High-power and high-energy large cylindrical battery with tabs on same side and assembly process of high-power and high-energy large cylindrical battery

Abstract

The large cylindrical battery comprises a cylindrical shell, one end of the shell is provided with an opening, a cover plate assembly capable of being welded in a sealed mode is arranged on the opening in a matched mode, the cover plate assembly comprises a disc-shaped cover plate, and the disc-shaped cover plate is provided with a plurality of tabs. The cover plate is conductively connected with a first terminal which is arranged in an outward protruding manner and a through hole which is arranged in a penetrating manner, the through hole is provided with a second terminal which is arranged in an insulating and sealing manner, and a separation area which extends along the radial direction is separated between the first terminal and the second terminal; the second terminal is provided with a welding area which is formed by protruding inwards, and the welding area abuts against the tab of the roll core and is connected with the tab of the roll core in a welding mode. The large cylindrical battery has the advantages that the structure is simple and reasonable, the effective welding area of the shell can be enlarged, and the over-current capability and the heat dissipation capability can be ensured.

Description

Technical Field

[0001] The invention relates to the technical field of lithium batteries, and in particular to a high-power and high-energy large cylindrical battery with tabs on the same side. Background Art

[0002] Commercial lithium-ion batteries can be divided into three categories according to the packaging form: square, cylindrical, and soft pack; among them, large cylindrical batteries among cylindrical batteries have been a hot spot in the battery industry in recent years, especially in the fields of electric vehicles and energy storage. The design of this battery has attracted attention for its high energy density, excellent rate performance and good safety performance. Full-ear technology is a key feature of large cylindrical batteries. It significantly reduces the internal resistance of the battery by setting current collectors on the surface of the entire electrode, thereby improving the charging and discharging efficiency of the battery. The full-ear design makes the maximum distance of current transmission become the height of the electrode rather than the length, which is usually only 5%-20% of the electrode length, so the resistance is reduced by 5-20 times compared with the single-ear design. This design not only improves the rate performance of the battery, but also helps to improve the safety of the battery, because the full-ear has no concentrated heating point inside the battery, and the heat is evenly distributed inside, which has thermal management advantages for the entire battery package. High-rate discharge is another significant feature of large cylindrical batteries. High-rate batteries can provide faster charging speeds and higher power output, which is particularly important for application scenarios that require fast charging and discharging. For example, some high-rate batteries are able to support fast charging from 0 to 80% in a short period of time, which is of great significance for improving the convenience and practicality of charging electric vehicles.

[0003] In the prior art, the connection between a large cylindrical full-pole tab (a cut-and-stacked full-pole tab and the like) and the shell is usually through a busbar, which has a single disc shape, such as a busbar structure and a large cylindrical battery with publication number CN219959327U; or different forms such as a disc + conductive handle, such as a cylindrical battery busbar cover assembly with publication number CN221126086U. In these structures, the full-pole tab is first welded to the busbar, and then the busbar is welded to the shell (or terminal), wherein the effective connection area of ​​the busbar and the shell is limited, which reduces the overall current flow capacity and heat dissipation capacity of the battery cell, limiting the advantages of the full-pole tab battery. Summary of the invention

[0004] In view of the above-mentioned deficiencies in the prior art, the technical problem to be solved by the present invention is: how to provide a high-power, high-energy large cylindrical battery and assembly process with a single-side output ear that has a simple and reasonable structure and can increase the effective welding area of ​​the shell, thereby facilitating current flow capacity and heat dissipation capacity.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions: It includes a cylindrical shell and a winding core arranged in the shell; one end of the shell is provided with an opening, and the opening is matched with a cover plate assembly that can be sealably welded, the cover plate assembly includes a disc-shaped cover plate, and the cover plate can be conductively connected with a first terminal protruding outward and a conducting hole set through, the conducting hole has a second terminal set in an insulating and sealing manner, and the first terminal and the second terminal are separated by a separation area extending radially; the second terminal has a welding area formed by protruding inward, and the welding area abuts against the pole ear of the winding core and is welded together.

[0006] In the above structure, since the second terminal is insulated and sealed on the conduction hole, the bottom end of the second terminal protrudes inward and abuts on the winding core, so that there is a spatial distance between the winding core and the cover plate, and the pole ear of the winding core will not contact the cover plate. In this way, the cover plate and the pole ear are relatively insulated. Short circuit phenomenon is avoided. The pole ear of the winding core is conductive with the second terminal, and because the second terminal and the cover plate are insulated and connected to form a cover body, the first terminal and the second terminal on the cover plate form independent positive and negative electrodes. Since the busbar is saved, not only the resistance is reduced but also the current capacity is guaranteed. The inner cavity can accommodate a larger volume of the winding core, thereby improving the energy density of the battery.

[0007] Furthermore, an insulating sealing ring insulated from the conducting hole is sleeved on the second terminal; the outward end of the second terminal is radially expanded to form a flange, and the flange is flush with the first terminal; the insulating sealing ring is gasketed between the flange and the cover plate.

[0008] In this way, the second terminal can increase the area of ​​external conduction, and the insulating sealing ring is arranged between the cover plate and the second terminal, and the contact between the cover plate and the second terminal is blocked by the sealing insulating ring, thereby avoiding the current short circuit caused by mutual contact. Furthermore, a sealing groove extending in the circumferential direction is provided on the side wall of the insulating sealing ring, and the edge of the conducting hole is sealedly embedded in the sealing groove.

[0009] In this way, the sealing stability of the battery cover can be enhanced.

[0010] Furthermore, the side wall of the second terminal has a groove extending in the circumferential direction, and the groove is located below the flange; and a positioning ring is protrudingly provided on the inner side of the insulating sealing ring and is sealingly matched with the groove.

[0011] In this way, the positioning ring inside the insulating sealing ring can be embedded in the groove, thereby enhancing the stability of the second terminal sealing arrangement in the conducting hole, so that the second terminal is not likely to fall off from the conducting hole.

[0012] Furthermore, the middle portion of the second terminal is recessed inward to form a welding cavity, and the bottom of the welding cavity protrudes relative to the cover plate to form the welding area; a sealing sheet is welded to the opening of the welding cavity in a sealed manner.

[0013] In this way, the welding cavity with a concave middle portion can reduce the thickness of the second terminal to facilitate penetration welding between the second terminal and the pole ear of the winding core. After welding, a sealing sheet is arranged on the top of the welding cavity to ensure that the original conduction area to the outside remains unchanged.

[0014] Furthermore, an insulating pad is provided on the inner side of the first terminal so as to cover the inner side of the first terminal, and a protruding height of the insulating pad relative to the cover plate is smaller than a protruding height of the welding area.

[0015] Furthermore, the inner side of the cover plate has a boss protruding inwardly, the outer diameter of the boss matches the inner diameter of the shell and fits on the opening.

[0016] In this way, the boss that matches the inner diameter of the shell can better position the cover assembly and the shell, and the side of the boss can increase the contact area between the cover assembly and the shell opening, which is beneficial to welding and improves the production success rate. Furthermore, the other end of the shell is conductively and sealedly connected to a bottom plate, and the bottom plate is welded to the pole lug of the winding core.

[0017] An assembly process for a high-power, high-energy large cylindrical battery with a tab on the same side as described above is assembled using the following steps: A. First, connect the cover plate and the second terminal as a whole by injection molding, and measure the insulation and connection strength; B. Load the wound core into the shell through the opening; C. Apply pressure to the winding core so that the pole ear of the winding core is closely fitted with the bottom end of the shell, and then the bottom end of the shell is welded to the pole ear of the winding core; D. Fit the cover plate assembly onto the opening of the shell, so that the bottom of the second terminal of the cover plate fits tightly with the pole ear of the winding core, and connect the cover plate to the edge of the shell and the pole ear of the winding core through the welding area by welding machines; E. Place the sealing sheet and cover on the welding area and connect them by welding.

[0018] In summary, the high-power large cylindrical battery with the same-side tabs of the present invention has the advantages of simple and reasonable structure, can increase the effective welding area of ​​the shell, and is beneficial to ensuring the current flow capacity and heat dissipation capacity. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Schematic diagram of the split structure of this embodiment.

[0020] Figure 2It is a schematic diagram of the three-dimensional structure of this embodiment.

[0021] Figure 3 It is a schematic diagram of the cross-sectional structure of this embodiment.

[0022] Figure 4 for Figure 3 A partial enlarged view of .

[0023] Figure 5 It is a schematic diagram of the front structure of the cover.

[0024] Figure 6 A schematic diagram of the back structure of the cover.

[0025] Figure 7 It is a schematic diagram of the structure of the insulating sealing ring.

[0026] Figure 8 2 is a schematic diagram of the structure of the present embodiment when viewed from above. DETAILED DESCRIPTION

[0027] The present invention is further described in detail below in conjunction with embodiments.

[0028] When implementing: Figures 1 to 8 As shown, a large cylindrical battery shell structure with tabs on the same side includes a cylindrical shell 1 and a winding core 5 arranged in the shell 1; an opening 2 is provided at one end of the shell 1, and a cover plate assembly 4 that can be sealably welded is matched on the opening 2, and the cover plate assembly 4 includes a disc-shaped cover plate 41, and a first terminal 42 protruding outward and a through hole 43 arranged through the cover plate 41 can be conductively connected, and the through hole 43 has a second terminal 44 arranged in an insulating and sealing manner, and the first terminal 42 and the second terminal 44 are separated by a separation area extending in the radial direction; the second terminal 44 has a welding area formed by protruding inward, and the welding area abuts against the tab of the winding core 5 and is welded together.

[0029] In this embodiment, the second terminal is insulated and connected to the cover plate through the through hole, and the cover plate is connected to the battery housing. The first terminal and the second terminal on the cover plate form independent positive and negative electrodes. Since the busbar is saved, the pole ear of the winding core can be directly connected to the battery housing and the cover plate assembly, which not only reduces the resistance but also ensures the current flow capacity. The inner cavity can accommodate a larger volume of winding core, thereby improving the energy density of the battery.

[0030] like Figure 3 and Figure 4As shown, an insulating sealing ring 45 insulated from the conducting hole 43 is sleeved on the second terminal 44; the outward end of the second terminal 44 is radially expanded to form a flange 441, and the flange 441 is flush with the first terminal 42; the insulating sealing ring 45 is cushioned between the flange 441 and the cover plate 41. Specifically, the side wall of the insulating sealing ring 45 has a sealing groove extending in the circumferential direction, and the edge of the conducting hole 43 is sealedly embedded in the sealing groove; the side wall of the second terminal 44 has a groove extending in the circumferential direction, and the groove is located below the flange 441; the inner side of the insulating sealing ring 45 is protrudingly provided with a positioning ring that seals with the groove. In this way, the insulating sealing ring is cushioned between the conducting hole and the second terminal, and the second terminal and the cover plate assembly are blocked by the sealing insulating ring, thereby avoiding the current short circuit caused by mutual contact.

[0031] In this embodiment, Figure 1 , 3 As shown in FIG. 4 , the middle of the second terminal 4 is recessed inward to form a welding cavity, and the bottom of the welding cavity protrudes relative to the cover plate 41 to form the welding area; a sealing sheet is welded to the opening of the welding cavity. At the same time, an insulating pad is provided to cover the inner side of the first terminal 42, and the protruding height of the insulating pad relative to the cover plate 41 is less than the protruding height of the welding area.

[0032] like Figure 6 As shown, the inner side of the cover plate 41 has a boss protruding inward, the outer diameter of the boss matches the inner diameter of the shell 1, and fits on the opening 2. In this way, the cover plate and the shell can be coaxially matched by using the boss. In addition, the material between the shell and the cover plate can be increased, which is convenient for welding and avoids welding through.

[0033] like Figure 8 As shown, the other end of the shell 1 has a bottom plate 3 for welding the winding core, and the bottom plate 3 is conductively and sealedly connected to the shell 1; in this embodiment, the bottom plate 3 is integrally formed on the shell 1, and the bottom plate 3 has a C-shaped explosion-proof notch 31.

[0034] In this embodiment, the insulating sealing ring is arranged between the cover plate and the second terminal by means of injection molding. Since the cover plate is connected to the shell, the bottom plate of the shell is directly welded to the pole ear at one end of the core, and the other end of the core is directly contacted and welded to the second terminal. In this way, the first terminal and the second terminal are respectively connected to the positive and negative electrodes of the contacting core, avoiding the short circuit caused by the positive and negative electrodes contacting at the same end. Moreover, since the bottom plate and the second terminal are directly welded to the core, the effective welding area is increased. In addition, since the busbar is omitted, it is beneficial to reduce the resistance and improve the overall current capacity. At the same time, since the busbar is omitted, it can not only reduce the number of parts, reduce material costs, and simplify the assembly process, but also obtain a larger inner cavity space under the same outer dimensions, so that a larger volume of the core can be accommodated, the space utilization rate inside the battery is improved, and the volume energy density of the single cell is improved. The explosion-proof notch on the bottom plate forms a thinning area, which can ensure that when the internal pressure of the battery cell increases, it will first rupture and release pressure from the explosion-proof notch, thereby ensuring the safety of the battery.

[0035] In this embodiment, the high-power and high-energy large cylindrical battery with the tabs on the same side is assembled using the following steps: 1. Cover assembly: First, connect the cover and the second terminal as a whole by injection molding, and measure the insulation and connection strength; 2. Core-like shell: put the wound core into the shell from the open end; 3. Welding of the core and shell: Apply pressure to the core to make the lug of the core fit tightly with the bottom of the shell, and use the set laser welding parameters to perform penetration welding on the welding surface of the end plate to fully weld the bottom of the shell with the lug of the core; 4. Cover plate welding: fit the cover plate assembly onto the opening of the shell and ensure that it fits well, so that the bottom of the second terminal of the cover plate fits tightly with the pole ear of the winding core, and welds along the outer edge of the cover plate for one circle using the set laser welding process to form a good seal between the cover plate and the shell; use the set laser welding parameters to perform penetration welding in the welding area of ​​the second terminal to fully weld the second terminal to the pole ear of the winding core; 5. Battery sealing: Place the sealing sheet and cover on the welding area, and use the set laser welding parameters to weld along the gap between the second terminal and the end sheet for one circle, so that the sealing pin and the shell form a good seal.

[0036] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A high-power, high-energy large cylindrical battery with tabs on the same side, characterized in that: The invention comprises a cylindrical shell (1) and a winding core (5) arranged in the shell (1); an opening (2) is provided at one end of the shell (1); a cover plate assembly (4) which can be sealed and welded is matched on the opening (2); the cover plate assembly (4) comprises a disc-shaped cover plate (41); a first terminal (42) protruding outward and a through-hole (43) are conductively connected to the cover plate (41); a second terminal (44) is provided on the through-hole (43) in an insulating and sealing manner; a separation zone extending in the radial direction is separated between the first terminal (42) and the second terminal (44); the second terminal (44) has a welding zone protruding inward, the welding zone abuts against the pole ear of the winding core (5) and is welded to the pole ear.

2. The high-power, high-energy large cylindrical battery with tabs on the same side as claimed in claim 1, characterized in that: An insulating sealing ring (45) is sleeved on the second terminal (44) and is insulated from the conducting hole (43); an outward end of the second terminal (44) is radially expanded to form a flange (441), and the flange (441) is flush with the first terminal (42); and the insulating sealing ring (45) is cushioned between the flange (441) and the cover plate (41).

3. The high-power, high-energy large cylindrical battery with tabs on the same side as claimed in claim 2, characterized in that: The side wall of the insulating sealing ring (45) is provided with a sealing groove extending in the circumferential direction, and the edge of the conducting hole (43) is sealedly embedded in the sealing groove.

4. The high-power, high-energy large cylindrical battery with tabs on the same side as claimed in claim 3, characterized in that: The side wall of the second terminal (44) has a groove extending in the circumferential direction, the groove being located below the flange (441); a positioning ring is protrudingly provided on the inner side of the insulating sealing ring (45) and is sealingly matched with the groove.

5. The high-power, high-energy large cylindrical battery with tabs on the same side as claimed in claim 2, characterized in that: The middle portion of the second terminal (44) is recessed inwards to form a welding cavity, and the bottom of the welding cavity protrudes relative to the cover plate (41) to form the welding area.

6. The high-power, high-energy large cylindrical battery with tabs on the same side as claimed in claim 1, characterized in that: A sealing sheet is welded to the opening of the welding cavity in a sealed manner.

7. The high-power, high-energy large cylindrical battery with tabs on the same side as claimed in claim 1, characterized in that: An insulating pad is provided on the inner side of the first terminal (42) to cover the inside thereof, and a protruding height of the insulating pad relative to the cover plate (41) is smaller than a protruding height of the welding area.

8. The high-power, high-energy large cylindrical battery with tabs on the same side as claimed in claim 1, characterized in that: The inner side of the cover plate (41) has a boss protruding inwards, the outer diameter of the boss matches the inner diameter of the shell (1) and fits on the opening (2).

9. The high-power, high-energy large cylindrical battery with tabs on the same side as claimed in claim 1, characterized in that: The other end of the shell (1) is conductively and hermetically connected to a bottom plate (3), and the bottom plate (3) is welded to a pole lug of the winding core (5).

10. An assembly process for a high-power, high-energy large cylindrical battery with tabs on the same side as claimed in any one of claims 1 to 9, characterized in that: The steps include: S1. Using an injection molding process, the second terminal is insulated and sealedly arranged on the through hole of the cover plate, and the insulation performance and connection strength are measured; S2, loading the wound core into the shell through the opening; S3, applying pressure to the winding core, so that the pole ear of the winding core is closely fitted with the bottom end of the shell, and the bottom end of the shell is welded to the pole ear of the winding core; S4. Fit the cover plate assembly onto the opening of the shell, so that the welding area of ​​the second terminal fits tightly with the pole ear of the winding core and connects them by welding; weld the cover plate to the edge of the shell.

Images