Welded battery cell

Abstract

The utility model relates to the technical field of battery cells, and provides a welding battery cell, which comprises a lower shell assembly, an upper shell assembly and a lower shell assembly, the roll core is fixed in the accommodating cavity; the shell cover is connected to the opening and used for sealing the roll core, a shell cover flange is arranged on the periphery of the shell cover, and after the battery core is welded, a part of the shell cover flange is used for forming a welding area. Compared with the prior art, the lower shell assembly has the advantages that the lower shell flange is arranged at the joint of the shell cover and the lower shell assembly, when the roll core expands to extrude the shell cover, the lower shell flange absorbs extrusion force transmitted by the shell cover and stretches, and the situation that a large-area central area of the shell cover is not restrained and is low in rigidity is avoided; and finally, the service life of the battery cell is prolonged.

Description

Technical Field

[0001] The utility model relates to the technical field of battery cores, in particular to a welding battery core. Background Art

[0002] The structural characteristics of traditional square-shell battery cells result in a large area of ​​the battery cell shell being constrained at the four edges, preventing it from stretching freely. During the use of the battery cell, when the internal core expands, the expansion of the core on the four sides of the shell is restricted, causing the core to be under greater pressure at these locations. In contrast, the large central area of ​​the shell has lower rigidity due to the lack of constraints and is prone to bulging outward. Therefore, the force distribution of the core in traditional square-shell battery cells is extremely uneven. According to simulation results, the force difference between the edge and center of the core can be more than four times. This uneven force directly affects the cycle life of the battery cell. Utility Model Content

[0003] The technical problem to be solved by the utility model is to provide a welding battery core in view of the current status of the existing technology.

[0004] The technical solution adopted by the present invention to solve the above technical problems is as follows: a welding battery cell is proposed, comprising: a lower shell assembly, in which a receiving cavity and an opening communicating with the receiving cavity are provided;

[0005] a winding core fixed in the accommodating cavity;

[0006] A shell cover is connected to the opening for sealing the winding core, and a shell cover flange is constructed on the periphery of the shell cover. After the battery core is welded, a part of the shell cover flange is used to form a welding area; wherein,

[0007] The shell cover flange can be stretched when the winding core is expanded to provide a stretching space for the shell cover.

[0008] In the above-mentioned welded battery cell, the shell cover flange is integrally formed with the shell cover, and extends along the end surface of the shell cover in a direction away from the lower shell assembly.

[0009] In the above-mentioned welded battery cell, a lower shell flange is constructed at the opening of the lower shell assembly, and the lower shell flange and the shell cover flange can abut against each other when the shell cover and the lower shell assembly are assembled to provide positioning for the assembly of the shell cover.

[0010] In the above-mentioned welded battery cell, the welding area is formed at the end portion after the shell cover flange and the lower shell flange are tightly pressed against each other.

[0011] In the above-mentioned welded battery cell, the lower shell flange includes a first bent portion and a second bent portion, the first bent portion is connected between the lower shell assembly and the second bent portion, the first bent portion abuts against the bottom of the shell cover to provide a limit for the installation of the shell cover, and the second bent portion abuts against the shell cover flange and the ends are flush.

[0012] In the above-mentioned welded battery cell, the welding area covers a partial position of the second bent portion.

[0013] In the above-mentioned welded battery core, gaps are provided between the top of the winding core and the shell cover, and between the side walls of the winding core and the side walls of the accommodating cavity.

[0014] In the above-mentioned welded battery cell, the welding area is formed by laser welding.

[0015] In the above-mentioned welded battery cell, the welding area is formed by filler wire welding.

[0016] In the above-mentioned welded battery cell, the shell cover and the lower shell assembly are at least partially formed by stamping aluminum plates.

[0017] Compared with the prior art, the advantage of the present invention is that by arranging a lower shell flange at the connection between the shell cover and the lower shell assembly, when the winding core expands and squeezes the shell cover, the lower shell flange absorbs the extrusion force transmitted from the shell cover and stretches, thereby preventing the large area of ​​the central area of ​​the shell cover from bulging outward due to lack of constraint and low rigidity, thereby ultimately improving the service life of the battery cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the three-dimensional structure of a crimped welded battery cell of the present invention;

[0019] Figure 2 yes Figure 1 Exploded view in ;

[0020] Figure 3 This is a schematic diagram of the curling structure of a curling welded battery cell of the present invention;

[0021] Figure 4 This is a cross-sectional view of a crimped welded battery cell of the present invention when it is not expanded;

[0022] Figure 5 This is a cross-sectional view of a curling welded battery cell of the present invention when it expands.

[0023] In the figure, 100, winding core; 200, lower shell assembly; 210, accommodating chamber; 220, lower shell flange; 221, first bending portion; 222, second bending portion; 300, shell cover; 310, shell cover flange; 400, welding area; 500, gap. DETAILED DESCRIPTION

[0024] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

[0025] like Figures 1 to 5 As shown, a welding battery cell of the present invention includes: a shell cover 300, a lower shell assembly 200 and a winding core 100.

[0026] Specifically, the lower shell assembly 200 is a hollow cube structure. Of course, the lower shell assembly 200 can also be a hollow cylindrical structure. The lower shell assembly 200 is internally constructed with a receiving cavity 210 with an opening, and the opening direction is toward one end of the lower shell assembly 200 in the height direction. Of course, the opening direction can also be toward one end of the length direction or width direction of the lower shell assembly 200. The receiving cavity 210 is used to accommodate the winding core 100; the shell cover 300 is connected to the opening of the lower shell assembly 200, and the shell cover 300 is arranged to seal the receiving cavity 210 of the lower shell assembly 200, which can be used to prevent external The shell cover flange 310 is formed on the periphery of the shell cover 300 to provide a stretching space for the shell cover 300 when the core 100 expands. The shell cover flange 310 is constructed with a local welding portion, which is used to connect the shell cover 300 and the lower shell assembly 200. The shell cover 300 can stretch due to the expansion of the core 100, and the shell cover flange 310 can be stretched under the extrusion of the core 100 to provide a stretching space for the shell cover 300.

[0027] Figure 4 This is the state when the core 100 is not expanded. At this time, there is a gap 500 between the top of the core 100 and the shell cover 300, as well as between the side wall of the core 100 and the side wall of the accommodating cavity 210, which can be used to absorb part of the expansion of the core 100. When the battery cell is in use, the core 100 in the accommodating cavity 210 expands, first filling the above gap 500, and then contacting the shell cover 300 and applying pressure to the shell cover 300. After the shell cover 300 is under pressure, the pressure is transmitted to the shell cover flange 310. At this time, the shell cover flange 310 stretches after being under pressure, so that the shell cover flange 310 is unfolded. Figure 5 The state shown is achieved to prevent the problem that the central area of ​​the shell cover 300 has low rigidity and is prone to bulging outward due to lack of constraint, thereby achieving uniform force on the shell cover 300 and improving the service life of the battery cell.

[0028] It's important to note that the height of the cover flange 310 should exceed the height of the weld zone 400. Specifically, the weld zone 400 shouldn't occupy the entirety of the cover flange 310. This ensures that the cover 300 has room to deform when the core 100 expands. Theoretically, the maximum deformation of the cover 300 during expansion is equal to the height of the cover flange 310 minus the height of the weld zone 400 minus the thickness of the cover 300. The design must ensure that the theoretical maximum deformation of the cover 300 exceeds the maximum expansion of the core 100.

[0029] Based on the above technical solution, this solution also expands the structure of the battery cell as follows:

[0030] The housing cover flange 310 is integrally formed with the housing cover 300 and extends along an end surface of the housing cover 300 in a direction away from the lower housing assembly 200 .

[0031] A lower shell flange 220 is constructed at the opening of the lower shell assembly 200. The lower shell flange 220 and the shell cover flange 310 can abut against each other when the shell cover 300 and the lower shell assembly 200 are assembled to provide positioning for the assembly of the shell cover 300.

[0032] In the battery cell of this solution, when the shell cover 300 and the lower shell assembly 200 are assembled, the shell cover flange 310 and the lower shell flange 220 abut against each other to position the shell cover 300 and the lower shell assembly 200. Furthermore, the ends of the shell cover flange 310 and the lower shell flange 220 after being tightly abutted together form a welding plane, and a welding area 400 is formed by laser welding or wire welding.

[0033] The lower shell flange 220 includes a first bending portion 221 and a second bending portion 222. The first bending portion 221 is connected between the lower shell assembly 200 and the second bending portion 222. The first bending portion 221 abuts against the bottom of the shell cover 300 to provide a limit for the installation of the shell cover 300. The second bending portion 222 abuts against the shell cover flange 310 and the ends are flush.

[0034] The first bending portion 221 is preferably parallel to the end face of the shell cover 300, and the second bending portion 222 is preferably parallel to the outer wall of the lower shell assembly 200. Of course, there can be a certain angle between the end face between the first bending portion 221 and the shell cover 300, and between the second bending portion 222 and the side wall of the lower shell assembly 200. The second bending portion 222 is flush with the end of the shell cover flange 310 to make the welding plane smoother and improve the welding quality between the shell cover 300 and the lower shell assembly 200.

[0035] Preferably, the welding area 400 covers a portion of the second bent portion 222 .

[0036] Preferably, the shell cover 300 and the lower shell assembly 200 are at least partially stamped from aluminum plates.

[0037] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship and movement status of the various components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0038] In addition, terms such as "first," "second," and "an" in this utility model are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features indicated. Therefore, features specified as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of this utility model, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0039] In this utility model, unless otherwise specified or limited, the terms "connection" and "fixation" should be understood in a broad sense. For example, "fixation" can mean fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise specified. For those skilled in the art, the specific meanings of the above terms in this utility model can be understood according to specific circumstances.

[0040] In addition, the technical solutions between the various embodiments of the present invention can be combined with each other, but it must be based on the fact that ordinary technicians in this field can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by this utility model.

[0041] The specific embodiments described herein are merely examples of the spirit of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described, or replace them with similar methods, without departing from the scope defined by the spirit of the present invention.

Claims

1. A welding battery cell, characterized in that: include: a lower housing assembly, wherein a receiving cavity and an opening communicating with the receiving cavity are provided therein; a winding core fixed in the accommodating cavity; A shell cover is connected to the opening for sealing the winding core, and a shell cover flange is constructed on the periphery of the shell cover. After the battery core is welded, a part of the shell cover flange is used to form a welding area; wherein, The shell cover flange can be stretched when the winding core is expanded to provide a stretching space for the shell cover.

2. A welding core according to claim 1, characterized in that: The shell cover flange is integrally formed with the shell cover and extends along the end surface of the shell cover in a direction away from the lower shell assembly.

3. A welding battery according to claim 1, characterized in that: A lower shell flange is constructed at the opening of the lower shell assembly. The lower shell flange and the shell cover flange can abut against each other when the shell cover and the lower shell assembly are assembled to provide positioning for the assembly of the shell cover.

4. A welding core as claimed in claim 3, characterized in that: The welding area is formed at the end portion after the shell cover flange and the lower shell flange are tightly pressed against each other.

5. A welding battery according to claim 3, characterized in that: The lower shell flange includes a first bending portion and a second bending portion, the first bending portion is connected between the lower shell assembly and the second bending portion, the first bending portion abuts against the bottom of the shell cover to provide a limit for the installation of the shell cover, and the second bending portion abuts against the shell cover flange and the ends are flush.

6. A welding core as claimed in claim 5, characterized in that: The welding area covers a partial position of the second bent portion.

7. A welding battery according to claim 1, characterized in that: A gap is provided between the top end of the winding core and the shell cover, and between the side wall of the winding core and the side wall of the accommodating cavity.

8. A welding battery cell according to claim 1, characterized in that: The weld zone is formed by laser welding.

9. A welding battery cell according to claim 1, characterized in that: The welding zone is formed by filler wire welding.

10. The welding core according to claim 1, characterized in that: The shell cover and the lower shell assembly are at least partially formed by stamping aluminum plates.

Images