阅读说明：本技术 电化学装置和电子装置 (Electrochemical device and electronic device ) 是由 孙建政 李晓晨 于 2021-06-23 设计创作，主要内容包括：一种电化学装置,包括壳体、设置于壳体内的电极组件、第一极耳组及电连接于第一极耳组并从壳体内伸出的转接件。电极组件为卷绕结构且包括第一极片。第一极耳组包括M个连接第一极片的第一极耳。定义电极组件的厚度方向为第一方向,在第一方向上,电极组件包括N层第一极片,N大于M。M个第一极耳与第一极片分别连接。定义经过电极组件的卷绕中心轴且垂直于第一方向的平面为卷绕中心面。M个第一极耳设于卷绕中心面的两侧。第一极耳组包括连接转接件的第一连接部和连接第一极片的第二连接部。第二连接部的部分第一极耳连接第一连接部朝向电极组件的一侧。本申请还提供一种电子装置。本申请同时具有改善的高倍率充放电性能和安全性能。(An electrochemical device includes a housing, an electrode assembly disposed within the housing, a first set of tabs, and an adapter electrically connected to the first set of tabs and extending from the housing. The electrode assembly is of a wound structure and includes a first pole piece. The first pole lug group comprises M first pole lugs connected with the first pole piece. The thickness direction of the electrode assembly is defined as a first direction, in the first direction, the electrode assembly comprises N layers of first pole pieces, and N is larger than M. M first utmost point ears are connected respectively with first pole piece. A plane passing through a winding center axis of the electrode assembly and perpendicular to the first direction is defined as a winding center plane. The M first tabs are arranged on two sides of the winding central plane. The first pole lug group comprises a first connecting part connected with the adapter piece and a second connecting part connected with the first pole piece. Part of the first tab of the second connection part connects one side of the first connection part facing the electrode assembly. The application also provides an electronic device. The high-rate charge-discharge performance and the safety performance are improved.)

1. An electrochemical device comprises a shell, an electrode assembly arranged in the shell, a first electrode lug group and an adaptor electrically connected with the first electrode lug group and extending out of the shell, wherein the electrode assembly is of a winding structure and comprises a first pole piece, the first electrode lug group comprises M first pole lugs, the first pole lugs are connected with the first pole piece,

defining the thickness direction of the electrode assembly as a first direction, wherein the electrode assembly comprises N layers of first pole pieces, N is greater than M, and M first pole lugs are respectively connected with the first pole pieces; defining a plane passing through a winding central axis of the electrode assembly and perpendicular to the first direction as a winding central plane, wherein in the first direction, the M first tabs are arranged on two sides of the winding central plane;

the first pole lug group comprises a first connecting part connected with the adaptor and a second connecting part connected with the first pole piece, M first pole lugs are mutually stacked to form the first connecting part, and part of the second connecting part is connected with the first pole lugs, and the first connecting part faces one side of the electrode assembly.

2. The electrochemical device according to claim 1, wherein the first pole piece to which the first tab is attached and the first pole piece to which the first tab is not attached are alternately arranged in the first direction.

3. The electrochemical device according to claim 1, wherein the first connecting portion forms a U-shaped structure, the first connecting portion includes a first section, a second section and a third section, the first section is connected to the interposer, the second section is connected to the second connecting portion, the third section is connected between the first section and the second section in a bent manner, and the interposer is at least partially disposed in a space defined by the U-shaped structure.

4. The electrochemical device according to claim 3, wherein in the first direction, the first tab is attached to one of the outermost first pole pieces of the N first pole pieces, and the first tab is not attached to the other outermost first pole piece.

5. The electrochemical device of claim 4, wherein the electrochemical device further comprises:

a first adhesive member adhering a side of the first section facing away from the electrode assembly;

a second adhesive member that adheres a side of the second section facing away from the electrode assembly and a side surface of the electrode assembly in the first direction;

in the first direction, the first bonding piece is further arranged between two adjacent layers of the first pole pieces, the second connecting portion is located between the first bonding piece and the second bonding piece, the first bonding piece comprises a bending portion, and the bending portion is arranged on one side, facing the electrode assembly, of the second sub-portion.

6. The electrochemical device according to claim 5, wherein M first tabs are welded to each other to form a welding region at the second division, and the bent portion is provided at a side of the welding region facing the electrode assembly.

7. The electrochemical device according to claim 5, wherein the first tab is attached to each of the first electrode sheets disposed between the first and second bonding members.

8. The electrochemical device according to claim 3, wherein the first tabs are respectively attached to two outermost first pole pieces among the N first pole pieces.

9. The electrochemical device of claim 8, wherein the electrochemical device further comprises:

a first adhesive member that adheres a side of the first section facing away from the electrode assembly and a side surface of the electrode assembly in the first direction;

and a second adhesive member that adheres a side of the second section facing away from the electrode assembly and another side surface of the electrode assembly in the first direction in which the second connection portion is located between the first adhesive member and the second adhesive member.

10. The electrochemical device as claimed in claim 9, wherein M of the first tabs are welded to each other to form a welding zone at the second division.

11. The electrochemical device according to claim 5 or 9, wherein at least one of the first adhesive member or the second adhesive member is an insulating adhesive paper.

12. The electrochemical device according to claim 1, wherein the first pole piece comprises a current collector and an active material layer disposed on a surface of the current collector, and the first tab is integrally formed with the current collector.

13. An electronic device comprising the electrochemical device according to any one of claims 1 to 12.

Technical Field

The present disclosure relates to the field of energy storage technologies, and more particularly, to an electrochemical device and an electronic device having the same.

Background

With the popularization of consumer electronics products such as notebook computers, mobile phones, handheld game consoles, tablet computers, mobile power sources, unmanned aerial vehicles, electric vehicles and the like, the requirements of people on electrochemical devices (such as lithium ion batteries) are becoming stricter.

However, it is difficult for the electrochemical device to achieve both high-rate charge and discharge performance and safety performance.

Disclosure of Invention

In view of the shortcomings of the prior art, there is a need for an electrochemical device.

In addition, it is also necessary to provide an electronic device having the electrochemical device.

The application provides an electrochemical device, including the casing, set up electrode subassembly, first utmost point ear group in the casing and connect in first utmost point ear group and from the adaptor that the casing stretches out. The electrode assembly is of a wound structure and includes a first pole piece. The first pole lug group comprises M first pole lugs, and the first pole lugs are connected with the first pole piece. The thickness direction of the electrode assembly is defined as a first direction, in the first direction, the electrode assembly comprises N layers of first pole pieces, and N is larger than M. M first utmost point ears are connected respectively with first pole piece. A plane passing through a winding center axis of the electrode assembly and perpendicular to a first direction in which the M first tabs are disposed at both sides of the winding center plane is defined as a winding center plane. The first pole lug group comprises a first connecting part for connecting the adaptor and a second connecting part for connecting the first pole piece, and M first pole lugs are mutually stacked to form the first connecting part. Part of the first tab of the second connection part connects one side of the first connection part facing the electrode assembly.

This application sets up quantity M of first utmost point ear and is less than the number of piles N of first pole piece, consequently is favorable to reducing the degree of difficulty of rolling over utmost point ear and welded, simplifies the processing procedure. Secondly, M first tabs are respectively connected with M layers of the N layers of first pole pieces, and on the basis that the first tabs are arranged on two sides of the winding central plane, the number M of the first tabs can be changed according to requirements, so that the internal resistance of the pole pieces can be regulated and controlled, and the electrochemical device can meet different charge-discharge multiplying power requirements. And thirdly, due to the limiting effect of the part of the first tab of the second connecting part, the position of the first connecting part is more stable, and the first tab is not easy to be inserted backwards into the electrode assembly. Therefore, the problem of contact short circuit of the electrode lug caused by reverse insertion can be improved, and the safety of the electrochemical device is improved.

In some possible implementations, in the first direction, the first pole pieces connected with the first tab and the first pole pieces unconnected with the first tab are alternately arranged. Compared with an electrochemical device with a tab structure arranged on one side of the winding central plane, the electrochemical device has the advantages that the first tabs are alternately arranged on the first pole piece, so that part of the first tabs are arranged on one side, facing the electrode assembly, of the first connecting portion, and due to the limiting effect of the part of the first tabs, the contact short circuit risk of the first connecting portion caused by reverse insertion is reduced, and the safety is improved. Meanwhile, the number of the first tabs is the same as that of the electrochemical device with the tab structure arranged on one side of the winding central plane, so that the risk of difficult tab folding and welding processes caused by the increase of the number of the first tabs due to the need of considering safety is reduced.

In some possible implementations, the first connection portion forms a U-shaped structure. The first connection includes a first section, a second section, and a third section. The first subsection is connected with the adapter sheet, the second subsection is connected with the second connecting portion, and the third subsection is connected between the first subsection and the second subsection in a bending mode. The adapter is at least partially arranged in the space defined by the U-shaped structure.

In some possible implementation manners, in the first direction, a first tab is connected to an outermost first pole piece of the N layers of first pole pieces, and a first tab is not connected to another outermost first pole piece.

In some possible implementations, the electrochemical device further includes a first adhesive member and a second adhesive member. The first adhesive member adheres a side of the first subsection facing away from the electrode assembly. The second adhesive member adheres a side of the second section facing away from the electrode assembly and a side surface of the electrode assembly in the first direction. In the first direction, the first bonding piece is further arranged between two adjacent layers of first pole pieces, and the second connecting portion is located between the first bonding piece and the second bonding piece. The first bonding piece and the second bonding piece can reduce the risk that burrs and welding marks of the first connecting part penetrate through the shell to generate short circuit or liquid leakage. The first adhesive piece comprises a bent part, and the bent part is arranged on one side of the second sub-part facing the electrode assembly. The bending part also provides a limiting function for the first connecting part, and the risk of contact short circuit caused by reverse insertion of the first connecting part is further reduced.

In some possible implementations, a first tab is connected to each layer of the first electrode tab disposed between the first adhesive member and the second adhesive member. Therefore, the number of the first tabs can be further increased, and the charge and discharge multiplying power of the electrochemical device can be further improved.

In some possible implementations, the M first tabs are welded to each other to form a weld zone at the second section. The bent portion is disposed on a side of the welding region facing the electrode assembly. Because M first utmost point ears are fixed in the welding zone welding of second subsection, consequently can reduce the first utmost point ear mutual separation of second subsection and lead to first connecting portion to take place the risk of reverse insertion, further improve electrochemical device's security.

In some possible implementation manners, the two outermost first pole pieces of the N layers of first pole pieces are respectively connected with a first tab.

In some possible implementations, the electrochemical device further includes a first adhesive member and a second adhesive member. The first adhesive member adheres a side of the first section facing away from the electrode assembly and a side surface of the electrode assembly in the first direction. The second adhesive member adheres a side of the second section facing away from the electrode assembly and the other side surface of the electrode assembly in the first direction. In the first direction, the second connection portion is located between the first adhesive member and the second adhesive member. The first bonding piece and the second bonding piece can reduce the risk that burrs and welding marks of the first connecting part penetrate through the shell to generate short circuit or liquid leakage.

In some possible implementations, the M first tabs are welded to each other to form a weld zone at the second section. Because M first utmost point ears are fixed in the welding zone welding of second subsection, consequently can reduce the first utmost point ear mutual separation of second subsection and lead to first connecting portion to take place the risk of reverse insertion, further improve electrochemical device's security.

In some possible implementations, at least one of the first adhesive or the second adhesive is an insulating gummed paper.

In some possible implementations, the first pole piece includes a current collector and an active material layer disposed on a surface of the current collector. The first tab and the current collector are integrally formed.

The present application also provides an electronic device comprising the electrochemical device as described above.

Drawings

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

Fig. 2 is a sectional view taken along line II-II of the electrochemical device shown in fig. 1 with a housing removed.

Fig. 3 is a sectional view taken along III-III of the electrochemical device shown in fig. 1 with the housing removed.

Fig. 4 is a cross-sectional view along IV-IV of the electrochemical device shown in fig. 1 with the housing removed.

Fig. 5A is a top view of the electrochemical device shown in fig. 1 with the housing removed and in other embodiments.

Fig. 5B is a cross-sectional view of the electrochemical device shown in fig. 1 with the housing removed in other embodiments.

Fig. 6 is a cross-sectional view of the electrochemical device of fig. 1 with the housing removed in yet another embodiment.

Fig. 7A is a top view of an electrochemical device according to another embodiment of the present application.

Fig. 7B is a cross-sectional view of an electrochemical device according to another embodiment of the present application.

Fig. 8 is a sectional view of an electrochemical device according to still another embodiment of the present application.

Fig. 9 is a cross-sectional view of an electronic device according to an embodiment of the present application.

Description of the main elements

Electronic device 1

Housing 10

Body part 11

Edge seal 12

Electrode assembly 20

Side surfaces 20a, 20b

First pole piece 21

Second pole piece 22

Isolation diaphragm 23

First pole ear group 30

First tab 31

Second pole ear group 40

Second tab 41

First adapter 50

Second adapter 60

First adhesive member 70

Second adhesive member 80

Electrochemical device 100, 200, 300

First segment 201

Second segment 202

First bend 203

Second bend section 204

First current collector 211

First active material layer 212

Second current collector 221

Second active material layer 222

First connection portion 301

Second connecting portion 302

First subsection 3011

Second subsection 3012

Third subsection 3013

Welding zone 3014

Space S

Direction of winding D

First direction D₁

Second direction D₂

Winding center axis C

Winding center plane P

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

Detailed Description

The technical solutions in the embodiments of the present application are described in detail below clearly, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. Unless defined otherwise, all 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. The terminology used in the description of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

Hereinafter, embodiments of the present application will be described in detail. This application may, however, be embodied in many different forms and should not be construed as limited to the exemplary embodiments set forth herein. Rather, these exemplary embodiments are provided so that this disclosure will be thorough and detailed, and will fully convey the scope of the disclosure to those skilled in the art.

In addition, the dimensions or thicknesses of various components, layers, and/or layers may be exaggerated in the figures for clarity and conciseness. Like numbers refer to like elements throughout. As used herein, the term "and/or", "and/or" includes any and all combinations of one or more of the associated listed items. In addition, it should be understood that when element a is referred to as being "connected" element B, element a may be directly connected to element B, or intermediate element C may be present and element a and element B may be indirectly connected to each other.

Further, the use of "may" when describing embodiments of the present application refers to "one or more embodiments of the present application.

The terminology used herein is for the purpose of describing particular embodiments and is not intended to be limiting of the application. As used herein, the singular forms are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, values, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, values, steps, operations, elements, components, and/or groups thereof.

Spatially relative terms, such as "upper" and the like, may be used herein for convenience in description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device or apparatus in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "above" or "upper" other elements or features would then be oriented "below" or "lower" the other elements or features. Thus, the exemplary term "up" can include both an orientation of above and below. It will be understood that, although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments.

Referring to fig. 1 to 3, an electrochemical device 100 according to an embodiment of the present disclosure includes a housing 10, an electrode assembly 20, a first tab set 30, a second tab set 40, a first adaptor 50, and a second adaptor 60. The electrode assembly 20, the first tab set 30 and the second tab set 40 are disposed within the case 10.

As shown in fig. 1, in some embodiments, the casing 10 may be a packaging bag packaged by a packaging film (e.g., an aluminum plastic film), that is, the electrochemical device 100 is a pouch battery. The case 10 includes a body part 11 for receiving the electrode assembly 20 and a sealing edge 12 connected to the body part 11. In other embodiments, the electrochemical device 100 is not limited to a pouch battery, but may be a steel-case battery or an aluminum-case battery, and the like, and the present application is not limited thereto.

As shown in fig. 2 and 3, the electrode assembly 20 includes a first pole piece 21, a second pole piece 22, and a separator 23 disposed between the first pole piece 21 and the second pole piece 22. The separator 23 serves to prevent the first and second pole pieces 21 and 22 from being in direct contact, thereby reducing the risk of short-circuiting of the electrode assembly 20. As shown in fig. 2, the electrode assembly 20 is a wound structure, i.e., a first pole piece 21, a separator 23, and a second pole piece 22 are sequentially wound in a stacked manner to form the electrode assembly 20. Wherein the electrode assembly 20 has a winding center axis C perpendicular to the paper. The winding direction D is a direction of counterclockwise rotation in the direction of the winding center axis C shown in fig. 2.

The first electrode sheet 21 includes a first current collector 211 and a first active material layer 212 disposed on the first current collector 211. The second electrode sheet 22 includes a second current collector 221 and a second active material layer 222 disposed on the second current collector 221. In some embodiments, the first pole piece 21 may be a negative pole piece, and the second pole piece 22 may be a positive pole piece. The first current collector 211 may be, but is not limited to, a metal foil such as a copper foil or a nickel foil. The second current collector 221 may be, but is not limited to, a metal foil such as an aluminum foil or a nickel foil. In other embodiments, the first pole piece may be a positive pole piece and the second pole piece 22 may be a negative pole piece.

The first tab group 30 includes M first tabs 31(M is a natural number greater than 1), and the M first tabs 31 are connected to the first pole piece 21. Specifically, M first tabs 31 are connected to the first current collector 211 of the first pole piece 21, and more specifically, a plurality of first tabs 31 may be integrally formed with the first current collector 211 (i.e., the first tabs 31 are formed by cutting the first current collector 211). A first adapter 50 is electrically connected to the first pole ear group 30 and extends from the edge seal 12 of the housing 10 for connection to an external component (not shown). Therein, electricityThe pole assembly 20 also has a first direction D₁And a second direction D₂. First direction D₁The thickness direction of the electrode assembly 20. Second direction D₂For the direction in which the first tab 31 protrudes out of the first pole piece 21, e.g. the second direction D₂The length direction of the electrode assembly 20.

As shown in fig. 2 and 4, the second tab group 40 includes a plurality of second tabs 41, and the second tabs 41 have a polarity opposite to that of the first tabs 31. The plurality of second tabs 41 are connected to the second pole piece 22, specifically, the plurality of second tabs 41 are connected to the second current collector 221 of the second pole piece 22, and more specifically, the plurality of second tabs 41 may be integrally formed with the second current collector 221. A second adaptor 60 is electrically connected to the second pole ear set 40 and extends from the edge seal 12 of the housing 10 for connection to an external element.

As shown in fig. 2 and 3, in a first direction D₁In the above, defining the first current collector 211 and the first active material layer 212 on the surface of the first current collector 211 as a first electrode sheet 21, the electrode assembly 20 includes N first electrode sheets 21(N is a natural number greater than 1), and N is greater than M. For the sake of simplicity, fig. 2 and 3 may only exemplarily show a part of the first pole piece 21 in the electrode assembly 20, i.e., another part of the first pole piece 21 is omitted, so it is understood that the actual number of layers of the first pole piece 21 is not limited to that shown in the figures. Similarly, the number of layers of the second pole piece 22 is not limited to that shown in the figure. The M first tabs 31 are connected to the first pole piece 21, respectively. That is, the M first tabs 31 are respectively connected to M layers of the N first pole pieces 21, and the other (N-M) layers of the N first pole pieces 21 are not connected to the first tabs 31. A winding center axis C passing through the electrode assembly 20 and perpendicular to the first direction D₁Is a winding center plane P in a first direction D₁In the above, M first tabs 31 are provided on both sides of the winding center plane P.

Specifically, as shown in fig. 2, the electrode assembly 20 includes a first segment 201, a first bent segment 203, a second segment 202, and a second bent segment 204, which are connected in sequence, in the winding direction D. In some embodiments, the first segment 201 and the second segment 202 may be flat segments arranged in parallel. In other embodiments, the first segment 201 and the second segment 202 may also be bending segments, and the application is not limited thereto. The winding center plane P is provided between the first segment 201 and the second segment 202. Therefore, the M first tabs 31 are disposed on both sides of the winding center plane P, which means that a part of the M first tabs 31 is connected to the first pole piece 21 located in the first section 201, and another part of the M first tabs 31 is connected to the first pole piece 21 located in the second section 202.

More specifically, when N/2< M < N, M first tabs 31 may be arbitrarily distributed on both sides of the winding center plane P. When M is more than or equal to 2 and less than or equal to N/2, the number of the first tabs 31 on one side of the winding central plane P is more than or equal to 1, and the number of the first tabs 31 on the other side of the winding central plane P is more than or equal to 1.

As shown in fig. 3, the first tab set 30 includes a first connection portion 301 and a second connection portion 302. The first connection portion 301 is connected to the first switch 50, and the second connection portion 302 is connected between the first pole piece 21 and the first connection portion 301. The M first tabs 31 are stacked on each other to form the first connection portion 301. In some embodiments, at least two of the M first tabs 31 may be stacked in contact with each other as a part of the first connection portion 301. A portion of the first tab 31 of the second connection portion 302 connects the first connection portion 301 toward one side of the electrode assembly 20.

The second tab set 40 may have a similar structure to the first tab set 30, which is not described in detail.

The straight tab occupies the space of the electrode assembly head, reducing the energy density of the electrochemical device. Therefore, the tab needs to be bent before being welded to the adaptor. The electrochemical device of half utmost point ear structure (only connect a utmost point ear on each circle of utmost point piece, if, electrochemical device only has first utmost point ear of first section connection), stretch into casing to predetermined position with the adaptor when needs to, so that when welding with the utmost point ear of buckling, the utmost point ear of buckling takes place to insert backward and enters electrode assembly inside towards electrode assembly's direction easily under the effort of adaptor, have the risk that the short circuit even smoke and fire when causing follow-up use, reduce electrochemical device's safety in utilization. The electrochemical device with the full-lug structure (one lug is connected to each layer of the lugs) is beneficial to improving the charge-discharge multiplying power, also improves the difficulty of bending the lugs and welding, and improves the manufacturing process cost.

In the present application, one turn means that one turn is counted from a certain point on the electrode assembly 20 as a starting end, and another point along the winding direction D is an ending end, the ending end is in a straight line with the starting end and the center of the turn, and the starting end is between the ending end and the center of the turn. One turn forms two layers, i.e. one turn of the first pole piece 21 comprises two layers of the first pole piece 21.

This application sets up quantity M of first utmost point ear 31 and is less than the number of piles N of first pole piece 21, consequently is favorable to reducing the degree of difficulty of rolling over utmost point ear and welding, simplifies the processing procedure. Secondly, the M first tabs 31 are respectively connected to M layers of the N first pole pieces 21, and on the basis that the first tabs 31 are arranged on two sides of the winding central plane P, the number M of the first tabs 31 can be changed as required, so that the internal resistance of the pole pieces can be regulated and controlled, and the electrochemical device 100 can meet different charge-discharge rate requirements. Again, since a portion of the first tab 31 of the second connection portion 302 connects the first connection portion 301 toward one side of the electrode assembly 20, the first connection portion 301 is caused to be in the second direction D due to the restriction of the portion of the first tab 31₂The upper position is more stable and is less prone to reverse insertion under the action of the first adapter 50 when the first adapter 50 is inserted into the housing 10. Therefore, the problem of contact short circuit of the tab due to the reverse insertion can be improved, and the safety of the electrochemical device 100 can be improved. Furthermore, the insulating glue layer arranged for preventing the pole lug which is inserted backwards from contacting the end face of the electrode assembly in the prior art can be reduced, and the cost is reduced.

As shown in fig. 3, in some embodiments, the first connection portion 301 forms a U-shaped structure. The first connection portion 301 includes a first sub-portion 3011, a second sub-portion 3012 opposite to the first sub-portion 3011, and a third sub-portion 3013 connected between the first sub-portion 3011 and the second sub-portion 3012 in a bent manner. The first sub-section 3011 is connected to the first connecting member 50, and the second sub-section 3012 is connected to the second connecting portion 302. The first connecting portion 301 defines a space S opening toward the first connector 50. The first connecting member 50 is at least partially disposed in the space S defined by the U-shaped structure and can be welded and fixed to the first sub-portion 3011.

As shown in fig. 3Further, in some embodiments, in the first direction D₁The first pole piece 21 connected with the first pole tab 31 and the first pole piece 21 not connected with the first pole tab 31 are alternately arranged. That is, the number M of the first tabs 31 is a rounded integer N/2, and the number of the first tabs 31 is substantially the same as that of the electrochemical device having the half-tab structure. Compared with the electrochemical device with the half-pole lug structure, the first pole piece 21 with the N layers is alternately provided with the first pole lugs 31, so that part of the first pole lugs 31 are arranged on one side of the first connecting portion 301 facing the electrode assembly 20, and the limiting effect of the part of the first pole lugs 31 reduces the contact short circuit risk of the first connecting portion 301 caused by reverse insertion and improves the safety. Meanwhile, the number of the first tabs 31 is the same as that of the electrochemical device with a half-tab structure, so that the risk of difficult tab folding and welding processes caused by the increase of the number of the first tabs 31 due to the need of taking safety into consideration is reduced.

Referring to fig. 5A and 5B, in other embodiments, the number M of the first tabs 31 is greater than N/2, and the first tabs 31 may connect any M layers of the N layers of the first pole pieces 21. That is, the number M of the first tabs 31 may be increased as needed. Therefore, compared with the case where the first pole piece 21 connected with the first tab 31 and the first pole piece 21 not connected with the first tab 31 are alternately arranged, the internal resistance of the first pole piece 21 can be further reduced, and the charge-discharge rate requirement of the electrochemical device 100 can be improved.

As shown in fig. 3, in some embodiments, the two outermost first pole pieces 21 of the N first pole pieces 21 are respectively connected with a first tab 31. The electrochemical device 100 further includes a first adhesive member 70 and a second adhesive member 80. The first adhesive member 70 adheres the first sub-section 3011 to a side facing away from the electrode assembly 20 and the electrode assembly 20 in the first direction D₁And a side surface 20 a. In some embodiments, the side surface 20a of the electrode assembly 20 may be the first pole piece 21, the separation film 23, or other adhesive (not shown). The second adhesive member 80 adheres the second section 3012 to the side facing away from the electrode assembly 20 and the electrode assembly 20 in the first direction D₁And the other side surface 20 b. In some embodiments, the side surface 20b of the electrode assembly 20 may be the first pole piece 21 or may be a separatorThe release film 23 may be made of any other adhesive (not shown). In a first direction D₁The second connection portion 302 is located between the first adhesive member 70 and the second adhesive member 80. It can be understood that burrs may be formed when the first current collector 211 is cut to form the first tab 31, and welding marks may also be formed when the first connection portion 301 is welded to the first connecting member 50. The burrs and the weld marks may pierce the case 10 to cause a short circuit or leakage. By providing the first adhesive member 70 and the second adhesive member 80, the risk of the burrs and the weld marks of the first connecting portion 301 piercing the housing 10 to cause short-circuiting or liquid leakage can be reduced. The first adhesive member 70 and/or the second adhesive member 80 may be an insulating adhesive paper.

Further, in some embodiments, in the first direction D₁The width of the first adhesive member 70 is greater than the width of the first connection portion 301. In some embodiments, the difference between the width of the first adhesive member 70 and the width of the first connection portion 301 is 1mm to 50 mm. Further, in some embodiments, in the first direction D₁The width of the second adhesive member 80 is greater than the width of the first connection portion 301. In some embodiments, the difference between the width of the second connection portion 70 and the width of the first connection portion 301 is 1mm to 50 mm. In some embodiments, in the second direction D₂In addition, the length of the first adhesive member 70 adhered to the side surface 20a of the electrode assembly 20 is not less than 1mm, so that the first adhesive member 70 can be stably adhered to the electrode assembly 20. In some embodiments, in the second direction D₂In addition, the length of the second adhesive member 80 adhered to the side surface 20b of the electrode assembly 20 is not less than 1mm, so that the second adhesive member 80 can be firmly adhered to the first pole piece 21. In some embodiments, in the second direction D₂In addition, the length of the first adhesive member 70 beyond the edge of the electrode assembly 20 is not less than 2mm, so that the first adhesive member 70 can be stably adhered to the first connection part 301. In some embodiments, in the second direction D₂In addition, the length of the second adhesive member 80 beyond the edge of the electrode assembly 20 is not less than 2mm, so that the second adhesive member 80 can be stably adhered to the first connection part 301. It will be appreciated that in order to substantially reduce the risk of direct contact between the first pole piece 21 and the second pole piece 22, in the second direction D₂Of upper, isolating film 23The edges extend beyond the edges of the first pole piece 21 and the second pole piece 22. Thus in the second direction D₂In the above, the edge of the electrode assembly 20 is generally the edge of the separation film 23.

Referring to fig. 6, in other embodiments, M first tabs 31 may be welded to each other to form a weld zone 3014 at the second section 3012. It can be understood that if the M first tabs 31 are not fixed to each other at the first connection portion 301, when the first adaptor 50 extends into the housing 10, the first tabs 31 of the first connection portion 301 are easily separated from each other by the first adaptor 50. In the present invention, since the M first tabs 31 are welded and fixed to the welding region 3014 of the second sub-section 3012, the risk that the first tabs 31 (e.g., the first tab 31 on the right side in the direction of D1 in fig. 6) are separated from each other at the second sub-section 3012 and the first connection portion 301 is inserted backward can be further reduced, and the safety of the electrochemical device 100 can be further improved. In some embodiments, a weld zone 3014 may be provided at an end of the second section 3012 proximate to the third section 3013.

Referring to fig. 7A and 7B, another embodiment of the present disclosure further provides an electrochemical device 200. Different from the electrochemical device 100 in that it is arranged in the first direction D₁In the N layers of the first pole pieces 21, the first pole tab 31 is connected to the outermost first pole piece 21, and the first pole tab 31 is not connected to the other outermost first pole piece 21.

At this time, the first adhesive member 70 adheres the side of the first sub-section 3011 facing away from the electrode assembly 20. In a first direction D₁In addition, the first adhesive member 70 is also disposed between two adjacent pole pieces. The second adhesive member 80 adheres the second section 3012 to the side facing away from the electrode assembly 20 and the electrode assembly 20 in the first direction D₁And a side surface 20 b. In a first direction D₁The second connection portion 302 is located between the first adhesive member 70 and the second adhesive member 80. At this time, the first adhesive member 70 and the second adhesive member 80 can also reduce the risk of the burr of the first connecting portion 301 piercing the housing 10 to cause a short circuit or leakage. The first adhesive 70 includes a bent portion 71, and the bent portion 71 is disposed on a side of the second sub-portion 3012 facing the electrode assembly 20. Therefore, the bent portion 71 may also be in the second direction D₂To provide a restriction on the first connection portion 301With this, the risk of contact short-circuiting of the first connection portion 301 due to reverse insertion is further reduced. In addition, in a first direction D₁In addition, the first adhesive member 70 is disposed between two adjacent pole pieces to reduce the thickness in the second direction D₂And the energy density is improved.

As shown in fig. 7B, a first tab 31 is further connected to each layer of the first pole piece 21 disposed between the first adhesive member 70 and the second adhesive member 80. In this way, the number of the first tabs 31 can be further increased, thereby increasing the charge/discharge rate of the electrochemical device 100.

In some embodiments, the M first tabs 31 are welded to each other to form a weld zone 3014 at the second section 3012, thereby reducing the risk of the first tabs 31 at the second section 3012 separating from each other causing the first connection portion 301 to be inverted. The bent portion 71 may be provided at a side of the welding region 3014 facing the electrode assembly 20.

Referring to fig. 8, another embodiment of the present disclosure further provides an electrochemical device 300. Different from the electrochemical device 100, the first connection portion 301 is not U-shaped, but is entirely along the second direction D₂And (4) extending. During manufacturing, the first tab set 30 only needs to be bent at the connection position between the first connection portion 301 and the second connection portion 302, and the first connection portion 301 itself does not need to be bent, thereby facilitating the simplification of the manufacturing process.

The electrochemical devices 100, 200, and 300 of the present application include all devices capable of electrochemical reactions. Specifically, the electrochemical devices 100, 200, 300 include all kinds of primary batteries, secondary batteries, fuel cells, solar cells, and capacitors (e.g., super capacitors). Alternatively, the electrochemical devices 100, 200, 300 may be lithium secondary batteries including lithium metal secondary batteries, lithium ion secondary batteries, lithium polymer secondary batteries, and lithium ion polymer secondary batteries.

Referring to fig. 9, an electronic device 1 is also provided in an embodiment of the present application, where the electronic device 1 includes an electrochemical device 100 (or electrochemical devices 200 and 300). Among them, the electrochemical devices 100, 200, and 300 according to the present application are suitable for electronic devices 1 in various fields. In one embodiment, the electronic device 1 of the present invention may be, but is not limited to, a notebook computer, a pen-input computer, a mobile computer, an electronic book player, a cellular phone, a portable facsimile machine, a portable copier, a portable printer, a headphone, a video recorder, a liquid crystal television, a portable cleaner, a portable CD player, a mini-disc, a transceiver, an electronic organizer, a calculator, a memory card, a portable recorder, a radio, a backup power source, a motor, an automobile, a motorcycle, a power-assisted bicycle, a lighting fixture, a toy, a game machine, a clock, an electric power tool, a flashlight, a camera, a large household battery, a lithium ion capacitor, and the like.

Finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the present application and not for limiting, and although the present application is described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions can be made on the technical solutions of the present application without departing from the scope of the technical solutions of the present application.