A lithium-ion cylindrical secondary battery

Abstract

The utility model relates to cylindrical battery technical field, proposes a kind of lithium ion cylindrical secondary battery, including shell, positive pole, lower plastic and sealing ring;The end portion of shell is equipped with mounting hole;Lower plastic and the sealing ring are all attached and set in the shell, and the side of lower plastic away from the shell is equipped with clamping groove;Positive pole passes through the sealing ring and the mounting hole, and with the inner wall of the mounting hole interval arrangement, the one end of positive pole in the shell is equipped with inner riveting plate, the inner riveting plate supports the sealing ring, and with the clamping groove is clamped;The maximum thickness of lower plastic is H 63 , the thickness of lower plastic where the clamping groove is equipped is H 631 , H 631 / H 63 =50%-70%.The utility model can isolate shell and positive pole and shell and roll core by setting lower plastic, by reasonably limiting the specification of lower plastic, the assembly yield and safety risk of battery can be considered, to effectively improve the overall performance of battery.

Description

Technical Field

[0001] This utility model relates to the field of cylindrical battery technology, and in particular to a lithium-ion cylindrical secondary battery. Background Technology

[0002] Lithium-ion rechargeable batteries have become a core power source for portable electronic devices, hybrid vehicles, and electric vehicles due to their significant advantages such as high operating voltage, high energy density, and long cycle life. Among them, cylindrical structures occupy an important market share due to their high mechanical strength, high production efficiency, and excellent space utilization.

[0003] The terminals are an important component of a cylindrical lithium-ion secondary battery, serving as a key part for the electrical connection between the battery and external circuitry. Terminals are typically fixed to the battery casing using riveting. By applying pressure, plastic deformation occurs between the terminal and the battery casing, creating a strong mechanical and electrical connection. During the riveting process, some material from the terminal is deformed and fills the corresponding riveting holes or areas on the battery casing, achieving a tight bond between the two.

[0004] To improve the airtightness and insulation between the terminal and the battery casing, existing technologies typically place a plastic component between them. However, these technologies do not specify the dimensions of this plastic component. If the component is too thin, the terminal cannot secure it, causing it to rotate or detach, resulting in lower battery assembly yield and increased short-circuit risk. Conversely, if the component is too thick, the terminal needs to apply significant pressure to secure it, compromising the long-term airtightness at the terminal. Utility Model Content

[0005] In view of this, this utility model proposes a cylindrical lithium-ion secondary battery. By reasonably limiting the specifications of the plastic, it can balance the assembly yield and safety risks of the battery, and effectively improve the overall performance of the battery.

[0006] The technical solution of this utility model is implemented as follows: This utility model provides a cylindrical lithium-ion secondary battery, including a shell, a positive electrode post, a lower plastic component, and a sealing ring; the shell has a mounting hole at its end; the lower plastic component and the sealing ring are both abutted within the shell, and the lower plastic component has a slot on its side away from the shell; the positive electrode post passes through the sealing ring and the mounting hole, and is spaced apart from the inner wall of the mounting hole; one end of the positive electrode post located inside the shell has an inner rivet plate, which abuts against the sealing ring and engages with the slot; the maximum thickness of the lower plastic component is H. 63 The thickness of the lower plastic at the location where the slot is formed is H. 631 H 631 / H 63 =50%-70%.

[0007] Based on the above technical solution, preferably, it further includes a sealing aluminum sheet and a core; the core is disposed within the housing and electrically connected to the positive electrode post; the positive electrode post is provided with an injection hole, and the sealing aluminum sheet is sealed and fixed within the injection hole; the distance between the side of the sealing aluminum sheet away from the core and the core is H. 51 H 63 / H 51 =13.7%-20.5%.

[0008] Based on the above technical solutions, preferably, it also includes a positive electrode current collector, which is electrically connected to the winding core; a protrusion is provided in the middle of one side of the positive electrode current collector, which is welded and fixed to the inner riveting plate; the distance between the positive electrode current collector and the lower plastic is H. 64 H 64 / H 51 =23.9%-30.8%.

[0009] Based on the above technical solution, preferably, the lower plastic is annular and is fitted over the outside of the sealing ring; the annular width of the lower plastic is L. 62 The distance between the lower plastic periphery and the inner riveting plate is L. 63 L 63 / L 62 =74.6%-83.3%.

[0010] Based on the above technical solutions, preferably, the radius of the shell is R. 10 L 62 / R 10 =45.2%-53.9%.

[0011] Based on the above technical solutions, preferably, the distance between the mounting hole and the periphery of the housing is L. 61 L 61 / R 10 =56.1%-73.5%.

[0012] Based on the above technical solutions, preferably, the distance between the positive current collector and the inner riveting plate is H. 65 H 65 =0.8-1.2mm.

[0013] Based on the above technical solutions, preferably, it further includes a positive electrode tab layer, which is connected to the end of the winding core and welded and fixed to the positive electrode current collector. The positive electrode current collector has a clearance groove in the middle of the side away from the inner riveting plate, and the depth of the clearance groove is H. 66H 66 =0.8-1.2mm.

[0014] Based on the above technical solution, preferably, the thickness of the positive electrode tab is H. 67 H 67 =0.7-0.9mm.

[0015] Based on the above technical solutions, preferably, the radius of the shell is R. 10 H 51 =5.35-6.35mm, R 10 =21-25mm.

[0016] The lithium-ion cylindrical secondary battery of this invention has the following advantages over the prior art: (1) By setting the lower plastic, the shell and the positive terminal post and the shell and the core can be isolated. By reasonably limiting the specifications of the lower plastic, the assembly yield and safety risks of the battery can be taken into account, thereby effectively improving the overall performance of the battery.

[0017] (2) By reasonably limiting the specifications of the positive current collector and the positive electrode tab, not only can the safety performance and assembly yield of the battery be further improved, but also the capacity and energy density of the battery can be improved. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a cross-sectional view of a lithium-ion cylindrical secondary battery according to the present invention.

[0020] Figure 2 This is a cross-sectional view of the slot in a cylindrical lithium-ion secondary battery according to the present invention.

[0021] Figure 3 This is a cross-sectional view of the lower plastic portion of a lithium-ion cylindrical secondary battery according to this utility model.

[0022] Figure 4 This is a cross-sectional view of the sealing aluminum sheet in a lithium-ion cylindrical secondary battery according to the present invention.

[0023] The components are: 1. Shell; 101. Mounting hole; 2. Core; 3. Positive electrode post; 31. Inner riveting plate; 32. Outer riveting plate; 301. Injection hole; 4. Positive electrode ear layer; 5. Positive electrode current collector; 501. Protrusion; 502. Clearance groove; 6. Sealing aluminum sheet; 7. Lower plastic; 701. Slot; 8. Sealing ring; 9. Upper plastic. Detailed Implementation

[0024] The technical solutions of this utility model will be clearly and completely described below with reference to specific embodiments. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0025] This utility model discloses a cylindrical lithium-ion secondary battery, comprising a casing 1, a core 2, a positive electrode post 3, a positive electrode tab 4, a positive electrode current collector 5, a sealing aluminum sheet 6, a lower plastic 7, a sealing ring 8, and an upper plastic 9.

[0026] The housing 1 is a cylindrical structure with an internal cavity. A mounting hole 101 is provided at the positive end of the housing 1. The sealing ring 8 is abutted against the end inside the housing 1, and the upper plastic 9 is abutted against the end outside the housing 1. Both the sealing ring 8 and the upper plastic 9 are annular structures, and both the sealing ring 8 and the upper plastic 9 are coaxially arranged with the mounting hole 101.

[0027] The positive electrode post 3 passes through the sealing ring 8, the mounting hole 101, and the upper plastic 9 in sequence, so that one end of the positive electrode post 3 is located inside the housing 1 and the other end is located outside the housing 1, and the positive electrode post 3 is spaced apart from the inner wall of the mounting hole 101; the two ends of the positive electrode post 3 are riveted to form rivet plates. The rivet plate located inside the housing 1 is the inner rivet plate 31, and the rivet plate located outside the housing 1 is the outer rivet plate 32. The outer diameter of both the inner rivet plate 31 and the outer rivet plate 32 is larger than the inner diameter of the mounting hole 101. The inner rivet plate 31 abuts against the side of the sealing ring 8 away from the housing 1, and the outer rivet plate 32 abuts against the side of the upper plastic 9 away from the housing 1, thereby fixing the positive electrode post 3, the upper plastic 9, and the sealing ring 8 to the housing 1.

[0028] Meanwhile, both the sealing ring 8 and the upper plastic 9 are made of insulating material, which can prevent short circuits between the positive terminal 3 and the casing 1 and ensure the safety of the battery.

[0029] The lower plastic 7 is abutted inside the housing 1. The lower plastic 7 has a circular structure and is sleeved on the outside of the sealing ring 8. The lower plastic 7 and the sealing ring 8 are sealed and abutted together. The lower plastic 7 is also abutted between the inner riveting plate 31 and the housing 1 to improve the sealing between the positive electrode post 3 and the housing 1.

[0030] like Figures 1-4As shown, the lower plastic 7 is provided with a slot 701, and the inner rivet plate 31 is engaged with the slot 701, thereby strengthening the anti-rotation performance of the positive electrode post 3 and improving the sealing ability at the positive electrode post 3.

[0031] The core 2 is disposed inside the housing 1, the positive electrode post 3 is located at one end of the core 2, and the core 2 and the positive electrode post 3 are spaced apart. The positive electrode tab layer 4 is connected and disposed at the end of the core 2. The positive electrode current collector 5 is welded and fixed between the positive electrode tab layer 4 and the positive electrode post 3, thereby realizing the electrical connection between the core 2 and the positive electrode post 3.

[0032] like Figure 1 and Figure 4 As shown, the positive electrode current collector 5 has a protrusion 501 in the middle of the side near the positive electrode post 3. The protrusion 501 has a boss-shaped structure and is welded and fixed to the inner riveting plate 31. The positive electrode current collector 5 has a relief groove 502 in the middle of the side away from the inner riveting plate 31, so that there is a certain gap between the protrusion 501 and the core 2 and the positive electrode ear layer 4. When the protrusion 501 and the positive electrode post 3 are welded, the heat generated by welding is not easily transferred to the core 2 and the positive electrode ear layer 4, thus ensuring the assembly yield of the battery.

[0033] like Figure 1 As shown, the positive electrode post 3 is provided with an injection hole 301, and the sealing aluminum sheet 6 is sealed and fixed in the injection hole 301. When the positive electrode post 3, the core 2 and the positive electrode current collector 5 are assembled on the housing 1, electrolyte can be added into the housing 1 through the injection hole 301 so that the electrolyte wets the core 2. After the electrolyte is added, the sealing nail and the sealing aluminum sheet 6 are sealed and fixed in the injection hole 301, thereby sealing the injection hole 301 and avoiding the problem of electrolyte leakage.

[0034] like Figure 1 and Figure 4 As shown, the injection hole 301 has a stepped hole structure, which includes four stages with different inner diameters from top to bottom. The inner diameter of the four stages gradually decreases from top to bottom, and the inner diameter of the top three stages is relatively large, while the inner diameter of the bottom stage is relatively small.

[0035] When welding the positive electrode post 3 and the positive electrode current collector 5, the welding laser head can extend into the three stages above to weld the positive electrode post 3 and the positive electrode current collector 5; after the battery completes the liquid filling operation, the sealing nail is installed in the fourth stage, and the sealing aluminum sheet 6 is installed in the second stage. During the welding process of the sealing aluminum sheet 6 and the positive electrode post 3, the welding line will not protrude from the top side of the positive electrode post 3, so that the total height of the battery remains unchanged.

[0036] like Figures 1-4 As shown, the radius of shell 1 is R. 10 The distance between the sealing aluminum sheet 6 and the core 2 on the side away from the core 2 is H. 51The maximum thickness of the lower plastic 7 is H. 63 The thickness of the lower plastic 7 at the slot 701 is H. 631 The distance between the positive current collector 5 and the lower plastic 7 is H. 64 The distance between the positive current collector 5 and the inner riveting plate 31 is H. 65 The depth of the clearance groove 502 is H. 66 The thickness of the positive electrode layer 4 is H. 67 The distance between the mounting hole 101 and the periphery of the housing 1 is L. 61 The ring width of the lower plastic 7 is L. 62 The distance between the lower plastic 7th perimeter and the inner riveting plate 31 is L. 63 .

[0037] In some embodiments, R 10 =21-25mm, that is, the radius of shell 1 is 21mm, 23mm or 25mm, etc.

[0038] In some embodiments, H 51 =5.35-6.35mm, that is, the distance between the sealing aluminum sheet 6 and the core 2 on the side away from the core 2 is 5.35mm, 5.85mm or 6.35mm, etc.

[0039] In some embodiments, H 631 / H 63 =50%-70%, meaning the thickness of the lower plastic 7 at the slot 701 is 50%, 60%, or 70% of the maximum thickness of the lower plastic 7, etc. If H 631 / H 63 If the thickness is less than 50%, the thickness of the slot 701 on the lower plastic 7 is too small, the positive electrode post 3 cannot hold the lower plastic 7 tightly, the lower plastic 7 is prone to rotation and falling off, resulting in the failure of the sealing function of the lower plastic 7, the unreliability of the sealing of the lower plastic 7 cannot be guaranteed, and the risk of short circuit of the battery increases; if H 631 / H 63 If the thickness is greater than 70%, the thickness of the slot 701 on the lower plastic 7 is too large, and the positive electrode post 3 will also be unable to hold the lower plastic 7 tightly, resulting in the failure of the sealing function of the lower plastic 7 and the inability to guarantee the sealing reliability of the battery.

[0040] In some embodiments, H 63 / H 51 =13.7%-20.5%, meaning the maximum thickness of the lower plastic 7 is 13.7%, 17.1%, or 20.5% of the distance between the sealing aluminum sheet 6 (away from the core 2) and the core 2. If H 63 / H 51 If the thickness of the lower plastic 7 is less than 13.7%, the structural strength will be reduced, and the outer ring of the lower plastic 7 will be prone to collapse, leading to a decrease in the yield of internal battery assembly; if H 63 / H51 If the thickness of the lower plastic 7 is greater than 20.5%, the weight and manufacturing cost of the lower plastic 7 will increase, and the capacity and energy density of the battery will decrease.

[0041] In some embodiments, H 64 / H 51 =23.9%-30.8%, meaning the distance between the positive current collector 5 and the lower plastic 7 is 23.9%, 27.4%, or 30.8% of the distance between the sealing aluminum sheet 6 (away from the core 2) and the core 2. If H 64 / H 51 If the positive current collector 5 is less than 23.9%, the distance between the positive current collector 5 and the lower plastic 7 is too small, and the height of the protrusion 501 is too small. During the welding of the positive current collector 5 and the positive electrode post 3, the heat generated during welding will be transferred to the core 2, causing the separator in the core 2 to be burned, increasing the risk of a battery short circuit. If H 64 / H 51 If the positive current collector 5 is greater than 30.8%, the distance between the positive current collector 5 and the lower plastic 7 is too large, the height of the protrusion 501 is too large, the overall structural strength of the positive current collector 5 is reduced, and it is easy to collapse. When welding the positive current collector 5 and the positive terminal 3, welding defects such as incomplete welding are likely to occur.

[0042] In some embodiments, L 63 / L 62 =74.6%-83.3%, meaning the distance between the lower plastic 7 perimeter and the inner riveting plate 31 is 74.6%, 78.9%, or 83.3% of the width of the lower plastic 7 ring, etc. If L 63 / L 62 If the diameter is less than 74.6%, the distance between the lower plastic 7 and the inner riveting plate 31 is too small, the outer diameter of the lower plastic 7 is reduced, and it cannot effectively isolate the casing 1 from the positive electrode current collector 5 and the core 2, increasing the circuit risk and safety risk of the battery; if L 63 / L 62 If the gap between the lower plastic 7 and the inner riveting plate 31 is greater than 83.3%, the outer diameter of the lower plastic 7 will increase, and the lower plastic 7 will interfere with the shell 1 during the assembly process, affecting the assembly efficiency and assembly yield of the battery.

[0043] In some embodiments, L 62 / R 10 =45.2%-53.9%, meaning the ring width of the lower plastic 7 is 45.2%, 49.6%, or 53.9% of the radius of the shell 1, etc. If L 62 / R 10 If the diameter is less than 45.2%, the ring width of the lower plastic 7 is too small, and the outer diameter of the lower plastic 7 is reduced, which cannot effectively isolate the casing 1 from the positive current collector 5 and the core 2, increasing the risk of short circuit in the battery and raising the safety risk; if L 62 / R 10If the value is greater than 53.9%, then the ring width of the lower plastic 7 is too large, the outer diameter of the lower plastic 7 is increased or the inner diameter is too small. This will not only cause the lower plastic 7 to interfere with the shell 1 during the assembly process, affecting the assembly efficiency and assembly yield of the battery, but will also cause the lower plastic 7 to squeeze the sealing ring 8, resulting in a decrease in the sealing reliability of the battery.

[0044] In some embodiments, L 61 / R 10 =56.1%-73.5%, meaning the distance between the mounting hole 101 and the periphery of the housing 1 is 56.1%, 64.8%, or 73.5% of the radius of the housing 1, etc. If L 61 / R 10 If the distance between the mounting hole 101 and the periphery of the housing 1 is less than 56.1%, the outer diameter of the positive electrode post 3 at its center will decrease accordingly, resulting in a decrease in the inner diameter of the injection hole 301. This prevents the laser from reaching into the injection hole 301 to weld the positive electrode post 3 and the positive electrode current collector 5, easily leading to welding defects such as incomplete welds. If L 61 / R 10 If the distance between the mounting hole 101 and the periphery of the casing 1 is greater than 73.5%, the outer diameter of the positive electrode post 3, the lower plastic 7, the sealing ring 8 and the upper plastic 9 will increase accordingly, resulting in increased manufacturing cost and weight of the battery and decreased energy density of the battery.

[0045] In some embodiments, H 65 =0.8-1.2mm, meaning the distance between the positive current collector 5 and the inner riveting plate 31 is 0.8mm, 1mm, or 1.2mm, etc. If H 65 If the distance between the positive current collector 5 and the inner riveting plate 31 is less than 0.8mm, and the height of the protrusion 501 is too small, the heat generated during welding of the positive current collector 5 and the positive electrode post 3 will be transferred to the core 2, causing the separator in the core 2 to be burned, increasing the risk of battery short circuit; if H 65 If the gap between the positive current collector 5 and the inner riveting plate 31 is greater than 1.2mm, the height of the protrusion 501 will be too large, the overall structural strength of the positive current collector 5 will be reduced, and it will be easy to collapse. When welding the positive current collector 5 and the positive terminal 3, welding defects such as incomplete welding are likely to occur.

[0046] In some embodiments, H 66 =0.8-1.2mm, meaning the depth of the clearance groove 502 is 0.8mm, 1mm, or 1.2mm, etc. If H 66 If the depth of the clearance groove 502 is less than 0.8mm, and the height of the protrusion 501 is less than 0.8mm, the heat generated during welding of the positive current collector 5 and the positive electrode post 3 will be transferred to the core 2, causing the separator in the core 2 to be burned, increasing the risk of battery short circuit; if H 66If the depth of the clearance groove 502 is too large and the height of the protrusion 501 is too large, the overall structural strength of the positive current collector 5 will be reduced and it will be easy to collapse. When welding the positive current collector 5 and the positive terminal post 3, welding defects such as incomplete welding are likely to occur.

[0047] In some embodiments, H 67 =0.7-0.9mm, meaning the thickness of the positive electrode tab layer 4 is 0.7mm, 0.8mm, or 0.9mm, etc. If H 67 If the thickness is less than 0.7mm, the thickness of the positive electrode tab layer 4 is too small. During the welding of the positive electrode current collector 5 and the positive electrode tab layer 4, the heat generated during welding will be transferred to the core 2, causing the separator in the core 2 to be burned, increasing the risk of a battery short circuit. If H 67 If the thickness is greater than 0.9mm, the thickness of the positive electrode tab layer 4 will be too large, which will not only increase the weight of the battery, but also occupy the internal space of the battery, resulting in a decrease in the battery's capacity and energy density.

[0048] 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, improvements, etc., 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 cylindrical lithium-ion secondary battery, characterized in that: The device includes a housing (1), a positive electrode post (3), a lower plastic part (7), and a sealing ring (8); the housing (1) has an installation hole (101) at one end; the lower plastic part (7) and the sealing ring (8) are both abutted inside the housing (1), and the lower plastic part (7) has a slot (701) on the side away from the housing (1); the positive electrode post (3) passes through the sealing ring (8) and the installation hole (101), and is spaced apart from the inner wall of the installation hole (101); the positive electrode post (3) has an inner rivet plate (31) at one end inside the housing (1), the inner rivet plate (31) abuts against the sealing ring (8) and is engaged with the slot (701); The maximum thickness of the lower plastic (7) is H. 63 The thickness of the lower plastic (7) at the location where the slot (701) is opened is H. 631 H 631 / H 63 =50%-70%.

2. A lithium-ion cylindrical secondary battery as described in claim 1, characterized in that: It also includes a sealing aluminum sheet (6) and a core (2); the core (2) is disposed in the housing (1) and electrically connected to the positive electrode post (3); the positive electrode post (3) is provided with a liquid injection hole (301), and the sealing aluminum sheet (6) is sealed and fixed in the liquid injection hole (301); The distance between the sealing aluminum sheet (6) away from the core (2) and the core (2) is H. 51 H 63 / H 51 =13.7%-20.5%.

3. A lithium-ion cylindrical secondary battery as described in claim 2, characterized in that: It also includes a positive current collector (5), which is electrically connected to the core (2); a protrusion (501) is provided in the middle of one side of the positive current collector (5), and the protrusion (501) is welded and fixed to the inner riveting plate (31); The distance between the positive current collector (5) and the lower plastic (7) is H. 64 H 64 / H 51 =23.9%-30.8%.

4. A lithium-ion cylindrical secondary battery as described in claim 1, characterized in that: The lower plastic (7) is ring-shaped and is fitted on the outside of the sealing ring (8); The ring width of the lower plastic (7) is L. 62 The distance between the periphery of the lower plastic (7) and the inner riveting plate (31) is L. 63 L 63 / L 62 =74.6%-83.3%.

5. A lithium-ion cylindrical secondary battery as described in claim 4, characterized in that: The radius of the shell (1) is R. 10 L 62 / R 10 =45.2%-53.9%.

6. A lithium-ion cylindrical secondary battery as described in claim 5, characterized in that: The distance between the mounting hole (101) and the periphery of the housing (1) is L. 61 L 61 / R 10 =56.1%-73.5%.

7. A lithium-ion cylindrical secondary battery as described in claim 3, characterized in that: The distance between the positive current collector (5) and the inner rivet plate (31) is H. 65 H 65 =0.8-1.2mm.

8. A lithium-ion cylindrical secondary battery as described in claim 3, characterized in that: It also includes a positive electrode tab layer (4), which is connected to the end of the core (2) and welded to the positive electrode current collector (5). The positive electrode current collector (5) has a relief groove (502) in the middle on the side away from the inner riveting plate (31). The depth of the relief groove (502) is H. 66 H 66 =0.8-1.2mm.

9. A lithium-ion cylindrical secondary battery as described in claim 8, characterized in that: The thickness of the positive electrode layer (4) is H. 67 H 67 =0.7-0.9mm.

10. A lithium-ion cylindrical secondary battery as described in claim 2, 3, 7, 8 or 9, characterized in that: The radius of the shell (1) is R. 10 H 51 =5.35-6.35mm, R 10 =21-25mm.

Images