CN216528987U

CN216528987U - Secondary battery

Info

Publication number: CN216528987U
Application number: CN202122311767.4U
Authority: CN
Inventors: 武冬冬; 李恺
Original assignee: Jiangsu Zenio New Energy Battery Technologies Co Ltd
Current assignee: Jiangsu Zenio New Energy Battery Technologies Co Ltd
Priority date: 2021-09-24
Filing date: 2021-09-24
Publication date: 2022-05-13
Anticipated expiration: 2031-09-24

Abstract

The utility model discloses a secondary battery, which comprises a shell, an electrode assembly, a current collecting component and a top cover assembly, wherein the electrode assembly is accommodated in the shell and comprises a main body part and a first tab, and the first tab extends from one transverse end of the main body part; the current collecting component comprises a first substrate, the first substrate is connected with the first tab along the transverse direction and divides the first tab into an extending section and a connecting section, the part overlapped with the first substrate is the connecting section, and the part not overlapped with the first substrate is the extending section; the connecting section is folded back from the extending section along the longitudinal direction, and one side of the first substrate is clamped at the turning position of the extending section and the connecting section; the top cover assembly comprises a top cover plate and a first electrode terminal arranged on the top cover plate, and the first electrode terminal is connected with one end of the first substrate. Compared with the prior art, the secondary battery not only improves the transverse space utilization rate of the battery, but also is simple to process, damages the pole piece in the bending process, and has higher reliability.

Description

Secondary battery

Technical Field

The utility model relates to the field of secondary batteries, in particular to a secondary battery.

Background

The secondary battery generally includes an electrode assembly, a case, electrode terminals, and a current collecting member for electrically connecting the electrode assembly and the electrode terminals. In the molding process of the secondary battery, it is general to weld the tabs of the electrode assembly to the current collecting member and then bend the current collecting member and the tabs to reduce the space occupied by the current collecting member and the tabs. For example, in chinese patent CN208819970U, after the bendable pins are welded to the tabs, and the welding marks are changed from being parallel to the pole pieces to being perpendicular to the pole pieces, thereby saving the width space of the battery, improving the space utilization of the battery, and further improving the energy density. But this kind of structure exists to buckle to realize the degree of difficulty height, and can cause the problem of pole piece damage, and the reliability is low. Therefore, it is necessary to provide a technical solution to the above-mentioned problems.

SUMMERY OF THE UTILITY MODEL

The utility model aims to: aiming at the defects in the prior art, the utility model provides the secondary battery, and the battery provided by the utility model not only improves the transverse space utilization rate of the battery, but also has simple processing and higher reliability.

In order to achieve the purpose, the utility model adopts the following technical scheme:

a secondary battery comprising:

a housing;

an electrode assembly housed in the case, the electrode assembly including a main body portion and a first tab extending from one end of the main body portion in a transverse direction;

the current collecting component comprises a first substrate, the first substrate is connected with the first tab along the transverse direction and divides the first tab into an extending section and a connecting section, the part overlapped with the first substrate is the connecting section, and the part not overlapped with the first substrate is the extending section; the connecting section is folded back from the extending section along the longitudinal direction, and one side of the first substrate is clamped at the turning position of the extending section and the connecting section;

the top cover assembly comprises a top cover plate and a first electrode terminal arranged on the top cover plate, the top cover plate is connected with the shell, and the first electrode terminal is connected with one end of the first substrate.

Preferably, the length ratio of the extension section to the connection section is (1:9) - (7: 3).

Preferably, the main body part comprises a first battery cell and a second battery cell which are arranged along the longitudinal direction; one end of each of the first battery cell and the second battery cell extends to form a first tab; the first electrode lug of the first battery cell and the first electrode lug of the second battery cell are respectively connected to the same side of the first substrate along the transverse direction, and the two sides of the first substrate are respectively clamped at the turning positions of the extension section and the connection section of the first electrode lugs.

Preferably, the connecting section of one of the first tabs is folded back from the extending section thereof in the longitudinal direction, and the extending section of the other first tab is folded back from the connecting section thereof in the transverse direction.

Preferably, a first gap is left between the connecting sections of the two first tabs.

Preferably, the first substrate is welded to the connecting section, and the welding mark of the connecting section, which is folded back and is perpendicular to the main body portion, is formed on the first substrate.

Preferably, the first substrate extends in a height direction and is folded back in a transverse direction to be connected to the first electrode terminal.

Preferably, the other ends of the first battery cell and the second battery cell in the transverse direction extend to form a second tab; the current collecting member further includes a second substrate; the top cap assembly further comprises a second electrode terminal disposed on the top cap plate; one end of the second substrate is connected with the two second pole lugs, and the other end of the second substrate is connected with the second electrode terminal.

Preferably, the second substrate is welded to the two second pole pieces, and the welding mark is parallel to the main body portion.

Preferably, the second substrate extends in a height direction and is folded back in a transverse direction to be connected to the second electrode terminal.

Compared with the prior art, the utility model has the beneficial effects that: the secondary battery provided by the utility model has the advantages that the first substrate and the first electrode lug are connected together, the electrode lug is divided into the extension section and the connection section by taking the extension section and the extension section as boundaries, and then the first substrate is bent from the adjacent position of the connection section and the extension section so as to be clamped at the turning position of the connection section and the extension section, so that the utilization rate of the transverse space of the battery is improved, the first substrate is not bent, the connection section of the electrode lug is bent to drive the first substrate to be recycled, the bending realization difficulty is low, meanwhile, the extension section still exists between the connection section and the electrode component main body part, the electrode piece is not damaged in the bending process, the processing is simple, and the reliability of the integral preparation is higher.

Drawings

Fig. 1 is a front view of a secondary battery according to the present invention.

Fig. 2 is a plan view of the secondary battery of the present invention.

Fig. 3 is a plan view of the secondary battery of the present invention without a case.

Fig. 4 is a front view of a secondary battery connecting section according to the present invention when it is connected to a first substrate.

In the figure: 1-an electrode assembly; 11-a body portion; 111-a first cell; 112-a second cell; 12-a first tab; 121-a connecting segment; 122-an extension; 13-a second tab; 21-a first substrate; 22-a second substrate; 3-a top cover assembly; 31-a top cover plate; 32-a first electrode terminal; 33-a second electrode terminal; 4-shell.

Detailed Description

In order to make the technical solutions and advantages of the present invention clearer, the present invention and its advantages will be described in further detail below with reference to the following detailed description and the accompanying drawings, but the embodiments of the present invention are not limited thereto.

In the description of the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "fixed" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral part; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

The terms "first", "second", and the like, as used herein, are used to define components, are used only for convenience of distinguishing corresponding components, and have no special meaning if not stated otherwise, and therefore, should not be construed as limiting the scope of the present application.

The secondary battery of the present invention may be a lithium ion battery or a sodium ion battery.

The secondary battery, as shown in fig. 1, includes a case 4, an electrode assembly 1, a current collecting member, and a cap assembly 3.

Wherein, the electrode assembly 1 is accommodated in the casing 4, and comprises a main body part 11 and a first tab 12, and the first tab 12 extends from one end of the main body part 11 along the transverse direction; the main part 11 includes at least one naked electric core, can be 2, 4, 6 etc, and this first utmost point ear 12 refers to the utmost point ear of stretching out on a naked electric core, and this first utmost point ear 12 welding is on naked electric core or with naked electric core integrated into one piece, can be full utmost point ear, unipolar ear or many utmost point ears. The above-mentioned lateral direction is the X direction. Further, a second tab 13 extends from one end of the body 11 in the transverse direction, and the second tab 13 may be provided at the same end as the first tab 12 or may be a different end.

The bare cell comprises a first pole piece, a second pole piece with the polarity opposite to that of the first pole piece and a diaphragm arranged between the first pole piece and the second pole piece at intervals, and can be manufactured by winding or lamination.

The top cap assembly 3 includes a top cap plate 31 and first and

second electrode terminals

32 and 33 provided to the top cap plate 31, and the top cap plate 31 is coupled to the case 4 and covers the opening of the case 4, thereby enclosing the electrode assembly 1 within the case 4. The first electrode terminal 32 is electrically connected to the first tab 12, and the second electrode terminal 33 is electrically connected to the second tab 13.

The current collecting member includes a first base plate 21, the first base plate 21 is connected with the first tab 12 along the transverse direction and divides the first tab 12 into an extension section 122 and a connection section 121, the portion overlapping with the first base plate 21 is the connection section 121, and the portion not overlapping with the first base plate 21 is the extension section 122; the connection section 121 is folded back from the extension section 122 in the longitudinal direction and clamps one side of the first substrate 21 at the turning point of the extension section 122 and the connection section 121. The longitudinal direction is the Y direction.

The connection between the connection segment 121 and the first substrate 21 is welding, which may be any one of ultrasonic welding, laser welding or resistance welding, and the welding mark of the connection segment 121, which is folded back and the first substrate 21, is perpendicular to the main body 11. Preferably, the welding of the connection segment 121 to the first substrate 21 is ultrasonic welding. Compared with the bending mode of patent CN208819970U, the structure of the present invention does not bend the first substrate 21, and only drives the first substrate 21 to rotate through the connecting section 121, so that the solder marks of the connecting section 121 and the first substrate 21 are perpendicular to the main body portion 11, which reduces the bending difficulty and has wider usability.

When the first tab 12 is a multi-tab, the tabs are dislocated and extend from the main body 11 along the transverse end, the relative distance of all the first tabs 12 in the height direction is smaller than the width of the main body 11, and the relative distance of all the first tabs 12 in the longitudinal direction is smaller than the thickness of the battery cell, so that the interference of the battery cell thickness on the welding position of the connecting section 121 and the first substrate 21 is avoided.

The bonding area between the connecting segment 121 and the first substrate 21 may be 60-100% of the overlapping area between the connecting segment 121 and the first substrate 21, and if 100%, the two are in a full bonding state. Preferably, the welding area of the connection section 121 and the first substrate 21 may be 70-92% of the overlapping area of the connection section 121 and the first substrate 21, so as to avoid welding at the connection position of the connection section 121 and the extension section 122, and further facilitate the folding back of the connection section 121, and further clamp one side of the first substrate 21 at the turning position of the extension section 122 and the connection section 121.

After the connection segment 121 is folded back, the first substrate 21 extends along the height direction and is folded back in the transverse direction to be welded with the first electrode terminal 32, so as to lead out the tab.

Further, the length ratio of the extension section 122 to the connection section 121 is (1:9) to (7: 3). More preferably, the length ratio of the extension 122 to the connection segment 121 is (2:8) to (6: 4). It is further preferred that the length of the extension section 122 is less than or equal to the length of the connection section 121. The length of the extension section 122 is relatively short, the transverse space utilization rate of the battery is higher, the larger the connection area between the connection section 121 and the first substrate 21 is, the firmer the connection between the connection section and the first substrate is, and the overcurrent capacity is also stronger.

Specifically, the main body portion 11 includes a first battery cell and a second battery cell arranged in a longitudinal direction; a first tab 12 extends from one end of the first cell and one end of the second cell; the first tab 12 of the first cell and the first tab 12 of the second cell are respectively connected to the same surface of the first substrate 21 along the transverse direction, the surface is a large surface of the first substrate 21, and after being folded back, two sides of the first substrate 21 are respectively clamped at the turning positions of the extension section 122 and the connection section 121 of the two first tabs 12. This first electric core and second electric core are foretell naked electric core promptly.

The specific folding mode is as follows: the connection section 121 of one of the first tabs 12 is folded back from the extension section 122 thereof in the longitudinal direction, and the extension section 122 of the other first tab 12 is folded back from the connection section 121 thereof in the transverse direction. Therefore, with one battery cell as a base point, the connection section 121 of the battery cell is folded back from the extension section 122 thereof along the longitudinal direction, so as to drive the first substrate 21 and the other battery cell to be folded back, and then the extension section 122 of the other battery cell is folded back from the connection section 121 thereof along the transverse direction, so that the first battery cell and the second battery cell are changed from the initial transverse arrangement to the longitudinal arrangement, and the welding print of the connection section 121 and the first substrate 21 is changed from being parallel to being perpendicular to the main body portion 11.

After the first cell and the second cell are changed to be arranged in the longitudinal direction, the first substrate 21 extends in the height direction and is folded back in the transverse direction to be connected to the first electrode terminal 32. The height direction is the Z direction. The first substrate 21 has a square cross-sectional view before being folded back, and is turned into an l-shape after being connected to the first electrode terminal 32, wherein the bar is connected to the first electrode terminal 32, and the bar is connected to the first tab 12.

Preferably, a first gap is left between the connection sections 121 of the two first tabs 12. That is, a first gap is left in the welding of the first tab 12 of the first cell and the second cell on the first substrate 21, which is more favorable for welding the first tab 12 on the first substrate 21, and the welding is prevented from being influenced by the contact of the two tabs.

In addition, the other ends of the first cell and the second cell in the transverse direction extend to form a second pole lug 13; the second tab 13 is electrically connected to the second electrode terminal 33. When the second tab 13 is a multi-tab, the tabs are dislocated and extend from the main body 11 along the transverse end, and the relative distance of all the second tabs 13 in the height direction is smaller than the width of the main body 11, so that the problem of reduction of welding reliability caused by excessive tab layers can be avoided, a certain dislocation welding mode is designed, and the number of layers of single welding can be reduced.

The current collecting member further includes a second substrate 22, and the second tab 13 is welded to the second substrate 22, and the second substrate 22 is welded to the second electrode terminal 33, thereby electrically connecting the second tab 13 to the second electrode terminal 33.

One of the specific connection methods of the second electrode tab 13 and the second substrate 22 is as follows: the second base plate 22 is welded to the second tabs 13 of the two cells in the transverse direction, the weld is parallel to the main body 11, and then the second base plate 22 extends in the height direction and is folded back in the transverse direction to be connected to the second electrode terminal 33. The welding means may be any one of ultrasonic welding, laser welding or resistance welding.

The second connection mode of the second electrode tab 13 and the second substrate 22 is: the second tab 13 of the first cell and the second tab 13 of the second cell are respectively welded to one side of the second substrate 22 away from the main body 11 after being bent, and the second substrate 22 extends along the height direction and is folded back in the transverse direction to be connected with the second electrode terminal 33. The welding means may be any one of ultrasonic welding, laser welding or resistance welding.

Variations and modifications to the above-described embodiments may also occur to those skilled in the art, which fall within the scope of the utility model as disclosed and taught herein. Therefore, the present invention is not limited to the above-mentioned embodiments, and any obvious improvement, replacement or modification made by those skilled in the art based on the present invention is within the protection scope of the present invention. Furthermore, although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.

Claims

1. A secondary battery, characterized by comprising:

a housing;

the electrode assembly is accommodated in the shell and comprises a main body part and a first tab, and the first tab extends from one transverse end of the main body part to form an extension section and a connection section in sequence;

a current collecting member including a first substrate connected with the connection section in a transverse direction; the connecting section is folded back from the extending section along the longitudinal direction, and one side of the first substrate is clamped at the turning position of the extending section and the connecting section;

2. The secondary battery according to claim 1, wherein the length ratio of the extension section to the connection section is (1:9) to (7: 3).

3. The secondary battery of claim 1, wherein the main body portion comprises a first cell and a second cell arranged in a longitudinal direction; one end of each of the first battery cell and the second battery cell extends to form a first tab; the first electrode lug of the first battery cell and the first electrode lug of the second battery cell are respectively connected to the same surface of the first substrate along the transverse direction, and the two sides of the first substrate are respectively clamped at the turning positions of the extending sections and the connecting sections of the first electrode lugs.

4. The secondary battery according to claim 3, wherein the connection section of one of the first tabs is folded back in a longitudinal direction from the extension section thereof, and the extension section of the other of the first tabs is folded back in a transverse direction from the connection section thereof.

5. The secondary battery according to claim 4, wherein a first gap is left between the connection sections of the two first tabs.

6. The secondary battery according to claim 4, wherein the first substrate is welded to the connection section, and the welding mark of the connection section, which is folded back, is perpendicular to the main body portion.

7. The secondary battery according to claim 3, wherein the first substrate extends in a height direction and is connected to the first electrode terminal by being folded back in a transverse direction.

8. The secondary battery of any one of claims 3 to 7, wherein the other ends of the first cell and the second cell in the transverse direction extend to form a second tab; the current collecting member further includes a second substrate; the top cap assembly further comprises a second electrode terminal disposed on the top cap plate; one end of the second substrate is connected with the two second pole lugs, and the other end of the second substrate is connected with the second electrode terminal.

9. The secondary battery of claim 8, wherein the second substrate is welded to both of the second tabs and the solder printing is parallel to the body portion.

10. The secondary battery according to claim 9, wherein the second substrate extends in a height direction and is folded back in a transverse direction to be connected with the second electrode terminal.