumer electronics. However, with the rapid development of electric vehicles and mobile electronic devices, people have higher and higher requirements for battery energy density, power density, safety, durability, and cycle performance. In order to improve the energy density of high-power batteries in the prior art, the current collectors used are getting thinner and thinner, and the thickness of the tabs extended from the current collectors is also getting thinner and thinner, resulting in insufficient overcurrent capability of the tabs. , causing the tabs to overheat, thereby affecting the performance of the battery.

SUMMARY OF THE INVENTION

In view of the above situation, it is necessary to provide a pole piece that is beneficial to improve the overcurrent capability and reduce the temperature rise.

In addition, there is a need to provide an electrochemical device and an electronic device using the above-mentioned pole piece.

A pole piece of the present application includes a pole piece main body and a pole lug, and the pole lug is formed by extending the pole piece main body along a first direction. Wherein, the tab includes N bending parts and N+1 laminated parts, and one of the laminated parts is connected to the main body of the pole piece, N is a natural number greater than or equal to 1, and each bending part connects two laminated parts Department.

As a solution of the present application, each bending portion is disposed along a second direction perpendicular to the first direction.

As a solution of the present application, each bending portion is arranged along the first direction.

As a solution of the present application, the N bending parts include a first bending part and a second bending part, the first bending part is arranged along a second direction perpendicular to the first direction, and the second bending part is along the first bending part. Set in one direction.

As a solution of the present application, the pole piece further includes an electrical connection portion, and the electrical connection portion is connected between two adjacent stacked portions.

As a solution of the present application, the electrical connection portion is conductive glue or solder.

As a solution of the present application, the main body of the pole piece includes a current collector and an active material layer, the current collector includes a first region and a second region, the active material layer is arranged in the first region, and at least one side of the second region is connected from the active material layer. Exposed, one end of the laminated part close to the pole piece body is connected to the second region.

As a solution of the present application, the pole piece includes a plurality of pole tabs, and any two pole tabs are spaced apart and have the same or different structures.

An electrochemical device of the present application includes a first pole piece, a second pole piece, and a separator between the first pole piece and the second pole piece, wherein the first pole piece is the above pole piece.

As a solution of the present application, the first pole piece and the second pole piece are wound and arranged, the first pole piece is provided with a plurality of pole tabs, and the plurality of pole tabs are oppositely arranged.

As a solution of the present application, the first pole piece and the second pole piece are arranged in layers, and the electrochemical device includes a plurality of first pole pieces, and the tabs of the plurality of first pole pieces are oppositely arranged.

As a solution of the present application, any two tabs are independent of each other, or one tab is sleeved inside the other tab.

An electronic device of the present application includes the above electrochemical device.

In the pole piece of the present application, as well as the electrode assembly, electrochemical device and electronic device using the pole piece, since the pole tab includes a plurality of laminated portions arranged in layers, the pole piece can realize the space occupied by the pole tab in the width direction without increasing And under the premise of the number of tabs, the overcurrent capability of the tabs can be improved while avoiding the problem that the impedance of the thin tabs is too large, so as to meet the requirements of high-rate charging and discharging, and can reduce the temperature rise during charging and discharging. At the same time, it can also Reduce the impact on energy density and improve power density.

Description of drawings

FIG. 1 is a schematic structural diagram of a pole piece according to an embodiment of the present application.

FIG. 2 is a schematic structural diagram of a current collector and a tab according to an embodiment of the present application.

FIG. 3 is a schematic structural diagram of a pole piece according to an embodiment of the present application.

FIG. 4 is a schematic structural diagram of a pole piece according to an embodiment of the present application.

FIG. 5 is a schematic structural diagram of a pole piece according to an embodiment of the present application.

FIG. 6 is a schematic structural diagram of a pole piece according to an embodiment of the present application.

FIG. 7 is a schematic structural diagram of a pole piece according to an embodiment of the present application.

FIG. 8 is a schematic structural diagram of a pole piece according to an embodiment of the present application.

FIG. 9 is a schematic structural diagram of a pole piece according to an embodiment of the present application.

FIG. 10 is a schematic structural diagram of a pole piece according to an embodiment of the application.

FIG. 11 is a schematic structural diagram of a pole piece according to an embodiment of the application.

FIG. 12 is a schematic structural diagram of a pole piece according to an embodiment of the application.

FIG. 13 is a schematic structural diagram of a pole piece according to an embodiment of the application.

FIG. 14A is a schematic structural diagram of a pole piece according to an embodiment of the present application.

FIG. 14B is a schematic structural diagram of a pole piece according to an embodiment of the present application.

15 is a partial cross-sectional view of a pole piece according to an embodiment of the application.

FIG. 16 is a schematic structural diagram of a pole piece according to an embodiment of the application.

FIG. 17 is a schematic structural diagram of a pole piece according to an embodiment of the application.

FIG. 18 is a schematic structural diagram of a pole piece according to an embodiment of the application.

FIG. 19 is a schematic structural diagram of a pole piece according to an embodiment of the application.

FIG. 20 is a schematic structural diagram of an electrode assembly according to an embodiment of the present application.

FIG. 21 is a schematic structural diagram of a tab in an electrode assembly according to an embodiment of the application.

FIG. 22 is a schematic structural diagram of a tab in an electrode assembly according to an embodiment of the application.

FIG. 23 is a schematic structural diagram of an electrode assembly according to an embodiment of the application.

FIG. 24 is a schematic structural diagram of an electrochemical device according to an embodiment of the present application.

FIG. 25 is a schematic structural diagram of an electronic device according to an embodiment of the present application.

Description of main component symbols

极片 pole piece	1010
极片主体 pole piece body	1111

极耳 polar ear	1515
第一方向first direction	XX
集流体 current collector	111111
弯折部Bending part	151151
层叠部 Lamination section	153153
第二方向second direction	YY
活性材料层 active material layer	113113
第一层叠部 first lamination section	153a153a
第二层叠部 second lamination section	153b153b
第一弯折部first bending part	151a151a
第二弯折部second bending part	151b151b
第三层叠部 third lamination section	153c153c
第三弯折部The third bending part	151c151c
第四层叠部 Fourth Lamination Section	153d153d
电连接部 electrical connection	1717
第一区District 1	111a111a
第二区District 2	111b111b
电极组件 Electrode assembly	100100
第一极片 first pole piece	10a10a
第二极片 second pole piece	10b 10b

隔离膜isolation film	3030
导电部 Conductive part	1818
电化学装置 Electrochemical device	200200
电子装置 electronic device	300300

The following specific embodiments will further illustrate the present application in conjunction with the above drawings.

detailed description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all of the embodiments.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this application belongs. The terms used herein in the specification of the application are for the purpose of describing specific embodiments only, and are not intended to limit the application.

In this application, A and B are perpendicular, or A is perpendicular to B, which means that the angle formed between A and B is between 85° and 95°.

Some embodiments of the present application will be described in detail below with reference to the accompanying drawings. The embodiments described below and features in the embodiments may be combined with each other without conflict.

Referring to FIG. 1 , according to an embodiment of the present application, the pole piece 10 includes a pole piece body 11 and a pole lug 15 . The tabs 15 are formed by extending the pole piece body 11 along the first direction X.

Referring to FIG. 2 , the pole piece body 11 includes a current collector 111 . The tab 15 is formed by the current collector 111 extending from one end thereof.

Referring to FIGS. 3 to 19 , the tab 15 includes N bent portions 151 and N+1 stacked portions 153 , and one of the stacked portions 153 extends from the current collector 111 . Among them, N is a natural number greater than or equal to 1. Each bent portion 151 connects two stacked portions 153 .

Each bending portion 151 may be disposed along the first direction X or disposed along the second direction Y perpendicular to the first direction X. As shown in FIG. That is, the length direction of the bent portion 151 (that is, the length direction of the fold when the tab is bent) is along the first direction X or the second direction Y.

The pole piece body 11 further includes an active material layer 113 , and the active material layer 113 is disposed on the surface of the current collector 111 .

The pole pieces will be further described below through examples.

first embodiment

Referring to FIGS. 1 and 3 , the tab 15 includes a bent portion 151 and two stacked portions 153 , wherein the bent portion 151 is disposed along a second direction Y perpendicular to the first direction X. As shown in FIG. The two lamination parts 153 are a first lamination part 153a and a second lamination part 153b, respectively. One end of the first laminated portion 153 a is connected to the current collector 111 , and the other end is connected to the bent portion 151 . The second stacking portion 153b is stacked on the first stacking portion 153a, and one end of the second stacking portion 153b is connected to the bending portion 151 . That is, the tabs 15 are folded along the bending portion 151 in the second direction Y to form the above structure.

Second Embodiment

Referring to FIG. 4 , the tab 15 includes two bent portions 151 and three stacked portions 153 , wherein each bent portion 151 is disposed along a second direction Y perpendicular to the first direction X. As shown in FIG. The two bending parts 151 are respectively a first bending part 151a and a second bending part 151b. The three lamination parts 153 are a first lamination part 153a, a second lamination part 153b, and a third lamination part 153c, respectively. The first lamination part 153a, the second lamination part 153b and the third lamination part 153c are laminated in sequence, one end of the first lamination part 153a is connected to the pole piece body 11, and the first bending part 151a is connected to the first lamination part 153a away from the pole piece body 11 and the end of the adjacent second stacked portion 153b, the second bent portion 151b connects the end of the second stacked portion 153b away from the first bent portion 151a and the end of the adjacent third stacked portion 153c .

Third Embodiment

Referring to FIG. 5 , the tab 15 includes two bent portions 151 and three stacked portions 153 , wherein each bent portion 151 is disposed along a second direction Y perpendicular to the first direction X. As shown in FIG. The two bending parts 151 are respectively a first bending part 151a and a second bending part 151b. The three lamination parts 153 are the lamination first lamination part 153a, the second lamination part 153b, and the third lamination part 153c, respectively. One end of the first lamination portion 153a is connected to the pole piece body 11, the first bent portion 151a is connected to the end of the first lamination portion 153a facing away from the pole piece main body 11 and the end of the adjacent second lamination portion 153b, and the third lamination portion 153c is located between the first lamination part 153a and the second lamination part 153b, and the second bending part 151b connects the end of the second lamination part 153b away from the first bending part 151a and the end of the adjacent third lamination part 153c .

Fourth Embodiment

Referring to FIG. 6 , the difference from the third embodiment is that there are three bending parts 151 , and also includes a third bending part 151 c ; the number of stacking parts 153 is four, and also includes a fourth stacking part 153 d .

The fourth stacking portion 153d is disposed between the first stacking portion 153a and the third stacking portion 153c, and the third bending portion 151c connects the end of the third stacking portion 153c away from the second bending portion 151b and the adjacent fourth stacking portion 153c. The end portion of the laminated portion 153d.

Fifth Embodiment

Referring to FIG. 7 , the difference from the third embodiment is that there are three bending parts 151 , and also includes a third bending part 151 c ; the number of stacking parts 153 is four, and also includes a fourth stacking part 153 d .

The fourth stacking portion 153d is disposed between the second stacking portion 153b and the third stacking portion 153c, and the third bending portion 151c connects the end of the third stacking portion 153c away from the second bending portion 151b and the adjacent fourth stacking portion 153c. The end portion of the laminated portion 153d.

Sixth Embodiment

Referring to FIG. 8 and FIG. 9 , the difference from the first embodiment is that the bending portion 151 is disposed along the first direction X. As shown in FIG. The first stacked portion 153a extends from the current collector 111, and the bent portion 151 connects the end of the first stacked portion 153a along the first direction X and the end portion of the adjacent second stacked portion 153b along the first direction X . That is, the tabs 15 are folded along the bending portion 151 in the first direction X to form the above structure.

Seventh Embodiment

Referring to FIG. 10 , the difference from the second embodiment is that each bending portion 151 is disposed along the first direction X. As shown in FIG. The first lamination portion 153a extends from the pole piece body 11, and the first bending portion 151a connects the end of the first lamination portion 153a arranged along the first direction X and the adjacent second lamination portion 153b arranged along the first direction X The second bent portion 151b connects the end of the second stacked portion 153b away from the first bent portion 151a and the end of the adjacent third stacked portion 153c.

Eighth Embodiment

Referring to FIG. 11 , the difference from the third embodiment is that each bending portion 151 is disposed along the first direction X. As shown in FIG. The first lamination portion 153a extends from the pole piece main body 11, and the first bending portion 151a connects the end of the first lamination portion 153a arranged along the first direction X and the adjacent second lamination portion 153b arranged along the first direction X The second bent portion 151b connects the end of the second stacked portion 153b away from the first bent portion 151a and the end of the adjacent third stacked portion 153c.

Ninth Embodiment

Referring to Fig. 12 , the difference from the eighth embodiment is that there are three bending parts 151, and also includes a third bending part 151c; and there are four stacking parts 153, and also includes a fourth stacking part 153d.

Tenth Embodiment

Referring to FIG. 13 , the difference from the ninth embodiment is that the fourth lamination part 153d is disposed between the first lamination part 153a and the third lamination part 153c.

Eleventh Embodiment

Referring to FIG. 14A , the difference from the eighth embodiment is that the second bent portion 151b connects the end of the first stacked portion 153a away from the first bent portion 151a and the end of the adjacent third stacked portion 153c .

Twelfth Embodiment

Referring to FIG. 14B , the difference from the seventh embodiment is that the second lamination part 153b, the first lamination part 153a and the third lamination part 153c are laminated in sequence, and the first bending part 151a connects the first lamination part 153a along the second lamination part 153a. The end part arranged in one direction X and the end part of the adjacent second lamination part 153b arranged along the first direction X, the second bending part 151b connects the end part of the first lamination part 153a away from the first bending part 151a and the end part of the adjacent second lamination part 153b. the end of the adjacent third lamination portion 153c.

Thirteenth Embodiment

Referring to FIG. 15 , the difference from the third embodiment is that the first bending portion 151a is disposed along the second direction Y perpendicular to the first direction X, and the second bending portion 151b is disposed along the first direction X.

The first bent portion 151a connects the end of the first lamination portion 153a away from the pole piece body 11 and the end of the adjacent second lamination portion 153b. The third lamination portion 153c is located on the side of the second lamination portion 153b facing the first lamination portion 153a, and the second bending portion 151b connects the end of the first lamination portion 153a along the first direction X and the adjacent third lamination The end portion of the portion 153c disposed along the first direction X.

Fourteenth Embodiment

Referring to FIG. 16 , the pole piece 10 may further include at least one electrical connection portion 17 , and each electrical connection portion 17 is connected between two adjacent stacked portions 153 . Each electrical connection 17 may be, but is not limited to, conductive glue or solder. Specifically, in this embodiment, as shown in FIG. 16 , the electrical connection portion 17 is electrically connected between the first lamination portion 153 a and the second lamination portion 153 b.

fifteenth embodiment

Referring to FIG. 17 , the current collector 111 includes a first region 111 a and a second region 111 b , wherein the active material layer 113 is disposed in the first region 111 a , at least one side of the second region 111 b is exposed from the active material layer 113 , and the lamination portion 153 One end close to the pole piece body 11 is connected to the second region 111b. Specifically, in this embodiment, as shown in FIG. 17 , one end of the second lamination portion 153b close to the pole piece body 11 is electrically connected to the second region 111b.

Sixteenth Embodiment

Please refer to FIG. 18 , the pole piece 10 includes a plurality of tabs 15 , any two tabs 15 are arranged at intervals, and the structures of any two tabs 15 may be the same. In this embodiment, as shown in FIG. 18 , the pole piece 10 includes two tabs 15 , and each tab 15 includes a bent portion 151 disposed along the second direction Y perpendicular to the first direction X

Seventeenth Embodiment

Please refer to FIG. 19 , the pole piece 10 includes a plurality of tabs 15 , any two tabs 15 are arranged at intervals, and the structures of any two tabs 15 may be different. In this embodiment, as shown in FIG. 19 , the pole piece 10 includes two pole tabs 15 , wherein one pole tab 15 is folded once along the second direction Y perpendicular to the first direction X, and the other pole tab 15 is folded along the first Fold once in direction X.

In some embodiments, the shape of each lamination portion 153 is not limited to a rectangle, but can also be other shapes. For example, the lamination portion 153 connected to the pole piece main body 11 has a larger width at the end portion connected to the pole piece main body 11 than that away from the pole piece. The width of the end portion of the sheet main body 11 .

Referring to FIGS. 20 to 23 , the above-mentioned pole piece 10 is applied to the electrode assembly 100 . The electrode assembly 100 includes a first pole piece 10a, a second pole piece 10b, and an isolation film 30 located between the first pole piece 10a and the second pole piece 10b. The first pole piece 10a is the pole piece 10 provided by the present application.

As shown in FIG. 20 , the first pole piece 10 a , the separator 30 and the second pole piece 10 b are wound and arranged to form a wound electrode assembly 100 .

In some embodiments, a plurality of tabs 15 may be provided on the first pole piece 10a, and the plurality of tabs 15 are disposed opposite to each other. 21 , a plurality of tabs 15 are independent of each other and are stacked, and two adjacent tabs 15 can also be electrically connected through conductive parts 18 . Please refer to FIG. 22 , among any two tabs 15 , one tab 15 can be sleeved inside the other tab 15 . Electrical connection can also be achieved between two adjacent tabs 15 through the conductive portion 18 . In some embodiments, one tab 15 can be sleeved inside another tab 15 by arranging a plurality of unfolded tabs 15 relative to each other and then folding them. In other embodiments, the sleeve of one tab 15 within the other tab 15 may also be formed by other methods.

As shown in FIG. 23 , the first pole piece 10a and the second pole piece 10b may also be stacked, so that the electrode assembly 100 is finally stacked.

In some embodiments, the electrode assembly 100 includes a plurality of first pole pieces 10a, and the tabs 15 of the plurality of first pole pieces 10a are disposed opposite to each other. Wherein, the plurality of tabs 15 may be independent of each other (as shown in FIG. 21 ), or one tab 15 may be sleeved inside the other tab 15 (as shown in FIG. 22 ).

In some embodiments, the structure of the pole tabs in the second pole piece 10b may be the same as the structure of the pole tabs 15 in the above-mentioned pole piece 10 .

The electrode assembly 100 described above is applied to an electrochemical device or an electronic device. Wherein, the electrochemical device 200 (as shown in FIG. 24 ) can be, but not limited to, a battery. In some embodiments, the first direction X may be the length direction of the electrochemical device 200 , and the second direction Y may be the width direction of the electrochemical device 200 . In some embodiments, the first direction can also be the width direction of the electrochemical device 200 , and the second direction Y is the length direction of the electrochemical device 200 .

The electronic device 300 (as shown in FIG. 25 ) can be, but is not limited to, an electric toy, an electric vehicle, a mobile phone, a wearable device, a tablet, a computer, a drone, an energy storage device, and the like.

In the pole piece 10 of the present application, since the pole tab 15 includes a plurality of laminated portions 153 arranged in layers, the pole piece 10 can realize the occupied space of the pole tab 15 in the width direction (ie the second direction Y) and the pole tab without increasing the occupied space of the pole tab 15 . Under the premise of the number of 15, the overcurrent capability of the tab 15 is improved while avoiding the problem of excessively large impedance of the thin tab, so as to meet the requirements of high-rate charging and discharging, and can reduce the temperature rise during charging and discharging, and at the same time, it can also reduce Influence on energy density, increase power density.

In addition, for those of ordinary skill in the art, various other corresponding changes and deformations can be made according to the technical concept of the present application, and all these changes and deformations should belong to the protection scope of the claims of the present application.

Claims

A pole piece, comprising a pole piece main body and a pole lug, the pole lug is formed by extending the pole piece main body along a first direction,

Wherein, the tab includes N bending parts and N+1 stacked parts, and one of the stacked parts is connected to the main body of the pole piece, N is a natural number greater than or equal to 1, and each The bent portion connects the two stacked portions.
The pole piece of claim 1 , wherein each of the bent portions is disposed along a second direction perpendicular to the first direction.
The pole piece of claim 1, wherein each of the bent portions is disposed along the first direction.
The pole piece according to claim 1, wherein the N bent portions comprise a first bent portion and a second bent portion, and the first bent portion is along a second direction perpendicular to the first direction. direction, and the second bending portion is arranged along the first direction.
The pole piece according to claim 1, wherein the pole piece further comprises an electrical connection part, and the electrical connection part is connected between two adjacent stacked parts.
The pole piece according to claim 5, wherein the electrical connection portion is conductive glue or solder.
The pole piece of claim 1, wherein the pole piece body comprises a current collector and an active material layer, the current collector comprises a first region and a second region, the active material layer is disposed in the first region, and the At least one side of the second region is exposed from the active material layer, and one end of the laminated portion close to the pole piece body is connected to the second region.
The pole piece according to any one of claims 1 to 7, wherein the pole piece comprises a plurality of the pole tabs, and any two of the pole tabs are spaced apart and have the same structure or different structures.
An electrochemical device, comprising a first pole piece, a second pole piece and a separator between the first pole piece and the second pole piece, wherein the first pole piece is as claimed in claim 1 The pole piece described in any one of to 7.
The electrochemical device according to claim 9, wherein the first pole piece and the second pole piece are wound and arranged, a plurality of the pole tabs are provided on the first pole piece, and a plurality of the The tabs are set relative to each other.
The electrochemical device according to claim 9, wherein the first pole piece and the second pole piece are stacked, the electrochemical device comprises a plurality of first pole pieces, a plurality of the first pole pieces relative setting of the tabs.
The electrochemical device according to claim 10 or 11, wherein any two of the tabs are independent of each other, or one of the tabs is sheathed in the other of the tabs.
An electronic device comprising the electrochemical device according to any one of claims 9 to 12.