A cylindrical lithium-ion battery

Abstract

The utility model provides a kind of cylindrical lithium ion battery, including positive current collector and roll core, wherein, disc body is equipped on positive current collector, disc body and the full tab end surface of roll core are welded fixed;The radius of roll core is R0, and the shortest distance of disc body edge to roll core edge is L4, and the radius of roll core and the shortest distance of disc body edge to roll core edge satisfy: L4 / R0=8.6~12.6%.The cylindrical lithium ion battery passes through the proportion range of radius of roll core and the shortest distance of disc body edge to roll core edge by reasonable setting, can both ensure in shell wall to the deformation of axis center, also cannot easily contact the disc body edge of positive current collector, effectively reduce short-circuit risk;It can also ensure that disc body and roll core have enough weldable area, maintain the overcurrent capacity of welding wire, avoid that welding wire place temperature rises too high, to guarantee the safety and performance of battery.

Description

Technical Field

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

[0002] A cylindrical battery is a type of battery composed of components such as a positive electrode, a negative electrode, a separator, an electrolyte, and a casing. It is cylindrical in shape. Its structure typically includes components such as a casing, a cap, a positive electrode, a negative electrode, a separator, an electrolyte, a PTC element, gaskets, and a safety valve. The edges of the cylindrical battery tabs are equipped with insulating tape to prevent the tabs from contacting the casing wall, which could cause poor casing voltage. This ensures that the battery can charge and discharge normally and provides protection in abnormal conditions.

[0003] A single-pass cylindrical battery with publication number CN220086334U includes a core, a positive current collector, a casing, and an explosion-proof valve. The positive tab of the core is connected to the positive current collector to form a core assembly. The core assembly is disposed within the casing, and the bottom of the casing along its height direction is connected to the positive current collector. The casing has a mounting groove and a first liquid injection hole, and the positive current collector has a second liquid injection hole. The mounting groove, the first liquid injection hole, and the second liquid injection hole are sequentially connected and correspond to the center hole of the core. The explosion-proof valve is disposed in the mounting groove.

[0004] The current current collector has an unreasonable gap between the edge of the current collector and the edge of the core. If the gap is too small, the shell wall will easily come into contact with the edge of the positive current collector during mechanical sealing of the battery groove, increasing the risk of short circuit. If the gap is too large, the area that can be welded between the current collector and the core will be smaller, the current carrying capacity of the welding wire will be weakened, and the temperature rise will be increased, thus affecting the battery performance. Utility Model Content

[0005] In view of this, this utility model proposes a cylindrical lithium-ion battery. By reasonably setting the size of the reserved gap between the edge of the current collector and the edge of the winding core, a balance between battery safety and performance is achieved, effectively improving the overall performance of the battery.

[0006] The technical solution of this utility model is achieved as follows: This utility model provides a cylindrical lithium-ion battery, including a positive electrode current collector and a wound core, wherein,

[0007] The positive current collector is provided with a disk body, which is welded and fixed to the end face of the full-pole tab of the winding core;

[0008] The radius of the core is R0, and the shortest distance from the edge of the disc to the edge of the core is L4. The radius of the core and the shortest distance from the edge of the disc to the edge of the core satisfy: L4 / R0 = 8.6~12.6%.

[0009] Based on the above technical solutions, preferably, the shortest distance L4 from the edge of the disc to the edge of the core is in the range of 0.88 to 1.28 mm.

[0010] Based on the above technical solutions, preferably, the center of the core is pre-set with a liquid injection hole, the radius of the liquid injection hole is R4, and the radius of the liquid injection hole and the radius of the core satisfy: R4 / R0=15.7~18.7%.

[0011] Based on the above technical solutions, preferably, a through hole is provided in the center of the disc body, the radius of the through hole is R2, and the radius of the through hole and the radius of the core satisfy: R2 / R0 = 21.6~27.5%.

[0012] Based on the above technical solutions, preferably, the through hole and the injection hole are connected and on the same axis, the shortest distance from the edge of the through hole to the edge of the injection hole is L1, and the shortest distance from the edge of the through hole to the edge of the injection hole satisfies the following condition with the radius of the through hole: L1 / R2 = 20.5~37.5%.

[0013] Based on the above technical solutions, preferably, the disc body is provided with multiple vent holes located outside the through holes, the radius of the vent holes is R3, and the radius of the vent holes and the radius of the winding core satisfy: R3 / R0 = 11.8~17.7%.

[0014] Based on the above technical solutions, preferably, the shortest distance between the edge of the through hole and the edge of the vent hole is L2, and the shortest distance between the edge of the through hole and the edge of the vent hole satisfies the following condition with respect to the radius of the core: L2 / R0 = 8.1~13.9%.

[0015] Based on the above technical solutions, preferably, the shortest distance between the edge of the vent hole and the disc body is L3, and the shortest distance between the edge of the vent hole and the disc body satisfies the following condition with respect to the radius of the winding core: L3 / R0 = 21.4~27.3%.

[0016] Based on the above technical solutions, preferably, the positive electrode current collector also includes a tail body and a connecting part, wherein the disk body is fixedly connected to the tail body through the connecting part, and the connecting part is provided with arc transitions at both sides of the connection between the disk body and the tail body, and the disk body, the tail body and the connecting part are an integral structure, the shortest distance from the midpoint of the liquid injection hole to the connecting part is M10, and the shortest distance from the midpoint of the liquid injection hole to the connecting part satisfies the following condition with the radius of the core: M10 / R0 = 51.8~57.7%.

[0017] Based on the above technical solutions, preferably, the radius of the disc body is R1, and satisfies: R1 = 8.8~9.4mm; the radius of the core satisfies: R0 = 9.18~11.18mm; and the radius of the core is greater than the radius of the disc body.

[0018] The cylindrical lithium-ion battery of this invention has the following advantages over the prior art:

[0019] (1) By reasonably setting the ratio range of the radius of the core and the shortest distance from the edge of the disk to the edge of the core, it can ensure that the shell wall deforms towards the center of the axis and will not easily contact the edge of the positive current collector, thus effectively reducing the risk of short circuit; it can also ensure that the disk and the core have enough weldable area to maintain the current carrying capacity of the welding line and avoid excessive temperature rise at the welding line, thereby ensuring the safety and performance of the battery.

[0020] (2) By reasonably setting the ratio range between the injection hole radius and the core radius, the electrolyte can flow into the battery quickly and smoothly, which greatly improves the battery injection efficiency. This not only shortens the battery manufacturing time and improves production efficiency, but also reduces the occupation of equipment, manpower and other resources, thereby reducing the battery manufacturing cost.

[0021] (3) By reasonably setting the ratio range of the shortest distance between the edge of the through hole and the edge of the vent hole to the radius of the core, it is possible to ensure that the area between the through hole and the vent hole has sufficient structural strength, reduce the risk of short circuit in the battery, and ensure that the vent hole is not blocked by the encapsulated part during the encapsulation process, so that the gas can be smoothly discharged when the electrolyte is injected, maintain the electrolyte inflow rate, improve production efficiency, and reduce manufacturing costs.

[0022] (4) By reasonably setting the ratio of the shortest distance from the midpoint of the injection hole to the connection part to the radius of the core, it can ensure that the connection between the disc and the tail has sufficient current carrying capacity and structural strength, avoid becoming a weak area for current carrying and breakage; and avoid the appearance of excess areas on the disc, ensure the energy density of the battery and reduce manufacturing costs. Attached Figure Description

[0023] 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.

[0024] Figure 1 This is a schematic diagram of the cylindrical lithium-ion battery of this utility model;

[0025] Figure 2 This is a schematic diagram showing the markings of the liquid injection hole and through hole structure of the cylindrical lithium-ion battery of this utility model.

[0026] Figure 3This is a schematic diagram showing the vent and disc structure markings of the cylindrical lithium-ion battery of this utility model.

[0027] Figure 4 This is a schematic diagram showing the markings on the connection portion of the cylindrical lithium-ion battery of this utility model. Detailed Implementation

[0028] The technical solutions of this utility model will be clearly and completely described below with reference to the embodiments of this utility model. 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 of ordinary skill in the art without creative effort are within the protection scope of this utility model.

[0029] like Figure 1-4 As shown, a cylindrical lithium-ion battery of this utility model includes a positive electrode current collector 1 and a core 2. The positive electrode current collector 1 is provided with a disk body 11, and the disk body 11 is welded and fixed to the end face of the full electrode tab of the core 2. The radius of the core 2 is R0, and the shortest distance from the edge of the disk body 11 to the edge of the core 2 is L4. The radius of the core 2 and the shortest distance from the edge of the disk body 11 to the edge of the core 2 satisfy: L4 / R0 = 8.6~12.6%.

[0030] It should be noted that when the shortest distance L4 from the edge of the disc 11 to the edge of the core 2 is too small, that is, when the disc 11 of the positive current collector 1 is too large and close to the diameter of the core 2, the opening of the casing needs to be sealed by grooving mechanical sealing in the subsequent battery assembly stage. Grooving and mechanical sealing operations will cause the casing wall below the groove to deform towards the axial center. If the positive current collector 1 and the core 2 have been welded together at this time, and there are defects in the positive electrode coating, the deformed casing wall can easily come into contact with the positive current collector due to insufficient reserved gap. The edge of the disk 11 of the positive electrode current collector 1 is too large, which greatly increases the risk of short circuit and may cause safety accidents such as battery overheating, fire or even explosion. If the shortest distance L4 from the edge of the disk 11 to the edge of the core 2 is too large, the diameter of the disk 11 of the positive electrode current collector 1 will become smaller. The positive electrode current collector 1 and the full tab end face of the core 2 are fixed by welding. The smaller diameter of the disk 11 directly leads to a reduction in the weldable area of ​​the disk 11 and the core 2. This weakens the current carrying capacity of the corresponding welding wire, increases the temperature rise at the welding wire, and affects the performance of the battery.

[0031] In this embodiment, by reasonably setting the ratio range between the radius of the core 2 and the shortest distance from the edge of the disk 11 to the edge of the core, it is possible to ensure that even if the shell wall deforms towards the axial center during the mechanical sealing of the groove, it will not easily contact the edge of the disk 11 of the positive current collector 1, effectively reducing the risk of short circuit; at the same time, it is possible to ensure that the disk 11 and the core 2 have sufficient weldable area to maintain the current carrying capacity of the welding wire and avoid excessive temperature rise at the welding wire, thereby ensuring the safety and performance of the battery.

[0032] In this embodiment, the shortest distance L4 from the edge of the disc 11 to the edge of the core 2 ranges from 0.88 to 1.28 mm; the radius of the disc 11 is R1, and its range is R1 = 8.8 to 9.4 mm; the radius of the core 2 ranges from R0 = 9.18 to 11.18 mm.

[0033] Specifically, in this embodiment, the radius of the disc body 11 is R1 = 9.1 mm; the radius of the core 2 is R0 = 10.18 mm; and the shortest distance from the edge of the disc body 11 to the edge of the core 2 is L4 = 1.08 mm.

[0034] In this embodiment, the core 2 has a liquid injection hole 200 at its center. The radius of the liquid injection hole 200 is R4, and the radius of the liquid injection hole 200 and the radius of the core 2 satisfy: R4 / R0 = 15.7~18.7%.

[0035] It should be noted that if the radius R4 of the injection hole 200 is too small, that is, if the injection hole 200 is too small relative to the size of the core 2, the electrolyte will be restricted by the size of the injection hole 200 during the process of injecting the electrolyte from the top of the positive current collector 1 into the battery. This will narrow the channel for the electrolyte to flow into the battery, increase the resistance to electrolyte flow, and thus slow down the electrolyte flow rate, affecting the battery's injection efficiency, lengthening the battery's process time, and increasing the battery's manufacturing cost. If the radius R4 of the injection hole 200 is too large, the corresponding diameter of the core 2 will be larger, and the gap between it and the battery casing will be smaller. It is even possible that the core 2 cannot be smoothly inserted into the casing, making the insertion of the core 2 into the casing more difficult. The increased difficulty of the insertion process will increase the operator's operational difficulty and time cost, and at the same time, the defect rate will also increase, increasing the battery's manufacturing cost. The larger diameter of the core 2 will also occupy more space inside the battery, reducing the amount of active material that the battery can accommodate, thereby reducing the battery's energy density.

[0036] This embodiment ensures that the electrolyte can flow into the battery quickly and smoothly by reasonably setting the ratio range between the radius of the injection hole 200 and the radius of the core 2, which greatly improves the electrolyte injection efficiency of the battery. This not only shortens the battery manufacturing time and improves production efficiency, but also reduces the occupation of equipment, manpower and other resources, thereby reducing the manufacturing cost of the battery.

[0037] Specifically, in this embodiment, the radius R4 of the injection hole 200 is 1.75 mm.

[0038] In this embodiment, a through hole 100 is provided in the center of the disc body 11. The radius of the through hole 100 is R2, and the radius of the through hole 100 and the radius of the core 2 satisfy: R2 / R0 = 21.6~27.5%.

[0039] It should be noted that when the radius R2 of the through hole 100 is too small, that is, when the through hole 100 is too small relative to the size of the core 2, the electrolyte will be limited by the size of the through hole 100 when it is injected into the battery from above the positive current collector 1 plate 11. The through hole 100 being too small narrows the channel for the electrolyte to flow into the battery, increases the resistance to electrolyte flow, and thus leads to a longer time for the electrolyte to flow into the battery, a decrease in injection efficiency, and an increase in battery manufacturing costs. At the same time, during battery charging and use, gas will be generated inside the battery. An excessively small through hole 100 will also affect the gas discharge rate, leading to an increase in internal battery pressure and affecting battery performance and safety. If the radius of the through hole 100 is too large, the through hole 100 will occupy the welding area between the plate 11 and the core 2. The positive current collector 1 and the core 2 need to be fixed by welding. The size of the welding area directly affects the effective area of ​​the welding wire. A reduction in the effective area of ​​the welding wire reduces the current carrying capacity at the welding wire and increases the temperature rise at the welding wire, affecting battery performance.

[0040] In this embodiment, by reasonably setting the ratio range between the radius of the through hole 100 and the radius of the core 2, the size of the through hole 100 can ensure that the electrolyte flows into the battery quickly and smoothly, improving the electrolyte injection efficiency, while ensuring that the gas can be discharged in time to maintain the stability of the battery internal pressure; it can also ensure that the disc 11 and the core 2 have sufficient welding area to maintain the current carrying capacity of the welding wire and avoid excessive temperature rise at the welding wire, thereby ensuring the performance and safety of the battery.

[0041] Specifically, in this embodiment, the radius R2 of the through hole 100 is 2.5mm.

[0042] In this embodiment, the through hole 100 and the injection hole 200 are connected and on the same axis. The shortest distance from the edge of the through hole 100 to the edge of the injection hole 200 is L1, and the shortest distance from the edge of the through hole 100 to the edge of the injection hole 200 satisfies the following condition with the radius of the through hole 100: L1 / R2 = 20.5~37.5%.

[0043] It should be noted that during the manufacturing process of cylindrical lithium-ion batteries, the positive current collector 1 is welded to the positive electrode side surface of the core 2. Due to manufacturing process limitations, there will inevitably be positional tolerances when the positive current collector 1 is placed on the positive electrode side surface of the core 2. When the ratio of the shortest distance L1 from the edge of the through hole 100 to the edge of the injection hole 200 to the radius R2 of the through hole is too small, the gap between the two will be too small to accommodate the process deviation. As a result, the through hole 100 will occupy part of the injection hole 200, which will affect the speed at which the electrolyte flows into the battery. If L1 / R2 is too large, the contact area between the positive current collector 11 and the positive electrode side of the core 2 will be reduced. The positive current collector and the positive electrode side of the core 2 need to be fixed by welding, which will reduce the effective welding area accordingly. This will lead to a decrease in the current carrying capacity at the welding line and an increase in the temperature rise at the welding line, affecting the battery performance.

[0044] In this embodiment, by reasonably setting the ratio of the shortest distance from the edge of the through hole 100 to the edge of the injection hole 200 to the radius of the through hole 100, it is possible to ensure that the through hole 100 does not occupy the injection hole 200 when there are process tolerances, thus ensuring that the electrolyte can flow into the battery at a relatively fast speed; at the same time, it is possible to ensure that the disk body 11 of the positive electrode current collector 1 and the positive electrode side of the core 2 have sufficient contact area to maintain an effective welding area, ensure the current carrying capacity of the welding wire, and avoid excessive temperature rise at the welding wire, thereby ensuring the performance and safety of the battery.

[0045] Specifically, in this embodiment, the shortest distance L1 from the edge of the through hole 100 to the edge of the injection hole 200 is 0.75 mm.

[0046] In this embodiment, the disc body 11 has multiple vent holes 110, which are located outside the through hole 100. The radius of the vent hole 110 is R3, and the radius of the vent hole 110 and the radius of the core 2 satisfy: R3 / R0 = 11.8~17.7%.

[0047] It should be noted that in the manufacturing of cylindrical lithium-ion batteries, after the electrolyte is injected from the inlet, it first flows onto the positive current collector 11 and then flows into the battery through the various holes on the positive current collector 11. When the radius of the vent hole 110 is too small, that is, when the size of the vent hole 110 relative to the core 2 is too small, the rate at which the electrolyte flows into the battery decreases, thereby increasing the manufacturing cost of the battery. If the radius of the vent hole 110 is too large, the vent hole 110 will occupy the effective welding area of ​​the positive electrode side of the vent hole 11 and the core 2. The positive current collector 1 and the positive electrode side of the core 2 need to be fixed by welding. The size of the welding area directly affects the effective area of ​​the welding wire, resulting in a decrease in the current carrying capacity at the welding wire and an increase in the temperature rise at the welding wire, which affects the performance of the battery.

[0048] In this embodiment, by reasonably setting the ratio range between the radius of the vent hole 110 and the radius of the core 2, it is possible to ensure that the electrolyte flows into the battery at a faster speed, thereby increasing the injection speed and shortening the process time; at the same time, it is possible to ensure that the positive electrode side of the disc 11 and the core 2 has sufficient welding area to maintain the current carrying capacity of the welding wire and avoid excessive temperature rise at the welding wire, thereby ensuring the performance and safety of the battery.

[0049] Specifically, in this embodiment, the radius R3 of the exhaust hole 110 is 1.5 mm.

[0050] In this embodiment, the shortest distance between the edge of the through hole 100 and the edge of the vent hole 110 is L2, and the shortest distance between the edge of the through hole 100 and the edge of the vent hole 110 satisfies the following condition with respect to the radius of the core 2: L2 / R0 = 8.1~13.9%.

[0051] It should be noted that when the ratio of L2 to the radius R0 of the core 2 is too small, the distance between the through hole 100 and the vent hole 110 is too close, resulting in a significant reduction in the structural strength of this area, making it prone to deformation or even breakage. This process generates burrs and metal foreign objects, increasing the battery's self-discharge rate. Consequently, the battery loses charge more quickly during storage, and the metal foreign objects may also cause internal short circuits, increasing the battery's safety risks. If L2 / R0 is too large, it will cause the vent hole 110 to be too close to the core 2. At the very edge of the disk body 11, after the positive electrode current collector 1 and the core 2 are welded together, they will be coated in the next process. The positive electrode coating tape will wrap around the core 2 on the positive electrode side and then fold towards the positive electrode current collector 1 to ensure that the edge of the positive electrode current collector 1 is covered. If the vent hole 110 is too close to the edge of the disk body 11, the positive electrode current collector 1 will cover the vent hole 110, which will cause the electrolyte inflow rate to decrease and the electrolyte injection time to increase during liquid injection, thus increasing the battery manufacturing time and manufacturing cost.

[0052] In this embodiment, by reasonably setting the ratio range between the shortest distance between the edge of the through hole 100 and the edge of the vent hole 110 and the radius of the core 2, it is possible to ensure that the area between the through hole 100 and the vent hole 110 has sufficient structural strength, reducing the risk of short circuit in the battery; and it is also possible to ensure that the vent hole is not blocked by the encapsulated part during the encapsulation process, ensuring that the gas can be smoothly discharged when the electrolyte is injected, maintaining the electrolyte inflow rate, improving production efficiency, and reducing manufacturing costs.

[0053] Specifically, in this embodiment, the shortest distance L2 between the edge of the through hole 100 and the edge of the vent hole 110 is 1.12 mm.

[0054] In this embodiment, the shortest distance between the edge of the vent hole 110 and the disc body 11 is L3, and the shortest distance between the edge of the vent hole 110 and the disc body 11 satisfies the following condition with respect to the radius of the core 2: L3 / R0 = 21.4~27.3%.

[0055] It should be noted that when the ratio of L3 to the radius R0 of the core 2 is too small, the vent hole 110 will be too close to the edge of the disc 11, causing the positive electrode coating tape to cover the outer hole. This will result in a decrease in the electrolyte inflow rate during electrolyte injection, a longer injection time, an increase in battery manufacturing time, and an increase in manufacturing cost. When the ratio of L3 to the radius R0 of the core 2 is too large, the vent hole 110 will move towards the center of the disc 11, resulting in a short distance between the vent hole 110 and the through hole 100. This will reduce the strength, make the battery more prone to deformation and breakage, and generate burrs and metal foreign objects. The K value of the battery will increase, and the risk of short circuit in the battery will increase.

[0056] In this embodiment, by reasonably setting the ratio of the shortest distance between the edge of the vent hole 110 and the disk body 11 to the radius of the core 2, it is possible to avoid the vent hole 110 being covered by the positive electrode coating tape, ensuring that the gas can be smoothly discharged when the electrolyte is injected, maintaining the electrolyte inflow rate and improving production efficiency; at the same time, it is possible to ensure that there is a sufficient distance between the vent hole 110 and the through hole 100, ensuring the structural strength of this area, reducing the risk of short circuit in the battery, and ensuring the performance and safety of the battery.

[0057] Specifically, in this embodiment, the shortest distance L3 between the edge of the exhaust hole 110 and the disc body 11 is 2.48 mm.

[0058] In this embodiment, the positive current collector 1 also includes a tail body 12 and a connecting part 13. The disk body 11 is fixedly connected to the tail body 12 through the connecting part 13. The connecting part 13 has a rounded transition at both sides of the connection between it and the disk body 11 and the tail body 12. The disk body 11, the tail body 12 and the connecting part 13 are an integral structure. The shortest distance from the midpoint of the injection hole 200 to the connecting part 13 is M10. The shortest distance from the midpoint of the injection hole 200 to the connecting part 13 satisfies the following condition with the radius of the core 2: M10 / R0 = 51.8~57.7%.

[0059] It should be noted that when M10 / R0 is too small, the root of the connection part 13 at the connection between the disk body 11 and the tail body 12 is too close to the through hole 100, which reduces the current carrying capacity at this point, making it a weak current carrying area of ​​the disk body 11. The strength is also weakened, making it easy to break, generating metal foreign objects and burrs, and increasing the risk of short circuit. When M10 / R0 is too large, it will result in extra areas on the disk body 11 that do not need to support the solder wires and carry current, but it will increase the weight of the current collector, reduce the energy density of the battery, and increase the manufacturing cost.

[0060] In this embodiment, by reasonably setting the ratio range between the shortest distance from the midpoint of the injection hole 200 to the connecting part 13 and the radius of the core 2, it is possible to ensure that the connection between the disc body 11 and the tail body 12 has sufficient current carrying capacity and structural strength, avoiding it from becoming a weak area for current carrying and breaking; at the same time, it is possible to avoid the appearance of unnecessary areas on the disc body 11, ensuring the energy density of the battery and reducing manufacturing costs.

[0061] Specifically, in this embodiment, the shortest distance M10 from the midpoint of the injection hole 200 to the connecting part 13 is 5.57 mm.

[0062] 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 battery, characterized by, It includes a positive current collector (1) and a winding core (2), wherein, The positive current collector (1) is provided with a disk body (11), and the disk body (11) is welded and fixed to the end face of the full-pole tab of the core (2); The radius of the core (2) is R0, and the shortest distance from the edge of the disc (11) to the edge of the core (2) is L4. The radius of the core (2) and the shortest distance from the edge of the disc (11) to the edge of the core (2) satisfy: L4 / R0 = 8.6~12.6%.

2. The cylindrical lithium-ion battery as described in claim 1, characterized in that: The shortest distance L4 from the edge of the disc (11) to the edge of the core (2) ranges from 0.88 to 1.28 mm.

3. The cylindrical lithium-ion battery as described in claim 1, characterized in that: The core (2) has a liquid injection hole (200) pre-set at its center. The radius of the liquid injection hole (200) is R4, and the radius of the liquid injection hole (200) and the radius of the core (2) satisfy: R4 / R0 = 15.7~18.7%.

4. The cylindrical lithium-ion battery as described in claim 3, characterized in that: The center of the disc (11) has a through hole (100) with a radius of R2, and the radius of the through hole (100) and the radius of the core (2) satisfy: R2 / R0 = 21.6~27.5%.

5. The cylindrical lithium-ion battery as described in claim 4, characterized in that: The through hole (100) is connected to the injection hole (200) and is on the same axis. The shortest distance from the edge of the through hole (100) to the edge of the injection hole (200) is L1, and the shortest distance from the edge of the through hole (100) to the edge of the injection hole (200) satisfies the following condition with the radius of the through hole (100): L1 / R2 = 20.5~37.5%.

6. The cylindrical lithium-ion battery as described in claim 4, characterized in that: The disc body (11) has multiple vent holes (110) located outside the through hole (100). The radius of the vent hole (110) is R3, and the radius of the vent hole (110) and the radius of the core (2) satisfy: R3 / R0 = 11.8~17.7%.

7. The cylindrical lithium-ion battery as described in claim 4, characterized in that: The shortest distance between the edge of the through hole (100) and the edge of the vent hole (110) is L2, and the shortest distance between the edge of the through hole (100) and the edge of the vent hole (110) satisfies the following condition with respect to the radius of the core (2): L2 / R0 = 8.1~13.9%.

8. The cylindrical lithium-ion battery as described in claim 6, characterized in that: The shortest distance between the edge of the vent (110) and the disc (11) is L3, and the shortest distance between the edge of the vent (110) and the disc (11) and the radius of the core (2) satisfy: L3 / R0 = 21.4~27.3%.

9. The cylindrical lithium-ion battery as described in claim 3, characterized in that: The positive current collector (1) also includes a tail body (12) and a connecting part (13). The disk body (11) is fixedly connected to the tail body (12) through the connecting part (13). The connecting part (13) is provided with arc transition at both sides of the connection between the disk body (11) and the tail body (12). The disk body (11), the tail body (12) and the connecting part (13) are an integral structure. The shortest distance from the midpoint of the injection hole (200) to the connecting part (13) is M10. The shortest distance from the midpoint of the injection hole (200) to the connecting part (13) and the radius of the core (2) satisfy: M10 / R0 = 51.8~57.7%.

10. The cylindrical lithium-ion battery as described in claim 1, characterized in that: The radius of the disc (11) is R1, and satisfies: R1 = 8.8~9.4mm; the radius of the core (2) satisfies: R0 = 9.18~11.18mm; and the radius of the core (2) is greater than the radius of the disc (11).

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