CN220400856U - Battery cell and cylindrical battery - Google Patents

Abstract

The utility model relates to the field of batteries, in particular to a battery cell and a cylindrical battery, and aims to solve the problem that the welding stability of the end face of a tab of the conventional cylindrical battery and a switching piece is poor. For this purpose, the cell of the present utility model comprises: the pole piece is provided with a pole lug, the pole lug is arranged along the length direction of the pole piece, after the pole piece is wound, the pole lug forms a pole lug group, and the pole lug group consists of a single pole lug or a plurality of mutually overlapped pole lugs; the welding tab is arranged on the switching tab, and after the welding tab is welded with the tab group, the tab group is flattened on the annular end face of the pole piece, and the welding tab is positioned above the tab group. A cylindrical battery comprises the battery cell. The utility model adopts a mode that the tab group and the switching piece are welded and then flattened, and when the tab group and the switching piece are welded, the structure of the tab group can allow a welding head for ultrasonic welding to clamp the tab group and the welding piece for welding; compared with laser penetration welding, ultrasonic welding has higher efficiency and better stability.

Description

Battery cell and cylindrical battery

Technical Field

The utility model relates to the field of batteries, and particularly provides an electric core and a cylindrical battery.

Background

As a main measure for reducing carbon emission, a high-capacity lithium battery system is used as an alternative scheme of traditional fossil energy, is increasingly applied in the fields of transportation, energy storage and the like, and is suitable for special requirements of large-scale scenes, a power battery is innovatively developed in an appearance structure, three main current battery structures are formed at present, and the battery structures are mainly divided into a cylindrical battery, a square metal shell battery and a flexible package battery, and various battery structures have respective advantages and disadvantages in production efficiency, cost, performance and the like.

The full-tab large-size cylindrical battery improves the traditional cylindrical tab welding structure into a full-tab structure, the current conduction path is shorter, the charge-discharge multiplying power of the cylindrical battery is greatly improved, but meanwhile, the full-tab structure also brings some new problems, poor laser penetration welding stability of the full-tab and the switching piece is one of the key problems which restrict the full-tab large-cylindrical battery at present, the full-tab large-size cylindrical battery is formed into a flat tab end face through rubbing or flattening, the tab end face and the wafer-type switching piece are welded through a laser penetration welding process, the switching piece is further connected with the positive and negative electrode posts to assemble the battery, the wafer-type switching piece and the laser penetration welding process are beneficial to large-current discharge, the space utilization rate is high, but the stability of laser welding is poor, the welding reject ratio is high, and metal foreign matters generated by welding are not well controlled.

Accordingly, there is a need in the art for a new cylindrical battery to solve the above-described problems.

Disclosure of Invention

The utility model aims to solve the technical problem that the welding stability of the end face of the tab of the conventional cylindrical battery and the rotating tab is poor. For this purpose, the utility model provides a battery cell and a cylindrical battery, the battery cell comprises: the pole piece is provided with pole lugs along a first direction, and after the pole piece is wound, the pole lugs form a pole lug group which is composed of a single pole lug or a plurality of mutually overlapped pole lugs; the switching piece is provided with a welding piece, the welding piece is welded with the lug group, and the switching piece is turned outwards through the welding piece to flatten the lug group on the end face of the battery cell.

In the specific embodiment with the electric core, the number of the tab groups is at least 2.

In the specific embodiment with the electric core, the number of the welding tabs is the same as that of the tab groups.

In the specific embodiment with the electric core, the switching piece further comprises a connecting piece, the connecting piece is used for connecting a plurality of welding pieces, and the welding pieces are arranged around the connecting piece.

In the specific embodiment with the electric core, after the tab group is flattened, the welding piece does not exceed the edge of the end face of the electric core.

In the specific embodiment with the battery cell, the pole piece is provided with the clearance area, the clearance area is arranged at the starting end and/or the tail end of the first direction of the pole piece, and the pole lug is arranged in an area outside the clearance area.

In the specific embodiment with the battery cell, the distance between two adjacent tabs gradually increases along the first direction.

In the specific embodiment with the electric core, two tab groups are symmetrically arranged, and all the tabs are arranged on the same straight line on the end face of the electric core.

In the specific embodiment with the battery cell, the pole piece comprises a positive pole piece and a negative pole piece.

A cylindrical battery comprising the cell of any one of the above.

Under the condition of adopting the technical scheme, in order to change the original laser welding mode, the utility model sets a mode of welding and then flattening the tab group and the switching piece, and when the tab group and the switching piece are welded, as the tab group is vertical to the annular end face, no barrier exists on two sides of the tab group, and under the condition, a welding head capable of allowing ultrasonic welding clamps the tab group and the welding piece and then welds; compared with laser penetration welding, ultrasonic welding has higher efficiency and better stability. Meanwhile, the design of a plurality of lugs does not influence the current conduction capacity; after welding, the tab group and the welding piece are flattened, so that the space utilization rate of the battery is not affected.

Drawings

Preferred embodiments of the present utility model are described below with reference to the accompanying drawings, in which:

FIG. 1 is a schematic illustration of the structure of the present utility model prior to winding of a pole piece;

FIG. 2 is a schematic view of a tab set structure after winding a pole piece according to the present utility model, wherein the tab set is shown;

FIG. 3 is a schematic view of the structure of the tab assembly after shaping and pre-welding;

FIG. 4 is a schematic view of the structure of the switch plate of the present utility model;

FIG. 5 is a schematic view of the structure of the tab set and the welding tab of the present utility model;

fig. 6 is a schematic structural view of the tab set and the welding tab of the present utility model after being welded and flattened.

In the figure: 1. pole piece, 2, tab, 3, tab group, 4, switching piece, 5, welding piece, 6, connection piece, 7, keep away the dead zone.

Detailed Description

Preferred embodiments of the present utility model are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are merely for explaining the technical principles of the present utility model, and are not intended to limit the scope of the present utility model. Those skilled in the art can adapt it as desired to suit a particular application.

It should be noted that, in the description of the present utility model, terms such as "upper," "lower," "left," "right," "inner," "outer," and the like indicate directional or positional relationships, and are based on the directional or positional relationships shown in the drawings, which are merely for convenience of description, and do not indicate or imply that the relevant devices or elements must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the utility model. Furthermore, the ordinal terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

Furthermore, it should be noted that, in the description of the present utility model, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium. The specific meaning of the above terms in the present utility model can be understood by those skilled in the art according to the specific circumstances.

Furthermore, in order to more clearly show the core technical solution of the present utility model, descriptions of well-known structures of the cylindrical battery are omitted in the following description, but such omission is merely for convenience of description and does not mean that the cylindrical battery may have no such structures.

As shown in fig. 1-2, in this embodiment, in order to solve the problem of poor welding stability between the tab end face of the cylindrical battery and the wafer-type adaptor in the prior art, the present utility model provides a new electrical core, which includes: the pole piece 1, the pole piece 1 is provided with pole lugs 2 along a first direction, the first direction is the length direction of the pole piece 1, the X direction in fig. 1 represents the first direction, a cylinder is formed after the pole piece 1 is wound, two ends are annular end faces, the pole lugs 2 form a pole lug group 3, the pole lug group 3 is perpendicular to the annular end faces of the pole piece 1, the number of the pole lugs 2 is related to the length of the pole piece 1, the number of the pole lugs 2 can be selected according to actual conditions, and the number of the pole lug groups 3 to be formed can be formed, and each pole lug group 3 can be composed of a single pole lug 2 or a plurality of mutually overlapped pole lugs 2; the switching piece 4, the welding piece 5 has on the switching piece 4, and welding piece 5 and utmost point ear group 3 welding, switching piece 4 are turned over outwards through welding piece 5, flatten utmost point ear group 3 on the terminal surface of electric core. The subsequent assembly process is the same as the full tab structure; the welding tab 5 and the tab group 3 can be connected by selecting an ultrasonic welding process, the welding area of ultrasonic welding is large, the efficiency of ultrasonic welding is higher than that of laser penetration welding, the stability is better, and other welding modes with good stability can be selected.

After the tabs 2 are overlapped, a layered tab group 3 is formed, and before welding with the welding sheet 5, the layered tab group 3 may be pre-welded and cut, and welded into a whole and cut into a proper shape and size, so as to facilitate welding with the subsequent welding sheet 5, and the tab group 3 after pre-welding and cutting is shown in fig. 3.

In order to change the original laser welding mode, a mode that the tab group 3 and the welding sheet 5 are welded firstly and then flattened is provided, and when the tab group 3 and the welding sheet 5 are welded, as the tab group 3 is perpendicular to the annular end face, two sides of the tab group 3 are free of barriers, and under the condition, a welding head capable of allowing ultrasonic welding clamps the tab group 3 and the welding sheet 5 and then performs welding. Meanwhile, the reasonable number of the lugs 1 can not influence the current conduction capacity; after welding, the tab group 3 and the welding tab 5 are flattened, so that the space utilization rate of the battery is not affected.

Further, the larger the number of the tabs 2, the larger the overcurrent area of the battery, and preferably, the more the tab groups 3 are, the smaller the gaps between the tab groups 3 are, so that the welding times are increased, and the welding heads of the subsequent ultrasonic welding are inconvenient to clamp; taking two tab groups 3 as an example, as shown in fig. 1-2, a plurality of tabs 2 are mutually overlapped in the winding process to form two tab groups 3 which are symmetrical about the center of a battery core, and gaps between the tab groups 3 are larger, so that the performance requirement of the battery can be met, the subsequent welding steps can be simplified as much as possible, the symmetrical structure can better perform subsequent treatment, and the distance between the tabs 2 is also better determined; after the pole piece 1 is wound, the spaced pole lugs 2 are mutually overlapped, the first pole lug is overlapped with the third pole lug, the fifth pole lug, the seventh pole lug and the like, and the second pole lug is overlapped with the fourth pole lug, the sixth pole lug, the eighth pole lug and the like, so that two symmetrical pole lug groups 3 are formed. Since the two tab groups 3 are symmetrical about the center of the cell, all the tabs 2 constituting the tab groups 3 are arranged on a straight line on the end face of the cell.

Further, the number of the welding pieces 5 is the same as that of the tab group 3; if there is only one tab set 3, only 1 welding tab is required, and if the number of tab sets 3 is two, three or more, the same number of welding tabs 5 is required.

Further, in order to connect these welding tabs 5, the switching tab 4 further comprises a connecting tab 6. As shown in fig. 4-6, taking the number of the tab groups 3 as two as an example, two welding pieces 5 are needed, so that a switching piece 4 with a U-shaped structure is arranged, a connecting piece 6 is arranged in the middle, and two welding pieces 5 are respectively arranged on two sides of the connecting piece 6; before welding, the connecting sheet 6 is placed between the two positive electrode tab groups 12 parallel to the annular end face, the two welding sheets 5 are respectively attached to the two positive electrode tab groups 12, then welding flattening is carried out, and the welding sheets 5 are turned outwards to flatten the tab groups 3; after flattening, the connecting sheet 6 can be welded with the positive and negative metal terminals of the battery shell to assemble the battery, and the subsequent process belongs to mature technology and is not described in detail herein.

The connection pieces 6 may be disposed at the periphery of all the welding pieces 5, or the welding pieces 6 may be disposed at the center of the welding pieces 5, and it is preferable that the welding pieces 5 are disposed around the connection pieces 6 in consideration of the fact that flattening is required after the welding of the welding pieces 5 with the tab 2, as shown in fig. 4. If there are three tab groups 3, three welding tabs 5 are required, 3 welding tabs 5 may be provided around the connecting tab 6, with equal spacing angles between each welding tab 5.

Further, in order not to affect the subsequent processing steps, after the tab group 3 is flattened, neither the welding tab 5 nor the tab group 3 can exceed the edge of the end face of the battery cell. The cross section of the positive electrode tab 11 is rectangular; the cross-sectional shape of the welding piece 5 may be rectangular, or may be other cross-sectional shape as long as the welding requirements are satisfied and the edge of the annular end face is not exceeded.

Further, the pole piece 1 is provided with a clearance area 7, the clearance area 7 is arranged at the beginning end and/or the end of the pole piece 1 in the first direction, the pole lug 2 is arranged in an area outside the clearance area 7, for example, as shown in fig. 1, the pole lug 2 is arranged on 1/2 length of the middle of the pole piece 1 along the length direction of the pole piece 1, and 1/4 length of the head end and the tail end of the pole piece 1 is the clearance area 7. After the pole piece 1 is wound, the annular end face formed by winding the clearance area 7 is not provided with the pole lugs 2, so that the pole lug group 3 can be positioned at the central position of the annular end face, and a space is reserved for the subsequent placement of the transfer sheet 4 and flattening. The tab 2 may also be set from 1/3 of the pole piece 1, and this position may be adjusted according to the actual situation, as long as it does not deviate from the principle of the present utility model.

Further, the tab group 3 is formed by a single tab 2, and the distances between two adjacent tabs 2 can be equal or unequal; if the tab group 3 is composed of a plurality of tabs 2 overlapped with each other, as the winding radius of the pole piece 1 is gradually increased, in order to overlap with the tab 2 that has been previously wound, as shown in fig. 1, the distance between two adjacent tabs 2 is increased as the winding radius is increased in the first direction, i.e., the length direction of the pole piece 1.

Further, the pole piece 1 comprises a positive pole piece and a negative pole piece, the battery cell also comprises a diaphragm, and the positive pole piece, the diaphragm and the negative pole piece are sequentially stacked together and then wound to form the battery cell; the positive electrode tab group and the negative electrode tab group are respectively positioned at two ends of the battery cell and are perpendicular to the annular end face of the battery cell. Aluminum foil can be selected as a positive electrode plate, active materials are coated on the positive electrode plate, blank aluminum foil is reserved at the edge, and then die cutting is carried out on the blank aluminum foil at the edge to form a plurality of positive electrode lugs which are arranged at intervals; after the positive pole piece is wound, a plurality of positive pole lugs are mutually overlapped to form a positive pole lug group which is perpendicular to the annular end face of the positive pole piece, as shown in fig. 2; then the positive electrode transfer sheet is welded with the positive electrode tab group, the negative electrode transfer sheet is welded with the negative electrode tab group, the positive electrode transfer sheet can be made of aluminum material, and the negative electrode transfer sheet can be made of copper material.

A cylindrical battery comprising the cell of any one of the above.

Thus far, the technical solution of the present utility model has been described in connection with the preferred embodiments shown in the drawings, but it is easily understood by those skilled in the art that the scope of protection of the present utility model is not limited to these specific embodiments. Equivalent modifications and substitutions for related technical features may be made by those skilled in the art without departing from the principles of the present utility model, and such modifications and substitutions will fall within the scope of the present utility model.

Claims (10)

1. A cell, comprising:

the pole piece (1), the pole piece (1) is provided with a pole lug (2) along a first direction, after the pole piece (1) is wound, the pole lug (2) forms a pole lug group (3), and the pole lug group (3) is composed of a single pole lug (2) or a plurality of mutually overlapped pole lugs (2);

the battery cell comprises a battery cell, a lug group (3) and a switching piece (4), wherein the switching piece (4) is provided with a welding piece (5), the welding piece (5) is welded with the lug group (3), and the switching piece (4) is turned outwards through the welding piece (5) to flatten the lug group (3) on the end face of the battery cell.

2. The cell of claim 1, wherein the cell comprises a plurality of conductive traces,

the number of the tab groups (3) is at least 2.

3. The cell of claim 2, wherein the cell comprises a plurality of conductive traces,

the number of the welding pieces (5) is the same as that of the tab groups (3).

4. The cell of claim 3, wherein the cell,

the adapter piece (4) further comprises a connecting piece (6), the connecting piece (6) is used for connecting a plurality of welding pieces (5), and the welding pieces (5) are arranged around the connecting piece (6).

5. The cell of claim 1, wherein the cell comprises a plurality of conductive traces,

after the tab group (3) is flattened, the welding piece (5) does not exceed the edge of the end face of the battery cell.

6. The cell of claim 1, wherein the cell comprises a plurality of conductive traces,

the pole piece (1) is provided with a clearance area (7), the clearance area (7) is arranged at the starting end and/or the tail end of the pole piece (1) in the first direction, and the pole lug (2) is arranged in an area outside the clearance area (7).

7. The cell of claim 1, wherein the cell comprises a plurality of conductive traces,

along the first direction, the distance between two adjacent tabs (2) gradually increases.

8. The cell of claim 7, wherein the cell comprises a plurality of conductive traces,

the number of the electrode lug groups (3) is two, the two electrode lug groups (3) are symmetrically arranged, and all the electrode lugs (2) are arranged on one straight line on the end face of the battery cell.

9. The cell according to any of claims 1-8, wherein the pole piece (1) comprises a positive pole piece and a negative pole piece.

10. A cylindrical battery comprising a cell according to any one of claims 1-9.