CN114361732A

CN114361732A - Electrochemical device and electronic apparatus

Info

Publication number: CN114361732A
Application number: CN202111547965.9A
Authority: CN
Inventors: 李勇; 曾巧
Original assignee: Dongguan Amperex Technology Ltd
Current assignee: Dongguan Amperex Technology Ltd
Priority date: 2021-12-15
Filing date: 2021-12-15
Publication date: 2022-04-15
Anticipated expiration: 2041-12-15
Also published as: CN114361732B

Abstract

The application discloses an electrochemical device and an electronic apparatus. The electrochemical device comprises a shell and an electrode assembly accommodated in the shell, wherein the electrode assembly is of a winding structure and comprises a first pole piece, a second pole piece and a diaphragm arranged between the first pole piece and the second pole piece, the first pole piece extends to form a first pole lug on the first side of the electrode assembly, the second pole piece extends to form a second pole lug, one of the first pole lug and the second pole lug is positioned on the inner side of the electrode assembly, and the other one of the first pole lug and the second pole lug is positioned on the outer side of the electrode assembly. The tab is a part of the pole piece structure, which is not only convenient for coating the insulating material and the active material layer, and is beneficial to simplifying the pole piece process, but also can omit the welding of the tab and reduce the thickness of the electrode assembly; the tabs extend out from the same side of the electrode assembly, so that the scene requirement of the battery with smaller length can be met; in addition, the inner side and the outer side of the polar lugs with different polarities are arranged, so that the problem of short circuit can be solved.

Description

Electrochemical device and electronic apparatus

Technical Field

The present application relates to the field of batteries, and more particularly, to an electrochemical device and an electronic apparatus.

Background

An electrode assembly of an electrochemical device generally includes a current collector and a tab electrically connected to the current collector. During the manufacture of the electrode assembly, the current collectors of the electrode sheets are coated with insulating materials and active material layers, and it is necessary to leave tab welding locations, such as the so-called aluminum foil areas. The tab welding position is not only inconvenient for coating of insulating materials and active material layers, but also has larger thickness after being welded with the tab, thereby influencing the thickness and energy density of the battery, and in addition, burrs are easy to generate during welding, and the burrs are easy to pierce through a diaphragm between adjacent pole pieces and connect the tab with opposite polarity, thereby causing the problem of short circuit. In order to improve the short circuit problem and reduce the thickness of the battery, some manufacturers weld tabs with opposite polarities to opposite sides of the electrode assembly in the length direction, but this makes the length of the battery larger, which is not favorable for meeting the requirements of the battery with a smaller length.

Disclosure of Invention

Embodiments of the present disclosure provide an electrochemical device and an electronic apparatus, so as to reduce the thickness of a battery, improve the short circuit problem, and meet the requirement of a smaller length of the battery.

In a first aspect, an embodiment of the present application provides an electrochemical device, including a case and an electrode assembly accommodated in the case, where the electrode assembly includes a first pole piece, a second pole piece, and a separator disposed between the first pole piece and the second pole piece, the first pole piece, the separator, and the second pole piece are stacked and wound in a winding structure, the first pole piece extends to form a first tab on a first side of the electrode assembly, the second pole piece extends to form a second tab, and one of the first tab and the second tab is located on an inner side of the electrode assembly, and the other is located on an outer side of the electrode assembly.

The tab is formed by extending the pole piece, namely the tab is a part of the current collector of the pole piece, so that the coating of the insulating material and the active substance layer on the current collector is facilitated, the tab does not need to be welded, and the thickness of the electrode assembly can be reduced; the electrode lugs with different polarities extend out of the same side (namely the first side) of the electrode assembly, so that the scene requirement of the battery with smaller length can be met; in addition, the inner side and the outer side of the lugs with different polarities are arranged, so that the probability of mistaken contact is reduced, and the problem of short circuit can be solved.

In some embodiments, one of the first and second tabs is located at an inner ring of the electrode assembly and the other one is located at an outer ring of the electrode assembly.

In some embodiments, the first pole piece is a positive pole piece, the second pole piece is a negative pole piece, and along the winding direction, the length of the first tab has a first ratio to the length of the current collector of the first pole piece, and the length of the second tab has a second ratio to the length of the current collector of the second pole piece, and the second ratio is less than or equal to the first ratio. The overcurrent capacity of the negative electrode tab (namely the second tab) is greater than that of the positive electrode tab (namely the first tab), for example, the positive electrode tab is an aluminum foil, the negative electrode tab is a copper foil, the overcurrent capacity of the copper foil is greater, and the area of the negative electrode tab can be smaller. The area of the second pole lug is reduced, the probability of the second pole lug contacting with the first pole lug in a wrong way is reduced, and therefore the problem of short circuit is improved.

In some embodiments, along the direction perpendicular to the winding direction, the orthographic projections of the first tab and the second tab are arranged oppositely, so that the risk of electric connection of tabs with different polarities can be further reduced, and the problem of tab short circuit is solved.

In some embodiments, the first tab is formed by a protrusion of a first side of the current collector of the first pole piece, and the second tab is formed by a protrusion of a first side of the current collector of the second pole piece, the first side being adjacent to the first side of the electrode assembly.

In some embodiments, at least one of the first and second tabs is of unitary construction along the winding direction.

In some embodiments, the first tabs are spaced apart and the second tabs are spaced apart along the winding direction; the electrochemical device also comprises a first adapter and a second adapter, wherein the first adapter is electrically connected with at least one first tab and extends out of the shell from the inside of the shell; the second adapter is electrically connected with at least one second pole lug and extends out of the shell from the inside of the shell. In a scenario where the length of the tab is short and cannot extend from the encapsulation portion to the outside of the case, it may be advantageous for the electrode assembly to be electrically connected to an external device such as a load or a power supply device.

In some embodiments, the electrochemical device further comprises an insulator, a first adapter and a second adapter, the first adapter being electrically connected to the first tab and extending from within the housing and out of the housing; the second adapter is electrically connected with the second pole lug and extends out of the shell from the inside of the shell; the insulator is disposed between the first adapter and the second adapter, and optionally, the insulator extends between the first tab and the second tab to electrically insulate the first tab from the second tab.

In some embodiments, the first adapter and/or the second adapter comprise a connecting portion and an extension portion connected, and the length of the connecting portion is less than the length of the extension portion in the winding direction.

In some embodiments, one end of the extension is flush with the connection portion in the winding direction.

In some embodiments, both ends of the extension portion protrude from the connection portion in the winding direction.

In some embodiments, a first adaptor is attached to a side of the first tab and/or a second adaptor is attached to a side of the second tab.

In some embodiments, the first adaptor includes two connecting portions respectively connected to opposite sides of the first tab, and an extending portion connected to the two connecting portions and extending from inside the housing to outside the housing.

In a first aspect, embodiments of the present application provide an electronic device, including a load and any one of the electrochemical devices described above, the electrochemical device being configured to supply power to the load.

As described above, in the electrochemical device and the electronic apparatus of the embodiment of the present application, the tab is formed by extending the pole piece, that is, the tab is a part of the pole piece structure, which not only facilitates coating of the insulating material and the active material layer on the current collector, and facilitates simplification of the pole piece process, but also does not need to weld the tab, and can reduce the thickness of the electrode assembly; the lugs with different polarities extend out of the same side of the electrode assembly, so that the scene requirement of the battery with smaller length can be met; in addition, the inner side and the outer side of the polar lugs with different polarities are arranged, so that the problem of short circuit can be solved.

Drawings

Fig. 1 is a schematic structural view of an electrochemical device according to an embodiment of the present application;

FIG. 2 is a schematic view of a portion of a first embodiment of an electrode assembly of the present application;

FIG. 3 is a top view of the electrode assembly shown in FIG. 2;

FIG. 4 is a schematic cross-sectional view of the electrode assembly shown in FIG. 3 taken along the direction A-A';

FIG. 5 is a schematic view of the spread out tiling of the first embodiment of the first and second pole pieces of the present application;

FIG. 6 is a schematic view of an expanded lay-flat of a second embodiment of the first and second pole pieces of the present application;

FIG. 7 is a schematic illustration of an expanded lay-flat of a third embodiment of the first and second pole pieces of the present application;

FIG. 8 is a top view of a second embodiment of an electrode assembly of the present application;

FIG. 9 is a schematic cross-sectional view of the electrode assembly shown in FIG. 8 taken along the direction A-A';

FIG. 10 is a schematic structural diagram of three first connectors provided in an embodiment of the present application;

FIG. 11 is a schematic cross-sectional view of the first transition piece shown in FIG. 10 taken along the direction B-B

FIG. 12 is a top view of a third embodiment of an electrode assembly of the present application;

fig. 13 is a schematic view of the expanded lay-flat of the fourth embodiment of the first and second pole pieces of the present application;

fig. 14 is a top view of a fourth embodiment of an electrode assembly of the present application.

Detailed Description

In the electrochemical device and the electronic equipment of the embodiment of the application, the tab is formed by extending the pole piece, namely, the tab is a part of the pole piece structure, so that the coating of an insulating material and an active substance layer on a current collector is facilitated during the manufacturing of the pole piece, and the tab does not need to be welded, so that the thickness of an electrode assembly is reduced; the electrode lugs with different polarities extend out of the same side of the electrode assembly, so that the scene requirement of the battery with smaller length is met; in addition, the inner side and the outer side of the polar lugs with different polarities are arranged and separated, the risk of electric connection caused by mistaken contact is low, and therefore the problem of short circuit can be solved.

In order to make the objects, technical solutions and advantages of the present application more apparent, the technical solutions of the present application will be described below in detail with reference to specific embodiments and accompanying drawings. It should be apparent that the embodiments described below are only some embodiments of the present application, and not all embodiments. In the following embodiments and technical features thereof, all of which are described below may be combined with each other without conflict, and also belong to the technical solutions of the present application.

It should be understood that in the description of the embodiments of the present application, the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of describing technical solutions and simplifying the description of the respective embodiments of the present application, and do not indicate or imply that a device or an element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus should not be construed as limiting the present application.

First embodiment

Referring to fig. 1 to 11 together, an electrochemical device 10 includes a case 11 and an electrode assembly 12.

The casing 11 encloses the electrochemical device 10 and can be used to define the appearance of the electrochemical device 10, in some scenarios, the casing 11 includes a main body 11a and a sealing part 11b, the main body 11a forms a receiving cavity 11c, and elements such as the electrode assembly 12 and the electrolyte are embedded in the receiving cavity 11c, and the casing 11 is used to protect the elements, thereby improving the protection effect and the safety.

The sealing portion 11b may be formed by sealing the case 11 extending from the main body portion 11a, and the sealing portion 11b is used to seal the case 11, prevent the electrolyte in the case 11 from leaking from the sealing portion 11b, and prevent impurities such as water and air outside the case 11 from entering the case 11 from the sealing portion 11 b. The sealing portion 11b is also used for sealing the protruding region of the tab 13, for example, a tab glue 13a is provided at the joint of the sealing portion 11b and the tab 13, and the tab glue 13a is adhered and seals the joint of the tab 13 and the sealing portion 11 b.

The sealing portion 11b may be disposed at one end or a plurality of ends of the main body portion 11a, for example, in the scenario shown in fig. 1, the sealing portion 11b is disposed at four ends of the main body portion 11a, wherein the sealing portion 11b sealing the protruding region of the tab 13 may also be referred to as a top sealing portion.

The sealing part 11b is protruded from the body part 11a, and as shown in fig. 1, the sealing part 11b may extend in the second direction y, and the tab 13 may extend out of the sealing part 11b in the second direction y after being electrically connected to the electrode assembly 12. In the embodiment of the present application, the thickness direction of the electrochemical device 10 may be regarded as the first direction x, the width direction of the tab 13 may be regarded as the third direction z, and any two directions of the first direction x, the second direction y and the third direction z are perpendicular, it should be noted that, limited by the error in actual processing or measurement, the perpendicular does not require that the included angle between the two directions is necessarily 90 ° throughout the present application, but allows a deviation within a predetermined angle range (for example, ± 10 °), for example, the perpendicular may be understood as an included angle between any two directions of 80 ° to 100 °.

The electrode assembly 12 may be formed by winding a plurality of first pole pieces 121 and a plurality of second pole pieces 122, and it is understood that the electrode assembly 12 shown in fig. 2 and 3 is formed by winding one first pole piece 121 and one second pole piece 122, which are merely exemplary illustrations, and other embodiments may be formed by winding other numbers of first pole pieces 121 and second pole pieces 122 in other suitable ways; additionally, for ease of description, certain places herein (including the drawings) refer to one or more of these first and

second pole pieces

121, 122 as pole piece 12 a. In a scene that the electrochemical device 10 has positive and negative polarities, one of the first pole piece 121 and the second pole piece 122 is a positive pole piece, and the other is a negative pole piece, and a separator 123 for insulating the first pole piece 121 and the second pole piece 122 is disposed between the two, the dotted line shown in fig. 4 represents the separator 123, and both sides of the single pole piece 12a are disposed with the separators 123.

On a first side of the electrode assembly 12, the first pole piece 121 extends to form a first pole tab 131 and the second pole piece 122 extends to form a second pole tab 132. In the scenario shown in fig. 2 and 4, the first side of the electrode assembly 12 is the upper side of the electrode assembly 12, and it should be understood that the orientation of the first side varies with the change in the orientation of the electrode assembly 12.

Referring to fig. 2 to 5, the first electrode sheet 121 includes a first current collector 21 and a first active material layer 31 (shown by a shaded portion) disposed on a surface of the first current collector 21. The first current collector 21 includes a first surface and a second surface that are oppositely disposed in a thickness direction thereof, and are each provided with a first active material layer 31. One of the surfaces is shown in fig. 5, and is described herein as an example.

The shape of the first current collector 21 is not limited in the embodiments of the present application, and the rectangular first current collector 21 is described as an example herein. The first current collector 21 includes a first side 211, a second side 212, a third side 213, and a fourth side 214, the first side 211 and the second side 212 intersect perpendicularly, the third side 213 and the fourth side 214 intersect perpendicularly, the first side 211 and the third side 213 are disposed along the second direction y, when the first current collector 21 is unfolded and laid flat, the extending direction of the first side 211 and the second side 212 is the third direction z, and the second side 212 and the fourth side 214 are disposed along the third direction z. Throughout this application, the term "two bodies are disposed opposite to each other along a certain direction" means: in a certain direction, the two bodies are not in contact, i.e. have a distance different from zero.

In some embodiments, the first tab 131 may be formed by the first side 211 of the first current collector 21 protruding toward the second direction y, where the first side 211 is the side of the first current collector 21 closest to the first side of the electrode assembly 12. The width of the first tab 131 is W₁₁The length of the first side 211 (e.g., along the third direction z in fig. 2 when the first current collector 21 is unfolded and laid flat) is W₁₀And W is₁₁＜W₁₀. For the electrode assembly 12 of the winding type structure, the width of the first tab 131 is a length in the winding direction, and the lengths of the first side 211 and the first current collector 21 are lengths in the winding direction.

As shown in fig. 5 (a), the first active material layer 31 may entirely cover the region on the surface of the first current collector 21 except for the first tab 131. Alternatively, referring to fig. 6 (a) and fig. 7 (a), the surface of the first current collector 21 is further provided with a first insulating layer 41, and the first active material layer 31 and the first insulating layer 41 cover the region of the surface of the first current collector 21 except for the first tab 131. In the scenarios shown in fig. 5 and 6, the first tab 131 is not only located on one side of the first active material layer 31 in the third direction z, but also extends to one side of the first active material layer 31 in the second direction y. Whereas in the scenario shown in fig. 7, the first tab 131 is located only on one side of the first active material layer 31 in the third direction z. The first tab 131 shown in fig. 5 and 6 (a) may have a greater width and a higher overcurrent capacity, compared to the embodiment shown in fig. 7 (a).

The second pole piece 122 includes a second current collector 22, and a second active material layer 32 (shown in phantom) disposed on a surface of the second current collector 22. The second current collector 22 also includes oppositely disposed first and second surfaces, each of which has a second active material layer 32 disposed thereon. One of the surfaces is shown in fig. 5-7, and is described herein as an example.

Throughout the present application, the rectangular second current collector 22 is described as an example. The second current collector 22 includes a first side 221, a second side 222, a third side 223, and a fourth side 224, where the first side 221 and the second side 222 intersect perpendicularly, the third side 223 and the fourth side 224 intersect perpendicularly, the first side 221 and the third side 223 are disposed opposite to each other along the second direction y, and in the unfolded and tiled state of the second current collector 22, the extending directions of the first side 221 and the second side 222 are both the third direction z, and the second side 222 and the fourth side 224 are disposed opposite to each other along the third direction z.

In some embodiments, the second tab 132 may be formed by the first side 221 of the second current collector 22 protruding toward the second direction y, where the first side 221 is the side of the second current collector 22 closest to the first side of the electrode assembly 12. The width of the second tab 132 is W₂₁The length of the first side 221 (along the third direction z in fig. 2) is W₂₀And W is₂₁＜W₂₀. For the electrode assembly 12 of the roll-to-roll structure, the width of the second tab 132 is the length in the roll-to-roll direction, and the length of the first side 211 and the second current collector 22 is the length in the roll-to-roll direction.

As shown in diagram (b) of fig. 5, the second active material layer 32 may entirely cover the regions on the surface of the second current collector 22 other than the second tabs 132. Alternatively, referring to fig. 6 (b) and fig. 7 (b), the surface of the second current collector 22 is further provided with a second insulating layer 42, and the second active material layer 32 and the second insulating layer 42 cover the region of the surface of the second current collector 22 except for the second tab 132. In the scenario shown in fig. 5 and 6, the second tab 132 is not only located on one side of the second active material layer 32 in the third direction z, but also extends to one side of the second active material layer 32 in the second direction y. Whereas in the scenario shown in fig. 7, the second tab 132 is located only on one side of the second active material layer 32 in the third direction z. The second pole ear 132 shown in fig. 5 and 6 (b) may have a greater width and a higher overcurrent capacity than the embodiment shown in fig. 7 (b).

For ease of description, some of the text (including the drawings) refers to one or both of the first tab 131 and the second tab 132 as tab 13. One end of the tab 13 is electrically connected to the corresponding polarity of the electrode assembly 12, and the other end of the tab 13 extends out of the sealing portion 11 b. One of the first tab 131 and the second tab 132 is a negative electrode tab, and the other is a positive electrode tab. Taking the first pole piece 121 as a positive pole piece and the second pole piece 122 as a negative pole piece as an example, the first tab 131 connected to the first pole piece 121 is a positive pole tab, and the second tab 132 connected to the second pole piece 122 is a negative pole tab. In other embodiments, the first pole piece 121 and the first tab 131 connected thereto may also be a negative pole tab, and the second pole piece 122 and the second tab 132 connected thereto may be a positive pole tab.

The structure and shape of the tab 13 are not limited in the embodiments of the present application. For example, the tab 13 may have a rectangular strip structure as shown in fig. 2 to 6, and the size of any tab 13 may be adapted according to the requirement, and the material thereof includes but is not limited to aluminum, nickel, copper, and copper nickel plating and other alloys. For example, the material of the positive electrode tab can be aluminum foil or nickel-plated aluminum, and the material of the negative electrode tab can be copper foil or nickel-plated copper, so that the electrical connection performance with the negative electrode plate can be improved, and the structural strength of the negative electrode tab can be improved.

Tab 13 is formed by extending pole piece 12a, and tab 13 belongs to a part of the current collector of pole piece 12a, and on one side of the first side edge of the current collector, the current collector does not need to reserve the area electrically connected with tab 13, and can completely form an active material layer (and an insulating layer), thereby facilitating the coating of materials.

In addition, the pole piece 12a does not need to be welded with the tab 13, and in a state that the pole piece 12a is electrically connected with the tab 13, the thickness of the joint of the tab 13 and the pole piece 12a is still equal to that of the pole piece 12a, that is, the thickness of the pole piece 12a cannot be increased, so that the thickness of the electrode assembly 12 is favorably reduced.

In this embodiment, as shown in fig. 2 to fig. 7, the first pole piece 121 and the second pole piece 122 may be stacked, when the first side 211 of the first pole piece 121 and the first side 221 of the second pole piece 122 are disposed up and down, the first tab 131 and the second tab 132 are disposed opposite to each other along the third direction z, for example, according to the orientation shown in fig. 5, it can be seen that the first tab 131 is located on the left side of the first pole piece 121, the second tab 132 is located on the right side of the second pole piece 122, for the wound electrode assembly 12, in some scenarios, after the first and

second pole pieces

121 and 122 are wound, one of the first and

second tabs

131 and 132 is located at an inner circumference of the electrode assembly 12 and the other is located at an outer circumference of the electrode assembly 12, in the orientation shown in fig. 3, the first tab 131 is located at the inner circumference of the electrode assembly 12 and the second tab 132 is located at the outer circumference of the electrode assembly 12. The inner side and the outer side of the lugs 13 with different polarities are arranged, so that the contact risk of the lugs 13 with different polarities is reduced, and the problem of short circuit is solved.

Extending the tabs 13 on the same side (i.e., the first side) of the electrode assembly 12 is advantageous in meeting the requirements of a shorter battery than extending the tabs 13 on opposite sides of the electrode assembly 12.

In the scenario shown in fig. 3, the first tab 131 and the second tab 132 are oppositely disposed along the width direction (i.e., the third direction z) of the electrode assembly 12, so that the risk of electrically connecting the tabs 13 with different polarities can be further reduced, and the problem of short circuit of the tabs 13 can be improved. The first tab 131 is not wound, but extends in the third direction z. In other scenarios, the length of the first tab 131 (in the extending direction of the first side 211) is longer, as shown in fig. 8, the first tab 131 is wound along the winding direction of the pole piece 12a, and similarly, the second tab 132 may also be wound along the winding direction of the pole piece 12a, and after winding, the first tab 131 is still located at the inner ring of the electrode assembly 12, and the second tab 132 is still located at the outer ring of the electrode assembly 12.

It should be understood that in other scenarios, the relative arrangement of the first tab 131 and the second tab 132 may also include other designs, and only the orthographic projections of the first tab 131 and the second tab 132 are arranged relatively along the direction perpendicular to the winding direction (i.e. along the direction perpendicular to the plane of fig. 3), which may also be beneficial to improve the short circuit problem of the tab 13.

In some embodiments, for example, in a scenario where the first tab 131 is a positive tab and the second tab 132 is a negative tab, the first tab 121 is a positive tab, the second tab 122 is a negative tab, and the overcurrent capacity of the negative tab is greater than that of the positive tab, for example, the positive tab is an aluminum foil, the negative tab is a copper foil, and the overcurrent capacity of the copper foil is greater, so that the area of the negative tab may be smaller. The area of the second pole lug is reduced, the probability of the second pole lug contacting with the first pole lug in a wrong way is reduced, and therefore the problem of short circuit is improved. To achieve this, for example, in the winding direction, the length of the first tab 131 has a first ratio to the length of the current collector of the first pole piece 131, the length of the second tab 132 has a second ratio to the length of the current collector of the second pole piece 122, the second ratio is smaller than or equal to the first ratio, and the ratio of the length of the tab to the length of the current collector is small, which is beneficial to reduce the length (in the winding direction) and the area of the tab.

Referring to fig. 9, in some embodiments, the electrochemical device 10 may further include a first adaptor 141 and a second adaptor 142, both of which are electrically conductive elements, wherein the first adaptor 141 is electrically connected to the first tab 131 and extends from the inside of the housing 11 to the outside of the housing 11; the second adaptor 142 is electrically connected to the second pole ear 132 and extends from the inside of the housing 11 to the outside of the housing 11.

The first and

second adaptors

141 and 142 may be regarded as extensions of the respective connected tabs 13, but the thickness of the first and

second adaptors

141 and 142 may be greater than the thickness of the respective connected tabs 13. In a scenario where the tab 13 has a short length and cannot extend from the sealing portion 11b to the outside of the case 11, it is advantageous for the electrode assembly 12 to be electrically connected to an external device such as a load or a power supply device.

The embodiment of the present application does not limit the shapes of the first adaptor 141 and the second adaptor 142, and the shapes of the first adaptor 141 and the second adaptor 142 may be the same or different, and the following description will be given by taking the first adaptor 141 as an example and combining the shape of the unfolded and tiled state shown in fig. 10 and 11.

As shown in fig. 10 (a), the first adaptor 141 may have a rectangular shape, which may be beneficial to increase the connection area with the tab 13 (i.e., the first tab 131).

Referring to fig. 10 (b), the first connector 141 includes a connecting portion 1411 and an extending portion 1412, wherein along the extending direction of the first side 211, the length of the connecting portion 1411 is smaller than that of the extending portion 1412; along the extending direction of the first side 211, one end of the extending portion 1412 is flush with the connecting portion 1411, and the other end protrudes from the connecting portion 1411. The connection portion 1411 is connected to the tab 13 (i.e., the first tab 131), and the extension portion 1412 extends out of the housing 11. The extension 1412 has a large area for electrical connection with external devices such as a load or a power supply device, which may be beneficial to improving the stability of electrical connection and reducing the impedance of electrical connection.

Referring to fig. 10 (c), the first connector 141 also includes a connecting portion 1411 and an extending portion 1412 connected to each other, but unlike the case of fig. 10 (b), both ends of the extending portion 1412 protrude from the connecting portion 1411 along the extending direction of the first side 211, so that the area of the extending portion 1412 electrically connected to the external device is larger, the stability of the electrical connection is better, and the impedance of the electrical connection is lower.

With the connection member of any one of the aforementioned structures, in some scenarios, as shown in fig. 4 and (a) of fig. 11, the first connection member 141 may be connected to only one of the side surfaces of the first tab 131.

In other scenarios, referring to fig. 9 and fig. 11 (b), the first adapter 141 may include two connection portions 1411 and an extension portion 1412, the two connection portions 1411 are respectively connected to two opposite side surfaces of the tab 13 (i.e., the first tab 131), the extension portion 1412 is connected to the two connection portions 1411 and extends out of the housing 11 from the inside of the housing 11, an electrical connection area between the first adapter 141 and the tab 13 is large, electrical connection stability is good, and electrical connection impedance is low.

It should be understood that the second adaptor 142 may also adopt any one of the structural designs shown in fig. 10 and 11, i.e., the second adaptor 142 is connected to one of the side surfaces of the second pole ear 132; alternatively, the second adaptor 142 may include two connecting portions 1411 and an extending portion 1412, the two connecting portions 1411 are respectively connected to two opposite side surfaces of the tab 13 (i.e., the first tab 131), and the extending portion 1412 is connected to the two connecting portions 1411 and extends out of the housing 11 from the housing 11.

As shown in fig. 3, 4, 8 and 9, the electrochemical device 10 may further include an insulating member 15, and the insulating member 15 is disposed between the first interposer 141 and the second interposer 142, so as to reduce the risk of short circuit caused by the electrical connection between the first interposer 141 and the second interposer 142.

In some scenarios, the insulating member 15 further extends to between the first tab 131 and the second tab 132, which is beneficial for insulation between the first tab 131 and the second tab 132, further reduces the risk of short circuit caused by the electrical connection between the first adaptor 141 and the second adaptor 142, and improves the problem of short circuit of the tab 13.

Of course, in the embodiment in which the electrode assembly 12 is not provided with the first and

second adaptors

141 and 142, the insulator 15 may be directly disposed between the first and

second tabs

131 and 132, and the problem of short-circuiting of the tabs 13 may also be improved.

As shown in fig. 3, the insulating member 15 may be a planar sheet-like member disposed only between the first tab 131 and the second tab 132, and/or between the first adaptor 141 and the second adaptor 142. Alternatively, the insulator 15 may be a ring-shaped element, and when viewed in the second direction y, the insulator 15 partially surrounds or (as shown in fig. 8) completely surrounds the first tab 131 located at the inner ring, and the installation area of the insulator 15 is large, which is more beneficial to improve the insulation effect between the first tab 131 and the second tab 132.

Second embodiment

The embodiments of the present application use the same reference numerals to identify structural elements of the same name. On the basis of the description of the foregoing embodiment, but with reference to fig. 12 to 13, in the present embodiment, along the extending direction of the first side 211, for example, along the third direction z or along the winding direction of the first pole piece 121 in the state that the first current collector 21 is spread and laid flat, the first side 211 of the first current collector 21 protrudes to form a plurality of first tabs 131 arranged at intervals; along the extending direction of the first side 221, for example, along the third direction z or along the winding direction of the second pole piece 122 in the state that the second current collector 22 is spread and laid flat, the first side 221 of the second current collector 22 protrudes to form a plurality of second tabs 132 arranged at intervals.

The same current collector adopts a plurality of tabs 13 arranged at intervals, which is beneficial to releasing the stress generated by the bending of the current collector when the pole piece 12a is wound. Also, one or more (including all) of the plurality of tabs 13 may be used for electrical connection to perform charging and discharging of the electrochemical device 10. For example, the first adaptor 141 may be electrically connected to one or more of the first tabs 131, and the second adaptor 142 may be electrically connected to one or more of the second tabs 132, and the tabs 13 may be differently positioned on the electrode assembly 12, which may improve flexibility in the location of electrical connection between the adaptor and the electrode assembly 12.

In other embodiments, one of the first and

second tabs

131 and 132 is a unitary structure (e.g., the structure of the first embodiment) and the other is disposed at the interval described in the second embodiment along the winding direction.

For example, as shown in fig. 14, the first side 211 of the first current collector 21 protrudes out of the first tab 131 forming an integral structure; along the extending direction of the first side 221, for example, along the third direction z or along the winding direction of the second pole piece 122 in the state that the second current collector 22 is spread and laid flat, the first side 221 of the second current collector 22 protrudes to form a plurality of second tabs 132 arranged at intervals. After winding, the second tab 132 is located at the outer ring of the electrode assembly 12, and the first tab 131 is located at the inner ring of the electrode assembly 12. The inner ring is a continuous pole lug, so that the pole lug of the inner ring can be conveniently welded with a corresponding adapter, and a welding machine can be conveniently placed.

In a particular scenario, the electrochemical device 10 of the foregoing embodiments includes, but is not limited to, all kinds of primary batteries, secondary batteries, fuel cells, solar cells, and capacitor (e.g., supercapacitor) batteries, which may be pouch batteries. The electrochemical device 10 may preferably be a lithium secondary battery. In addition, the electrochemical device 10 may be in the form of a single battery, a battery cell, or a battery module.

Embodiments of the present application further provide an electronic device, including a load and the electrochemical device 10 of any of the above embodiments, where the electrochemical device 10 is configured to supply power to the load.

Electronic devices may be implemented in various specific forms, such as electronic products like unmanned aerial vehicles, electric cleaning tools, energy storage products, electric vehicles, electric bicycles, electric navigation tools, and so on. In a practical scenario, the electronic device specifically includes but is not limited to: the power supply comprises a standby power supply, a motor, an automobile, a motorcycle, a power-assisted bicycle, a bicycle electric tool, a household large-scale storage battery, a lithium ion capacitor and the like.

It will be understood by those skilled in the art that the configuration according to the embodiments of the present application can be applied to electronic devices of a stationary type, in addition to elements particularly for moving purposes.

Since the electronic apparatus has the electrochemical device 10 according to any one of the foregoing embodiments, the electronic apparatus can produce the advantageous effects of the electrochemical device 10 according to the corresponding embodiment.

It should be understood that the above-mentioned embodiments are only some examples of the present application, and not intended to limit the scope of the present application, and all structural equivalents made by those skilled in the art using the contents of the present specification and the accompanying drawings are also included in the scope of the present application.

Although the terms "first, second, etc. are used herein to describe various information, such information should not be limited to these terms. These terms are only used to distinguish one type of information from another. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well. The terms "or" and/or "are to be construed as inclusive or meaning any one or any combination. An exception to this definition will occur only when a combination of elements, functions, steps or operations are inherently mutually exclusive in some way.

Claims

1. An electrochemical device, including the casing and accept in the electrode subassembly in the casing, the electrode subassembly includes first pole piece, second pole piece and locates the first pole piece with the diaphragm between the second pole piece, characterized in that, first pole piece, the diaphragm with the second pole piece range upon range of and convolute into the coiling structure, in the first side of electrode subassembly, first pole piece extends and forms first utmost point ear, the second pole piece extends and forms the second utmost point ear, one of first utmost point ear and the second utmost point ear is located the inboard of electrode subassembly, the other is located the outside of electrode subassembly.

2. The electrochemical device according to claim 1, wherein one of the first tab and the second tab is located at an inner ring of the electrode assembly and the other one is located at an outer ring of the electrode assembly.

3. The electrochemical device according to claim 1, wherein the first pole piece is a positive pole piece, the second pole piece is a negative pole piece, and a length of the first tab and a length of a current collector of the first pole piece have a first ratio and a length of the second tab and a length of a current collector of the second pole piece have a second ratio along a winding direction, and the second ratio is smaller than or equal to the first ratio.

4. The electrochemical device according to any one of claims 1 to 3, wherein orthographic projections of the first tab and the second tab are oppositely disposed in a direction perpendicular to a winding direction.

5. The electrochemical device as recited in claim 1, wherein at least one of the first tab and the second tab is of unitary construction along a winding direction.

6. The electrochemical device as claimed in claim 1, wherein the first tabs are spaced apart and the second tabs are spaced apart in a winding direction;

the electrochemical device further comprises a first adapter and a second adapter, wherein the first adapter is electrically connected with at least one first electrode lug and extends out of the shell from the shell; the second adaptor is electrically connected with at least one second pole lug and extends out of the shell from the shell.

7. The electrochemical device of claim 1 further comprising an insulator disposed between said first tab and said second tab to electrically insulate said first tab from said second tab.

8. The electrochemical device of claim 1, further comprising an insulator, a first adapter, and a second adapter,

the first adapter is electrically connected with the first tab and extends out of the shell from the shell; the second adaptor is electrically connected with the second pole lug and extends out of the shell from the shell; the insulating piece is arranged between the first adapter piece and the second adapter piece to electrically insulate the first pole lug and the second pole lug.

9. The electrochemical device according to claim 8, wherein the first and/or second adapter comprises a connecting portion and an extension portion connected, and a length of the connecting portion is smaller than a length of the extension portion in a winding direction.

10. The electrochemical device according to claim 9, wherein one end of the extension portion is flush with the connection portion or both ends of the extension portion protrude from the connection portion in the winding direction.

11. The electrochemical device according to claim 9 or 10,

the first adapter is connected to one side face of the first pole lug, and/or the second adapter is connected to one side face of the second pole lug.

12. The electrochemical device as claimed in claim 9 or 10, wherein the first coupling member includes two connection portions connected to opposite sides of the first tab, respectively, and an extension portion connected to the two connection portions and extending from the inside of the case to the outside of the case.

13. An electronic device comprising a load and an electrochemical device as claimed in any one of claims 1 to 12 for supplying power to the load.