Cover plate assembly and high-magnification cylindrical battery
By optimizing the design of the cover plate assembly and the insulating coating of the casing, the problem of excessively long conductive handle was solved, resulting in a reduction in the internal resistance and heat generation of the conductive handle, thereby improving the high-rate performance and production efficiency of the battery.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- LANJING NEW ENERGY (JIAXING) CO LTD
- Filing Date
- 2025-04-10
- Publication Date
- 2026-05-08
AI Technical Summary
The conductive stem of existing cylindrical batteries needs to be folded twice, resulting in excessive length, increased internal resistance and heat generation, which limits high-rate application scenarios.
Design a cover plate assembly in which the welding area of the busbar protrudes toward the cover plate when the conductive handle is not folded. The pre-fold line of the conductive handle is located on the vertical line between the cover plate and the busbar. After the cover plate is folded, it is coaxially connected with the busbar. Only one fold is required, which shortens the length of the conductive handle. An insulating coating is applied to the inner wall of the housing to replace the high-temperature tape at the end of the core.
By shortening the length of the conductive stem through a single folding structure, internal resistance and heat generation are reduced, improving the high-rate charge and discharge capability, while reducing production costs and increasing yield.
Smart Images
Figure CN224217577U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of cylindrical battery technology, and in particular to a cover plate assembly and a high-rate cylindrical battery. Background Technology
[0002] Currently, with the rapid development of the new energy industry, society's requirements for the energy density, safety performance, and fast charging performance of lithium-ion batteries are further increasing. Large cylindrical batteries, as a widely accepted solution, are ushering in a broad market space. In existing mass-produced applications, the positive and negative terminals of cylindrical batteries are mostly connected to the cover plate via conductive handles. During assembly, the busbar is first connected to the cover plate via the conductive handle, and then welded to the tab. At this point, the conductive handle is located between the cover plate and the core, requiring the conductive handle to be folded twice. Figure 1 The diagram shows a Z-shaped fold, with the cover plate and the core coaxial. Because the conductive shank needs to accommodate the Z-shaped fold, it requires a longer shank, leading to increased internal resistance and high heat generation when carrying large currents, making it unsuitable for high-rate applications. Utility Model Content
[0003] In view of the shortcomings of the prior art, the technical problem to be solved by this utility model is: how to provide a cover plate assembly and high-rate cylindrical battery with a reasonable structural design that can shorten the length of the conductive handle, which is conducive to reducing the internal resistance of the battery and reducing the heat generation.
[0004] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:
[0005] A cover plate assembly includes a cover plate and a busbar. The busbar has a conductive shank extending radially. One end of the conductive shank away from the busbar is connected to the inner side of the cover plate. The busbar has a recessed welding area that protrudes towards the side of the cover plate when the conductive shank is folded. Multiple welding areas are evenly distributed along the circumference of the busbar. The conductive shank has a pre-fold line located on the perpendicular bisector of the line connecting the center of the cover plate and the busbar. The cover plate is coaxially mounted on the busbar by folding along the pre-fold line.
[0006] In the above structure, the welding area of the busbar protrudes towards the side where the cover plate is located when the conductive handle is not folded. After the conductive handle is connected to the cover plate, the welding area of the busbar is welded to the tabs of the winding core. At this time, the cover plate is located on the side of the conductive handle facing the winding core, that is, the cover plate is set in reverse. Since the pre-fold line of the conductive handle is located on the perpendicular bisector of the cover plate and the busbar, that is, the pre-fold line is equal to the center distance of the cover plate and the busbar, the cover plate can be folded 180° along the pre-fold line to fit exactly on the busbar and be coaxial with the winding core. Since the conductive handle only needs to be folded once, compared with the Z-type folding structure, the length of the conductive handle can be shortened by more than 15%, reducing the internal resistance of the conductive handle, reducing the heat generation under high current conditions, and improving the high-rate charge and discharge capability.
[0007] Furthermore, the welding area extends in a strip shape along the radial direction of the busbar, and the welding area is located outside the coverage area of the cover plate when the conductive handle is not folded.
[0008] This allows the welding area to be fully exposed, facilitating reliable welding of the busbar to the lugs of the winding core.
[0009] Furthermore, the welding area is provided in four sections, and two of the welding areas located on the same side in the width direction of the conductive handle are connected to each other in a V-shape.
[0010] Furthermore, the busbar has a V-shaped weight-reducing groove on the side opposite to the conductive handle, and the two sides of the weight-reducing groove are close to the corresponding welding area.
[0011] In this way, the weight reduction tank can reduce materials and lower costs without affecting the performance of the busbar, and also facilitate the rapid immersion of electrolyte into the core.
[0012] Furthermore, the busbar has a concentrically arranged central hole in the middle, and the edge of the central hole protrudes in the direction toward the cover plate to form an annular boss, the outer diameter of the annular boss matching the inner diameter of the central hole of the core to be assembled.
[0013] A high-rate cylindrical battery includes a casing and a core, one end of which is welded with a cover plate assembly as described above.
[0014] Furthermore, the inner wall of the housing has an insulating coating that is annularly coated in the circumferential direction. The insulating coating is located at the end of the housing and is disposed at at least one end of the housing.
[0015] Since cylindrical batteries typically have tabs on both sides, high-temperature tape needs to be applied to the ends of the core for insulation to prevent short circuits. However, this tape application adds a production step and is prone to producing defective products, reducing the overall line yield. Furthermore, the tape cannot be perfectly flat, resulting in exposed tape or ineffective insulation when the core is installed and the casing is closed. Additionally, the tape is prone to melting during the high-temperature welding process in the next step. By applying a ring-shaped insulating coating to the ends of the casing, insulation between the core and the casing at the tab locations is achieved, eliminating the need for the high-temperature tape application step. This reduces costs and improves yield.
[0016] Furthermore, the thickness of the insulating coating is 5–20 micrometers, and the width is 5–20 mm.
[0017] Furthermore, the insulating coating is applied to the housing using thermal bonding, spraying, or adhesive bonding processes.
[0018] Furthermore, the insulating coating is made of PP, PTFE, PPS, PFA, non-polar oxides, or insulating varnish.
[0019] In summary, this utility model has the advantages of reasonable structural design, which can shorten the length of the conductive handle, thereby reducing the internal resistance of the battery and reducing heat generation. Attached Figure Description
[0020] Figure 1 This is a schematic diagram of an existing conductive handle folding structure.
[0021] Figure 2 This is a schematic diagram of the front structure of the cover plate assembly in this embodiment.
[0022] Figure 3 This is a schematic diagram of the rear structure of the cover plate assembly in this embodiment.
[0023] Figure 4 This is a schematic diagram of the back structure of the cover plate assembly in the folded state of the conductive handle.
[0024] Figure 5 This is a schematic diagram of the shell structure. Detailed Implementation
[0025] The present invention will be further described in detail below with reference to the embodiments.
[0026] In practical implementation: such as Figures 2-5As shown, a high-rate cylindrical battery includes a casing 6 and a winding core. One end of the winding core is welded with a cover plate assembly. The cover plate assembly includes a cover plate 1 and a busbar 2. The busbar 2 has a conductive handle 3 extending radially. The end of the conductive handle 3 away from the busbar 2 is connected to the inner side of the cover plate 1. The busbar 2 has a recessed welding area 4. The welding area 4 protrudes relative to the side where the cover plate 1 is located when the conductive handle 3 is not folded. Multiple welding areas 4 are evenly distributed along the circumference of the busbar 2. The conductive handle 3 has a pre-fold line 5. The pre-fold line 5 is located on the perpendicular bisector of the line connecting the centers of the cover plate 1 and the busbar 2. The cover plate 1 is folded along the pre-fold line 5 and coaxially covers the busbar 2.
[0027] The welding area 4 extends in a strip shape along the radial direction of the busbar 2, and is located outside the coverage area of the cover plate 1 when the conductive handle 3 is not folded. This allows the welding area to be fully exposed, facilitating reliable welding of the busbar to the tabs of the winding core via the welding area.
[0028] The busbar 2 has a concentrically arranged central hole in the middle, and the edge of the central hole protrudes in the direction toward the cover plate 1 to form an annular boss. The outer diameter of the annular boss matches the inner diameter of the central hole of the core to be assembled.
[0029] The welding area 4 has four sections, and two welding areas 4 located on the same side of the conductive handle 3 in the width direction are connected to each other in a V-shape. The busbar 2 has a V-shaped weight-reduction groove on the side opposite to the conductive handle 3, and the two sides of the weight-reduction groove are close to the corresponding welding area 4. The weight-reduction groove can reduce material and lower costs without affecting the performance of the busbar, and also facilitates the rapid immersion of electrolyte into the winding core.
[0030] Because the welding area of the busbar protrudes towards the side where the cover plate is located when the conductive handle is folded, after the conductive handle is connected to the cover plate, the welding area of the busbar is welded to the tabs of the winding core. At this time, the cover plate is located on the side of the conductive handle facing the winding core, that is, the cover plate is set in reverse. Since the pre-fold line of the conductive handle is located on the perpendicular bisector of the cover plate and the busbar, that is, the pre-fold line is equal to the center distance of the cover plate and the busbar, the cover plate can be folded 180° along the pre-fold line to fit exactly on the busbar and be coaxial with the winding core. Since the conductive handle only needs to be folded once, compared with the Z-type folding structure, the length of the conductive handle can be shortened by more than 15%, reducing the internal resistance of the conductive handle, reducing the heat generation under high current conditions, and improving the high-rate charge and discharge capability.
[0031] like Figure 5As shown, the inner wall of the housing 6 has an insulating coating 7 applied in a ring shape along the circumference. The insulating coating 7 is located at the ends of the housing 6 and is disposed at both ends of the housing 6. The thickness of the insulating coating 7 is 5-20 micrometers, and the width is 5-20 mm. The material of the insulating coating 7 is PP, PTFE, PPS, PFA, non-polar oxide, or insulating varnish, and it is applied to the housing using thermal bonding, spraying, or adhesive processes. It has properties such as insulation, resistance to electrolytes, and high temperature resistance.
[0032] Since cylindrical batteries typically have tabs on both sides, high-temperature tape needs to be applied to the ends of the core for insulation to prevent short circuits. However, this tape application adds a production step and is prone to producing defective products, reducing the overall line yield. Furthermore, the tape cannot be perfectly flat, resulting in exposed tape or ineffective insulation when the core is installed and the casing is closed. Additionally, the tape is prone to melting during the high-temperature welding process in the next step. By applying a ring-shaped insulating coating to the ends of the casing, insulation between the core and the casing at the tab locations is achieved, eliminating the need for the high-temperature tape application step. This reduces costs and improves yield.
[0033] In practice, an insulating coating is applied to the contact area between the casing and the tabs. This coating insulates the charge on the tabs from the casing. For single-channel or double-channel casings, the battery casing is uncharged, and the contact areas between the casing and both the positive and negative tabs are coated with an insulating coating. When the core is inserted into the casing, the portion of the tab extending beyond the separator contacts the insulating coating, thus insulating the casing from the tabs. For single-channel or double-channel casings, the battery casing is charged, and the contact area between the casing and the tab on the non-electrode side is coated with an insulating coating. The casing and the other tab carry the same charge, and contact between the tab and the casing has no effect on the battery. For single-channel casings, the battery typically has a terminal post at the sealed end, insulated from the casing by an insulating gasket. The edge of the insulating gasket is raised to cover the portion of the tab extending beyond the separator, further insulating the casing from the tab.
[0034] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.
Claims
1. A cover plate assembly comprising a cover plate (1) and a busbar (2), the busbar (2) having a conductive shank (3) extending radially; characterized in that, The conductive handle (3) is connected to the inner side of the cover plate (1) at one end away from the busbar (2). The busbar (2) has a recessed welding area (4). The welding area (4) is relatively protruding towards the side where the cover plate (1) is located when the conductive handle (3) is not folded. Multiple welding areas (4) are evenly distributed along the circumference of the busbar (2). The conductive handle (3) has a pre-fold line (5). The pre-fold line (5) is located on the perpendicular line of the line connecting the center of the cover plate (1) and the busbar (2). The cover plate (1) is folded along the pre-fold line (5) and coaxially covers the busbar (2).
2. The cover plate assembly as claimed in claim 1, characterized in that, The welding area (4) extends in a strip shape along the radial direction of the busbar (2), and the welding area (4) is located outside the coverage area of the cover plate (1) when the conductive handle (3) is not folded.
3. The cover plate assembly as claimed in claim 2, characterized in that, The welding area (4) is provided in four sections, and two of the welding areas (4) located on the same side of the width direction of the conductive handle (3) are connected to each other in a V-shape.
4. The cover plate assembly as claimed in claim 3, characterized in that, The busbar (2) has a V-shaped weight-reducing groove on the side away from the conductive handle (3), and the two sides of the weight-reducing groove are close to the corresponding welding area (4).
5. The cover plate assembly as claimed in claim 1, characterized in that, The busbar (2) has a concentrically arranged central hole in the middle. The edge of the central hole protrudes in the direction toward the cover plate (1) to form an annular boss. The outer diameter of the annular boss matches the inner diameter of the central hole of the core to be assembled.
6. A high-rate cylindrical battery, characterized in that, It includes a housing and a core, one end of which is welded with a cover plate assembly as described in any one of claims 1 to 5.
7. The high-rate cylindrical battery as described in claim 6, characterized in that, The inner wall of the housing has an insulating coating that is applied in a ring shape along the circumference. The insulating coating is located at the end of the housing and is disposed at at least one end of the housing.
8. The high-rate cylindrical battery as described in claim 7, characterized in that, The insulating coating has a thickness of 5–20 micrometers and a width of 5–20 mm.
9. The high-rate cylindrical battery as described in claim 7, characterized in that, The insulating coating is applied to the housing using thermal bonding, spraying, or adhesive processes.
10. The high-rate cylindrical battery as described in claim 7, characterized in that, The insulating coating is made of PP, PTFE, PPS, PFA, non-polar oxides, or insulating varnish.