CN117199549A - Battery cell, energy storage device and electronic equipment - Google Patents

Abstract

The embodiment of the application provides a battery cell, an energy storage device and electronic equipment. The battery core is provided with an end face, and a plurality of tab groups are arranged on the end face; the plurality of tab groups are distributed along the circumferential direction of the battery core, and adjacent tab groups are partially overlapped together; the tab group comprises a first sub-tab group and a second sub-tab group, and the first sub-tab group is arranged closer to the center of the end face relative to the second sub-tab group; the first sub-tab group comprises at least one first tab, the first tab is bent to form a first part and a second part, and the partial projection of the second part in the axial direction of the battery cell overlaps with the first part; the second sub-tab group comprises a plurality of second tabs which are all arranged on the end face in a flat way, and the adjacent second tabs are overlapped with each other in the radial direction of the battery cell; wherein the adjacently arranged first tab and second tab overlap each other; the battery cell also comprises a lead-out part, wherein the lead-out part is covered on the tab group and is connected with the tab group.

Description

Battery cell, energy storage device and electronic equipment

Technical Field

The embodiment of the application relates to the technical field of batteries, in particular to a battery cell, an energy storage device and electronic equipment.

Background

The lithium ion battery has the characteristics of high energy density, high power density, good cycle performance, no memory effect, green environmental protection and the like, becomes an energy storage tool of portable office equipment, is widely applied to various electronic products such as mobile communication equipment, mobile phones, mobile cameras, notebook computers, mobile phones and the like, and is also expected to become an energy supply system of future electric automobiles.

The battery cell comprises a pole piece, when the pole piece is coated, an empty foil area (also called as a pole lug part) at the edge of a current collector is reserved, and the forming mode of the pole lug comprises two modes: one is to cut the empty foil area at the edge of the current collector before winding to form a tab; in addition, the electrode lug is formed by cutting the empty foil area at the edge of the current collector after winding, wherein the electrode lug is formed after winding, so that the phenomenon that the electrode lug shields the center of the battery cell easily occurs, and the normal use of the battery cell is influenced.

Disclosure of Invention

The application aims to provide a novel technical scheme of a battery cell, an energy storage device and electronic equipment.

In a first aspect, the present application provides a cell. The battery cell is provided with an end face, and a plurality of tab groups are arranged on the end face;

the electrode lug groups are distributed along the circumferential direction of the battery core, and adjacent electrode lug groups are partially overlapped together;

each tab group comprises a first sub-tab group and a second sub-tab group, and the first sub-tab group is arranged closer to the center of the end face than the second sub-tab group;

the first sub-tab group comprises at least one first tab, the first tab is bent to form a first part and a second part, and the partial projection of the second part in the axial direction of the battery cell is overlapped with the first part;

the second sub-tab group comprises a plurality of second tabs, the second tabs are all arranged on the end face in a flat mode, and the second tabs arranged adjacently are overlapped with each other in the radial direction of the battery cell;

wherein the first tab and the second tab adjacently disposed overlap each other;

the battery cell also comprises a lead-out part, and the lead-out part is covered on the tab group and is connected with the tab group.

Optionally, the second portion is disposed away from the end face relative to the first portion;

the first portion is disposed facing away from the center of the end face, and the second portion is disposed facing toward the center of the end face.

Optionally, the electric core is provided with a central hole, and the electric core further comprises a sleeve;

a bending area is formed between the first part and the second part;

the sleeve comprises a cylinder and a cover body connected with the cylinder, the cylinder stretches into the central hole, the first part is located below the cover body, the second part is located above the cover body, and the part of the cover body is located in the bending area.

Optionally, the second portion is disposed away from the end face relative to the first portion; in the radial direction of the battery cell, the second part extends out of the first part, and a blank area is arranged between the second part and the center of the end face.

Optionally, the tab group includes a first tab group and a second tab group, the first tab group and the second tab group are alternately arranged, and the first tab group and the second tab group are different in shape.

Optionally, the first tab group has a first side surface and a second side surface, and in the circumferential direction of the battery cell, the first side surface and the second side surface are disposed opposite to each other and are parallel to each other.

Optionally, the second tab group has a third side surface and a fourth side surface, the third side surface and the fourth side surface are disposed opposite to each other in the circumferential direction of the battery cell, and an extension surface of the third side surface and an extension surface of the fourth side surface intersect.

Optionally, the battery cell further includes a pole piece, the pole piece includes a first pole piece and a second pole piece, the end face includes a first end face, a tab group provided on the first end face is connected with the first pole piece, and an insulation part is provided between the tab group and the second pole piece.

Optionally, the extraction part comprises a cover plate and an extraction plate, and the extraction plate is arranged on the cover plate; the cover plate is covered on the tab group.

In a second aspect, an energy storage device is provided. The energy storage device comprises a housing and a battery cell according to the first aspect;

the lead-out part is connected with the shell.

In a third aspect, an electronic device is provided. The electronic device comprises an energy storage device as described in the second aspect.

According to an embodiment of the present application, a battery cell is provided. The first tab in the first sub-tab group is bent, so that the first sub-tab group is far away from the center of the end face, the first tab of the first sub-tab group does not shield the center of the end face, and normal use of the battery cell is not affected.

Other features of the present specification and its advantages will become apparent from the following detailed description of exemplary embodiments thereof, which proceeds with reference to the accompanying drawings.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the specification and together with the description, serve to explain the principles of the specification.

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

Fig. 2 is a schematic structural diagram of a second pole piece according to an embodiment of the present application.

Fig. 3 to fig. 5 are schematic views illustrating a manufacturing process structure of a battery cell according to an embodiment of the present application.

Fig. 6 to fig. 8 are schematic structural diagrams of a battery cell according to an embodiment of the present application.

Fig. 9 is a schematic structural diagram of an energy storage device according to an embodiment of the application.

Fig. 10 to 11 are schematic diagrams of a second structure of the battery cell according to the embodiment of the present application.

Fig. 12 is a schematic diagram of a second structure of the energy storage device according to the embodiment of the present application.

Fig. 13 is a schematic structural diagram of a battery cell with a lead-out portion according to an embodiment of the present application.

Reference numerals illustrate:

1. a pole piece; 10. a first pole piece; 101. a first coating section; 102. a first uncoated portion; 11. a second pole piece; 111. a second coating section; 112. a second uncoated portion; 100. a battery cell;

20. the first sub-tab group; 201. a first tab; 2011. a first portion; 2012. a second portion;

21. the second sub-tab group; 211. a second lug;

23. the first tab group; 231. a first side surface; 232. a second side surface;

24. a second ear group; 241. a third side surface; 242. a fourth side surface;

25. pre-bending the first tab group; 26. pre-bending the second lug group; 271. a first cutting surface; 272. a second cut surface; 273. a third cut surface; 274. a fourth cut surface;

3a, a first end face; 3b, a second end face;

4. a center portion;

5. a lead-out part; 51. a cover plate; 52. a lead-out plate; 5a, a first extraction part; 5b, a second extraction part;

6. a sleeve; 61. a column; 62. a cover body;

200. a housing.

Detailed Description

Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that: the relative arrangement of the components and steps, numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present application unless it is specifically stated otherwise.

The following description of at least one exemplary embodiment is merely exemplary in nature and is in no way intended to limit the application, its application, or uses.

Techniques and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but should be considered part of the specification where appropriate.

In all examples shown and discussed herein, any specific values should be construed as merely illustrative, and not a limitation. Thus, other examples of exemplary embodiments may have different values.

It should be noted that: like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further discussion thereof is necessary in subsequent figures.

Embodiments of the present application provide a battery cell 100. Specifically, a multi-tab cell 100 is provided.

Referring to fig. 1-13, the battery cell 100 has an end face provided with a plurality of tab groups;

the tab groups are arranged along the circumferential direction of the battery cell 100, and adjacent tab groups are partially overlapped together.

Each tab group comprises a first sub-tab group 20 and a second sub-tab group 21, and the first sub-tab group 20 is arranged closer to the center of the end face than the second sub-tab group 21;

the first sub-tab group 20 includes at least one first tab 201, the first tab 201 is bent to form a first portion 2011 and a second portion 2012, and a partial projection of the second portion 2012 in the axial direction of the battery cell 100 overlaps the first portion 2011;

the second sub-tab group 21 includes a plurality of second tabs 211, the plurality of second tabs 211 are all disposed on the end surface in a flat manner, and the second tabs 211 disposed adjacently overlap each other in the radial direction of the battery cell 100;

wherein the first tab 201 and the second tab 211 which are adjacently disposed overlap each other;

the battery cell 100 further includes an extraction portion 5, where the extraction portion 5 is covered on the first tab group 23 and the second tab group 24 and is connected to the first tab group 23 and the second tab group 24.

Specifically, the battery cell 100 has an end face and a center portion 4, the center portion 4 is formed during winding, the center portion 4 may be a hollow center portion 4, or the center portion 4 may be a solid center portion 4, or the center portion 4 may be an axis. In the axial direction of the cell 100, the center portion 4 penetrates the cell 100, and the end of the center portion 4 is located on the end face of the cell 100. Where the center portion 4 is a hollow center portion 4, the cell 100 forms a center hole. Referring to fig. 6-8, the central portion 4 is a central bore into which the sleeve 6 extends.

Referring to fig. 6-8, and referring to fig. 10-11, the end face of the battery cell 100 has a plurality of tab groups, for example, the battery cell 100 has a first end face 3a and a second end face 3b, the first end face 3a has a plurality of tab groups, and the second end face 3b also has a plurality of tab groups.

It should be noted that, the tab group is formed by winding the pole piece 1 and the diaphragm, cutting the pole piece 1 located at one axial side of the battery cell 100, and then flattening the cut pole piece 1. For example, after winding, the first pole piece 10 is located at one side of the axial direction of the battery cell 100, the first pole piece 10 is cut, and the cut first pole piece 10 is processed, so that a first tab group is formed at the first end face 3 a. The first tab group comprises a plurality of tab groups; for example, after winding, the second tab 11 is located at the other side of the axial direction of the battery cell 100, the second tab 11 is cut and the cut second tab 11 is processed so that a second tab group including a plurality of tab groups is formed at the second end face 3 b. Wherein the polarities of the first tab group and the second tab group are opposite.

The first end face 3a and the second end face 3b of the battery cell 100 each have a plurality of tab groups arranged on the first end face 3a and the second end face 3b along the circumferential direction of the battery cell 100. For example, the first end face 3a and the second end face 3b are arranged to be full of tab groups.

The tab groups adjacently arranged are partially overlapped together, so that the situation that one tab group is not connected with the lead-out part 5 is avoided, and the correct lead-out of the current of the battery cell 100 is ensured.

In the embodiment of the present application, each tab group includes a first sub-tab group 20 and a second sub-tab group 21, where the first sub-tab group 20 is disposed closer to the center of the end surface than the second sub-tab group 21; for example, the first sub-tab group 20 is located inside the second sub-tab group 21, and the second sub-tab group 21 is located outside the first sub-tab group 20.

In the prior art, the tabs of the tab group are uniformly flattened towards the direction close to the center of the end face, so that after the tabs positioned on the inner side are flattened, the phenomenon that the tabs shield the center of the end face easily occurs, for example, the tabs shield the center part 4 of the battery cell 100, and the normal use of the battery cell 100 is affected.

In the embodiment of the present application, the first tab 201 in the first sub-tab group 20 located at the inner side is bent, so that the length of the flattened first tab 201 is shortened, the first tab 201 is disposed on the end surface, and the phenomenon that the first tab 201 shields the center of the end surface is avoided.

Specifically, referring to fig. 6-8, and referring to fig. 10-11, the first tab 201 is bent to form a first portion 2011 and a second portion 2012, and a partial projection of the second portion 2012 in the axial direction of the battery cell 100 overlaps the first portion 2011. The first tab 201 after bending is disposed opposite to the first tab 201 without bending in the axial space of the battery cell 100, so that the length of the first tab 201 is shortened, and the first tab 201 does not cover the center of the end face even in the subsequent operation process. For example, in the subsequent operation process, the second sub-tab group 21 is pressed, so that when the second tab 211 in the second sub-tab group 21 is flatly disposed on the end surface, the first sub-tab group 20 is disposed towards the center of the end surface under the action of external force, and the first tab 201 will not block the center of the end surface.

The second sub-tab group 21 includes a plurality of second tabs 211, and the second tabs 211 are arranged along the radial direction of the battery cell 100, so that the plurality of second tabs 211 are prevented from being scattered and irregularly distributed on the end surface of the battery cell 100. For example, in the embodiment of the present application, the plurality of second tabs 211 in the second sub-tab group 21 are all regularly arranged on the end surface and are arranged in a flat and overlapping manner, so that the plurality of second tabs 211 in the same second sub-tab group 21 are connected, and the current is led out from the same side of the axial direction of the battery cell 100.

In addition, the first tab 201 and the second tab 211 that are adjacently disposed overlap each other, which is advantageous for connecting a plurality of tabs in the same tab group, so as to facilitate current extraction from the same side of the axial direction of the battery cell 100.

The battery cell 100 further comprises a lead-out part 5, wherein the lead-out part 5 is arranged on the end face of the battery cell 100 and welded with the tab group of the end face, and current is led out through the lead-out part 5.

Therefore, in the embodiment of the present application, the first tab 201 in the first sub-tab group 20 is bent, so that the first sub-tab group 20 is disposed away from the center of the end surface, and the first tab 201 of the first sub-tab group 20 does not cover the center of the end surface, so that the normal use of the battery cell 100 is not affected.

In addition, the tab group is formed by winding the pole piece 1 and the diaphragm. Therefore, the plurality of tabs included in each tab group can be arranged along the radial direction of the battery core 100, so that the dislocation phenomenon of the plurality of tabs in the winding process is avoided, and the plurality of tabs are convenient to connect.

In one embodiment, referring to fig. 7, the second portion 2012 is disposed distally from the end surface relative to the first portion 2011; the first portion 2011 is disposed away from the center of the end face, and the second portion 2012 is disposed near the center of the end face.

In this embodiment, the first tab 201 in the first sub-tab group 20 is bent to form a first portion 2011 and a second portion 2012, wherein one end of the first portion 2011 is connected to the pole piece 1, the other end of the first portion 2011 is connected to the second portion 2012, one end of the second portion 2012 is connected to the first portion 2011, and the other end of the second portion 2012 is a free end.

The first portion 2011 is disposed in a direction away from the center of the end face, e.g., an end of the first portion 2011 remote from the end face is disposed in a direction away from the center of the end face, and the second portion 2012 is disposed in an opposite direction toward the center of the end face, e.g., a free end of the second portion 2012 is disposed toward the center of the end face.

For example, the first portion 2011 is disposed obliquely toward a direction away from the center of the end face, and the second portion 2012 is disposed obliquely toward a direction near the center of the end face, in which case the first portion 2011 and the second portion 2012 may not be cut together; or the first portion 2011 is disposed towards the direction away from the center of the end face, the second portion 2012 is disposed towards the direction near the center of the end face, and the first portion 2011 and the second portion 2012 are fitted together.

In this embodiment, the bending direction of the first tab 201 is limited, so that the end face center of the bent first sub-tab group 20 is not blocked, and normal use of the battery cell 100 is not affected.

In one embodiment, referring to fig. 6-8, the cell 100 has a central hole, and the cell 100 further includes a sleeve 6;

a bending region is formed between the first portion 2011 and the second portion 2012;

the sleeve 6 comprises a cylinder 61 and a cover 62 connected with the cylinder 61, the cylinder 61 extends into the central hole, the first part 2011 is located below the cover 62, the second part 2012 is located above the cover 62, and part of the cover 62 is located in the bending area.

In this embodiment, the first tab 201 in the first sub-tab group 20 is bent to form a first portion 2011 and a second portion 2012, wherein one end of the first portion 2011 is connected to the pole piece 1, the other end of the first portion 2011 is connected to the second portion 2012, one end of the second portion 2012 is connected to the first portion 2011, and the other end of the second portion 2012 is a free end.

The first portion 2011 is disposed in a direction away from the center of the end face, e.g., an end of the first portion 2011 remote from the end face is disposed in a direction away from the center of the end face, and the second portion 2012 is disposed in an opposite direction toward the center of the end face, e.g., a free end of the second portion 2012 is disposed toward the center of the end face.

Thus, a bending angle may be formed between the first portion 2011 and the second portion 2012 (i.e., the first portion 2011 and the second portion 2012 are not cut) and an opening is formed therebetween, and an open end of the opening is disposed toward a center of the end face. For example, the cell 100 also includes a central hole centered on the end face, the open end of the opening being disposed toward the central hole.

The opening defines a inflection region within which the cover 62 is located. In this embodiment, the first tab 201 is processed such that the first tab 201 does not obstruct the central aperture.

Specifically, the first pole piece 10, the diaphragm and the second pole piece 11 are respectively put into a winding needle to be wound, one side of the axial direction of the wound battery cell 100 is provided with the first pole piece 10, and the other side of the axial direction of the wound battery cell 100 is provided with the second pole piece 11, wherein the first pole piece 10 is taken as an example for cutting.

Referring to fig. 3 to 8, the first pole piece 10 is cut along the axial direction of the battery cell 100, and the first pole piece 10 is divided into pre-bent tab groups. Then, a sleeve 6 is sleeved in the central hole of the electric core 100, the sleeve 6 presses the first tab 201 outwards (towards the direction away from the central part 4) to form a preflex-fold structure, the preflex-fold structure comprises a first part 2011 and a second part 2012, the first part 2011 is pressed under the sleeve 6, and the second part 2012 is inclined towards the direction away from the central part 4;

then, the second sub-tab group 21 is pressed toward the center portion 4, and the second portion 2012 is attached to the upper surface of the sleeve 6 by an external force. In this embodiment, the sleeve 6 is used to bend the first tab 201 in the first sub-tab group 20, so that the length of the first tab 201 is shortened, and the first tab 201 does not block the central hole.

In one embodiment, the second portion 2012 is disposed distally from the end face relative to the first portion 2011; in the radial direction of the cell 100, the second portion 2012 protrudes from the first portion 2011, wherein a blank area is provided between the second portion 2012 and the center of the end face.

In this embodiment, the first tab 201 in the first sub-tab group 20 is bent to form a first portion 2011 and a second portion 2012, wherein one end of the first portion 2011 is connected to the pole piece 1, the other end of the first portion 2011 is connected to the second portion 2012, one end of the second portion 2012 is connected to the first portion 2011, and the other end of the second portion 2012 is a free end. Therefore, after the first tab 201 is bent, the second portion 2012 is disposed away from the end surface corresponding to the first portion 2011 in the axial direction of the battery cell 100.

Specifically, the first tab 201 is bent to form a first portion 2011 and a second portion 2012, the free end of the second portion 2012 is disposed toward the end face center, and a blank area is disposed between the free end of the second portion 2012 and the end face center, so that the first tab 201 does not cover the end face center. For example, the battery cell 100 has the center portion 4, the center portion 4 is located at the center of the end surface, and the first tab 201 is bent to shorten the length of the first tab 201, so that the first tab 201 does not shield the center portion 4 and normal use of the battery cell 100 is not affected.

In an alternative embodiment, the sleeve 6 may be inserted into the central portion 4 according to the above embodiment, so as to bend the first tab 201 in the first sub-tab group 20.

Or other tooling jigs are adopted to bend the first tab 201 in the first sub-tab group 20, and then the other tooling jigs are taken out. Although the fixture is taken out, since the first tab 201 is bent, the second portion 2012 is disposed toward the center portion 4 even under an external force, and the second portion 2012 does not cover the center portion 4. The structure of the battery cell provided in fig. 10-11 is different from the structure of the battery cell provided in fig. 6-8 in that the sleeve or the tooling fixture is taken out from the battery cell provided in fig. 10-11.

In an alternative embodiment, the first tab 201 is bent by the sleeve 6 or the tooling fixture, and two sides of the first portion 2011 are aligned with two sides of the second portion 2012, so that the structure of the first tab 201 after bending is relatively neat. And pressing the second sub-tab group 21 by other jigs, so that the second tabs 211 in the second sub-tab group 21 are neatly and flatly arranged on the end surface.

Or, when the overwhelming uniformity of the first tab 201 is not considered, the fixture is used to overwhelm the first tab 201 in the first sub-tab group 20 at will (for example, when the first portion 2011 and the second portion 2012 have a dislocation in the circumferential direction of the battery cell 100, etc.), and then the second sub-tab group 21 is overwhelmed at will, for example, when the adjacent second tab 211 support has a dislocation in the circumferential direction of the battery cell 100, etc.

In one embodiment, referring to fig. 6-8, and referring to fig. 10-11, the tab group includes a first tab group 23 and a second tab group 24, the first tab group 23 and the second tab group 24 are alternately arranged, and the first tab group 23 and the second tab group 24 are different in shape.

In this embodiment, the end face of the battery cell 100 has a plurality of tab groups, the tab groups are arranged along the circumferential direction of the battery cell 100, and the adjacent tab groups are partially overlapped. For example, the plurality of tab groups includes a first tab group 23 and a second tab group 24, and the first tab group 23 and the second tab group 24 are disposed adjacent to each other and partially overlap together. Thus, the end face of the battery cell 100 is covered with the lead-out part 5, and the lead-out part 5 is connected with any one tab group or any several tab groups, so that the correct lead-out of the current of the battery cell 100 is ensured.

In this embodiment, the shapes of the first tab group 23 and the second tab group 24 are defined differently, so that on one hand, the tab groups are conveniently distinguished, and one tab group is conveniently flattened correspondingly. Referring to fig. 3 to 8, for example, the first tab group 23 may be formed by flattening the first tab group 25 (the first tab group 25 is the first tab group 23 that has not been flattened after the cutting of the pole piece 1), and then the second tab group 24 may be formed by flattening the second tab group 26 (the second tab group 26 is the second tab group 24 that has not been flattened after the cutting of the pole piece 1).

Alternatively, after the pre-bent first tab group 25 and the pre-bent second tab group 26 are sequentially flattened, a portion of the second tab group 24 may be located above the first tab group 23. For example, by adjusting the flattened angles of the pre-bent first tab group 25 and the pre-bent second tab group 26, a portion of the second tab group 24 may be located above the first tab group 23.

In one embodiment, referring to fig. 3-8, and referring to fig. 10-11, the first tab group 23 has a first side surface 231 and a second side surface 232, and the first side surface 231 and the second side surface 232 are disposed opposite to and parallel to each other in the circumferential direction of the battery cell 100.

Specifically, taking the first pole piece 10 on one axial side of the battery cell 100, the first pole piece 10 is cut along the axial direction of the battery cell 100, and the first tab group 23 and the second tab group 24 are formed by flattening the cut first pole piece 10 as an example for explanation:

the first pole piece 10 is cut along the axial direction of the battery core 100 to form a first tab group 23, the first side surface 231 and the second side surface 232 of the first tab group 23 are parallel to each other, for example, the first tab group 23 is flatly disposed on the end surface, and the first tab group 23 has a rectangular structure. Each tab in the first tab group 23 is also rectangular in structure.

For example, the first pole piece 10 is cut along the axial direction of the electric core 100 to form a group of parallel cutting surfaces, the parallel cutting surfaces include a first cutting surface 271 and a second cutting surface 272, and the first cutting surface 271 and the second cutting surface 272 define the structure of the first tab group 23 (i.e. the pre-bent first tab group 25) which is not flattened.

In this embodiment, the structure of the first tab group 23 is defined so as to facilitate cutting of the first pole piece 10 on the one hand, and to partially overlap the first tab group 23 and the second tab group 24 on the other hand.

In one embodiment, referring to fig. 3-8, and fig. 10-11, the second tab group 24 has a third side surface 241 and a fourth side surface 242, the third side surface 241 and the fourth side surface 242 are disposed opposite to each other in the circumferential direction of the battery cell 100, and an extension plane of the third side surface 241 and an extension plane of the fourth side surface 242 intersect.

In this embodiment, taking the first pole piece 10 on one axial side of the battery cell 100, the first pole piece 10 is cut along the axial direction of the battery cell 100, and the first pole piece 10 after the cutting is flattened to form the first tab group 23 and the second tab group 24 as an example for explanation:

the first pole piece 10 is cut along the axial direction of the battery core 100 to form a second tab group 24, an extension surface of the first side surface 231 of the second tab group 24 intersects with an extension surface of the second side surface 232, for example, the second tab group 24 is flatly disposed on the end surface, and the second tab group 24 has a fan-shaped structure. Each tab in the second tab group 24 is also a fan-shaped structure.

For example, the first pole piece 10 is cut along the axial direction of the battery cell 100 to form at least two sets of mutually parallel cut surfaces. For example, one set of mutually parallel cutting surfaces includes a first cutting surface 271 and a second cutting surface 272, and the other set of mutually parallel cutting surfaces includes a third cutting surface 273 and a fourth cutting surface 274, wherein the first cutting surface 271 and the third cutting surface 273 are disposed adjacent to each other, and extension surfaces of the two cutting surfaces intersect, and the third cutting surface 273 and the first cutting surface 271 define the structure of the second tab group 24 (i.e., the pre-bent second tab group 26) that is not flattened.

In this embodiment, the structure of the second tab group 24 is defined so as to facilitate cutting the first pole piece 10 on the one hand, and to partially overlap the first tab group 23 and the second tab group 24 on the other hand.

In an alternative embodiment, the width dimension of the second tab group 24 gradually decreases in a radial direction from the central portion 4 to near the central portion 4. For example, the second tab group 24 has a fan-shaped structure.

In this embodiment, the structure of the second tab group 24 is defined, the width dimension of the second tab group 24 is gradually changed, and after the pre-bending second tab group 26 is flattened, the second tab group 24 and the first tab group 23 are conveniently contacted together.

In an alternative embodiment, the second tabs 211 included in the second sub-tab group 21 are all disposed flat toward the center of the end face.

In this embodiment, the second tabs 211 included in the second sub-tab group 21 are all disposed flat toward the direction approaching the center of the end face (i.e., the center portion 4). For example, taking the first electrode sheet 10 as an example, the first electrode sheet 10 (the first electrode sheet 10 includes the first uncoated portion 102 and the first coated portion 101) located on one side in the axial direction of the battery cell 100 is subjected to cutting treatment (the cutting direction is: along the axial direction of the battery cell 100), and then the first uncoated portion 102 is flattened along the boundary of the first uncoated portion 102 and the first coated portion 101, wherein the flattening direction is the direction toward the center portion 4, so that the second tab 211 connected to the first electrode sheet 10 is flatly located on the end face.

Each second tab 211 in the second sub-tab group 21 included in the tab group has a uniform flattening direction, so that the shape of the flattened tab group is more neat.

In one embodiment, the pole piece 1 includes a first pole piece 10 and a second pole piece 11, the end faces include a first end face 3a, a tab group of the first end face 3a is connected to the first pole piece 10, and an insulation part is provided between the tab group and the second pole piece 11.

In this embodiment, the first end face 3a of the battery cell 100 has a tab group, the tab group includes a first tab group 23 and a second tab group 24, after the first tab group 23 and the second tab group 24 are flattened, the tabs included in the first tab group 23 and the second tab group 24 are disposed on the first end face 3a, and an insulating portion is between the first tab group 23 and the second tab group 24 and the second tab 11, so as to avoid direct contact between the tab connected with the first pole piece 10 and the second tab 11, and thus short circuit phenomenon of the battery cell 100 is avoided. The insulation may be, for example, a membrane provided between the first pole piece 10 and the second pole piece 11.

For example, referring to fig. 1 and 2, when the first electrode sheet 10, the separator, and the second electrode sheet 11 are stacked and wound, the upper end portion of the second electrode sheet 11 in the width direction is not overlapped with the upper end portion of the first electrode sheet 10 in the width direction. Wherein the first pole piece 10 is provided with a first uncoated portion 102 at an upper end portion in the width direction.

The upper end portion of the second pole piece 11 in the width direction is disposed so as not to overlap with the upper end portion of the first pole piece 10 in the width direction, specifically, the upper end portion of the second pole piece 11 in the width direction is lower than the upper end portion of the first pole piece 10 in the width direction, while the upper end portion of the separator between the first pole piece 10 and the second pole piece 11 is disposed higher than the upper end portion of the second pole piece 11, for example, the upper end portion of the second pole piece 11 in the width direction is lower than the boundary between the first uncoated portion 102 and the first coated portion 101 in the first pole piece 10. The upper end of the separator is higher than the interface of the first uncoated portion 102 and the first coated portion 101 in the first pole piece 10.

Thus, after winding, the first uncoated portion 102 is cut along the axial direction of the battery cell 100, and cut to the interface between the first uncoated portion 102 and the first coated portion 101, and then after flattening the first uncoated portion 102, the separator is flattened, and the first uncoated portion 102 and the second pole piece 11 are separated by the separator, so that the first uncoated portion 102 and the second pole piece 11 are prevented from contacting.

Similarly, when the first pole piece 10, the separator, and the second pole piece 11 are laminated and wound, the lower end portion of the first pole piece 10 in the width direction is provided so as not to overlap the lower end portion of the second pole piece 11 in the width direction, specifically, the lower end portion of the first pole piece 10 in the width direction is higher than the lower end portion of the second pole piece 11 in the width direction, and the lower end portion of the separator between the first pole piece 10 and the second pole piece 11 is provided lower than the lower end portion of the first pole piece 10. For example, the lower end portion of the first pole piece 10 in the width direction is higher than the boundary between the second uncoated portion 112 and the second coated portion 111 in the second pole piece 11. The lower end of the diaphragm is disposed lower than the lower end of the first pole piece 10.

In an alternative embodiment, the lead-out portion 5 may be welded to one of the tab groups; or the lead-out portion 5 is welded to each tab group provided on the end face.

In one embodiment, referring to fig. 13, the lead-out portion 5 includes a cover plate 51 and a lead-out plate 52, the lead-out plate 52 being disposed on the cover plate 51; the cover plate 51 is disposed on the first tab group 23 and the second tab group 24.

Specifically, a cover plate 51 is disposed on an end surface of the battery cell 100, and the cover plate 51 covers the first tab group 23 and the second tab group 24. The cover plate 51 is welded to at least one of the first tab group 23 and the second tab group 24. In this way, a welding point is formed between the first tab group 23 and the cover plate 51, and/or between the second tab group 24 and the cover plate 51. Optionally, the cover plate 51 is welded to each tab group on the end face of the cell 100.

The lead-out portion 5 includes a cover plate 51 and a lead-out plate 52, which may be integrally formed at the cover plate 51 and the lead-out plate 52. The end tab 52 is adapted to be connected to the housing 200.

It should be noted that, when the cover plate 51 is welded to the first tab group 23 or the second tab group 24, the first tab group 23 and the second tab group 24 disposed adjacent thereto are partially overlapped, so that the current of the battery cell 100 is ensured to be normally led out. For example, the cover plate 51 is welded with the first tab group 23, and the second tab group 24 and the first tab group 23 are partially overlapped, which is equivalent to that the cover plate 51 is indirectly connected with the second tab group 24, so that the normal extraction of the current of the battery cell 100 is ensured.

In a second aspect, an energy storage device is provided. Referring to fig. 9 and 12, the energy storage device includes a housing 200 and a battery cell 100 according to the first aspect;

the lead-out portion 5 is connected to the housing 200.

For example, the energy storage device is a battery. The battery includes a case 200, and the lead-out portion 5 of the battery cell 100 is electrically connected to the case 200. For example, the case 200 includes a case body and a cap assembly, and the lead-out portion 5 of the battery cell 100 may be electrically connected to the case body, or the lead-out portion 5 of the battery cell 100 may be also electrically connected to the cap assembly.

Referring to the figure, a tab group is provided on an upper end surface (first end surface 3 a) of the battery cell 100, the tab group includes a first tab group 23 and a second tab group 24, a first lead-out portion 5a is provided on the upper end surface of the battery cell 100 in a covering manner, the first lead-out portion 5a is welded to the first tab group 23 and/or the second tab group 24, and the first lead-out portion 5a is connected to a cap assembly of the case 200.

The lower end face (second end face 3 b) of the battery cell 100 is also provided with a tab group, the tab group includes a first tab group 23 and a second tab group 24, the lower end face of the battery cell 100 is covered by a second lead-out portion 5b, the second lead-out portion 5b is welded with the first tab group 23 and/or the second tab group 24, and the second lead-out portion 5b is connected with the shell body of the shell 200.

In a third aspect, an electronic device is provided. The electronic device comprises an energy storage device as described in the second aspect. For example, the electronic device may be a cell phone, tablet, watch, etc., or other type of smart wearable device.

The foregoing embodiments mainly describe differences between the embodiments, and as long as there is no contradiction between different optimization features of the embodiments, the embodiments may be combined to form a better embodiment, and in consideration of brevity of line text, no further description is given here.

While certain specific embodiments of the application have been described in detail by way of example, it will be appreciated by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the application. It will be appreciated by those skilled in the art that modifications may be made to the above embodiments without departing from the scope and spirit of the application. The scope of the application is defined by the appended claims.

Claims (11)

1. The battery cell is characterized by comprising an end face, wherein a plurality of tab groups are arranged on the end face;

the electrode lug groups are distributed along the circumferential direction of the battery core, and adjacent electrode lug groups are partially overlapped together;

each tab group comprises a first sub-tab group (20) and a second sub-tab group (21), and the first sub-tab group (20) is arranged closer to the center of the end face than the second sub-tab group (21);

the first sub-tab group (20) comprises at least one first tab (201), the first tab (201) is bent to form a first portion (2011) and a second portion (2012), and a partial projection of the second portion (2012) in the axial direction of the battery cell overlaps with the first portion (2011);

the second sub-tab group (21) comprises a plurality of second tabs (211), the plurality of second tabs (211) are evenly arranged on the end face, and the adjacent second tabs (211) are overlapped with each other in the radial direction of the battery cell;

wherein the first tab (201) and the second tab (211) adjacently disposed overlap each other;

the battery cell also comprises a lead-out part (5), and the lead-out part (5) is covered on the tab group and is connected with the tab group.

2. The cell of claim 1, wherein the second portion (2012) is disposed away from the end face relative to the first portion (2011);

the first portion (2011) is disposed toward a direction away from the center of the end face, and the second portion (2012) is disposed toward a direction near the center of the end face.

3. A cell according to claim 1, characterized in that the cell has a central hole, the cell further comprising a sleeve (6);

-a bending zone is formed between the first portion (2011) and the second portion (2012);

the sleeve (6) comprises a cylinder (61) and a cover body (62) connected with the cylinder (61), the cylinder (61) stretches into the central hole, the first part (2011) is located below the cover body (62), the second part (2012) is located above the cover body (62), and part of the cover body (62) is located in the bending area.

4. The cell of claim 1, wherein a second portion (2012) is disposed away from the end face relative to the first portion (2011);

in the radial direction of the cell, the second portion (2012) protrudes from the first portion (2011), wherein a blank area is provided between the second portion (2012) and the end face center.

5. The cell according to any one of claims 1-4, wherein the tab group comprises a first tab group (23) and a second tab group (24), the first tab group (23) and the second tab group (24) being alternately arranged, the first tab group (23) and the second tab group (24) being different in shape.

6. The cell of claim 5, wherein the first tab group (23) has a first side surface (231) and a second side surface (232), the first side surface (231) and the second side surface (232) being disposed opposite and parallel to each other in a circumferential direction of the cell.

7. The cell of claim 5, wherein the second tab group (24) has a third side surface (241) and a fourth side surface (242), the third side surface (241) and the fourth side surface (242) being disposed opposite each other in a circumferential direction of the cell, and an extension plane of the third side surface (241) and an extension plane of the fourth side surface (242) intersect.

8. The cell of claim 1, further comprising a pole piece, the pole piece comprising a first pole piece (10) and a second pole piece (11), the end face comprising a first end face, the first end face having a tab group connected to the first pole piece (10) and an insulation between the tab group and the second pole piece (11).

9. The cell according to claim 1, characterized in that the outlet (5) comprises a cover plate (51) and an outlet plate (52), the outlet plate (52) being arranged on the cover plate (51); the cover plate (51) is covered on the tab group.

10. An energy storage device comprising a housing and the cell of any one of claims 1-9;

the lead-out part (5) is connected with the shell.

11. An electronic device comprising the energy storage device of claim 10.