CN114171829A

CN114171829A - Battery and battery device

Info

Publication number: CN114171829A
Application number: CN202210129414.9A
Authority: CN
Inventors: 许久凌; 许博伟; 张璐璐
Original assignee: China Lithium Battery Technology Co Ltd
Current assignee: China Lithium Battery Technology Co Ltd
Priority date: 2022-02-11
Filing date: 2022-02-11
Publication date: 2022-03-11
Anticipated expiration: 2042-02-11
Also published as: CN114171829B

Abstract

The application relates to the technical field of batteries and discloses a battery and a battery device. The battery comprises a lower shell and an upper shell, wherein the lower shell and the upper shell are sealed through welding, the sealing welding line is composed of at least two welding tracks arranged on the peripheral side of the battery shell, and the welding track on each peripheral side is a continuous straight line. In the battery provided by this embodiment, the sealing weld line between the lower case and the upper case is surrounded by a plurality of welding tracks, each peripheral side welding track is a continuous straight line, and the corners of adjacent peripheral sides do not have arc-shaped transitional welding tracks; compared with a mode of transition connection by adopting a welding track of the arc section, the welding track of the straight line type is only adopted, so that the control precision of the welding head is guaranteed during welding, the linear speed of the welding head is kept stable, phenomena such as broken welding or insufficient welding are avoided, welding failure can be avoided, the welding sealing yield of the battery shell can be improved, and the safety performance of the battery is further improved.

Description

Battery and battery device

Technical Field

The invention relates to the technical field of batteries, in particular to a battery and a battery device.

Background

In the square battery in the prior art, the edge corner of the shell is an arc-shaped R corner, when the shell is subjected to sealing welding, an arc-shaped welding track is formed in the corner, and due to the fact that the control accuracy of a welding head is insufficient, when four R corners are welded, the linear velocity at the R corner position and the linear velocity at a linear position cannot be completely consistent, namely, a welding pool at the corner position cannot be pushed away, so that a cold joint or a broken joint phenomenon often easily occurs at the corner position, and welding sealing failure is caused.

Disclosure of Invention

The invention provides a battery and a battery device for improving the sealing performance of the battery.

In a first aspect, the present application provides a battery including a lower case and an upper case, the lower case and the upper case being sealed by welding, the seal weld line being composed of at least two weld traces provided on the peripheral side of the battery case, and the weld trace on each peripheral side being a continuous straight line.

In the battery provided by this embodiment, the sealing weld line between the lower case and the upper case is surrounded by a plurality of welding tracks, each peripheral side welding track is a continuous straight line, and the corners of adjacent peripheral sides do not have arc-shaped transitional welding tracks; compared with a mode of transition connection by adopting a welding track of the arc section, the welding track of the straight line type is only adopted, so that the control precision of the welding head is guaranteed during welding, the linear speed of the welding head is kept stable, phenomena such as broken welding or insufficient welding are avoided, welding failure can be avoided, the welding sealing yield of the battery shell can be improved, and the safety performance of the battery is further improved.

In addition, a continuous and uninterrupted welding track is adopted on each peripheral side of the battery shell, so that the welding energy is continuous and stable, the welding efficiency can be improved, the welding strength and yield of each welding track can be ensured, and the sealing yield of the battery shell on each peripheral side is improved.

In a second aspect, the present application provides a battery device, wherein the battery module includes the above battery.

In the battery device provided by the embodiment, the welding sealing yield of the battery shell is high, the phenomena of broken welding or insufficient welding and the like are not easy to occur, the sealing effect of the battery shell can be improved, and the safety performance of the battery device is further improved.

Drawings

For a better understanding of the invention, reference may be made to the embodiments illustrated in the following drawings. The components in the drawings are not necessarily to scale, and some relevant components may be omitted in order to emphasize and clearly illustrate the technical features of the present disclosure. In addition, the relevant elements or components may be arranged differently as is known in the art.

Fig. 1 is a schematic cross-sectional view of a battery case according to an embodiment of the present invention;

fig. 2 is a schematic top view of a battery case according to an embodiment of the present invention;

fig. 3 is a schematic top view of a battery case according to an embodiment of the present invention;

fig. 4 is a schematic top view of a lower case of a battery case according to an embodiment of the present invention;

fig. 5 is an exploded view of a battery according to an embodiment of the present invention.

Reference numerals:

1-a lower shell; 10-opening; 11-flanged edge; 12-inner periphery; 13-outer periphery; 2-an upper shell;

3-sealing the welding line; 31-welding track; 4-explosion-proof wire; and 5-electric core.

Detailed Description

The technical solutions in the exemplary embodiments of the present disclosure will be clearly and completely described below with reference to the drawings in the exemplary embodiments of the present disclosure. The example embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the present disclosure, and it is, therefore, to be understood that various modifications and changes may be made to the example embodiments without departing from the scope of the present disclosure.

In a first aspect, as shown in fig. 1, 2, 3 and 5, the present application provides a battery comprising a lower case 1 and an upper case 2, the lower case 1 and the upper case 2 being sealed by welding, the sealing weld line 3 of which is composed of at least two weld traces 31 disposed on the peripheral side of the battery case, each weld trace 31 on the peripheral side being a continuous straight line.

In the battery provided by the embodiment, the sealing weld line 3 between the lower casing 1 and the upper casing 2 is surrounded by a plurality of welding tracks 31, each welding track 31 on the peripheral side is a continuous straight line, and the corners of adjacent peripheral sides do not have arc section transition welding tracks; compared with a mode of transition connection by adopting a welding track of an arc section, the welding track only adopts the linear welding track 31, so that the control precision of a welding head is guaranteed during welding, the linear speed of the welding head is kept stable, the phenomena of broken welding or insufficient welding and the like are avoided, the welding failure can be avoided, the welding sealing yield of the battery shell can be improved, and the safety performance of the battery is further improved.

In addition, a continuous and uninterrupted welding track 31 is adopted on each peripheral side of the battery shell, so that the welding energy is continuously and stably, the welding efficiency can be improved, the welding strength and the yield of each welding track 31 can be ensured, and the sealing yield of the battery shell on each peripheral side is improved.

In some embodiments, as shown in fig. 2 and 3, at least two of the sealing weld lines 3 intersect with each other, and the welding tracks 31 are connected to each other, so that the sealing weld lines 3 can be closed to achieve a sealing effect.

Illustratively, the sealing weld line 3 is composed of four weld traces 31, the four weld traces 31 are respectively located around the battery case, and any two adjacent weld traces 31 are in a cross connection and are in a shape of a Chinese character 'jing', so that a closed loop of the sealing weld line 3 is realized, and the sealing weld effect is achieved.

Of course, the sealing weld line 3 may not present a closed loop, for example, two adjacent welding tracks 31 are not connected, and in this case, the two welding tracks 31 may be sealed and connected by other means, so as to achieve the effect of sealing and connecting the lower case 1 and the upper case 2, for example, by means of local adhesion.

In addition, the sealing weld line 3 is not limited to be composed of four welding traces 31, for example, the lower case 1 and the upper case 2 may be integrally formed, and the two are directly connected at one side edge, and in actual use, the upper case 2 is turned over and turned over on the lower case 1 by using the side edge as a pivot axis, and then the two are welded at other involutory edges, thereby achieving case sealing. That is, one peripheral sides of the lower case 1 and the upper case 2 are integrally connected, and the other three peripheral sides can be welded by using three welding traces, in this case, the seal weld line 3 is composed of three welding traces 31.

In some embodiments, as shown in fig. 1, 4 and 5, the lower shell 1 is provided with a flange 11, and the flange 11 is disposed around the opening 10 of the lower shell 1 and has a ring structure; specifically, the inner periphery 12 of the flange 11 is square, and the corners of the square inner periphery 12 are arc-shaped, that is, the inner wall of the lower casing 1 encloses a square area, and the corners of the inner wall of the lower casing 1 are arc-shaped.

Illustratively, as shown in fig. 1, 2, 3 and 4, the upper case 2 is seal-welded to a flange 11 of the lower case 1, the sealing weld line 3 is disposed on the flange 11, and the sealing weld line 3 is at a right angle at a corner of an inner periphery 12 of the flange 11.

Specifically, the right angle corner of the arc-shaped corner of the inner wall of the lower shell 1 is matched with the sealing weld line 3, so that the corner of the battery shell has a larger space for storing gas, the larger the battery is, the more corresponding gas production is, the more spaces for storing gas are reserved at the corner, and the situation that the large surface and the side surface of the battery shell bulge can be avoided. Like this, can avoid regulating and control the gas storage space through adjusting battery elasticity ratio, if adjust battery elasticity ratio, the battery is inside too loose then corresponding internal resistance is great, and too tight can lead to unable the recovering after the electric core inflation, influences electric core life, consequently, adjusts and controls the gas storage space through adjusting battery elasticity ratio concrete implementation nature relatively poor.

In addition, the arc-shaped corner of the inner wall of the lower shell 1 is matched with the right-angle corner of the sealing welding line 3, so that the arrangement space at the corner of the flange edge 11 is larger, the arrangement of the explosion-proof line 4 at the corner of the flange edge 11 is facilitated, and explosion is carried out through the corner.

In some embodiments, as shown in fig. 1, 2, 3, 4 and 5, the lower case 1 is provided with a flange 11, the flange 11 is disposed around the opening 10 of the lower case 1, the periphery 13 of the flange 11 is square, and the corners of the square periphery 13 are arc-shaped. Further, the upper shell 2 is hermetically welded with the flange 11, and the outer periphery of the upper shell 2 does not exceed the outer periphery 13 of the flange 11, i.e. the outer periphery 13 of the flange 11 is the outermost periphery of the whole battery shell; specifically, the outer peripheral edge of the upper housing 2 is aligned with the outer peripheral edge 13 of the flange 11, or is recessed by a certain dimension with respect to the outer peripheral edge 13 of the flange 11.

Specifically, set up to the arc with the periphery 13 corner of flange 11, for conventional right-angle shape, can avoid appearing the circumstances of point discharge, in addition, can avoid between battery case and the battery case mutual fish tail to lead to electric leakage and/or short circuit to, can also avoid the fish tail workman, thereby be favorable to transport and later stage in groups.

Illustratively, as shown in fig. 1 and 5, the upper case 2 may have a cover plate structure, and directly covers the opening of the lower case 1, and the outer peripheral edge of the upper case 2 is the outer peripheral edge of the cover plate. Or, the upper casing 2 may be a shell type structure, the upper casing 2 is also provided with a flange, the flange of the upper casing 2 is connected with the flange 11 of the lower casing 1, and the outer peripheral edge of the upper casing 2 refers to the outer side edge of the flange.

In some embodiments, as shown in fig. 2 and 3, the battery of the present embodiment is further provided with an explosion-proof wire 4.

Illustratively, as shown in fig. 1 and 3, the explosion-proof wire 4 is disposed at a corner of an opening edge of the lower case 1, that is, the explosion-proof wire 4 is disposed at a corner of the sealing weld line 3.

The space at the corner of the edge of the opening of the lower shell 1 is large, so that the explosion-proof wire 4 can be conveniently arranged; in addition, the gas storage space at the corner is large, the stress is concentrated, and the local directional blasting function is convenient to realize.

Alternatively, the explosion-proof wire 4 may not be disposed at the corner, for example, as shown in fig. 2, the explosion-proof wire 4 is disposed along a certain welding track 31, that is, along a certain side edge of the opening of the lower case 1.

Illustratively, the explosion-proof line 4 is formed by welding the lower shell 1 and the upper shell 2, that is, the explosion-proof line 4 is a section of welding line area formed by welding the lower shell 1 and the upper shell 2, and specifically, the explosion-proof line 4 is located on the inner side of the sealing welding line 3, that is, in the sealing area of the upper shell and the lower shell 1.

Specifically, the explosion-proof line 4 is disposed in the sealing region, and is formed by welding the lower case 1 and the upper case 2, and as the stress concentration region, when the internal gas pressure increases to the critical pressure, the explosion-proof line 4 is cracked earlier than the sealing weld line 3 so that the gas in the battery is released.

In the embodiment, the explosion-proof line 4 is formed by welding the prefabricated stress concentration points, and the original mode of independently designing the explosion-proof valve is replaced, so that the processing technology can be simplified, the battery manufacturing procedure can be shortened, and the battery assembly cost can be reduced; moreover, the design of the explosion-proof wire 4 is suitable for various batteries, is not limited by the thickness of the battery shell, has strong universality and can effectively ensure the safety performance of various batteries.

For example, in the case of a battery having an ultra-thin case, since the case is thin, it is not suitable to provide a weak area such as a scratch or a thinned portion on the case to form an explosion-proof area, and in this case, the function of local directional explosion can be achieved by providing the explosion-proof line 4 in a welded form.

Of course, the explosion-proof line in the present application is not limited to the form of a welding line formed by welding the lower housing 1 and the upper housing 2, and may be in other forms such as scratches, which may be determined according to actual requirements.

Illustratively, as shown in fig. 2 and 3, the length of the explosion-proof wire 4 is less than the length of any one of the welding tracks 31. The explosion-proof wire 4 has a shorter welding length and more concentrated stress, and will rupture earlier than the sealing weld line 3, so that the gas in the battery can be released.

Illustratively, the ratio of the projection length of the explosion-proof wire 4 on any one welding track 31 to the length of the welding track 31 is less than 1/2.

The length of the welding line of the explosion-proof wire 4 is shorter, so that the stress is concentrated, and the length of the explosion-proof wire 4 is smaller than the length of the welding track of the normal battery package; in this embodiment, to the setting of the length ratio of explosion-proof line 4 and welding track 31, can make explosion-proof line 4 preferentially explode under specific pressure, and then make the gas in the battery in time get rid of, avoid taking place the safety risk.

In some embodiments, as shown in fig. 2 and 3, the explosion-proof thread 4 is in a sharp angle shape, that is, the explosion-proof thread 4 is a folding line and is surrounded with a sharp corner. The local position of the welding wire is prefabricated into a sharp corner shape, a stress concentration point can be formed, when the internal air pressure is increased to critical pressure, the sharp corner cracks in advance compared with the welding wire at a normal straight position due to stress concentration, an exhaust channel is formed, and gas is exhausted in time. Specifically, the size of the opening of the explosion-proof valve can be controlled by designing the opening and closing angle alpha, the height h and the like of the sharp corner.

Illustratively, the angle α of the sharp corner of the explosion-proof line 4 is 30 ° to 180 °, i.e., greater than or equal to 30 ° and less than 180 °, and may specifically be 30 °, 60 °, 90 °, 120 °, 150 °, for example. Further, the height h of the sharp corner may be 1mm to 5mm, for example, 1mm, 2mm, 3mm, 4mm, 5 mm. Specifically, the sharp corner belongs to one corner of the triangle, and the height h of the sharp corner refers to the distance between the sharp corner and the side of the triangle opposite to the sharp corner.

Specifically, through selecting the angle alpha, the height h, the setting position and the like of the sharp corner of the explosion-proof valve, the battery can be controlled to exhaust at a specific position under a specific air pressure condition at a specific exhaust amount.

Of course, the explosion-proof line 4 is not limited to the pointed shape in the above embodiment, and may be in the shape of, for example, a circular arc, a straight line, or the like.

In some embodiments, the explosion proof wire 4 is connected to the seal weld wire 3. Thus, the effect of stress concentration can be further improved, and the explosion-proof wire 4 is guaranteed to be exploded preferentially under specific pressure.

Specifically, as shown in fig. 5, the battery provided by the present application further includes a battery cell 5 located in the battery case, where the battery cell 5 is sealed between the upper casing 2 and the lower casing 1.

Specifically, the battery provided by the present application is a square battery, for example, a square lithium ion battery.

In a second aspect, the present application also provides a battery device comprising a battery as in any of the above.

Specifically, the battery device can be a battery module or a battery pack.

Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the disclosed invention. This disclosure is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the disclosure and including such departures from the present disclosure as come within known or customary practice within the art to which the disclosure pertains. It is intended that the specification and example embodiments be considered as exemplary only, with a true scope and spirit of the disclosure being indicated by the following claims.

It will be understood that the present disclosure is not limited to the precise arrangements described above and shown in the drawings and that various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims

1. A battery is characterized by comprising a lower shell and an upper shell, wherein the lower shell and the upper shell are sealed by welding, a sealing welding line is composed of at least two welding tracks arranged on the peripheral side of a battery shell, and the welding track on each peripheral side is a continuous straight line.

2. The battery of claim 1, wherein at least two of the welding traces intersect.

3. The battery according to claim 2, wherein the seal bonding wire is composed of four of the welding tracks disposed on four sides of the battery case, respectively, and any two adjacent welding tracks are connected in a crisscross manner.

4. The battery according to claim 1, wherein the lower case is provided with a flange, an inner circumference of the flange is formed in a square shape, corners of the inner circumference of the flange are formed in a circular arc shape, the sealing weld line is provided on the flange, and the sealing weld line is formed at right angles at the corners of the inner circumference of the flange.

5. The battery according to claim 1, wherein the lower case is provided with a flange having a square outer circumference, and corners of the outer circumference of the flange are rounded; the upper shell and the flange edge are welded in a sealing mode, and the periphery of the upper shell does not exceed the periphery of the flange edge.

6. The battery according to any one of claims 1 to 5, further comprising an explosion-proof wire provided at a corner of an opening edge of the lower case.

7. The battery of claim 6, wherein the explosion proof wire is formed by welding the lower case and the upper case, inside the seal weld line.

8. The battery of claim 6, wherein the length of the explosion-proof wire is less than the length of any of the welding tracks.

9. The battery of claim 6, wherein the ratio of the projected length of the explosion proof wire on any one of the welding tracks to the length of the welding track is less than 1/2.

10. The battery of claim 6 wherein said explosion proof wire is connected to said seal weld line.

11. The battery of claim 6, wherein the explosion-proof wire is in the shape of a sharp corner.

12. The battery of claim 11, wherein the explosion-proof line has a sharp angle of greater than or equal to 30 ° and less than 180 °.

13. A battery device comprising a battery according to any of claims 1-12.