A cylindrical battery positive electrode cover assembly

Abstract

The present invention relates to the field of batteries, and specifically to a positive electrode cover plate assembly for a cylindrical battery, comprising a positive electrode column, a positive terminal, a positive current collector, and a negative current collector. The bottom of the positive electrode column is connected to the positive current collector by welding, and a liquid injection hole is provided at the center of the positive electrode column. The outside of the positive electrode column is connected to the positive terminal by welding, and the outside of the positive terminal is sequentially sleeved with a first insulating member and a substrate in the vertical direction. The first insulating member is used to insulate and isolate the positive terminal from the substrate. An aluminum shell is provided on the outside of the bottom of the substrate, and a battery cell is provided at the lower end of the positive current collector inside the aluminum shell, and a sealing component is provided at the bottom of the battery cell. The liquid injection hole is concentrated at the center of the positive electrode column, which can improve the liquid injection efficiency and the electrolyte infiltration effect, and can also avoid the problem of difficult PACK welding positioning; the positive electrode column is integrated on the positive current collector, which can reduce the resistivity.

Description

Technical Field

[0001] The invention relates to the field of batteries, and in particular to a positive electrode cover plate assembly for a cylindrical battery. Background Art

[0002] Lithium-ion batteries have outstanding performance in the field of chemical energy storage devices due to their significant advantages such as high energy density, no memory effect, long cycle life and environmental friendliness, and have received great attention from industries such as electric vehicles and 3C. In practical applications, lithium batteries are usually used in groups in series and parallel, and the consistency of lithium batteries has become a key factor affecting the performance of series and parallel battery packs. Lithium battery packs with good consistency can ensure that the charging and discharging process of the battery pack is more stable and efficient, extend the overall service life of the battery pack, and reduce safety risks during use. Poor consistency may lead to problems such as accelerated capacity decay of the battery pack and unbalanced charging and discharging, which seriously affect the performance and application effect of the battery pack. Therefore, in-depth research and improvement of the consistency of lithium batteries is of great significance to further promote the efficient application of lithium-ion batteries in various industries.

[0003] Compared with the prior art, the Chinese invention patent with announcement number CN114024104B discloses a cover plate assembly for a cylindrical lithium battery. Although it also effectively fixes the collector plate and the terminal through a multi-layer welding structure, it is found during processing and use that the battery is currently sealed and fixed by welding during processing. However, due to the stress caused by heat in the metal itself during welding, and the transmission of electrical energy is essentially carried out through the collector plate, if the deformation of the collector plate causes partial resistance changes, it will affect the life of the battery. Summary of the invention

[0004] The purpose of the present invention is to provide a cylindrical battery positive electrode cover assembly in order to solve the above-mentioned problem.

[0005] The present invention achieves the above-mentioned purpose through the following technical solutions: A positive electrode cover plate assembly for a cylindrical battery, comprising a positive electrode column, a positive terminal, a positive current collector, and a negative current collector, wherein the bottom of the positive electrode column is connected to the positive current collector by welding, a liquid injection hole is provided through the center of the positive electrode column, the outside of the positive electrode column is connected to the positive terminal by welding, a first insulating member and a substrate are sequentially sleeved on the outside of the positive terminal in a vertical direction, the first insulating member is used to insulate and isolate the positive terminal from the substrate, an aluminum shell is provided on the outside of the bottom of the substrate, a battery cell is provided inside the aluminum shell at the lower end of the positive current collector, and a sealing assembly is provided at the bottom of the battery cell; A sealing ring is arranged between the positive electrode column and the substrate, the upper ends of the sealing ring and the second insulating member are in contact with the substrate, the second insulating member is arranged between the substrate and the positive current collecting disk, and the sealing ring and the second insulating member are used to achieve sealing and insulating effects; A plurality of strain grooves are evenly arranged in an array on the positive electrode current collecting disk, and the strain grooves penetrate the positive electrode current collecting disk from top to bottom; A guide groove is formed on the inner wall of the liquid injection hole at the center of the positive electrode column; A sealing aluminum nail is installed at the injection hole position of the positive electrode column, and a sealing glue nail is arranged at the lower end of the sealing aluminum nail and located on the upper side of the guide groove.

[0006] Preferably: the sealing assembly includes a negative electrode current collector arranged at the bottom of the battery cell, a first insulating sheet is arranged at the bottom of the negative electrode current collector, a negative electrode cover plate is arranged on the bottom of the first insulating sheet on the aluminum shell, a safety valve is arranged on the negative electrode cover plate, and a positive electrode cover plate is arranged on the top of the aluminum shell.

[0007] Preferably, the positive electrode column is integrated on the positive current collecting disk, thereby increasing the contact area between the positive electrode column and the positive current collecting disk and reducing the resistance.

[0008] Preferably, the injection hole is located at the center of the positive electrode column, and the guide groove is a spiral groove to improve positioning accuracy.

[0009] Preferably, the positive terminal is connected to the substrate via the sealing ring, and the positive terminal and the positive electrode column are interference fit.

[0010] Preferably, the positive electrode post is connected to the positive electrode current collecting plate by welding.

[0011] Preferably, a positive electrode insulating sheet is integrated on the positive electrode cover plate, which effectively reduces the assembly process and improves production efficiency.

[0012] Preferably, the positive current collecting disk and the positive pole are both provided with a central hole, and the diameters of the central holes decrease successively, and cooperate with the guide groove on the positive pole to avoid poor subsequent liquid injection due to assembly tolerance.

[0013] Preferably, a plurality of the strain grooves are distributed on the positive electrode current collecting disk along a spiral, and the strain grooves are oblique holes.

[0014] Compared with the prior art, the beneficial effects are as follows: 1. Concentrating the injection hole at the center of the positive electrode column can improve the injection efficiency and electrolyte infiltration effect, and at the same time avoid the problem of difficult PACK welding positioning; the positive electrode column is integrated on the positive current collector to reduce the resistivity; 2. The positive terminal formed in the positive electrode column is used to improve the smooth addition of electrolyte during the injection process, and the strain groove formed on the positive current collector is used to balance the metal stress deformation caused by the heat during the welding process when the positive current collector is welded, thereby avoiding the deviation of resistance in the metal metallographic layer caused by thermal stress deformation, thereby avoiding the instability of current transmission. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0016] Figure 1 It is a partial structural schematic diagram of a positive electrode cover plate assembly of a cylindrical battery according to the present invention; Figure 2 It is a schematic diagram of the overall structure of a cylindrical battery positive electrode cover assembly according to the present invention; Figure 3 It is an internal cross-sectional view of a positive electrode cover plate assembly of a cylindrical battery according to the present invention; Figure 4 It is a partial detail diagram of a positive electrode cover plate assembly of a cylindrical battery according to the present invention; Figure 5 It is a schematic structural diagram of a positive electrode current collector plate of a positive electrode cover plate assembly of a cylindrical battery according to the present invention; Figure 6 It is a cross-sectional view of a positive electrode current collector of a positive electrode cover assembly of a cylindrical battery according to the present invention; Figure 7 It is a schematic diagram of the positive pole column structure of a cylindrical battery positive cover plate assembly described in the present invention.

[0017] The following are the descriptions of the reference numerals: 1. Substrate; 2. Aluminum shell; 3. Positive pole; 4. Sealing aluminum nail; 5. Second insulating part; 6. Positive current collector; 7. Sealing glue nail; 8. Guide groove; 9. Positive terminal; 10. Sealing ring; 11. Battery cell; 12. First insulating part; 13. Negative current collector; 14. First insulating sheet; 15. Negative cover; 16. Safety valve; 17. Positive cover; 61. Strain groove. DETAILED DESCRIPTION

[0018] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0019] The present invention will be further described below in conjunction with the accompanying drawings: like Figure 1-Figure 7 As shown, a cylindrical battery positive electrode cover plate assembly includes a positive electrode column 3, a positive terminal 9, a positive current collector 6, and a negative current collector 13. The bottom of the positive electrode column 3 is connected to the positive current collector 6 by welding, and a liquid injection hole is provided at the center of the positive electrode column 3. The outside of the positive electrode column 3 is connected to the positive terminal 9 by welding. The outside of the positive terminal 9 is sequentially sleeved with a first insulating member 12 and a substrate 1 in the vertical direction. The first insulating member 12 is used to insulate and isolate the positive terminal 9 from the substrate 1. An aluminum shell 2 is provided on the outside of the bottom of the substrate 1, and a battery cell 11 is provided at the lower end of the positive current collector 6 inside the aluminum shell 2, and a sealing component is provided at the bottom of the battery cell 11; A sealing ring 10 is provided between the positive electrode column 3 and the substrate 1. The upper ends of the sealing ring 10 and the second insulating member 5 are in contact with the substrate 1. The second insulating member 5 is provided between the substrate 1 and the positive current collecting plate 6. The sealing ring 10 and the second insulating member 5 are used to achieve sealing and insulating effects. A plurality of strain grooves 61 are evenly arranged in an array on the positive electrode current collecting plate 6, and the strain grooves 61 penetrate the positive electrode current collecting plate 6 from top to bottom; A guide groove 8 is formed on the inner wall of the liquid injection hole at the center of the positive electrode column 3; A sealing aluminum nail 4 is installed at the injection hole of the positive electrode column 3 , and a sealing glue nail 7 is arranged at the lower end of the sealing aluminum nail 4 and on the upper side of the guide groove 8 .

[0020] Preferably: the sealing assembly includes a negative electrode current collecting disc 13 arranged at the bottom of the battery cell 11, a first insulating sheet 14 is arranged at the bottom of the negative electrode current collecting disc 13, a negative electrode cover plate 15 is arranged on the aluminum shell 2 at the bottom of the first insulating sheet 14, a safety valve 16 is arranged on the negative electrode cover plate 15, and a positive electrode cover plate 17 is arranged on the top of the aluminum shell 2.

[0021] Preferably, the positive electrode column 3 is integrated on the positive electrode current collecting disk 6, which increases the contact area between the positive electrode column 3 and the positive electrode current collecting disk 6 and reduces the resistance.

[0022] Preferably, the injection hole is located at the center of the positive electrode column 3, and the guide groove 8 is a spiral groove to improve the positioning accuracy.

[0023] Preferably, the positive terminal 9 is connected to the substrate 1 through a sealing ring 10 , and the positive terminal 9 and the positive electrode column 3 are interference fit.

[0024] Preferably, the positive electrode column 3 is connected to the positive electrode current collecting plate 6 by welding.

[0025] Preferably, a positive electrode insulating sheet is integrated on the positive electrode cover plate 17, which effectively reduces the assembly process and improves production efficiency.

[0026] Preferably, the positive current collecting plate 6 and the positive pole 3 are both provided with a central hole, and the diameters of the central holes decrease successively, and cooperate with the guide groove 8 on the positive pole 3 to avoid poor subsequent liquid injection due to assembly tolerance.

[0027] Preferably, a plurality of strain grooves 61 are distributed on the positive electrode current collecting plate 6 along a spiral, and the strain grooves 61 are oblique holes.

[0028] Working principle: During use and installation, the positive pole column 3 is welded to the positive current collector 6, the positive current collector 6 is welded to the pole ear of the battery cell 11, the positive pole column 3 passes through the positive cover plate 17 and the center hole of the positive terminal 9 from bottom to top, the positive pole column 3 is welded to the positive terminal 9, and the battery cell 11 is sealed and welded with the positive cover plate 17 after entering the aluminum shell 2; The positive terminal 9 formed in the positive electrode column 3 is used to improve the smooth addition of electrolyte during the injection process, and utilizes the strain groove 61 formed on the positive current collecting plate 6; During the annular welding process of the positive electrode current collector 6, stress deformation will be generated, and the gap of the strain groove 61 is used to release the metal deformation caused by the stress deformation; The built-in spiral strain groove 61 is used to guide the current at the macro level, thereby avoiding the resistance error of the metallographic layer caused by stress deformation, which causes the instability of current conduction; Because the strain groove 61 is a spiral inner hole, according to regional analysis, it can be understood that the heat dissipation method has changed, and the heat dissipation surface between unit areas has increased, thereby improving the heat dissipation effect during use.

[0029] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of the present invention to be protected.

Claims

1. A cylindrical battery positive electrode cover assembly, characterized in that: The invention comprises a positive pole column (3), a positive terminal (9), a positive current collecting plate (6), and a negative current collecting plate (13); the bottom of the positive pole column (3) is connected to the positive current collecting plate (6) by welding; a liquid injection hole is provided through the center of the positive pole column (3); the outside of the positive pole column (3) is connected to the positive terminal (9) by welding; the outside of the positive terminal (9) is provided with a first insulating member (12) and a substrate (1) in sequence along the vertical direction; the first insulating member (12) is used to insulate and isolate the positive terminal (9) from the substrate (1); an aluminum shell (2) is provided on the outside of the bottom of the substrate (1); a battery cell (11) is provided inside the aluminum shell (2) and located at the lower end of the positive current collecting plate (6); and a sealing component is provided at the bottom of the battery cell (11); A sealing ring (10) is arranged between the positive electrode column (3) and the substrate (1); the upper ends of the sealing ring (10) and the second insulating member (5) are in contact with the substrate (1); the second insulating member (5) is arranged between the substrate (1) and the positive current collecting plate (6); the sealing ring (10) and the second insulating member (5) are used to achieve sealing and insulating effects; A plurality of strain grooves (61) are evenly arranged in an array on the positive electrode current collecting disk (6), and the strain grooves (61) penetrate the positive electrode current collecting disk (6) from top to bottom, and the plurality of strain grooves (61) are distributed on the positive electrode current collecting disk (6) along a spiral, and the strain grooves (61) are oblique holes; A guide groove (8) is formed on the inner wall of the liquid injection hole at the center of the positive electrode column (3); A sealing aluminum nail (4) is installed at the injection hole of the positive electrode column (3), and a sealing glue nail (7) is provided at the lower end of the sealing aluminum nail (4) and on the upper side of the guide groove (8).

2. A cylindrical battery positive electrode cover assembly according to claim 1, characterized in that: The sealing assembly comprises a negative electrode current collecting disc (13) arranged at the bottom of the battery cell (11), a first insulating sheet (14) being arranged at the bottom of the negative electrode current collecting disc (13), a negative electrode cover plate (15) being arranged on the bottom of the first insulating sheet (14) and on the aluminum shell (2), a safety valve (16) being arranged on the negative electrode cover plate (15), and a positive electrode cover plate (17) being arranged on the top of the aluminum shell (2).

3. The cylindrical battery positive electrode cover assembly according to claim 1, characterized in that: The positive electrode column (3) is integrated on the positive electrode current collecting disk (6), thereby increasing the contact area between the positive electrode column (3) and the positive electrode current collecting disk (6) and reducing the resistance.

4. A cylindrical battery positive electrode cover assembly according to claim 2, characterized in that: The injection hole is located at the center of the positive electrode column (3), and the guide groove (8) is a spiral groove, which improves the positioning accuracy.

5. The cylindrical battery positive electrode cover assembly according to claim 3, characterized in that: The positive terminal (9) is connected to the substrate (1) via the sealing ring (10), and the positive terminal (9) and the positive pole (3) are interference fit.

6. A cylindrical battery positive electrode cover assembly according to claim 4, characterized in that: The positive electrode pole (3) is connected to the positive electrode current collecting plate (6) by welding.

7. The cylindrical battery positive electrode cover assembly according to claim 5, characterized in that: The positive electrode cover plate (17) is integrated with a positive electrode insulating sheet, which effectively reduces the assembly process and improves production efficiency.

8. The cylindrical battery positive electrode cover assembly according to claim 6, characterized in that: The positive electrode current collecting disk (6) and the positive electrode pole (3) are both provided with a central hole, and the diameters of the central holes decrease successively, and cooperate with the guide groove (8) on the positive electrode pole (3) to avoid poor subsequent liquid injection due to assembly tolerance.

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