Cylindrical battery and electric device

Abstract

The application provides a cylindrical battery and an electric device, and relates to the technical field of batteries.The cylindrical battery comprises a shell, a cap and an electrode assembly, one end of the shell is provided with an opening, the cap is arranged at the opening to close the opening, the electrode assembly is arranged in the shell, a part of the side wall of the shell is inwardly recessed to form a limiting portion, and the electrode assembly is limited between the limiting portion and the inner bottom wall of the shell, so that the stability of the electrode assembly can be improved.

Description

Technical Field

[0001] This application relates to the field of battery technology, and more specifically, to a cylindrical battery and an electrical device. Background Technology

[0002] Cylindrical batteries offer significant cost-effectiveness and production efficiency advantages due to their standardized dimensions and highly mature winding manufacturing process.

[0003] In cylindrical batteries, the stability of the electrode assembly within the battery casing is crucial. Shaking of the electrode assembly can cause a series of problems, such as mechanical damage, electrochemical interface disruption, and thermal management failure. These problems can seriously impair the reliability, lifespan, and safety of the battery. Utility Model Content

[0004] The purpose of this application includes, for example, providing a cylindrical battery that can improve the stability of the electrode assembly.

[0005] The purpose of this application also includes providing an electrical device that can improve the stability of electrode assemblies.

[0006] The embodiments of this application can be implemented as follows: In a first aspect, embodiments of this application provide a cylindrical battery, which includes a housing, a cap, and an electrode assembly. One end of the housing has an opening, and the cap is disposed at the opening to close the opening. The electrode assembly is disposed inside the housing, and a portion of the side wall of the housing is recessed inward to form a limiting portion, and the electrode assembly is limited between the limiting portion and the inner bottom wall of the housing.

[0007] Optionally, the limiting part is provided with a first limiting surface and a second limiting surface along the height direction of the housing, and the electrode assembly is limited between the first limiting surface and the inner bottom wall of the housing; the end of the housing near the cap is bent inward to form a retaining edge, and a sealing ring is provided between the retaining edge and the second limiting surface, and the cap is embedded in the sealing ring.

[0008] Optionally, the cylindrical battery satisfies: 0.991≤H1 / H2≤0.995, where H1 is the height of the electrode assembly and H2 is the distance between the bottom of the electrode assembly and the first limiting surface.

[0009] Optionally, a first insulating pad is provided at the end of the retaining edge away from the electrode assembly, and the cylindrical battery also includes a sleeve, which is fitted onto both the housing and the first insulating pad.

[0010] Optionally, the limiting part is annular, and the cylindrical battery satisfies: 1.13≤D1 / D2≤1.15, where D1 is the diameter of the electrode assembly and D2 is the inner diameter of the limiting part.

[0011] Optionally, a safety valve is provided on the side of the cap facing the electrode assembly.

[0012] Optionally, the cylindrical battery further includes a positive electrode busbar and a second insulating pad. The positive electrode busbar is disposed on the top of the electrode assembly, and the second insulating pad is disposed on the side of the positive electrode busbar away from the electrode assembly. The limiting portion presses against the second insulating pad.

[0013] Optionally, both the positive electrode busbar and the second insulating pad are provided with through holes, and the positions of the through holes on the positive electrode busbar and the through holes on the second insulating pad are matched.

[0014] Optionally, the cylindrical battery further includes a negative electrode busbar, which is disposed between the bottom of the electrode assembly and the inner bottom wall of the housing.

[0015] Secondly, this application also provides an electrical device, including the aforementioned cylindrical battery.

[0016] The beneficial effects of the cylindrical battery and power device provided in this application include, for example, achieving reliable axial positioning of the electrode assembly by confining the electrode assembly between the limiting part and the bottom wall of the housing. The design of the limiting part helps to improve the electrical stability of the cylindrical battery under dynamic loads and reduce side reactions and interface degradation caused by the shaking of the electrode assembly, thereby extending the battery's service life and improving safety. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is an exploded view of the cylindrical battery in the embodiment of this application; Figure 2 This is a cross-sectional view illustrating the assembly relationship between the electrode assembly and the housing in an embodiment of this application; Figure 3 for Figure 2 Enlarged view of section A; Figure 4 This is a cross-sectional view showing the mating relationship between the sealing ring and the cap in an embodiment of this application.

[0019] Icons: 10-Cylindrical battery; 100-Casing; 110-Opening; 120-Limiting part; 121-First limiting surface; 122-Second limiting surface; 130-Side guard; 131-First insulating gasket; 140-Sealing ring; 200-Cap; 210-Safety valve; 300-Electrode assembly; 400-Sleeve; 500-Positive busbar; 600-Second insulating gasket; 700-Negative busbar. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0021] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0022] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0023] In the description of this application, it should be noted that if terms such as "upper," "lower," "inner," or "outer" are used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship that the utility model product is usually placed in during use, they are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0024] Furthermore, the terms "first" and "second" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0025] It should be noted that, where there is no conflict, the features in the embodiments of this application can be combined with each other.

[0026] Please refer to Figures 1-4The embodiments of this application provide a cylindrical battery 10, including a housing 100, a cap 200 and an electrode assembly 300. One end of the housing 100 is provided with an opening 110, and the cap 200 is disposed at the opening 110 to close the opening 110. The electrode assembly 300 is disposed inside the housing 100, and a portion of the side wall of the housing 100 is recessed inward to form a limiting portion 120. The electrode assembly 300 is limited between the limiting portion 120 and the inner bottom wall of the housing 100.

[0027] It should be noted that the axial fixation of the electrode assembly 300 within the housing 100 is crucial to prevent displacement or shaking during use. If the electrode assembly 300 experiences relative movement during battery operation or when subjected to external vibration or impact, it could lead to serious consequences such as active material peeling, separator wear, or even internal short circuits. Therefore, in this embodiment, the sidewall portion of the housing 100 is recessed inward using a grooving process to form a limiting portion 120. This limiting portion 120, as part of the structure of the housing 100 itself, extends continuously along the circumference of the housing 100, and its function is to work together with the inner bottom wall of the housing 100 to form an axial clamping of the electrode assembly 300.

[0028] Specifically, the bottom of the electrode assembly 300 abuts against the inner bottom wall of the housing 100, while the top of the electrode assembly 300 abuts against the limiting part 120. When the battery undergoes the assembly process or is in actual operating conditions, the limiting part 120 can effectively resist the axial displacement tendency of the electrode assembly 300 caused by thermal expansion, mechanical vibration or drop impact, thereby preventing the electrode assembly 300 from loosening or local stress concentration.

[0029] By confining the electrode assembly 300 between the limiting portion 120 and the inner bottom wall of the housing 100, reliable axial positioning of the electrode assembly 300 is achieved, and the overall rigidity and consistency of the internal structure of the battery are enhanced. The design of the limiting portion 120 helps to improve the electrical stability of the cylindrical battery 10 under dynamic loads and reduces side reactions and interface degradation caused by the shaking of the electrode assembly 300, thereby extending the battery's lifespan and improving safety.

[0030] In this embodiment, the limiting part 120 is provided with a first limiting surface 121 and a second limiting surface 122 along the height direction of the housing 100, and the electrode assembly 300 is limited between the first limiting surface 121 and the inner bottom wall of the housing 100; the end of the housing 100 near the cap 200 is bent inward to form a retaining edge 130, and a sealing ring 140 is provided between the retaining edge 130 and the second limiting surface 122, and the cap 200 is embedded in the sealing ring 140.

[0031] The first limiting surface 121 is located on the side of the limiting part 120 near the top of the electrode assembly 300, and is used to cooperate with the inner bottom wall of the housing 100 to clamp and fix the electrode assembly 300 in the axial direction, thereby preventing the electrode assembly 300 from axially displacing during use; the second limiting surface 122 is located on the side of the limiting part 120 near the cap 200, and mainly bears the supporting role of the sealing ring 140 and the cap 200. After the housing 100 near the cap 200 is assembled, it is processed by pre-folding and sealing and mechanical squatting, so that the end of the housing 100 near the cap 200 is bent radially inward to form a retaining edge 130, which is inwardly turned and surrounds the cap 200.

[0032] A receiving space is formed between the retaining edge 130 and the second limiting surface 122. The sealing ring 140 is disposed within this receiving space and compressed between the retaining edge 130 and the second limiting surface 122, thereby establishing a reliable radial and axial sealing interface. The cap 200 is embedded in the sealing ring 140 and is both circumferentially limited and axially constrained. The sealing ring 140, on the one hand, blocks the gas leakage path between the housing 100 and the cap 200, ensuring the stability of the electrolyte environment inside the battery and its ability to isolate external moisture. On the other hand, it also buffers the mechanical stress applied to the cap 200 during the sealing process, preventing the housing 100 from cracking or the seal from failing due to excessive local pressure.

[0033] In this embodiment, the cylindrical battery 10 satisfies: 0.991≤H1 / H2≤0.995, where H1 is the height of the electrode assembly 300 and H2 is the distance between the bottom of the electrode assembly 300 and the first limiting surface 121.

[0034] The ratio range of H1 and H2 is based on systematic experimental verification of the assembly state, stress, and long-term stability of the electrode assembly 300. Specifically, after the electrode assembly 300 is installed in the housing 100, its top needs to maintain a small but precise gap or light contact with the first limiting surface 121. If H1 / H2 is too small, the top of the electrode assembly 300 may not be able to fully approach or contact the first limiting surface 121, which may cause the electrode assembly 300 to easily move axially under vibration or impact conditions, resulting in damage such as electrode tab fatigue fracture or separator wear, which in turn leads to an increase in battery internal resistance, capacity decay, or even internal short circuit.

[0035] Conversely, if H1 / H2 is too large, the first limiting surface 121 will be too close to the top of the electrode assembly 300. During the sealing process of the cap 200, as the opening 110 end of the housing 100 bends inward to form the retaining edge 130, a significant axial pressure will be applied to the cap 200 and the components below it. This pressure will be transmitted to the top of the electrode assembly 300, which may cause the electrode assembly 300 to be subjected to a large compressive force. This may not only cause local abnormal density of the electrode assembly 300 and uneven electrolyte wetting, but may also cause electrode wrinkling, diaphragm perforation or electrode tab structure deformation due to stress concentration. In severe cases, it may even induce short circuit or thermal runaway risk. In addition, the excessive compression of the electrode assembly 300 will also increase the degree of deformation of the limiting part 120 and increase the probability of cracking of the limiting part 120.

[0036] Based on this, controlling H1 / H2 within the range of 0.991 to 0.995 means that the height of the electrode assembly 300 is slightly less than the height of the first limiting surface 121, leaving a very small reserved space between them or achieving slight pre-pressure contact. This design avoids axial loosening of the electrode assembly 300 within the housing 100 and prevents overpressure damage during the sealing process.

[0037] In this embodiment, a first insulating pad 131 is provided at the end of the flange 130 away from the electrode assembly 300. The cylindrical battery 10 also includes a sleeve 400, which is fitted onto both the housing 100 and the first insulating pad 131.

[0038] The first insulating pad 131 is disposed at the top of the retaining edge 130, i.e. the side away from the electrode assembly 300. The first insulating pad 131 is made of an insulating material with heat resistance, pressure resistance and good dielectric strength, such as polypropylene (PP), polyethylene terephthalate (PET) or nylon, and is used to block the electrical contact path between the housing 100 and the external structural components.

[0039] The sleeve 400 is a cylindrical structure, usually made of polyvinyl chloride (PVC), heat shrink tubing or other polymer insulating materials. It wraps around the side wall of the housing 100 and the first insulating gasket 131, achieving insulation on the outside of the housing 100 while also limiting the first insulating gasket 131.

[0040] The first insulating gasket 131 provides insulation to the top of the housing 100, while the sleeve 400 provides external coverage for the housing 100, serving the functions of insulation, scratch protection, corrosion resistance, and mechanical protection. The sleeve 400's restraint of the first insulating gasket 131 ensures that even if the battery is subjected to external pressure, vibration, or during assembly welding, the housing 100 will not accidentally connect to other conductive components due to displacement of the first insulating gasket 131.

[0041] In this embodiment, the cylindrical battery 10 further includes a positive electrode busbar 500 and a second insulating pad 600. The positive electrode busbar 500 is disposed on the top of the electrode assembly 300, and the second insulating pad 600 is disposed on the side of the positive electrode busbar 500 away from the electrode assembly 300. The limiting part 120 presses against the second insulating pad 600.

[0042] The electrode assembly 300 is a cylindrical structure with a central hole formed by winding a positive electrode plate, a negative electrode plate, and a separator using a needle winding method. The electrode assembly 300 has tabs at both ends, which are flattened to form full-tab structures for both positive and negative electrodes. The positive and negative electrodes are respectively located at both ends of the axial direction of the electrode assembly 300. The positive electrode busbar 500 is electrically connected to the full-tab structure at the top of the electrode assembly 300 by welding (such as ultrasonic welding or laser welding). The second insulating gasket 600 is made of a high-temperature resistant, high-dielectric-strength insulating material, such as polypropylene (PP), polyester film (PET), or mica sheet. Its main function is to prevent accidental conduction between the positive electrode busbar 500 and the housing 100.

[0043] During battery assembly, after the electrode assembly 300 is installed into the housing 100, the positive electrode busbar 500 is first placed on top of the electrode assembly 300, followed by the second insulating pad 600. When the side wall of the housing 100 forms a limiting part 120 through a grooving process, the cap 200 is assembled, and then a retaining edge 130 is formed by mechanical sealing, the first limiting surface 121 of the limiting part 120 applies a pressing force to the second insulating pad 600 from top to bottom. This pressure is transmitted to the positive electrode busbar 500 through the second insulating pad 600, thereby firmly pressing it onto the top of the electrode assembly 300, forming a stable electrical contact state.

[0044] This design not only ensures a reliable positive conduction path but also utilizes the limiting part 120 as a limiting structure for holding the positive busbar 500 and the second insulating pad 600. Furthermore, because the second insulating pad 600 is in a compressed state, it is less prone to displacement or loosening during long-term use, further enhancing insulation reliability.

[0045] In this embodiment, both the positive electrode busbar 500 and the second insulating pad 600 are provided with through holes, and the through holes on the positive electrode busbar 500 and the second insulating pad 600 are positioned to match each other.

[0046] A through-hole refers to an opening structure that penetrates the thickness direction of the positive electrode busbar 500 and the second insulating pad 600. Its shape can be circular, elliptical, or polygonal, and the shapes of the through-holes on the positive electrode busbar 500 and the second insulating pad 600 can be different. There can be multiple through-holes, evenly distributed on the surfaces of the positive electrode busbar 500 and the second insulating pad 600. The through-holes on the positive electrode busbar 500 and the second insulating pad 600 are positioned to match, thus forming a continuous through-channel in their stacked state, allowing gas or electrolyte to flow from inside the electrode assembly 300 to the cap 200 or to permeate in the reverse direction.

[0047] When the battery is filled with electrolyte and left to stand, the electrolyte needs to penetrate from the top of the housing 100 downwards into the electrode assembly 300. By setting through holes on the positive electrode busbar 500 and the second insulating pad 600, the electrolyte can flow into the electrode assembly 300 quickly through these through holes, which significantly shortens the immersion time, improves production efficiency, and ensures uniform wetting of the electrode interface.

[0048] Meanwhile, during the first charge of the battery, an SEI film will form on the surface of the negative electrode and a small amount of gas will be generated. In subsequent use, the side reaction may also continue to release a small amount of gas. By setting matching through holes on the positive electrode busbar 500 and the second insulating pad 600, the gas can be discharged axially upwards, enter the area below the cap 200 through the through hole channel, and finally be discharged through the micro gap between the sealing ring 140 and the housing 100 or the exhaust path of the safety valve 210, so as to avoid battery expansion caused by gas pressure accumulation.

[0049] The cylindrical battery 10 also includes a negative electrode busbar 700, which is disposed between the bottom of the electrode assembly 300 and the inner bottom wall of the housing 100.

[0050] The negative electrode busbar 700 is disc-shaped, and its outer diameter matches the inner diameter of the housing 100. One end of the negative electrode busbar 700 is electrically connected to the tab structure at the bottom of the electrode assembly 300 by welding, and the other end is fixed to the inner bottom wall of the housing 100 by laser welding, resistance welding or friction welding, so that the bottom of the housing 100 becomes the negative electrode output terminal of the battery.

[0051] During battery assembly, after the electrode assembly 300 is inserted into the housing 100 through the opening 110, its bottom face first contacts the negative electrode busbar 700. The negative electrode busbar 700 is then pressed between the electrode assembly 300 and the inner bottom wall of the housing 100. In subsequent welding processes, the negative electrode busbar 700 forms a firm bond with the bottom of the housing 100. Furthermore, protrusions can be provided on the outer bottom wall of the housing 100 to facilitate welding during battery assembly and to provide cushioning and shock absorption in the event of a battery drop.

[0052] In this embodiment, the limiting part 120 is annular, and the cylindrical battery 10 satisfies: 1.13≤D1 / D2≤1.15, where D1 is the diameter of the electrode assembly 300 and D2 is the inner diameter of the limiting part 120.

[0053] The D1 / D2 ratio range is set based on a comprehensive consideration of the long-term mechanical stability of the electrode assembly 300. If D1 / D2 is too small, the first limiting surface 121 cannot provide adequate limiting for the electrode assembly 300, and the radial width of the second limiting surface 122 is also small, resulting in insufficient support for the sealing ring 140 and the cap 200. Conversely, since the limiting part 120 is formed by a grooving process, if D1 / D2 is too large, the housing 100 will undergo plastic deformation during the rolling process to form the limiting part 120; if D2 is too small, the grooving depth will be too large, resulting in severe local thinning of the housing 100 wall thickness, which may easily lead to cracking or fatigue failure of the housing 100 and reduce structural durability.

[0054] Based on this, controlling D1 / D2 within the range of 1.13 to 1.15 means that the diameter of the electrode assembly 300 is slightly larger than the inner diameter of the limiting part 120. This design enhances the compactness and vibration resistance of the electrode assembly 300. At the same time, the deformation of the housing 100 required for the grooving process is moderate at this ratio, and the material of the housing 100 is within a safe strain range, effectively avoiding the risk of rolling cracks.

[0055] In this embodiment, a safety valve 210 is provided on the side of the cap 200 facing the electrode assembly 300.

[0056] It should be noted that the safety valve 210 is a mechanical power-off structure, also known as a CID (Current Interrupt Device), which is integrated inside the cap 200. When the internal gas pressure of the battery gradually rises and reaches a set critical value, the gas pressure acts on the safety valve 210 below the cap 200, causing it to arch upwards and push the safety valve 210 to achieve a physical circuit break.

[0057] Safety valve 210 is located on the side of cap 200 near electrode assembly 300, between positive busbar 500 and cap 200, forming a complete conductive path from the positive terminal of electrode assembly 300 through positive busbar 500, safety valve 210 to the outer surface of cap 200. Under normal operating conditions, this conductive path remains open, allowing normal current output; once the internal pressure exceeds the safety limit, safety valve 210 activates to disconnect the conductive path, preventing the battery from continuing to discharge.

[0058] The following are the performance test results for different proportions of H1 and H2:

[0059] It is evident that when the ratios of each height are within the preferred range (tests 2, 3, and 4), the results of each test are satisfactory. When the ratios of each height are outside the preferred range (tests 1 and 5), the overall test results are unsatisfactory.

[0060] Specifically, when the height ratio is too small (Test 1), the limiting effect on the electrode assembly 300 is poor, which reduces the stability and reliability of the contact resistance of the electrode assembly 300, thereby reducing its service life. When the height ratio is too large (Test 5), it is easy to cause excessive compression of the electrode assembly 300, causing the housing 100 to crack. At the same time, the electrode assembly 300 is prone to deformation and damage during use, which further reduces the battery's service life.

[0061] The following are the performance test results for D1 and D2 at different scales:

[0062] It is evident that when the ratios of each diameter are within the preferred range (tests 2, 3, and 4), the results of each test are satisfactory. When the ratios of each diameter are outside the preferred range (tests 1 and 5), the overall test results are unsatisfactory.

[0063] Specifically, when the diameter ratio is too small (Test 1), the limiting effect on the electrode assembly 300 is poor, which reduces the stability and reliability of the contact resistance of the electrode assembly 300 and thus reduces its service life. When the diameter ratio is too large (Test 5), it is easy to cause excessive extrusion of the electrode assembly 300, causing the groove to crack. At the same time, the electrode assembly 300 is prone to deformation and damage during use, which further reduces the battery's service life.

[0064] In summary, by limiting H1 / H2 and D1 / D2, the forming effect of the limiting part 120 can be guaranteed, the drop resistance of the cylindrical battery 10 can be improved, and thus the service life of the cylindrical battery 10 can be increased.

[0065] Embodiments of this application also provide an electrical device, including the cylindrical battery 10 described above. For example, the electrical device can be a vehicle, ship, spacecraft, etc. Vehicles can be gasoline-powered vehicles or new energy vehicles; new energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc.; spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc. Embodiments of this application do not impose any special limitations on the aforementioned electrical device.

[0066] In summary, the embodiments of this application provide a cylindrical battery 10 and an electrical device. The cylindrical battery 10 includes a housing 100, a cap 200, and an electrode assembly 300. By confining the electrode assembly 300 between the limiting part 120 and the inner bottom wall of the housing 100, reliable axial positioning of the electrode assembly 300 is achieved. The design of the limiting part 120 helps to improve the electrical stability of the cylindrical battery 10 under dynamic loads and reduces side reactions and interface degradation caused by the shaking of the electrode assembly 300, thereby extending the battery's service life and improving safety.

[0067] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A cylindrical battery, characterized in that, The device includes a housing (100), a cap (200), and an electrode assembly (300). One end of the housing (100) has an opening (110), and the cap (200) is disposed at the opening (110) to close the opening (110). The electrode assembly (300) is disposed inside the housing (100), and a portion of the side wall of the housing (100) is recessed inward to form a limiting part (120). The electrode assembly (300) is limited between the limiting part (120) and the inner bottom wall of the housing (100).

2. The cylindrical battery according to claim 1, characterized in that, The limiting part (120) is provided with a first limiting surface (121) and a second limiting surface (122) along the height direction of the housing (100). The electrode assembly (300) is limited between the first limiting surface (121) and the inner bottom wall of the housing (100). The end of the housing (100) near the cap (200) is bent inward to form a retaining edge (130). A sealing ring (140) is provided between the retaining edge (130) and the second limiting surface (122). The cap (200) is embedded in the sealing ring (140).

3. The cylindrical battery according to claim 2, characterized in that, The cylindrical battery (10) satisfies: 0.991≤H1 / H2≤0.995, where H1 is the height of the electrode assembly (300) and H2 is the distance between the bottom of the electrode assembly (300) and the first limiting surface (121).

4. The cylindrical battery according to claim 2, characterized in that, The end of the flange (130) away from the electrode assembly (300) is provided with a first insulating pad (131). The cylindrical battery (10) also includes a sleeve (400), which is fitted onto both the housing (100) and the first insulating pad (131).

5. The cylindrical battery according to claim 1, characterized in that, The limiting part (120) is annular, and the cylindrical battery (10) satisfies: 1.13≤D1 / D2≤1.15, where D1 is the diameter of the electrode assembly (300) and D2 is the inner diameter of the limiting part (120).

6. The cylindrical battery according to claim 1, characterized in that, A safety valve (210) is provided on the side of the cap (200) facing the electrode assembly (300).

7. The cylindrical battery according to claim 1, characterized in that, The cylindrical battery (10) further includes a positive electrode busbar (500) and a second insulating pad (600). The positive electrode busbar (500) is disposed on the top of the electrode assembly (300), and the second insulating pad (600) is disposed on the side of the positive electrode busbar (500) away from the electrode assembly (300). The limiting part (120) presses against the second insulating pad (600).

8. The cylindrical battery according to claim 7, characterized in that, Both the positive electrode busbar (500) and the second insulating pad (600) are provided with through holes, and the through holes on the positive electrode busbar (500) and the second insulating pad (600) are matched in position.

9. The cylindrical battery according to claim 1, characterized in that, The cylindrical battery (10) also includes a negative electrode busbar (700), which is disposed between the bottom of the electrode assembly (300) and the inner bottom wall of the housing (100).

10. An electrical device, characterized in that, Includes the cylindrical battery as described in any one of claims 1-9.

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