Curled edge welding battery cell
By incorporating folds and bends at the connection between the outer casing and the cover of the square-shell battery cell, the compressive force during the expansion of the core is absorbed, thus solving the problem of uneven stress distribution in traditional square-shell battery cells and improving the lifespan and structural stability of the battery cell.
Patent Information
- Application Number
- CN202423156839.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-20
- Publication Date
- 2025-12-12
- Estimated Expiration
- 2034-12-20
AI Technical Summary
The uneven stress on the core of traditional square-shell battery cells leads to a shortened cycle life, especially since the stress is high on the four sides of the shell and the central area has low stiffness and is prone to bulging.
A rolled-edge welded battery cell is designed by setting folded and bent parts at the connection between the outer shell and the cover, and using the welded part to connect the outer shell and the cover, absorbing and transmitting the compressive force when the core expands, providing stretching space, and preventing the central area from bulging out.
It improves the lifespan of the battery cell, keeps the casing flat, adapts to extreme environments, enhances welding quality, prevents casing breakage, and optimizes stress distribution.
Smart Images
Figure CN223665547U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to the technical field of electric core, concretely is a kind of edge welding electric core. BACKGROUND
[0002] Square Cell or Prismatic Cell is a common battery type, characterized by square or rectangular housing. Compared with cylindrical cells, square cell has the following characteristics in design and application: materials: the housing is usually made of metal (such as aluminum or steel), with good mechanical strength and leak-proof performance, internal structure: usually contains one or more wound or laminated electrode groups, which are packaged in electrolyte to form the core part of the battery, pole: the positive and negative poles of the square cell are usually located at the top or side of the housing, for easy connection and use.
[0003] The structural characteristics of traditional square cell make the large area of the cell shell constrained at the four edges, unable to stretch freely. During the use of the cell, the expansion of the internal winding core is limited at the four edges of the shell, causing the winding core to bear a large pressure at these locations. In contrast, the central area of the shell has low stiffness due to the lack of constraints, and is prone to bulge outward. Therefore, the stress distribution of the winding core in the traditional square cell is extremely uneven, and according to the simulation results, the stress difference between the edge and the center of the winding core can be more than four times. This uneven stress directly affects the cycle life of the cell. SUMMARY
[0004] The utility model provides a kind of edge welding electric core to solve the technical problems of the prior art.
[0005] The utility model solves the above-mentioned technical problems by adopting the following technical scheme: an edge welding electric core is proposed, which includes a winding core.
[0006] An outer shell is provided with an accommodation cavity with an opening inside, which is used to accommodate the winding core.
[0007] A shell cover is connected to the opening of the outer shell, and is arranged to seal the accommodation cavity of the outer shell.
[0008] A folding part is formed at the connection between the outer shell and the shell cover, which provides stretching space for the outer shell when the winding core expands. The folding part is provided with at least a partial welding part for connecting the shell cover and the outer shell.
[0009] The shell cover can not be in contact with the winding core when the winding core is not in an expanded state, and can be stretched under the extrusion of the winding core after the winding core expands.
[0010] In the crimped and welded battery cell, a top of the folded portion is not higher than an end surface of a connection between the outer shell and the shell cover, so as to keep the top end surface of the shell cover flat.
[0011] In the crimped and welded battery cell, the shell cover is configured with a first extension portion, the outer shell is configured with a second extension portion, and the first extension portion and the second extension portion are abutted and at least once bent towards the outer shell to form the folded portion.
[0012] In the crimped and welded battery cell, the outer shell is configured with a first crimped portion, the shell cover is configured with a second crimped portion, and the first crimped portion and the second crimped portion are nested to form the folded portion.
[0013] In the crimped and welded battery cell, the welding portion is configured to be located at a top of the folded portion away from the outer shell.
[0014] In the crimped and welded battery cell, before the welding portion is formed, a welding wire is filled between a bottom of the folded portion and the outer shell.
[0015] The crimped and welded battery cell further solves the above technical problems and comprises:
[0016] a winding core;
[0017] an outer shell, which is internally configured with an accommodating cavity with an opening, and the accommodating cavity is used for accommodating the winding core;
[0018] a shell cover, which is connected at the opening of the outer shell and is arranged to seal the accommodating cavity of the outer shell;
[0019] a folded portion, which is formed at a connection between the outer shell and the shell cover, and the folded portion is configured with at least a local welding portion, and the welding portion is used for connecting the outer shell and the shell cover;
[0020] a bent portion, which is arranged at one side of the outer shell towards the folded portion;
[0021] The shell cover can not contact the winding core when the winding core is not in an inflated state, and the shell cover can be stretched under the extrusion of the winding core after the winding core is inflated.
[0022] In the crimped and welded battery cell, the welding portion is configured to be located at a top of the folded portion away from the outer shell.
[0023] In the crimped and welded battery cell, the welding portion is configured to be located at a side of the folded portion.
[0024] In the above-mentioned crimping welding cell, the outer shell is integrated with a pole connected with the cell, and the outer shell and the shell cover are formed by stamping an aluminum plate.
[0025] Compared with the prior art, the utility model has the following advantages:
[0026] (1) By setting the folding part at the connection between the outer shell and the shell cover, when the cell expands and presses the shell cover, the folding part absorbs the pressing force transmitted by the shell cover and expands, preventing the large central area of the outer shell from bulging outward due to lack of constraint and low rigidity, and ultimately improving the service life of the cell.
[0027] (2) By keeping the top of the folding part not higher than the end surface of the connection between the outer shell and the shell cover, the top end surface of the shell cover is kept flat, and the folding part does not affect the installation of other components on the outside of the cell.
[0028] (3) By bending the first extension of the outer shell and the second extension of the shell cover against each other and then bending at least once towards the outer shell to form the folding part, the space of the folding part after stretching under stress is increased, thereby improving the stretching limit of the folding part when the cell is stressed to expand, and enabling the cell to better adapt to more extreme working environments.
[0029] (4) By setting the welding part at the bottom of the folding part, the direction of the folding part's expansion is more biased towards the position of the shell cover 300, and this configuration is suitable for the position where the cell is installed, with enough space near the shell cover for the folding part to expand.
[0030] (5) By performing filler welding between the bottom of the folding part and the outer shell, the gap between the bottom of the folding part and the outer shell is filled, thereby improving the welding quality between the outer shell and the shell cover.
[0031] (6) By setting the folding part at the connection between the outer shell and the shell cover, and setting the bending part between the outer shell and the folding part, when the cell expands and presses the shell cover, the bending part absorbs the pressing force transmitted by the shell cover and expands, preventing the large central area of the outer shell from bulging outward due to lack of constraint and low rigidity, and ultimately improving the service life of the cell.
[0032] (7) By stamping the outer shell and the shell cover from an aluminum plate, the outer shell and the shell cover can be prevented from breaking when the folding part and the bending part are formed, ensuring the smooth formation of the cell. BRIEF DESCRIPTION OF DRAWINGS
[0033] Figure 1 is a schematic diagram of the three-dimensional structure of Example One;
[0034] Figure 2 is an exploded view in Figure 1 ;
[0035] Figure 3 is a schematic diagram of the edge-welding structure of Example One;
[0036] Figure 4 is a schematic diagram of another edge-welding structure of Example One;
[0037] Figure 5 is a sectional view of the battery cell of Example One when not expanded;
[0038] Figure 6 is a sectional view of the battery cell of Example One when expanded;
[0039] Figure 7 is a schematic diagram of the three-dimensional structure of Example Two;
[0040] Figure 8 is an exploded view of Figure 7
[0041] Figure 9 is a schematic diagram of the edge-welding structure of Example Two;
[0042] Figure 10 is a sectional view of the battery cell of Example Two when not expanded;
[0043] Figure 11 is a sectional view of the battery cell of Example Two when expanded.
[0044] In the figure, 100, the winding core; 200, the outer shell; 210, the accommodating cavity; 220, the first edge-welding; 300, the shell cover; 310, the second edge-welding; 400, the folding part; 410, the first welding part; 420, the second welding part; 430, the third welding part; 500, the bending part. DETAILED DESCRIPTION
[0045] The following are specific embodiments of the present application and further describe the technical solutions of the present application in combination with the accompanying drawings, but the present application is not limited to these embodiments.
[0046] Example One
[0047] As shown in Figures 1 to 6 , the present application provides an edge-welding battery cell, which comprises a winding core 100, an outer shell 200, a shell cover 300, and a folding part 400.
[0048] The outer shell 200 is a hollow cuboid structure, and the outer shell 200 can also be a hollow cylindrical structure. The outer shell 200 is internally structured with a containing cavity 210 having an opening. The opening is arranged to communicate the containing cavity 210 with the outside air before the cell loading shell cover 300 is loaded, so as to allow the roll core 100 to enter the outer shell 200. The opening direction is towards one end of the height direction of the outer shell 200. Of course, the opening direction can also be towards one end of the length direction or the width direction of the outer shell 200.
[0049] The containing cavity 210 is used to contain the roll core 100. Preferably, at least one connecting structure is arranged between the containing cavity 210 and the roll core 100. The connecting structure is configured to fix the roll core 100 in the containing cavity 210, so as to prevent the roll core 100 from shaking during transportation or use, thereby ensuring the safety performance of the cell during transportation and use.
[0050] The shell cover 300 is connected to the opening of the outer shell 200. The shell cover 300 is arranged to seal the containing cavity 210 of the outer shell 200. The shell cover 300 is arranged to prevent water, dust and the like in the external environment from affecting the normal work of the roll core 100 in the containing cavity 210, and to prevent the impact force from being transmitted to the roll core 100 when the cell is subjected to a slight impact.
[0051] The folding part 400 is formed at the connection between the outer shell 200 and the shell cover 300, so as to provide a stretching space for the outer shell 200 when the roll core 100 expands. The folding part 400 is structured with at least a partial welding part for connecting the shell cover 300 and the outer shell 200. The shell cover 300 can not be in contact with the roll core 100 when the roll core 100 is not in an expanded state, and the shell cover 300 can be stretched under the extrusion of the roll core 100 after the roll core 100 expands.
[0052] Figure 5 For the state of the roll core 100 not being expanded, there is a gap between the roll core 100 and the shell cover 300, which can be used to absorb part of the expansion of the roll core 100. When the roll core 100 in the containing cavity 210 expands during use, the gap is first filled, and then the shell cover 300 is contacted and pressure is applied to the shell cover 300. After the shell cover 300 bears the pressure, the pressure is transmitted to the folding part 400. At this time, the folding part 400 is stretched after bearing the pressure, so that the folding part 400 is unfolded to the state shown in the figure, thereby preventing the central area of the outer shell 200 from bulging outward due to the lack of constraint and the low rigidity, and improving the service life of the cell. Figure 6
[0053] In the embodiment, the folding part 400 is arranged at the connection between the outer shell 200 and the shell cover 300, and when the winding core 100 expands and presses the shell cover 300, the folding part 400 absorbs the pressing force transmitted by the shell cover 300 and expands, thereby preventing the central area of the outer shell 200 from bulging outward due to the lack of constraint and low rigidity, and finally improving the service life of the battery cell.
[0054] Based on the above technical scheme, the structure of the battery cell is further extended as follows:
[0055] In the embodiment, the top of the folding part 400 is not higher than the end surface of the connection between the outer shell 200 and the shell cover 300, so as to keep the top end surface of the shell cover 300 flat and prevent the folding part 400 from affecting the installation of other components on the outside of the battery cell.
[0056] The battery cell may need to be installed synchronously with other components during use, or due to the narrow installation space of the battery cell, there is no much space left after the battery cell is installed. In order to minimize the influence of the battery cell on the installation of other components or to improve the utilization efficiency of the installation space of the battery cell, the height of the top of the folding part 400 is set to be not higher than the end surface of the connection between the outer shell 200 and the shell cover 300 in the present scheme. In addition, such design can also make the overall appearance of the battery cell more coordinated.
[0057] The shell cover 300 is configured with a first extension part, the outer shell 200 is configured with a second extension part, and the first extension part and the second extension part are bent at least once towards the outer shell 200 after abutting to form the folding part 400.
[0058] Based on the above embodiment, the folding part 400 in the present scheme is folded after the first extension part and the second extension part of the shell cover 300 and the outer shell 200 abut. This operation mode is mainly to enable the folding part 400 to be folded multiple times. The more times the folding part 400 is folded, the larger the stretching space of the folding part 400 under stress, thereby improving the stretching limit of the folding part 400 when the winding core 100 is expanded under stress, and enabling the battery cell to better adapt to more extreme working environments.
[0059] In the embodiment, the first extension part and the shell cover 300, and the second extension part and the outer shell 200 are integrally stamped.
[0060] The outer shell 200 is configured with a first curled edge 220, and the shell cover 300 is configured with a second curled edge 310. The first curled edge 220 and the second curled edge 310 are nested with each other to form the folding part 400.
[0061] Based on the above embodiment, the folding part 400 in the scheme is configured in the following way: first, a first edge 220 is configured on the outer shell 200, then a second edge 310 is configured on the shell cover 300, and then the first edge 220 and the second edge 310 are nested with each other to form the folding part 400. This way of operation is relatively simple, which can reduce the production difficulty of the battery cell.
[0062] Preferably, the welding part is configured at the bottom of the folding part 400.
[0063] Based on the above embodiment, referring to Figure 3 , the third welding part 430 is a welding position. In this case, when the winding core 100 expands, the direction in which the folding part 400 extends is more biased towards the position of the shell cover 300. This configuration is suitable for the position where the battery cell of the scheme is installed. There is enough space near the shell cover 300 for the folding part 400 to expand.
[0064] When the welding part is located at the bottom of the folding part 400, the third welding part 430 is located at a gap between the folding part 400 and the outer shell 200. Before the welding part is formed, the gap between the bottom of the folding part 400 and the outer shell 200 is filled with welding wire to fill the gap, thereby improving the welding quality between the outer shell 200 and the shell cover 300.
[0065] Embodiment two
[0066] As Figures 7 to 11 shown, a winding edge welded battery cell of the scheme includes: a winding core 100, an outer shell 200, a shell cover 300, a folding part 400, and a bending part 500.
[0067] Specifically, the outer shell 200 is preferably a hollow cube structure, and an accommodating cavity 210 with an opening is configured inside the outer shell 200. The accommodating cavity 210 is used to accommodate the winding core 100, and the opening is used to put the winding core 100 into the outer shell 200. Preferably, in this embodiment, a connecting structure for fixing the winding core 100 is arranged on the accommodating cavity 210. The connecting structure is used to prevent the winding core 100 from shaking relative to the outer shell 200 during transportation or use.
[0068] The shell cover 300 is connected at the opening of the outer shell 200, and the shell cover 300 is arranged to seal the accommodating cavity 210 of the outer shell 200, so as to prevent water, dust and the like in the external environment from affecting the normal work of the winding core 100 in the accommodating cavity 210. In addition, the shell cover 300 can prevent the impact force from being transmitted to the winding core 100 when the battery cell is subjected to a slight impact.
[0069] The folding part 400 is formed at the joint of the outer shell 200 and the shell cover 300, and is used to preliminarily connect the outer shell 200 and the shell cover 300. The folding part 400 is provided with at least a partial welding part, which is used to connect the outer shell 200 and the shell cover 300, and prevent the outer shell 200 and the shell cover 300 from being separated by the winding core 100 when the winding core 100 is in an expanded state;
[0070] The bending part 500 is arranged on the side of the outer shell 200 facing the folding part 400.
[0071] The shell cover 300 is not in contact with the winding core 100 when the winding core 100 is not in an expanded state, and is driven to stretch the bending part 500 under the extrusion of the winding core 100 after the winding core 100 is expanded.
[0072] Figure 10 For the state when the winding core 100 is not expanded, there is a gap between the winding core 100 and the shell cover 300, which can be used to absorb the partial expansion of the winding core 100. When the winding core 100 in the accommodating cavity 210 expands during use, the gap is filled first, and then the shell cover 300 is contacted and pressure is applied to the shell cover 300. After the shell cover 300 bears the pressure, the pressure is transmitted to the bending part 500. At this time, the bending part 500 bears the pressure and stretches, so that the bending part 500 is unfolded into Figure 11 The state shown, thereby preventing the problem that the large-area central region of the outer shell 200 lacks constraint, has low rigidity, and is easy to protrude outward, and improving the service life of the battery cell.
[0073] In the embodiment, the folding part 400 is arranged at the joint of the outer shell 200 and the shell cover 300, and the bending part 500 is arranged between the folding part 400 and the outer shell 200. When the winding core 100 expands and extrudes the shell cover 300, the bending part 500 absorbs the extrusion force transmitted by the shell cover 300 and stretches, thereby preventing the problem that the large-area central region of the outer shell 200 lacks constraint, has low rigidity, and is easy to protrude outward, and finally improving the service life of the battery cell.
[0074] Preferably, the welding part is arranged at the top of the folding part 400 away from the outer shell 200.
[0075] Based on the above embodiment, referring to Figure 9 , the first welding part 410 is a welding position. In this case, when the winding core 100 expands, the stretching direction of the bending part 500 is more inclined to the position of the outer shell 200. This configuration is suitable for the position where the battery cell of the present solution is installed, and there is enough space for the bending part 500 to stretch near the outer shell 200.
[0076] Preferably, the welding part is arranged at the side of the folding part 400.
[0077] Based on the above embodiments, with reference to Figure 9 , the second welding portion 420 is a welding position, in this case, when the winding core 100 expands, the stretching direction of the bending portion 500 is located on both sides close to the connection between the outer shell 200 and the shell cover 300, and this configuration is suitable for the position where the battery core is installed, and there is enough space for the bending portion 500 to stretch on both ends of the connection between the outer shell 200 and the shell cover 300.
[0078] Preferably, the welding portion does not cover the entire position of the connection between the outer shell 200 and the shell cover 300, so that when the winding core 100 expands and presses the shell cover 300, the folding portion 400 can also stretch, thereby increasing the deformation range of the battery core.
[0079] Preferably, the welding portion is formed by laser welding or electromagnetic pulse welding. Laser welding is a technology that uses a high-energy laser beam as a heat source to connect materials. Its working principle is that the high temperature generated by the focused laser beam makes the material (usually metal) melt in a very short time, and then quickly cools and solidifies to form a weld. Electromagnetic pulse welding is a technology that uses the instantaneous electromagnetic force generated by a strong pulse current to achieve high-speed collision between metal materials and form a weld. Laser welding can reduce the heat-affected zone during welding due to the concentration of laser energy, and electromagnetic pulse welding can reduce the heat-affected zone during welding due to the extremely fast welding process. Both of them can reduce the thermal deformation of the outer shell 200 and the shell cover 300.
[0080] The outer shell 200 is integrated with a pole column electrically connected to the winding core 100, and the outer shell 200 and the shell cover 300 are formed by stamping an aluminum plate. The aluminum plate has good ductility, which means it can be stretched, bent and pressed into complex shapes without breaking. This is because the grain structure of aluminum allows it to rearrange when stressed, thereby absorbing deformation energy. Stamping the outer shell 200 and the shell cover 300 from an aluminum plate can prevent the outer shell 200 and the shell cover 300 from breaking when the folding portion 400 and the bending portion 500 are formed.
[0081] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present application are only used to explain the relative positional relationship, movement condition, etc. between the components in a certain specific posture, and if the specific posture changes, the directional indications will also change accordingly.
[0082] In addition, the descriptions such as "first", "second", "one", etc. in the present application are only for the purpose of description and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features with "first" and "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise specifically limited.
[0083] In the present application, unless otherwise specifically defined and limited, the terms "connection", "fixing" and the like should be broadly understood, for example, "fixing" can be fixed connection, or detachable connection, or integrated; can be mechanical connection, or electrical connection; can be directly connected, or indirectly connected through intermediate medium; can be the internal communication of two elements or the interaction relationship of two elements, unless otherwise specifically limited. For ordinary skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.
[0084] In addition, the technical solutions of each embodiment of the present application can be combined with each other, but it must be based on the realization of the ordinary skilled in the art, when the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, nor within the scope of protection required by the present application.
[0085] The specific embodiments described herein are merely illustrative of the present application. Those skilled in the art of the present application can make various modifications or supplements to the described specific embodiments or replace them with similar ways, but will not deviate from the scope defined by the spirit of the present application.
Claims
1. A rolled-edge welded battery cell, characterized in that, include: Core; The outer casing has an internally constructed receiving cavity with an opening for receiving the winding core; A cover, which is connected to the opening of the outer casing, the cover being arranged to seal the receiving cavity of the outer casing; A folding portion, formed at the connection between the outer shell and the cover, is used to provide stretching space for the outer shell when the core expands. The folding portion has at least a partial welded portion for connecting the cover and the outer shell. The cover may not be in contact with the core because the core is not in an expanded state, and the folded portion may extend under the compression of the core after the core expands.
2. The edge-welded battery cell as described in claim 1, characterized in that, The top of the folded portion is not higher than the end face at the connection between the outer shell and the cover, so as to keep the top end face of the cover flat.
3. The edge-welded battery cell as described in claim 1, characterized in that, The cover has a first extension and the outer shell has a second extension. When the first extension and the second extension are pressed together, they are bent at least once toward the outer shell to form the fold.
4. A rolled-edge welded battery cell as described in claim 1, characterized in that, The outer shell has a first rolled edge, and the cover has a second rolled edge. The first rolled edge and the second rolled edge are nested together to form the folded portion.
5. A rolled-edge welded battery cell as described in claim 1, characterized in that, The welded portion is located at the bottom of the folded portion.
6. A rolled-edge welded battery cell as described in claim 5, characterized in that, Before the welded part is formed, welding wire is filled between the bottom of the folded part and the outer shell.
7. A rolled-edge welded battery cell, characterized in that, include: Core; The outer casing has an internally constructed receiving cavity with an opening for receiving the winding core; A cover, which is connected to the opening of the outer casing, the cover being arranged to seal the receiving cavity of the outer casing; A folding portion is formed at the connection between the outer shell and the cover, and the folding portion has at least a partial welded portion for connecting the outer shell and the cover. A bending portion is provided on the side of the outer casing facing the bending portion; The cover may not be in contact with the core because the core is not in an expanded state, and the bending portion may extend under the compression of the core after the core expands.
8. A rolled-edge welded battery cell as described in claim 7, characterized in that, The welded portion is configured to be located at the top of the folded portion away from the outer casing.
9. A rolled-edge welded battery cell as described in claim 7, characterized in that, The welded portion is located on the side of the folded portion.
10. A rolled-edge welded battery cell as described in any one of claims 1 to 9, characterized in that, The outer casing has an integrated pole post that is electrically connected to the winding core, and the outer casing and the cover are formed by stamping aluminum plate.