Battery cell and electric device
By adopting the layered structure of multi-layered electrodes and overlap welding design in the lithium-ion battery cell, the problems of dummy welding and increased internal resistance are solved, and the service life and performance of the battery are improved.
Patent Information
- Application Number
- CN202422147086.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-02
- Publication Date
- 2025-07-11
- Estimated Expiration
- 2034-09-02
AI Technical Summary
During the production process of lithium-ion battery cells, multi-layer foil electrodes are prone to occur during welding, resulting in insufficient overflow area, increased internal resistance of the core, and local high temperature, affecting the core life and performance.
The layered structure of multi-layered electrodes is adopted, and the connecting structure of at least one first solder and at least two second solder prints is adopted. The second solder print coincides with the first solder print part to enhance the connection strength, reduce the probability of dummy soldering, and avoid an increase in the battery overflow area and an increase in the internal resistance of the core.
It improves the connection stability between the electrode and the adapter, extends the service life of the battery cell, improves the performance of the battery, and avoids the problems of local high temperature and increased internal resistance.
Smart Images
Figure CN223093065U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the technical field of batteries, and specifically relates to a battery cell and an electrical device using the same. Background Art
[0002] In battery production, especially in the production of lithium-ion batteries, during the production process of battery cells, it is necessary to connect the tabs of multiple cell bodies to the adapter plates. When using welding to achieve the connection between the two, and when the tab is a multi-layer foil structure, when welding the tab of the multi-layer foil, it is easy to have the phenomenon of false soldering, and it is easy to cause insufficient current-carrying area, increased internal resistance of the cell body, and local high-temperature phenomenon, affecting the life and performance of the cell body. Summary of the Utility Model
[0003] In view of this, this application provides a battery cell, which solves the problems of high probability of false soldering, insufficient current-carrying area, increased internal resistance of the cell body, local high temperature, reduced service life of the cell body, and poor performance. This application also provides an electrical device including the above battery cell.
[0004] In order to achieve the above object, this application provides the following technical solutions:
[0005] A battery cell includes multiple cell bodies, a first adapter plate, a second adapter plate, a first connection structure, and a second connection structure. The first tab and the second tab of the cell body are both layered structures. Between the layers of the layered structure, between the first adapter plate and the first tab, and between the second adapter plate and the second tab are connected by the first connection structure and the second connection structure; wherein,
[0006] The first connection structure includes at least one first welding mark, the second connection structure includes at least two second welding marks, and at least part of the second connection structure coincides with the first connection structure.
[0007] Optionally, each second welding mark coincides with at least part of the first welding mark.
[0008] Optionally, each first connection structure includes one first welding mark, and at least two second welding marks of the second connection structure are both located within the first welding mark.
[0009] Optionally, at least two of the second welding marks are arranged at equal intervals.
[0010] Optionally, the distance between adjacent second welding marks is K, where K satisfies: 5mm ≤ K ≤ 10mm.
[0011] Optionally, the minimum distance between the edges of the at least two second welding marks and the edge of the first welding mark is F, where F satisfies: F ≥ 2mm.
[0012] Optionally, the length direction of the first welding mark is perpendicular to the direction in which the first tab extends out of the core body.
[0013] Optionally,
[0014] In the direction perpendicular to the direction in which the first tab extends out of the core body, the length of the first welding mark is A, where A satisfies: 16 mm ≤ A ≤ 18 mm;
[0015] In the direction in which the first tab extends out of the core body, the width of the first welding mark is B, where B satisfies: 5 mm ≤ B ≤ 7 mm.
[0016] Optionally,
[0017] In the direction perpendicular to the direction in which the first tab extends out of the core body, the total length of at least two second welding marks is C, where C satisfies: 15 mm ≤ C ≤ 17 mm;
[0018] In the direction in which the first tab extends out of the core body, the total width of at least two second welding marks is D, where D satisfies: 4 mm ≤ D ≤ 6 mm.
[0019] Optionally, in the direction in which the first tab extends out of the core body, the minimum distance between the first welding mark and the edge of the core body is E, where E satisfies: E ≥ 3 mm.
[0020] An electrical device includes the battery cell described in any one of the above.
[0021] The battery cell provided by this application realizes the connection between layers of the layered structure, between the first adapter plate and the first tab, and between the second adapter plate and the second tab through the first connection structure with at least one welding mark and the second connection structure with at least two welding marks, and at least part of the second welding mark in the second connection structure coincides with the first welding mark in the first connection structure. In this way, the probability of false soldering in the overlapping area can be reduced, thereby avoiding the increase in the overcurrent area of the battery, the increase in the internal resistance of the core body, and local high temperature, improving the service life of the core body and the performance of the core body. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained according to the provided drawings without creative efforts.
[0023] Figure 1 It is a schematic structural diagram of the battery cell provided in this embodiment;
[0024] Figure 2Schematic diagram of the first welding for the battery cell;
[0025] Figure 3 Schematic diagram of the two - time welding for the battery cell;
[0026] Figure 4 For Figure 3 Enlarged view of area G.
[0027] Figures 1-4 In:
[0028] 1 - cell body, 2 - first adapter piece, 3 - second adapter piece, 4 - first welding mark, 5 - second welding mark;
[0029] 11 - first tab, 12 - second tab. Detailed implementation manners
[0030] This application provides a battery cell. This application also provides an electrical device including the above - mentioned battery cell.
[0031] Next, the technical solutions in the embodiments of this application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are only a part of the embodiments of this application, rather than all the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of this application.
[0032] As Figures 1 through 4 shown, the embodiments of this application provide a battery cell, which mainly includes a plurality of cell bodies 1, a first adapter piece 2, a second adapter piece 3, a first connection structure, and a second connection structure. The first tab 11 and the second tab 12 of the cell body 1 are both layered structures. Exemplarily, the first tab 11 is a layered copper tab or nickel tab, and the second tab 12 is a layered aluminum tab. The layers of the layered structure, between the first adapter piece and the first tab, and between the second adapter piece and the second tab are connected through the first connection structure and the second connection structure.
[0033] In a certain embodiment, the layers of the layered structure are connected through the first connection structure. The first connection structure realizes the connection between the layers of the layered structure, that is, at least one first welding mark 4 realizes the connection inside the first tab 11; the first adapter piece 2 is connected to the first tab 11 of each cell body 1 through the second connection structure, and the second adapter piece 3 is connected to the second tab 12 of each cell body 1 through the second connection structure. Different parts of the first connection structure are respectively connected to the first tabs 11 of a plurality of cell bodies 1 to guide the first tabs 11 of the plurality of cell bodies 1 to the first pole column of the cell body; different parts of the second connection structure are respectively connected to the second tabs 12 of a plurality of cell bodies 1 to guide the second tabs 12 of the plurality of cell bodies 1 to the second pole column of the cell body.
[0034] Among them, the first connection structure includes at least one first welding mark 4. Through the first welding mark 4, the single pieces of the first tab 11 of the layered structure are tightly welded together to form a whole, and the single pieces of the second tab 12 of the layered structure are tightly welded together to form a whole. This setting effectively avoids short circuits caused by the spread of the tab layers and their reverse insertion into the body, improving the welding safety and reliability. The second connection structure includes at least two second welding marks 5, and the second connection structure at least partially overlaps with the first connection structure. Here, by having at least two second welding marks 5 at least partially overlap with at least the first welding mark 4, the welding strength of the overlapping part of the first welding mark 4 and the second welding mark 5 can be increased, reducing the probability of false soldering at the overlapping part, and thereby enhancing the connection strength between the first tab 11 and the first adapter piece 2 and between the second tab 12 and the second adapter piece 3. Through the first welding mark 4 and the second welding mark 5, the first tab 11 and the first adapter piece 2 and the second tab 12 and the second adapter piece 3 are connected into one body. Compared with the solution of achieving the above connection by only setting one welding mark, it avoids the breakage of the tab caused by excessive welding power, avoids the splashing of metal debris, and reduces potential safety hazards; moreover, it solves the problems of traditional riveting and bolt connection due to insufficient joint reliability, loosening caused by vibration during the use of the core, avoiding an increase in the internal resistance of the battery pack and even thermal runaway. This setting improves the welding quality and production efficiency of the core. The structure is simple and highly practical, making the connection between the first tab 11 and the first connection piece and between the second tab 12 and the second connection piece tight and firm without increasing the overall thickness of the structure. In addition, setting at least two second welding marks 5 can improve the problem of tab tearing caused by too long welding marks during the welding process of the first tab 11 and the first adapter piece 2, and improve the problem of tab tearing caused by too long welding marks during the welding process of the second tab 12 and the second adapter piece 3.
[0035] It should be noted that the size of the overlapping area between the second connection structure and the first connection structure is not limited here. The second connection structure can partially overlap with the first connection structure, or the second connection structure can completely overlap with the first connection structure.
[0036] It should also be noted that the welding methods formed by the first welding mark 4 and the second welding mark 5 can be the same or different. Exemplarily, both the first welding mark 4 and the second welding mark 5 are formed by ultrasonic welding.
[0037] It should be noted again that the number of the first welding marks 4 included in each first connection structure is not limited. The first welding mark 4 can be one or more; the number of the second welding marks 5 included in each second connection structure is not limited. The second welding mark 5 can be two or more.
[0038] For the battery cell with the above structure, the connection between the layers of the laminated structure, between the first jumper 2 and the first tab 11, and between the second jumper 3 and the second tab 12 is realized through the first connection structure with at least one welding mark 4 and the second connection structure with at least two welding marks 5. Moreover, the second welding mark 5 in the second connection structure at least partially overlaps with the first welding mark 4 in the first connection structure. This can reduce the probability of false soldering in the overlapping area, thereby avoiding the increase in the over-current area of the battery, the increase in the internal resistance of the cell 1, local high temperature, improving the service life of the cell 1, and enhancing the performance of the cell 1.
[0039] In some embodiments, each second welding mark 5 at least partially overlaps with the first welding mark 4. With this arrangement, the overlapping area between the second welding mark 5 and the first welding mark 4 can be increased and distributed at different positions of the first welding mark 4, which can further reduce the probability of false soldering and enhance the stability of the connection between the first tab 11 and the first jumper 2 and the connection between the second tab 12 and the second jumper 3.
[0040] In some embodiments, each first connection structure includes one first welding mark 4, and at least two second welding marks 5 of the second connection structure are all located within the first welding mark 4. That is, all the second welding marks 5 of the second connection structure are located within the first welding mark 4, which can increase the area of the overlapping region between the first connection structure and the second connection structure, further reduce the probability of false soldering, avoid the increase in the over-current area of the battery, avoid the increase in the internal resistance of the cell 1, avoid local high temperature of the battery, improve the service life of the cell 1, and enhance the performance of the cell 1. In this way, the welding energy can be better controlled, and the damage to the tabs can be reduced.
[0041] It should be noted that the number of second welding marks 5 included in each second connection structure is not limited, and the second welding marks 5 can be two or more.
[0042] In some embodiments, at least two second welding marks 5 are arranged at equal intervals. Specifically, by ensuring that the intervals between the second welding marks 5 are equal, the problem of tab tearing caused by too long welding marks during the welding process of the first tab 11 and the first jumper 2 can be improved, as well as the problem of tab tearing caused by too long welding marks during the welding process of the second tab 12 and the second jumper 3. Moreover, the consistency of the welding mark positions during the welding process is improved, and the stability of the battery after welding is enhanced.
[0043] In addition, the intervals between adjacent second welding marks 5 can also be unequal.
[0044] In some embodiments, the spacing between adjacent second welding imprints 5 is K, where K satisfies: 5 mm ≤ K ≤ 10 mm. By controlling the spacing between adjacent second welding imprints 5 within the above range, on the one hand, it can prevent the problems of tab folding and side spreading caused by excessive spacing between adjacent second welding imprints 5, facilitating the pasting of the insulating film and improving the welding quality; on the other hand, it can avoid the problem of tab tearing caused by multiple layers of tabs during the welding process. By controlling the spacing between the second welding imprints 5, the welding position is ensured to be stable, and the stability and consistency of the lithium-ion battery are improved.
[0045] Exemplarily, the spacing K between adjacent second welding imprints 5 can be: 5 mm, 5.2 mm, 6 mm, 7 mm, 8 mm, 9 mm, 9.8 mm, 10 mm, etc.
[0046] In some embodiments, the minimum distance F between the edges of at least two second welding imprints 5 and the edge of the first welding imprint 4 satisfies: F ≥ 2 mm. That is, it is ensured that each second welding imprint 5 is not set at the edge position of the first welding imprint 4. In this way, while improving the welding strength between the first tab 11 and the first adapter piece 2 and the welding strength between the second tab 12 and the second adapter piece 3, the problem of false soldering caused by excessive tab layers can be avoided. Furthermore, the forming quality of the welding is controlled, damage to the tabs is prevented, the welding quality is improved, and the service performance of the battery is improved.
[0047] Exemplarily, the minimum distance F between the edge of the second welding imprint 5 and the edge of the first welding imprint 4 can be: 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, etc.
[0048] In some embodiments, the length direction of the first welding imprint 4 is perpendicular to the direction in which the first tab 11 extends out of the core body 1. With this setting, the set length of the first welding imprint 4 can be increased, and the connection stability between the layers of the layered structure of the first tab 11 and the second tab 12 can be improved; and the set length of the second welding imprint 5 can be increased, the connection stability between the first tab 11 and the first adapter piece 2 can be improved, and the connection stability between the second tab 12 and the second adapter piece 3 can be improved.
[0049] It should be noted that the direction in which the first tab 11 extends out of the core body 1 is Figure 3 the direction indicated by the arrow Z in the figure, and this direction is the same as the direction in which the second tab 12 extends out of the core body 1.
[0050] In some embodiments, in the direction perpendicular to the direction in which the first tab 11 extends from the core 1, the length of the first weld mark 4 is A, where A satisfies: 16 mm ≤ A ≤ 18 mm; in the direction in which the first tab 11 extends from the core 1, the width of the first weld mark 4 is B, where B satisfies: 5 mm ≤ B ≤ 7 mm. Here, ensuring that the length and width of the first weld mark 4 are within the above ranges can improve the connection stability between the layers of the laminated structure of the first tab 11 and the second tab 12. Moreover, in order to reduce the probability of poor soldering between the tab and the adapter plate, the second weld mark 5 is located within the first weld mark 4, which can improve the soldering convenience of the second weld mark 5, increase the soldering area of the second weld mark 5 welded to the first weld mark 4, improve the connection stability between the first tab 11 and the first adapter plate 2, and improve the connection stability between the second tab 12 and the second adapter plate 3.
[0051] Exemplarily, the length A of the first weld mark 4 can be: 16 mm, 16.2 mm, 16.5 mm, 17 mm, 17.5 mm, 17.8 mm, 18 mm, etc. The width B of the first weld mark 4 can be: 5 mm, 5.2 mm, 5.5 mm, 6 mm, 6.5 mm, 6.8 mm, 7 mm, etc.
[0052] In some embodiments, in the direction perpendicular to the direction in which the first tab 11 extends from the core 1, the total length of at least two second weld marks 5 is C, where C satisfies: 15 mm ≤ C ≤ 17 mm; in the direction in which the first tab 11 extends from the core 1, the total width of at least two second weld marks 5 is D, where D satisfies: 4 mm ≤ D ≤ 6 mm. Specifically, the current-carrying area of the tab welding is obtained by multiplying the welding width of the tab, the thickness of the tab foil, the number of layers of the tab foil, and the current-carrying coefficient. When the thickness of the tab foil, the number of layers of the tab foil, and the current-carrying coefficient are fixed, the current-carrying area is ensured by controlling the weld mark area. Here, ensuring that the total length and total width of at least two second weld marks 5 are within the above ranges can improve the welding quality and the performance of the core 1 while ensuring the current-carrying area.
[0053] Exemplarily, the length C of the second weld mark 5 can be: 15 mm, 15.2 mm, 15.5 mm, 16 mm, 16.5 mm, 16.8 mm, 17 mm, etc. The width D of the second weld mark 5 can be: 4 mm, 4.2 mm, 4.5 mm, 5 mm, 5.5 mm, 5.8 mm, 6 mm, etc.
[0054] In some embodiments, in the direction where the first tab 11 extends out of the core 1, the minimum distance between the first weld mark 4 and the edge of the core 1 is E, where E satisfies: E ≥ 3 mm. Specifically, such a setting can prevent the first weld mark 4 from being set on the core 1, avoid interference of the edge of the core 1 near the first tab 11 with the first weld mark 4, and improve the welding forming quality between the layers of the layered structure of the first tab 11 and the second tab 12.
[0055] Exemplarily, the minimum distance E between the first weld mark 4 and the edge of the core 1 can be: 3 mm, 3.5 mm, 4 mm, 5 mm, 6 mm, 7 mm, etc.
[0056] As an example, when the first tab 11 is ultrasonically welded, the amplitude range is 40 - 60%, the system pressure range is 0.1 - 0.2 Mpa, the welding time range is 0.2 - 0.3 s, the welding power range is 75 - 85%, the spacing between adjacent second weld marks 5 is 5 - 8 mm, and the required overlap area of the weld marks is 60 - 70 mm 2 , and it is required to satisfy the welding tensile force ≥ 100 N; the welding area ≥ 75%.
[0057] Control Example 1
[0058] Only ultrasonic welding is performed on the first tab 11 to realize the connection between the first tab 11 and the first adapter piece 2.
[0059] Examples 1 - 8
[0060] First, ultrasonic welding is performed on the layered structure of the first tab 11 to form the first weld mark 4, and then ultrasonic welding is performed on the first tab 11 and the first adapter piece 2 to form the second weld mark 5. The welding area is 4.5 * 16 mm, and the welding power is 7000 W. In Examples 1 - 8, energy, amplitude, and pressure are used as variables respectively, and it is required to satisfy the welding tensile force ≥ 100 N; the welding area ≥ 75%. The following table shows the data.
[0061] Table 1 Comparison Table of Welding Process Parameters, Welding Tensile Force, and Residual Area
[0062]
[0063]
[0064] Based on the data of the above control group and experimental group, it can be concluded that the connection between the first tab 11 and the first adapter piece 2 is realized through the first weld mark 4 and the second weld mark 5, which can satisfy the welding tensile force ≥ 100 N and the welding area ≥ 75%; the weld marks are clear and flat after welding; in the control group, due to the large number of tab layers, the required welding power is large, and the welding difficulty is high, and a clear single weld mark structure cannot be formed. Therefore, the welding difficulty of the comparison group is large, the required welding power is large, and the equipment cannot meet the requirements, and the welding residual area requirements cannot be met.
[0065] In summary, the double welding mark ultrasonic final welding is used for the battery cell to replace the conventional single welding mark structure or the joint modes of riveting and bolt connection. This can effectively reduce the welding difficulty, and during the welding process, the force on the tab and the adapter piece is small, which can avoid the fracture of the tab connected to the core body 1, thereby significantly improving the welding yield rate.
[0066] The basic principles of the present application have been described in combination with specific embodiments. However, it should be noted that the advantages, advantages, effects, etc. mentioned in the present application are only examples rather than limitations, and it cannot be considered that these advantages, advantages, effects, etc. are essential for each embodiment of the present application. In addition, the above-disclosed specific details are only for the purpose of illustration and easy understanding, rather than limitations, and the above details do not limit the present application to necessarily adopt the above specific details to implement.
[0067] The block diagrams of the devices, apparatuses, equipment, and systems involved in the present application are only illustrative examples and do not intend to require or imply that they must be connected, arranged, and configured in the manner shown in the block diagrams. As those skilled in the art will recognize, these devices, apparatuses, equipment, and systems can be connected, arranged, and configured in any manner. Words such as "including", "comprising", "having", etc. are open-ended words, meaning "including but not limited to", and can be used interchangeably with each other. The words "or" and "and" used herein refer to the word "and / or" and can be used interchangeably with each other, unless the context clearly indicates otherwise. The word "such as" used herein refers to the phrase "such as but not limited to" and can be used interchangeably with each other.
[0068] It should also be noted that in the devices, equipment, and methods of the present application, each component or each step can be decomposed and / or recombined. These decompositions and / or recombinations should be regarded as equivalent solutions of the present application.
[0069] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use the present application. Various modifications to these aspects will be very apparent to those skilled in the art, and the general principles defined herein can be applied to other aspects without departing from the scope of the present application. Therefore, the present application is not intended to be limited to the aspects shown herein, but rather to the broadest scope consistent with the principles and novel features disclosed herein.
[0070] It should be understood that the qualifiers "first", "second", "third", "fourth", "fifth", and "sixth" used in the description of the embodiments of the present application are only for more clearly elaborating the technical solutions and cannot be used to limit the protection scope of the present application.
[0071] The foregoing description has been presented for purposes of illustration and description. Furthermore, this description is not intended to limit embodiments of the present application to the form disclosed herein. Although several example aspects and embodiments have been discussed above, those skilled in the art will recognize some of their variations, modifications, alterations, additions, and subcombinations.
Claims
1. A battery cell, characterized in that, It includes a plurality of cores, a first adapter piece, a second adapter piece, a first connection structure and a second connection structure. The first tab and the second tab of the core are both in a layered structure. The layers of the layered structure, between the first adapter piece and the first tab, and between the second adapter piece and the second tab are connected by the first connection structure and the second connection structure; wherein, the first connection structure includes at least one first solder mark, the second connection structure includes at least two second solder marks, and the second connection structure at least partially overlaps with the first connection structure.
2. The battery cell according to claim 1, characterized in that, Each of the second solder marks at least partially overlaps with the first solder mark.
3. The battery cell according to claim 1, characterized in that, Each of the first connection structures includes one first solder mark, and at least two second solder marks of the second connection structure are both located within the first solder mark.
4. The battery cell according to claim 3, wherein, At least two of the second solder marks are arranged at equal intervals.
5. The battery cell according to claim 4, characterized in that, The distance between adjacent second solder marks is K, where K satisfies: 5mm ≤ K ≤ 10mm.
6. The battery cell according to claim 3, wherein The minimum distance between the edges of the at least two second solder marks and the edge of the first solder mark is F, where F satisfies: F ≥ 2mm.
7. The battery cell according to claim 1, wherein The length direction of the first solder mark is perpendicular to the direction in which the first tab extends out of the core.
8. The battery cell according to claim 7, wherein in the direction perpendicular to the direction in which the first tab extends out of the core, the length of the first solder mark is A, where A satisfies: 16mm ≤ A ≤ 18mm; in the direction in which the first tab extends out of the core, the width of the first solder mark is B, where B satisfies: 5mm ≤ B ≤ 7mm.
9. The battery cell according to claim 7, wherein in the direction perpendicular to the direction in which the first tab extends out of the core, the total length of at least two second solder marks is C, where C satisfies: 15mm ≤ C ≤ 17mm; in the direction in which the first tab extends out of the core, the total width of at least two second solder marks is D, where D satisfies: 4mm ≤ D ≤ 6mm.
10. The battery cell according to claim 3, characterized in that, in the direction in which the first tab extends out of the core, the minimum distance between the first solder mark and the edge of the core is E, where E satisfies: E ≥ 3mm.
11. An electrical device, characterized in that, It includes a battery cell according to any one of claims 1-10.