A cylindrical lithium battery

Abstract

The utility model relates to a cylindrical battery technical field, proposes a cylindrical lithium cell, including casing, negative cover, roll core, negative tab and negative current collector, the negative cover is fixedly arranged in the end of casing, the roll core sets up in the casing, one end of negative tab is connected with roll core, and the other end protrudes the end of roll core, the negative current collector is fixedly arranged between negative tab and negative cover, still include stop frame, the stop frame is fixed in the negative current collector far from the negative cover one end and between negative cover, the interval of roll core and negative cover is H 100 , the height of stop frame is H 16 , H 16 / H 100 =62.5% 87.5%. The utility model discloses a stop frame between negative current collector and negative cover is arranged, and the specification of stop frame is limited, can effectively promote the anti -shaking ability of roll core, to improve the safety performance of battery.

Description

Technical Field

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

[0002] A cylindrical lithium battery is a lithium-ion battery encapsulated in a cylindrical shell. It consists of components such as a positive electrode, a negative electrode, an electrolyte, a separator, and a casing. It stores and releases electrical energy by moving lithium ions between the positive and negative electrodes and has been widely used in consumer electronics, electric vehicles, and energy storage.

[0003] The core is the core component of a cylindrical lithium battery. For example, the invention patent with publication number CN119297430A discloses a cylindrical battery structure and preparation method, which sets a negative current collector between the top plate of the negative electrode cover and the negative electrode tab to realize the conduction between the negative terminal of the core and the top plate of the negative electrode cover.

[0004] In the above technical solution, the negative electrode current collector needs to occupy a certain space. When the battery is used in a working condition with frequent vibration, the core will shake due to the deformation of the negative electrode current collector, which will cause the connection between the core and other components to break easily, resulting in battery failure. Utility Model Content

[0005] In view of this, the present invention proposes a cylindrical lithium battery, in which a stop bracket is set between the negative electrode current collector and the negative electrode cover plate, and the specifications of the stop bracket are limited, which can effectively improve the anti-shaking ability of the core and thus improve the safety performance of the battery.

[0006] The technical solution of this utility model is implemented as follows: This utility model provides a cylindrical lithium battery, including a casing, a negative electrode cover plate, a core, a negative electrode tab, and a negative electrode current collector. The negative electrode cover plate is fixedly disposed at the end of the casing; the core is disposed inside the casing; one end of the negative electrode tab is connected to the core, and the other end extends out of the end of the core; the negative electrode current collector is fixedly disposed between the negative electrode tab and the negative electrode cover plate; it also includes a stop bracket, which abuts and is fixed between the end of the negative electrode current collector away from the negative electrode cover plate and the negative electrode cover plate; the distance between the core and the negative electrode cover plate is H. 100 The height of the stop bracket is H. 16 H 16 / H 100 =62.5%-87.5%.

[0007] Based on the above technical solutions, preferably, the stop frame is a ring-shaped structure; the radius of the housing is R. 10 The ring width of the stop bracket is W. 11 W 11 / R10 =6.5%-10.9%.

[0008] Based on the above technical solution, preferably, a forming groove is punched on the side of the negative electrode cover away from the core, so that an assembly boss is formed on the side of the negative electrode cover closer to the core; the distance between the forming groove and the periphery of the negative electrode cover is L. 13 The distance between the stop bracket and the mounting boss is W. 12 W 12 / L 13 =11.8%-23.5%.

[0009] Based on the above technical solutions, preferably, the minimum distance between the end of the negative electrode current collector away from the negative electrode cover plate and the inner wall of the housing is W. 13 W 13 / W 11 =47.5%-67.5%.

[0010] Based on the above technical solutions, preferably, the overall height of the negative electrode current collector is H. 13 H 13 / H 100 =50%-75%.

[0011] Based on the above technical solutions, preferably, the depth of the forming groove is H. 14 H 14 / H 100 =18.7%-31.2%.

[0012] Based on the above technical solutions, preferably, the overall height of the negative electrode tab is H. 15 H 15 / H 100 =9.4%-15.6%.

[0013] Based on the above technical solution, preferably, an explosion-proof groove is formed on the side of the negative electrode cover away from the core, and the distance between the explosion-proof groove and the forming groove is L. 11 L 11 =1.46mm-1.86mm.

[0014] Based on the above technical solutions, preferably, the circumferential width of the forming groove is L. 12 L 12 =4.3mm-5.3mm.

[0015] Based on the above technical solutions, preferably, the radius of the shell is R. 10 R 10 =21mm-25mm, H 100=1.2mm-2mm.

[0016] The cylindrical lithium battery of this invention has the following advantages over the prior art: (1) By setting a stop frame between the negative electrode current collector and the negative electrode cover plate, and limiting the specifications of the stop frame, the anti-shaking ability of the core can be effectively improved, thereby improving the safety performance of the battery.

[0017] (2) By setting a molding groove and an assembly boss on the negative electrode cover plate, not only can a welding position be provided for the negative electrode current collector, but the structural strength of the negative electrode cover plate can also be enhanced; by setting an explosion-proof groove on the negative electrode cover plate, the gas generated during battery thermal runaway can be discharged in time, further improving the safety performance of the battery.

[0018] (3) By further defining the position and specifications of the negative electrode cover and negative electrode tab, not only can the assembly efficiency of the battery be improved, but also the energy density of the battery can be increased, thereby improving the overall performance of the battery. Attached Figure Description

[0019] 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.

[0020] Figure 1 This is a cross-sectional view of a cylindrical lithium battery according to the present invention.

[0021] Figure 2 This is a cross-sectional view of the forming groove in a cylindrical lithium battery according to the present invention.

[0022] Figure 3 This is a cross-sectional view of the stop frame in a cylindrical lithium battery according to the present invention.

[0023] Figure 4 This is a cross-sectional view of the position between the stop bracket and the mounting boss in a cylindrical lithium battery according to this utility model.

[0024] The components are: 1. Shell; 2. Negative electrode cover plate; 201. Molding groove; 202. Assembly boss; 203. Explosion-proof groove; 3. Core; 4. Negative electrode tab; 5. Negative electrode current collector; 6. Stop bracket. Detailed Implementation

[0025] 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.

[0026] The present invention relates to a cylindrical lithium battery, comprising a casing 1, a negative electrode cover plate 2, a positive electrode cover plate, a core 3, a negative electrode tab 4, a positive electrode tab, a positive electrode current collector, a negative electrode current collector 5, and a stop bracket 6.

[0027] The housing 1 is a cylindrical structure. The negative electrode cover plate 2 and the positive electrode cover plate are fixedly installed at both ends of the housing 1. The housing 1, the negative electrode cover plate 2 and the positive electrode cover plate are all made of conductive material. In order to avoid short circuit of the battery, it is preferable to insulate the positive electrode cover plate from the housing 1. If necessary, an insulating structure can also be provided between the negative electrode cover plate 2 and the housing 1.

[0028] The housing 1, negative electrode cover 2, and positive electrode cover form a sealed cavity. The core 3 is disposed in the cavity inside the housing 1. The two ends of the core 3 are the positive end and the negative end, respectively. One end of the positive electrode tab is fixedly disposed at the positive end of the core 3 and electrically connected to the positive electrode material of the core 3. The other end of the positive electrode tab extends out of the positive end of the core 3. One end of the negative electrode tab 4 is fixedly disposed inside the negative end of the core 3 and electrically connected to the negative electrode material of the core 3. The other end of the negative electrode tab 4 extends out of the negative end of the core 3.

[0029] The positive current collector is fixedly disposed between the positive electrode tab and the positive electrode cover plate, and the positive current collector is electrically connected to both the positive electrode tab and the positive electrode cover plate. The negative current collector 5 is fixedly disposed between the negative electrode tab 4 and the negative electrode cover plate 2, and the negative current collector 5 is electrically connected to both the negative electrode tab 4 and the negative electrode cover plate 2, thereby enabling the positive electrode cover plate and the negative electrode cover plate 2 to conduct electricity to the positive and negative terminals of the core 3, respectively, thus realizing the transfer of electrical energy.

[0030] like Figure 1 As shown, a forming groove 201 is punched out on the side of the negative electrode cover plate 2 away from the core 3, so that the side of the negative electrode cover plate 2 close to the core 3 protrudes to form an assembly boss 202. One end of the negative electrode current collector 5 is welded and fixed to the flattened negative electrode tab 4, and the other end of the negative electrode current collector 5 is welded and fixed to the assembly boss 202. The middle section of the negative electrode current collector 5 is bent into an S-shape so that the negative electrode cover plate 2 and the shell 1 can be welded and fixed when the negative electrode current collector 5 is welded.

[0031] like Figure 2As shown, an explosion-proof groove 203 is also provided on the side of the negative electrode cover plate 2 away from the core 3, and the explosion-proof groove 203 is located inside the forming groove 201. The structural strength of the position where the explosion-proof groove 203 is provided on the negative electrode cover plate 2 is relatively weak. When the battery experiences thermal runaway, a large amount of gas is generated inside the battery. This gas will break through the position of the explosion-proof groove 203, thereby allowing the gas to be discharged from the casing 1 in time and avoiding accidents such as explosions. Similarly, a corresponding explosion-proof structure is also provided on the positive electrode cover plate.

[0032] The stop bracket 6 is used to enhance the secure fixing of the winding core 3 within the housing 1, preventing the winding core 3 from shaking during use and ensuring the safe operation of the battery. Figures 1-4 As shown, the stop bracket 6 is fixed between the end of the negative electrode collector plate 5 away from the negative electrode cover plate 2 and the negative electrode cover plate 2.

[0033] The stop frame 6 is preferably a circular structure, which provides uniform resistance to the core 3, keeping the core 3 stable within the housing 1. Similarly, in order to improve the stability and symmetry of the battery, the forming groove 201 and the explosion-proof groove 203 are also circular, and the stop frame 6, the forming groove 201 and the explosion-proof groove 203 are all coaxially arranged with the core 3.

[0034] like Figures 1-4 As shown, the radius of shell 1 is R. 10 The distance between the negative terminal of the core 3 and the negative terminal cover 2 is H. 100 The overall height of the negative electrode current collector 5 is H. 13 The depth of the forming groove 201 is H. 14 The overall height of the negative electrode tab 4 is H. 15 The height of the stop bracket 6 is H 16 The distance between the explosion-proof groove 203 and the forming groove 201 is L. 11 The circumferential width of the forming groove 201 is L. 12 The distance between the molding groove 201 and the periphery of the negative electrode cover plate 2 is L. 13 The ring width of stop 6 is W. 11 The distance between the stop bracket 6 and the mounting boss 202 is W. 12 The minimum distance between the end of the negative electrode current collector 5 furthest from the negative electrode cover plate 2 and the inner wall of the housing 1 is W. 13 .

[0035] In some embodiments, H 16 / H 100 =62.5%-87.5%, meaning the height of the stop bracket 6 is 62.5%, 75%, or 87.5% of the distance between the negative end of the core 3 and the negative electrode cover plate 2. The function of the stop bracket 6 is to support the negative electrode current collector 5, preventing the core 3 from shaking within the housing 1, thus ensuring the weld does not break; if H 16 / H 100If the height of the stop bracket 6 is less than 62.5%, the stop bracket 6 will have a weak supporting effect, the core 3 will be prone to shaking, and the welding position will break, leading to battery failure; if H 16 / H 100 If the height of the stop bracket 6 is greater than 87.5%, then the stop bracket 6 will exert too much force on the negative current collector 5 and the core 3, which may easily cause damage to the core 3 and increase the risk of short circuit in the battery.

[0036] In some embodiments, W 11 / R 10 =6.5%-10.9%, meaning the ring width of the stop bracket 6 is 6.5%, 8.7%, or 10.9% of the radius of the housing 1, etc. If W 11 / R 10 If W < 6.5%, the ring width of the stop bracket 6 is too small, reducing the contact area between the stop bracket 6 and the negative electrode current collector 5. The stop bracket 6 cannot provide sufficient stable supporting force for the negative electrode current collector 5 and the winding core 3, causing the winding core 3 to easily shake. 11 / R 10 If the circumference is greater than 10.9%, the ring width of the stop bracket 6 will be too large, and the stop bracket 6 will interfere with the assembly boss 202, affecting the assembly of the stop bracket 6 and the negative electrode cover plate 2, resulting in a decrease in battery assembly efficiency and affecting battery production capacity.

[0037] In some embodiments, W 12 / L 13 =11.8%-23.5%, meaning the distance between the stop bracket 6 and the assembly boss 202 is 11.8%, 17.6%, or 23.5% of the distance between the molding groove 201 and the periphery of the negative electrode cover plate 2, etc. If W 12 / L 13 If the distance between the stop bracket 6 and the assembly boss 202 is less than 11.8%, the stop bracket 6 will interfere with the negative electrode cover plate 2 during battery assembly, resulting in decreased battery assembly efficiency and yield. 12 / L 13 If the distance between the stop bracket 6 and the mounting boss 202 is greater than 23.5%, the mounting boss 202 needs to be moved inward toward the center of the negative electrode cover plate 2, which reduces the area of ​​the explosion-proof structure on the negative electrode cover plate 2. When the battery experiences thermal runaway, the gas inside the casing 1 cannot be discharged in time, resulting in a decrease in the safety performance of the battery.

[0038] In some embodiments, W 13 / W 11 =47.5%-67.5%, meaning the minimum distance between the end of the negative electrode current collector 5 furthest from the negative electrode cover plate 2 and the inner wall of the housing 1 is 47.5%, 57.5%, or 67.5% of the ring width of the stop frame 6, etc. If W 13 / W 11If W < 47.5%, then the minimum distance between the end of the negative electrode current collector 5 furthest from the negative electrode cover plate 2 and the inner wall of the casing 1 is too small, and the negative electrode current collector 5 is too close to the casing 1. During battery assembly, the negative electrode current collector 5 will scrape against the inner wall of the casing 1, causing metal debris to be generated inside the battery, increasing the risk of short circuit; if W 13 / W 11 If the distance is greater than 67.5%, the minimum distance between the end of the negative electrode current collector 5 away from the negative electrode cover plate 2 and the inner wall of the shell 1 is too large. The contact area between the stop bracket 6 and the negative electrode current collector 5 is reduced. During the battery assembly process, the stop bracket 6 may not hold the negative electrode current collector 5, resulting in the failure of the holding effect of the stop bracket 6.

[0039] In some embodiments, H 13 / H 100 =50%-75%, meaning the overall height of the negative electrode current collector 5 is 50%, 62.5%, or 75% of the distance between the negative terminal of the core 3 and the negative electrode cover plate 2, etc. Since the negative electrode current collector 5 needs to be bent twice to be fully inserted into the casing, the negative electrode cover plate 2 is welded to the casing 1 to complete the battery assembly. If H 13 / H 100 If the height is less than 50%, the overall height of the negative electrode current collector 5 is too small. During the bending process of the negative electrode current collector 5, the negative electrode current collector 5 is subjected to excessive compression, resulting in greater pressure on the core 3 and increasing the risk of short circuit in the battery; if H 13 / H 100 If the height of the negative current collector 5 is greater than 75%, the overall height of the negative current collector 5 will be too large, which will occupy the internal space of the battery or make the negative current collector tab 4 too close to the end of the core 3. When the negative current collector 5 occupies the internal space of the battery, it will reduce the energy density of the battery. When the negative current collector 5 causes the negative current collector tab 4 to be too close to the end of the core 3, it will make the negative current collector tab 4 easy to contact the positive electrode material of the core 3, increasing the risk of short circuit of the battery.

[0040] In some embodiments, H 14 / H 100 =18.7%-31.2%, meaning the depth of the forming groove 201 is 18.7%, 25%, or 31.2% of the distance between the negative end of the core 3 and the negative cover plate 2, etc. If H 14 / H 100 If the depth of the forming groove 201 is less than 18.7%, the space at the negative electrode current collector 5 inside the battery will be too large. When the battery is used in a vibrating environment, the negative electrode current collector 5 is prone to vibration, which can cause the welding position of the negative electrode current collector 5 to break, leading to battery failure. 14 / H 100If the depth of the molding groove 201 is greater than 31.2%, the processing difficulty of the negative electrode cover plate 2 will increase, the consistency of the battery will deteriorate, and at the same time, the mounting boss 202 will occupy the internal space of the battery, which will not only reduce the energy density of the battery, but also cause the negative electrode current collector 5, negative electrode tab 4 and core 3 to be subjected to greater pressure, increasing the risk of short circuit in the battery.

[0041] In some embodiments, H 15 / H 100 =9.4%-15.6%, meaning the overall height of the negative electrode tab 4 is 9.4%, 12.5%, or 15.6% of the distance between the negative end of the core 3 and the negative electrode cover plate 2, etc. If H 15 / H 100 If the negative electrode tab 4 is less than 9.4%, then the overall height of the negative electrode tab 4 is too small, meaning that the flattening pressure during the processing of the negative electrode tab 4 is too high. This causes the negative electrode tab 4 to be too close to the negative end of the core 3, making it prone to short-circuiting with the positive electrode material of the core 3, increasing the risk of short circuit in the battery. If H 15 / H 100 If the height is greater than 15.6%, the overall height of the negative electrode tab 4 will be too large, which will occupy the space for installing the negative electrode current collector 5. This will result in a more compact structure after the negative electrode current collector 5 is bent into the shell, which will put greater pressure on the negative electrode current collector 5, the negative electrode tab 4 and the core 3, leading to an increased risk of short circuit in the battery.

[0042] In some embodiments, R 10 =21mm-25mm, that is, the radius of shell 1 is 21mm, 23mm or 25mm, etc.

[0043] In some embodiments, H 100 =1.2mm-2mm, that is, the distance between the negative end of the core 3 and the negative cover plate 2 is 1.2mm, 1.6mm or 2mm, etc.

[0044] In some embodiments, L 11 =1.46mm-1.86mm, meaning the distance between the explosion-proof groove 203 and the molding groove 201 is 1.46mm, 1.66mm, or 1.86mm, etc. The explosion-proof groove 203 weakens the structural strength of the negative electrode cover plate 2 to achieve the battery's explosion-proof effect. The mounting boss 202 formed by the molding groove 201 not only provides an installation platform for the negative electrode current collector 5 but also strengthens the structural strength of the negative electrode cover plate 2. If L 11 If the distance is less than 1.46mm, the gap between the explosion-proof groove 203 and the molding groove 201 is too small, meaning they are too close. This results in a greater gas pressure causing the explosion-proof groove 203 to rupture. Consequently, when the battery experiences thermal runaway, the negative electrode structure of the negative electrode cover 2 is less likely to be breached, leading to a decrease in battery safety performance. 11If the gap is greater than 1.86mm, the distance between the explosion-proof groove 203 and the molding groove 201 is too large, which reduces the area of ​​the explosion-proof structure on the negative electrode cover plate 2. When the battery experiences thermal runaway, the gas inside the casing 1 cannot be discharged in time, resulting in a decrease in the safety performance of the battery.

[0045] In some embodiments, L 12 =4.3mm-5.3mm, meaning the circumferential width of the forming groove 201 is 4.3mm, 4.8mm, or 5.3mm, etc. The forming groove 201 is used to form the assembly boss 202. If L 12 If the diameter is less than 4.3mm, the circumferential width of the forming groove 201 is too small, meaning the area of ​​the mounting boss 202 is smaller. This reduces the weldable area between the mounting boss 202 and the negative electrode current collector 5, resulting in a reduced flow area between the negative electrode current collector 5 and the mounting boss 202. Consequently, the temperature rise at the welding position increases, affecting battery performance. If L 12 If the width is greater than 5.3mm, the ring width of the forming groove 201 is too large, which will not only increase the processing difficulty of the negative electrode cover plate 2, but also cause the explosion-proof groove 203 to move inward towards the center point of the negative electrode cover plate 2, resulting in a reduction in the area of ​​the explosion-proof structure on the negative electrode cover plate 2. When the battery experiences thermal runaway, the gas inside the casing 1 cannot be discharged in time, leading to a decrease in the safety performance of the battery.

[0046] 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 battery, comprising a casing (1), a negative electrode cover plate (2), a winding core (3), a negative electrode tab (4), and a negative electrode current collector (5), wherein the negative electrode cover plate (2) is fixedly disposed at the end of the casing (1); the winding core (3) is disposed inside the casing (1); one end of the negative electrode tab (4) is connected to the winding core (3), and the other end extends out of the end of the winding core (3); the negative electrode current collector (5) is fixedly disposed between the negative electrode tab (4) and the negative electrode cover plate (2); Its features are: It also includes a stop bracket (6), which abuts and is fixed between the end of the negative electrode collector (5) away from the negative electrode cover plate (2) and the negative electrode cover plate (2); The distance between the core (3) and the negative electrode cover plate (2) is H. 100 The height of the stop bracket (6) is H. 16 H 16 / H 100 =62.5%-87.5%.

2. A cylindrical lithium battery as described in claim 1, characterized in that: The stop frame (6) has a ring structure; The radius of the shell (1) is R. 10 The ring width of the stop bracket (6) is W. 11 W 11 / R 10 =6.5%-10.9%.

3. A cylindrical lithium battery as described in claim 1, characterized in that: The negative electrode cover plate (2) is punched with a forming groove (201) on the side away from the core (3), so that the negative electrode cover plate (2) is formed with an assembly boss (202) on the side close to the core (3). The distance between the molding groove (201) and the periphery of the negative electrode cover plate (2) is L. 13 The distance between the stop bracket (6) and the mounting boss (202) is W. 12 W 12 / L 13 =11.8%-23.5%.

4. A cylindrical lithium battery as described in claim 2, characterized in that: The minimum distance between the end of the negative electrode current collector (5) away from the negative electrode cover plate (2) and the inner wall of the housing (1) is W. 13 W 13 / W 11 =47.5%-67.5%.

5. A cylindrical lithium battery as described in claim 1, characterized in that: The overall height of the negative electrode current collector (5) is H. 13 H 13 / H 100 =50%-75%.

6. A cylindrical lithium battery as described in claim 3, characterized in that: The depth of the forming groove (201) is H. 14 H 14 / H 100 =18.7%-31.2%.

7. A cylindrical lithium battery as described in claim 1, characterized in that: The overall height of the negative electrode tab (4) is H. 15 H 15 / H 100 =9.4%-15.6%.

8. A cylindrical lithium battery as described in claim 3, characterized in that: The negative electrode cover plate (2) has an explosion-proof groove (203) on the side away from the core (3); The distance between the explosion-proof groove (203) and the molding groove (201) is L. 11 L 11 =1.46mm-1.86mm.

9. A cylindrical lithium battery as described in claim 3, characterized in that: The circumferential width of the forming groove (201) is L. 12 L 12 =4.3mm-5.3mm.

10. A cylindrical lithium battery as described in any one of claims 1-9, characterized in that: The radius of the shell (1) is R. 10 R 10 =21mm-25mm, H 100 =1.2mm-2mm.

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