Connecting structure of cylindrical power battery cathode composite collector plate and new energy automobile
By designing a joint structure of flexible deformable strip nickel plate and laser welding in a cylindrical power battery, the welding position impact problem caused by loading vibration is solved, the battery's earthquake resistance and welding stability are improved, and the production cost is reduced , suitable for cylindrical battery connections of new energy vehicles.
Patent Information
- Application Number
- CN202420086249.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-01-12
- Publication Date
- 2024-12-13
- Estimated Expiration
- 2034-01-12
AI Technical Summary
When the cylindrical power battery is vibrated, the welding position impact is caused by the internal core jump, which is prone to open circuit failure risk, and the resistance welding of the copper current collecting plate and the steel shell is unstable, and it is easy to weld and stick to needles, and it lacks effective improvement. measure.
Design a cylindrical power battery negative electrode composite current collecting disk structure, including a strip-shaped current collecting disk and a strip-shaped nickel plate arranged in the middle. The nickel plate can be flexible in the axial direction to release impact stress, and improve welding stability through nickel material , a connection method is adopted that combines laser welding and resistance welding.
It effectively avoids the risk of open circuit of welding positions, improves the seismic performance and welding stability of the battery, reduces production costs, and improves the loading reliability and production efficiency of the battery.
Smart Images
Figure CN222168626U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of batteries, and in particular to a connection structure of a composite current collecting plate of a negative electrode of a cylindrical power battery and a new energy vehicle. Background Art
[0002] At present, lithium-ion or sodium-ion cylindrical power batteries have gradually become the mainstream products in the new energy industry, especially the new energy vehicle industry, due to their high energy density, good capacity consistency, and ability to support high-rate charge and discharge. More and more manufacturers continue to pursue the compactness of cylindrical power battery structure optimization to improve energy density. Common problems are: 1. The circular collector plate commonly used in cylindrical power batteries is more complex in design and uses more metal materials, resulting in high battery production costs and heavier batteries; 2. A few manufacturers use a rectangular strip as the minimalist structure of the cylindrical power battery collector plate, which is first connected to the full pole. When the lugs are laser welded and the middle part of the current collector is welded to the shell bottom by resistance welding, the welding position of the entire lug will be pulled, and the entire lug, current collector and shell bottom form a rigid connection. When the vehicle is loaded and vibrated, the larger internal winding core will jump and directly impact the welding position, which is easy to fall off, resulting in the risk of open circuit failure of the battery. For the cost control of power batteries, copper is generally preferred for the negative current collector, because pure nickel collectors are too expensive. However, when resistance welding is used to weld the copper current collector to the bottom of the steel shell, welding instability / easy cold welding / needle sticking are prone to occur. At present, there are no effective improvement measures in the industry. Summary of the invention
[0003] The purpose of the utility model is to provide a connection structure of a composite current collector of a negative electrode of a cylindrical power battery and a new energy vehicle, so as to solve the problem that when the existing cylindrical power battery is installed and vibrated, the larger winding core inside directly impacts the welding position between the shell bottom and the winding core, resulting in the risk of open circuit failure of the cylindrical power battery.
[0004] In order to achieve the above-mentioned purpose, the utility model provides a connection structure of a negative composite current collecting disk of a cylindrical power battery, wherein the negative composite current collecting disk comprises a strip current collecting disk and a strip nickel plate arranged in the middle of the strip current collecting disk, the strip current collecting disk having a middle part and a first side part and a second side part located on both sides of the middle part, the strip nickel plate having a first end and a second end, the first end being fixedly connected to the middle part of the strip current collecting disk, the second end extending outward and the second end being arranged corresponding to the central hole of the cylindrical power battery winding core, the winding core having a negative electrode full pole ear, the first side part and the second side part of the strip current collecting disk being respectively welded to the negative electrode full pole ear, and the second end of the strip nickel plate being welded to the bottom shell of the cylindrical power battery.
[0005] Preferably, the strip-shaped current collecting plate is made of copper or copper-nickel-plated material.
[0006] Preferably, the end surface of the second end is semicircular, and the second end is arranged to cover the central hole.
[0007] Preferably, the first side portion is connected to the negative electrode full tab by laser welding to form a first welding track, and there is at least one first welding track. The second side portion is connected to the negative electrode full tab by laser welding to form a second welding track, and there is at least one second welding track.
[0008] Preferably, the first welding trajectory and the second welding trajectory are both arranged in a straight line or a spiral shape, the first welding trajectory extends from the inner side of the winding core to the outer side, and the extension direction of the first welding trajectory is inclined relative to the length direction of the strip collecting disk; the second welding trajectory extends from the inner side of the winding core to the outer side, and the second welding trajectory is inclined relative to the length direction of the strip collecting disk.
[0009] Preferably, the strip-shaped current collecting plate is in the shape of a trapezoid, a rectangle or a parallelogram.
[0010] Preferably, the width of the middle portion of the strip-shaped nickel plate is greater than or equal to 6 mm and less than or equal to 15 mm.
[0011] Preferably, the strip-shaped nickel plate is connected to the bottom shell by resistance welding.
[0012] Preferably, the strip-shaped nickel plate is arranged perpendicular to the strip-shaped current collecting plate.
[0013] The utility model also discloses a new energy vehicle, comprising a cylindrical power battery, wherein the cylindrical power battery comprises a winding core and a shell for accommodating the winding core, the shell comprises a bottom shell, and the winding core and the bottom shell are connected using the connection structure of the above-mentioned cylindrical power battery negative electrode composite current collecting disk.
[0014] Compared with the prior art, the utility model configures the negative electrode composite current collecting disk to include a strip current collecting disk and a strip nickel plate arranged in the middle of the strip current collecting disk. The strip nickel plate of the negative electrode composite current collecting disk can be deformed relative to the strip current collecting disk in the axial direction of the cylindrical power battery. When the vibration of loading causes the strip current collecting disk to have a large jump caused by the full pole ear of the negative electrode of the winding core, the strip nickel plate in the middle can release the impact stress through flexible deformation, avoiding the risk of open circuit at the welding position between the bottom shell and the strip nickel plate. At the same time, the material of the strip nickel plate is nickel, which can effectively ensure the welding effect of the negative electrode composite current collecting disk and the bottom shell, and can avoid the problems of unstable welding, easy cold welding and sticking needles, so as to improve the seismic performance of the cylindrical power battery and assist in improving the battery production rate. The connection structure of the negative electrode composite current collecting disk of the cylindrical power battery of the utility model is suitable for the connection between the winding core and the bottom shell of the cylindrical battery for new energy vehicles. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Figure 1 This is a structural diagram of the negative electrode composite current collecting disk of the utility model.
[0016] Figure 2 This is a structural diagram of the strip-shaped current collecting disk of the negative electrode composite current collecting disk of the utility model after being connected to the winding core. At this time, the strip-shaped current collecting disk is trapezoidal.
[0017] Figure 3 It is a bottom view of the strip-shaped current collecting disc of the negative electrode composite current collecting disc of the utility model after being connected to the winding core.
[0018] Figure 4 This is a structural diagram of the utility model after the winding core connected with the negative electrode composite current collecting disk is installed into the cylindrical power battery shell.
[0019] Figure 5 for Figure 4 AA section view.
[0020] Figure 6 This is a structural diagram of another structure of the strip-shaped current collecting disk of the utility model after being connected to the winding core. At this time, the strip-shaped current collecting disk is a parallelogram. DETAILED DESCRIPTION
[0021] In order to explain the technical content, structural features and effects achieved by the present invention in detail, the following is a detailed description in conjunction with the implementation modes and the accompanying drawings.
[0022] like Figures 1 to 6 As shown, an embodiment of the utility model discloses a connection structure of a negative composite current collecting disk of a cylindrical power battery. The negative composite current collecting disk 10 includes a strip current collecting disk 1 and a strip nickel plate 2 arranged in the middle of the strip current collecting disk 1. The strip current collecting disk 1 has a middle part and a first side part 11 and a second side part 12 located on both sides of the middle part. The strip nickel plate 2 has a first end 21 and a second end 22. The first end 21 is fixedly connected to the middle part of the strip current collecting disk 1, and the second end 22 extends outward and the second end 22 is arranged corresponding to the central hole 31 of the cylindrical power battery winding core 3. The winding core 3 has a negative electrode full pole ear. The first side part 11 and the second side part 12 of the strip current collecting disk 1 are respectively welded to the negative electrode full pole ear, and the second end 22 of the strip nickel plate 2 is welded to the bottom shell 51 of the cylindrical power battery.
[0023] Specifically, Figures 1 to 6As shown, the strip nickel plate 2 is arranged perpendicularly to the strip current collecting disk 1, that is, the length direction of the strip nickel plate 2 is perpendicular to the length direction of the strip current collecting disk 1, and the strip nickel plate 2 and the strip current collecting disk 1 can be welded and connected by resistance welding or ultrasonic welding. The material of the strip current collecting disk 1 is copper or copper-plated nickel. The strip current collecting disk 1 has a first surface connected to the strip nickel plate 2 and a second surface opposite to the first surface. The first surface is arranged toward the bottom shell 51, and the second surface is arranged toward the winding core 3. The bottom shell 51 is the bottom of the cylindrical power battery shell 5, which can be a separate bottom welding piece or can be integrally formed with the shell 5.
[0024] In the embodiment of the utility model, the negative electrode composite current collecting disk 10 is configured to include a strip current collecting disk 1 and a strip nickel plate 2 arranged in the middle of the strip current collecting disk 1. The strip nickel plate 2 of the negative electrode composite current collecting disk 10 can be deformed relative to the strip current collecting disk 1 in the axial direction of the cylindrical power battery. When the loading vibration causes the negative electrode full pole ear of the winding core 3 to drive the strip current collecting disk 1 to have a large jump, the middle strip nickel plate 2 can release the impact stress through flexible deformation to avoid the risk of open circuit at the welding position between the bottom shell 51 and the strip nickel plate 2. At the same time, the material of the strip nickel plate 2 is nickel, which can effectively ensure the welding effect of the negative electrode composite current collecting disk 10 and the bottom shell 51, and can avoid the problems of unstable welding, easy cold welding, and needle sticking, so as to improve the seismic performance of the cylindrical power battery and assist in improving the battery production rate.
[0025] In the embodiment of the utility model, the end surface of the second end 22 is semicircular, and the second end 22 covers the central hole 31. Specifically, Figures 1 to 3 As shown, the main body of the strip nickel plate 2 is rectangular, and the end face of the second end 22 is semicircular, the diameter of the end face of the second end 22 is larger than the diameter d of the center hole 31, and the distance L between the center of the end face of the second end 22 and the strip collecting plate 1 is larger than the radius of the center hole 31 so that the second end 22 covers the center hole 31, thereby performing effective welding and making the welding stronger.
[0026] In the embodiment of the utility model, the first side portion 11 is connected to the full tab of the negative electrode by laser welding to form a first welding track 41, and the first welding track 41 is at least one, and the second side portion 12 is connected to the full tab of the negative electrode by laser welding to form a second welding track 42, and the second welding track 42 is at least one. Specifically, as Figure 3As shown, the first welding track 41 and the second welding track 42 are both arranged in a straight line, the first welding track 41 extends from the inner side of the winding core 3 to the outer side, and the extending direction of the first welding track 41 is arranged obliquely relative to the length direction of the strip current collecting disk 1; the second welding track 42 extends from the inner side of the winding core 3 to the outer side, and the second welding track 42 is arranged obliquely relative to the length direction of the strip current collecting disk 1. By arranging the first welding track 41 and the second welding track 42 to be arranged obliquely relative to the length direction of the strip current collecting disk 1, the welding length and the firmness of the welding can be increased.
[0027] In some other embodiments, the first welding track 41 and the second welding track 42 may also be arranged in a spiral shape or other structure.
[0028] In the embodiment of the utility model, the strip-shaped current collecting plate 1 is trapezoidal. Figures 1 to 3 As shown, the strip collecting plate 1 is arranged in a trapezoidal shape, and the strip collecting plate 1 extends to the edge of the winding core 3 to increase the welding area. In other embodiments, the strip collecting plate 1 can also be rectangular or parallelogram-shaped, such as Figure 6 As shown, the strip-shaped current collecting plate 1 is in the shape of a parallelogram. Under the condition that the length of the welding track 41 a is kept substantially unchanged, the area of the strip-shaped current collecting plate 1 a can be further reduced, thereby saving costs.
[0029] In the embodiment of the utility model, the width of the middle part of the strip nickel plate 2 is greater than or equal to 6 mm and less than or equal to 15 mm. Figure 3 As shown, the width W of the middle portion of the strip nickel plate 2 is greater than or equal to 6 mm and less than or equal to 15 mm.
[0030] In the embodiment of the utility model, the strip nickel plate 2 is connected to the bottom shell 51 by resistance welding. Specifically, the connection method of the connection structure of the negative composite current collector of the cylindrical power battery is as follows: first, the negative composite current collector 10 can be supplied in the form of coils, which are directly cut when used, or in the form of loose parts, and the full pole ears at both ends of the winding core 3 are flattened or flattened for pretreatment; then the full pole ears of the negative electrode of the winding core 3 are fixed to the first side 11 and the second side 12 of the strip current collector 1 by laser welding, and the strip nickel plate 2 is set corresponding to the center hole 31; then the winding core 3 connected with the negative composite current collector 10 is put into the shell, and the negative composite current collector 10 faces the side of the bottom shell 51, and finally, the welding needle is introduced into the center hole 31 of the winding core 3 and the strip nickel plate 2 is fixed to the bottom shell 51 by resistance welding.
[0031] The utility model also discloses a new energy vehicle, including a cylindrical power battery, wherein the cylindrical power battery includes a winding core 3 and a shell 5 for accommodating the winding core 3, wherein the shell 5 includes a bottom shell 51, and the winding core 3 and the bottom shell 51 are connected using the connection structure of the above-mentioned cylindrical power battery negative electrode composite current collecting disk. In the embodiment of the utility model, the negative electrode composite current collecting disk 10 is configured to include a strip current collecting disk 1 and a strip nickel plate 2 arranged in the middle of the strip current collecting disk 1. The strip nickel plate 2 of the negative electrode composite current collecting disk 10 can be deformed relative to the strip current collecting disk 1 in the axial direction of the cylindrical power battery. When the loading vibration causes the negative electrode full pole ear of the winding core 3 to drive the strip current collecting disk 1 to have a large jump, the middle strip nickel plate 2 can release the impact stress through flexible deformation, avoiding the risk of open circuit at the welding position between the bottom shell 51 and the strip nickel plate 2. At the same time, the material of the strip nickel plate 2 is nickel, which can effectively ensure the welding effect of the negative electrode composite current collecting disk 10 and the bottom shell 51, and can avoid the problems of unstable welding, easy cold welding, and needle sticking, so as to improve the seismic performance of the cylindrical power battery and assist in improving the battery production rate. The connection structure of the negative electrode composite current collecting disk of the cylindrical power battery of the utility model is particularly suitable for the connection between the cylindrical battery winding core and the bottom shell for new energy vehicles.
[0032] The above disclosure is only a preferred example of the present invention, and certainly cannot be used to limit the scope of rights of the present invention. Therefore, equivalent changes made according to the scope of the patent application of the present invention still fall within the scope covered by the present invention.
Claims
1. A connection structure of a composite current collector for a negative electrode of a cylindrical power battery, characterized in that: The negative electrode composite current collecting disk includes a strip-shaped current collecting disk and a strip-shaped nickel plate arranged in the middle of the strip-shaped current collecting disk, the strip-shaped current collecting disk has a middle part and a first side part and a second side part located on both sides of the middle part, the strip-shaped nickel plate has a first end and a second end, the first end is fixedly connected to the middle part of the strip-shaped current collecting disk, the second end extends outward and the second end is arranged corresponding to the central hole of the cylindrical power battery winding core, the winding core has a negative electrode full pole ear, the first side part and the second side part of the strip-shaped current collecting disk are respectively welded to the negative electrode full pole ear, and the second end of the strip-shaped nickel plate is welded to the bottom shell of the cylindrical power battery.
2. The connection structure of the negative electrode composite current collector of a cylindrical power battery according to claim 1, characterized in that: The strip-shaped current collecting plate is made of copper or copper-nickel-plated material.
3. The connection structure of the negative electrode composite current collector of a cylindrical power battery according to claim 1, characterized in that: The end surface of the second end is semicircular, and the second end is arranged to cover the central hole.
4. The connection structure of the negative electrode composite current collector of a cylindrical power battery according to claim 1, characterized in that: The first side portion is connected to the negative electrode full tab by laser welding to form a first welding track, and there is at least one first welding track. The second side portion is connected to the negative electrode full tab by laser welding to form a second welding track, and there is at least one second welding track.
5. The connection structure of the negative electrode composite current collector of a cylindrical power battery according to claim 4, characterized in that: The first welding trajectory and the second welding trajectory are both arranged in a straight line or a spiral shape, the first welding trajectory extends from the inner side of the winding core to the outer side, and the extension direction of the first welding trajectory is inclined relative to the length direction of the strip collecting disk; the second welding trajectory extends from the inner side of the winding core to the outer side, and the second welding trajectory is inclined relative to the length direction of the strip collecting disk.
6. The connection structure of the negative electrode composite current collector of a cylindrical power battery according to claim 1, characterized in that: The strip-shaped current collecting plate is in the shape of a trapezoid, a rectangle or a parallelogram.
7. The connection structure of the negative electrode composite current collector of a cylindrical power battery according to claim 1, characterized in that: The width of the middle portion of the strip nickel plate is greater than or equal to 6 mm and less than or equal to 15 mm.
8. The connection structure of the negative electrode composite current collector of a cylindrical power battery according to claim 1, characterized in that: The strip-shaped nickel plate is connected to the bottom shell by resistance welding.
9. The connection structure of the negative electrode composite current collector of a cylindrical power battery according to claim 1, characterized in that: The strip-shaped nickel plate is arranged perpendicularly to the strip-shaped current collecting plate.
10. A new energy vehicle, characterized in that: It comprises a cylindrical power battery, the cylindrical power battery comprises a winding core and a shell for accommodating the winding core, the shell comprises a bottom shell, and the winding core and the bottom shell are connected by using the connection structure of the negative electrode composite current collecting disk of the cylindrical power battery according to any one of claims 1 to 9.