Cylindrical battery and electric device

Abstract

This application provides a cylindrical battery and an electrical device, relating to the field of battery technology. The cylindrical battery includes a casing, an electrode assembly, electrode terminals, and a current collector. The electrode assembly is disposed within the casing. The electrode terminals are insulatedly connected to the casing, and each electrode terminal includes a first recess, with at least a portion of the bottom of the first recess forming a first connecting portion. The current collector includes a body portion and a protrusion disposed on the body portion facing the first connecting portion. At least a portion of the top of the protrusion forms a second connecting portion. The first connecting portion and the second connecting portion are welded to form a welded portion. A first sealing element is provided between the electrode terminals and the protrusion and around the welded portion. By providing a first sealing element between the electrode terminals and the protrusion and around the welded portion, a secondary seal is achieved between the electrode terminals and the current collector, thereby preventing micro-welding cracks during the welding of the electrode terminals and the current collector, which could lead to leakage, and significantly improving the manufacturing yield of the battery.

Description

Technical Field

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

[0002] With the rapid development of the electric vehicle market, cylindrical batteries have always been a focus of the domestic power battery industry, characterized by high energy density and excellent fast-charging rate. However, the manufacturing process of cylindrical batteries involves a significant amount of welding. This welding process requires ensuring both high-strength adhesion and a tight seal, making it challenging to manufacture. A common problem is that while the weld strength may be good, micro-cracks may exist in the welded area, leading to leakage. Therefore, improving the leakage problem during the welding process of cylindrical batteries is a technical issue that urgently needs to be addressed by those in the field. Utility Model Content

[0003] The purpose of this application is to provide a cylindrical battery and an electrical device to solve the technical problem that the welding area of ​​the cylindrical battery in the prior art is prone to cracking and leakage.

[0004] To achieve the above objectives, the technical solution adopted in this application is as follows:

[0005] In a first aspect, this application provides a cylindrical battery, comprising: a housing, an electrode assembly, electrode terminals, and a current collector, wherein the electrode assembly is disposed within the housing; the electrode terminals are insulatedly connected to the housing, and the electrode terminals include a first recess, at least a portion of the bottom of the first recess forming a first connection portion; the current collector includes a body portion and a protrusion disposed on the body portion facing the first connection portion, at least a portion of the top of the protrusion forming a second connection portion, the first connection portion and the second connection portion being welded to form a welded portion, and a first sealing member being provided between the electrode terminals and the protrusion and surrounding the welded portion.

[0006] In one or more embodiments of this application, the electrode terminal further includes a second recess, which is disposed on the side of the electrode terminal facing the current collector, and the projection of the second recess in the thickness direction of the electrode terminal covers the projection of the first recess in the thickness direction of the electrode terminal. The protrusion is at least partially accommodated in the second recess and the second connecting portion is fitted with the first connecting portion. The first sealing member is disposed around the welding portion between the bottom of the second recess and the top of the protrusion.

[0007] In one or more embodiments of this application, the thickness of the protrusion at the second connection is greater than the thickness of the first connection. Along the thickness direction of the first connection, the welded portion extends from the side of the first connection away from the protrusion to the second connection and extends into the interior of the protrusion.

[0008] In one or more embodiments of this application, a third recess is provided on the side of the protrusion facing the first connecting portion, a second connecting portion is formed at the bottom of the third recess, the first connecting portion is accommodated in the third recess, and the bottom of the third recess is fitted with the bottom surface of the first connecting portion.

[0009] The second recess is provided with an annular groove around the first connecting part, and the first sealing member is provided in the annular groove and abuts against the bottom of the annular groove and the top surface of the protrusion.

[0010] In one or more embodiments of this application, the protrusion forms an annular platform around the outer side of the third recess, the annular platform being at least partially accommodated within an annular groove, the bottom surface of the first seal in the thickness direction abutting against the platform surface of the annular platform, and the top surface of the first seal in the thickness direction abutting against the bottom of the annular groove.

[0011] In one or more embodiments of this application, the protrusion forms an annular platform around the outer side of the third recess, and a stepped structure is provided on the outer side of the annular platform. At least a portion of the annular platform and the stepped structure are accommodated within an annular groove. The bottom surface of the first seal in the thickness direction abuts against the stepped surface of the stepped structure and the platform surface of the annular platform, and the top surface of the first seal in the thickness direction abuts against the bottom of the annular groove; or...

[0012] The protrusion forms an annular platform around the outer side of the third concave portion. A stepped structure is provided on the outer side of the annular platform. At least part of the annular platform and the stepped structure are accommodated in the annular groove. The bottom surface of the first seal in the thickness direction abuts against the stepped surface of the stepped structure, and the top surface of the first seal in the thickness direction abuts against the bottom of the annular groove.

[0013] In one or more embodiments of this application, a stepped structure is provided on the outer edge of the protrusion, the bottom surface of the first seal in the thickness direction abuts against the stepped surface of the stepped structure, and the top surface of the first seal in the thickness direction abuts against the bottom surface of the second recess.

[0014] In one or more embodiments of this application, the second recess is provided with an annular groove around the first connecting portion, the bottom surface of the first seal in the thickness direction abuts against the step surface of the stepped structure, and the top surface of the first seal in the thickness direction abuts against the bottom of the annular groove.

[0015] In one or more embodiments of this application, the top surface of the first seal in the thickness direction is higher than the mating surface of the second connection portion and the first connection portion, and the bottom surface of the first seal in the thickness direction is lower than the mating surface of the second connection portion and the first connection portion.

[0016] Secondly, this application also provides an electrical device, including the cylindrical battery described in any of the first aspects.

[0017] Based on the above technical solution, the cylindrical battery and power device of this application have at least the following beneficial technical effects:

[0018] The cylindrical battery of this application has a first recess on the electrode terminal, at least a portion of the bottom of the first recess forming a first connecting portion, a protrusion on the side of the current collector facing the first connecting portion, at least a portion of the top of the protrusion forming a second connecting portion, and the electrode terminal and the current collector are sealed together by welding the first connecting portion and the second connecting portion together to form a welded portion. By providing a first sealing element between the electrode terminal and the protrusion and around the welded portion, a secondary seal is achieved between the electrode terminal and the current collector, thereby preventing the existence of micro-welding cracks during the welding of the electrode terminal and the current collector, which could lead to leakage, and greatly improving the manufacturing yield of the battery. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application, 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 application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a longitudinal cross-sectional view of one embodiment of the cylindrical battery of this application.

[0021] Figure 2 yes Figure 1 A schematic diagram of the mounting structure of the electrode terminals and the casing in the cylindrical battery of the embodiment shown.

[0022] Figure 3 yes Figure 1 A schematic diagram of the current collector in the cylindrical battery of the embodiment shown.

[0023] Figure 4 yes Figure 1 A longitudinal cross-sectional view of the current collector in the cylindrical battery of the embodiment shown.

[0024] Figure 5 yes Figure 1 An enlarged view of the portion of the cylindrical battery in the embodiment shown, where the electrode terminals are connected to the current collector.

[0025] Figure 6 This is a longitudinal cross-sectional view of another embodiment of the cylindrical battery of this application.

[0026] Figure 7 yes Figure 6 A schematic diagram of the mounting structure of the electrode terminals and the casing in the cylindrical battery of the embodiment shown.

[0027] Figure 8 yes Figure 6 A schematic diagram of the current collector in the cylindrical battery of the embodiment shown.

[0028] Figure 9 yes Figure 6 A longitudinal cross-sectional view of the current collector in the cylindrical battery of the embodiment shown.

[0029] Figure 10 yes Figure 6 A longitudinal cross-sectional view of the protrusion of the current collector in the cylindrical battery of the embodiment shown.

[0030] Figure 11 yes Figure 6 An enlarged view of the portion of the cylindrical battery in the embodiment shown, where the electrode terminals are connected to the current collector.

[0031] Figure 12 This is a longitudinal cross-sectional schematic diagram of another embodiment of the cylindrical battery of this application.

[0032] Figure 13 yes Figure 12 A schematic diagram of the mounting structure of the electrode terminals and the casing in the cylindrical battery of the embodiment shown.

[0033] Figure 14 yes Figure 12 A schematic diagram of the current collector structure in the cylindrical battery of the embodiment shown.

[0034] Figure 15 yes Figure 12 A longitudinal cross-sectional view of the current collector in the cylindrical battery of the illustrated embodiment.

[0035] Figure 16 yes Figure 12 A longitudinal cross-sectional view of the current collector protrusion in the cylindrical battery of the illustrated embodiment.

[0036] Figure 17 This is a longitudinal cross-sectional schematic diagram of another embodiment of the cylindrical battery of this application.

[0037] Figure 18 yes Figure 17 A schematic diagram of the mounting structure of the electrode terminals and the casing in the cylindrical battery of the embodiment shown.

[0038] Figure 19 yes Figure 17 A schematic diagram of the current collector structure in the cylindrical battery of the embodiment shown.

[0039] Figure 20 yes Figure 17 A longitudinal cross-sectional view of the current collector in the cylindrical battery of the illustrated embodiment.

[0040] Figure 21 yes Figure 17 A longitudinal cross-sectional view of the current collector protrusion in the cylindrical battery of the illustrated embodiment.

[0041] Figure 22 This is a longitudinal cross-sectional schematic diagram of another embodiment of the cylindrical battery of this application.

[0042] Figure 23 yes Figure 22 A schematic diagram of the mounting structure of the electrode terminals and the casing in the cylindrical battery of the embodiment shown.

[0043] Figure 24 yes Figure 22 A schematic diagram of the current collector in the cylindrical battery of the embodiment shown.

[0044] Figure 25 yes Figure 22 A longitudinal cross-sectional view of the current collector in the cylindrical battery of the embodiment shown.

[0045] Figure 26 yes Figure 22 A longitudinal cross-sectional view of the protrusion of the current collector in the cylindrical battery of the embodiment shown.

[0046] In the figure: 1-Housing; 2-Electrode terminal; 3-Current collector; 4-First seal; 5-First insulation; 6-Second seal; 7-Second insulation; 8-Electrode assembly; 20-Welding part; 21-First recess; 22-First connection part; 23-Second recess; 30-Body part; 31-Protrusion; 32-Reinforcing rib; 231-Annular groove; 310-Third recess; 311-Second connection part; 312-Annular platform; 313-Step structure. Detailed Implementation

[0047] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0048] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0049] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. 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. Therefore, they should not be construed as limitations on this application.

[0050] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0051] In related technologies, cylindrical batteries involve numerous welding processes. Among these, the through-welding connection between the positive electrode connector and the positive electrode terminal is of paramount importance. A laser penetrates the surface of the positive electrode terminal, welding it to the internal positive electrode connector. This welding process requires both high-strength adhesion and a tight seal, making it quite challenging to manufacture. Therefore, during manufacturing, it is common for welds to have good strength but contain micro-cracks, allowing electrolyte to leak from the welded surface between the positive electrode terminal and the positive electrode connector, resulting in battery leakage.

[0052] Based on the above considerations, and in order to solve the technical problem that cracks easily appear in the welded areas of cylindrical batteries in the prior art, leading to leakage, this application provides a cylindrical battery and an electrical device.

[0053] The electrical devices disclosed in this application can be vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, power tools, energy storage devices, amusement equipment, elevators and lifting equipment, etc. Electric toys include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, or electric airplane toys, etc.; power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc.; energy storage devices can be energy storage walls, base station energy storage, container energy storage, etc.; amusement equipment can be carousels, drop towers, etc.

[0054] This application describes an electrical device using a vehicle as an example. The vehicle can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. A battery is installed inside the vehicle, and the battery can be located at the bottom, front, or rear of the vehicle. The battery can be used to power the vehicle; for example, it can serve as the vehicle's operating power source. The vehicle may also include a controller and a motor. The controller controls the battery to supply power to the motor, for example, to meet the power needs of starting, navigation, and driving the vehicle. The battery can not only serve as the vehicle's operating power source but also as its driving power source, replacing or partially replacing gasoline or natural gas to provide driving power to the vehicle.

[0055] The aforementioned battery can be a battery pack or a battery module. When the battery is a battery pack, the battery pack specifically includes a battery management system (BMS) and multiple battery cells. Multiple battery cells can be electrically connected in series, parallel, or a combination of series and parallel connections, and communicate with the battery management system, which controls and monitors the operating status of each battery cell. Alternatively, multiple battery cells can first be combined with a module management system to form a battery module, and then these battery modules can be electrically connected in series, parallel, or a combination of series and parallel connections to form a battery pack together with the battery management system.

[0056] The cylindrical battery described in this application can be understood as a battery cell or cell with a cylindrical shape. A cylindrical battery can be a secondary battery or a primary battery, and can also be a lithium-ion battery, a sodium-ion battery, or a magnesium-ion battery. Specifically, in the embodiments of this application, it can be a lithium-ion battery with a cylindrical shape.

[0057] Please refer to Figures 1 to 5 , Figures 6 to 11 , Figures 12 to 16 , Figures 17 to 21 or Figures 22 to 26 In the illustrated embodiment, the cylindrical battery of this application includes a casing 1, an electrode assembly 8, electrode terminals 2, and a current collector 3. One end of the casing 1 can be a closed structure. The casing 1 can be cylindrical in shape, with an internal cavity for accommodating the electrode assembly 8, electrolyte, current collector 3, and other functional components. The electrode assembly 8 is disposed within the casing 1 and can also be cylindrical. The electrode terminals 2 are insulatedly connected to the casing 1. The electrode terminals 2 can also be referred to as terminals, and are structural components that can lead or introduce current. The electrode terminals 2 include a first recess 21, which can be understood as a groove structure formed inwardly on the surface of the electrode terminal 2 opposite to the electrode assembly 8. At least a portion of the bottom of the first recess 21 forms a first connecting portion 22; it can be understood that the bottom of the first recess 21 refers to the bottom of the groove of the first recess 21. The current collector 3 is an electrical connector for connecting the tabs of the electrode assembly 8 and the electrode terminals 2. The current collector 3 includes a body portion 30 and a protrusion 31 disposed on the side of the body portion 30 facing the first connecting portion 22. At least a portion of the top of the protrusion 31 forms a second connecting portion 311, and the top of the protrusion 31 can refer to the side of the protrusion 31 facing away from the electrode assembly 8. The first connecting portion 22 and the second connecting portion 311 are welded to form a welding portion 20. A first sealing member 4 is provided between the electrode terminal 2 and the protrusion 31 and around the welding portion 20. It should be noted that the first sealing member 4 can be a sealing ring. The material of the first sealing member 4 can be PTFT, which has the characteristics of acid and alkali resistance and long life, and can ensure the safety of the battery during long-term use.

[0058] In the technical solution of this application embodiment, the cylindrical battery of this application provides a first recess 21 on the electrode terminal 2, at least a portion of the bottom of the first recess 21 forms a first connecting portion 22, a protrusion 31 is provided on the side of the current collector 3 facing the first connecting portion 22, and at least a portion of the top of the protrusion 31 forms a second connecting portion 311. The electrode terminal 2 and the current collector 3 are sealed together by welding the first connecting portion 22 and the second connecting portion 311 with a concave-convex design to form a welding portion 20. By providing a first sealing member 4 between the electrode terminal 2 and the protrusion 31 and around the welding portion 20, the electrode terminal 2 and the current collector 3 are achieved with a secondary seal, thereby preventing the existence of micro welding cracks during the welding of the electrode terminal 2 and the current collector 3, which could lead to leakage, and greatly improving the manufacturing yield of the battery.

[0059] In some embodiments, electrode terminal 2 can be a positive electrode terminal, in which case current collector 3 is a positive current collector, and the material of current collector 3 can be aluminum. Of course, in some other embodiments, electrode terminal 2 can also be a negative electrode terminal, in which case current collector 3 is a negative current collector, and the material can be copper.

[0060] In some embodiments, such as Figure 3 and Figure 4 , Figure 8 and Figure 9 , Figure 14 and Figure 15 , Figure 19 and Figure 20 or Figure 24 and Figure 25 As shown, the body portion 30 of the current collector 3 can be disc-shaped. A protrusion 31 is disposed in the middle of the body portion 30. The protrusion 31 can be a columnar structure disposed on the surface of the body portion 30. The protrusion 31 and the body portion 30 can be fixed together by laser welding. A plurality of spaced reinforcing ribs 32 are provided on the surface of the body portion 30, each reinforcing rib 32 extending radially along the body portion 30. In some embodiments, the included angle between two adjacent reinforcing ribs 32 can be 120°. This arrangement improves the overall strength of the current collector 3 and prevents deformation of the current collector 3. In some embodiments, in order to avoid obstructing the connection between the surface of the current collector 3 and the tabs of the electrode assembly 8, the reinforcing ribs 32 and the protrusions 31 can be disposed on the same surface of the body portion 30, that is, the reinforcing ribs 32 and the protrusions 31 are disposed on the surface of the body portion 30 away from the electrode assembly 8.

[0061] In some embodiments, please refer to Figure 1 and Figure 2 , Figure 6 and Figure 7 , Figure 12 and Figure 13 , Figure 17 and Figure 18 or Figure 22 and Figure 23 The housing 1 has a through hole for mounting the electrode terminal 2, which passes through the through hole. A first insulating member 5, which can be made of plastic, is provided between the surface of the housing 1 outside the cavity and the electrode terminal 2 to insulate the housing 1 and the electrode terminal 2. A second insulating member 7, which can also be made of plastic, is provided on the surface of the housing 1 inside the cavity to insulate the housing 1 and the current collector 3. The first insulating member 5 and the second insulating member 7 can prevent short circuits between the housing 1 and the current collector 3, which have different polarities, and between the housing 1 and the electrode terminal 2, thereby providing insulation. In some embodiments, to prevent leakage at the through hole, a second sealing member 6 is provided between the wall of the through hole and the electrode terminal 2. The second sealing member 6 can be a sealing ring. Part of the second sealing member 6 is sandwiched between the wall of the through hole and the electrode terminal 2, and part of the second sealing member 6 extends from the wall of the through hole into the cavity of the housing 1 and fits against the inner surface of the housing 1, thereby ensuring the sealing at the through hole.

[0062] In some embodiments, please refer to Figure 2 , Figure 7 , Figure 13 , Figure 18 or Figure 23 The electrode terminal 2 also includes a second recess 23, which is located on the side of the electrode terminal 2 facing the current collector 3. The second recess 23 can be understood as a groove structure formed by recessing the surface of the electrode terminal 2 facing the current collector 3. The projection of the second recess 23 in the thickness direction of the electrode terminal 2 covers the projection of the first recess 21 in the thickness direction of the electrode terminal 2. That is, the projection area of ​​the first recess 21 in the thickness direction of the electrode terminal 2 falls within the projection area of ​​the second recess 23 in the thickness direction of the electrode terminal 2, so that the protrusion 31 can be accommodated in the second recess 23. The protrusion 31 is at least partially accommodated in the second recess 23, and the second connecting part 311 fits against the first connecting part 22, improving the sealing effect of the welding surfaces of the first connecting part 22 and the second connecting part 311. The first sealing member 4 is disposed around the welding part 20 between the bottom of the second recess 23 and the top of the protrusion 31.

[0063] In the technical solution of this application embodiment, by providing a second recess 23 on the electrode terminal 2, the second recess 23 can be used to accommodate the protrusion 31 and the first sealing member 4. The projection of the second recess 23 in the thickness direction of the electrode terminal 2 covers the projection of the first recess 21 in the thickness direction of the electrode terminal 2, thereby making the first connecting portion 22 at the bottom of the first recess 21 thinner, which facilitates the laser to pass through the first connecting portion 22 and to be attached and welded to the second connecting portion 311 of the protrusion 31, thereby improving the welding effect.

[0064] In some embodiments, such as Figure 5 or Figure 11As shown, along the radial direction of the collector 3, the maximum diameter L8 of the protrusion 31 is smaller than the minimum outer diameter L9 of the second recess 23, that is, L8 < L9, for example, L8 = 11 mm, L9 = 12 mm, so that it can be accommodated in the second recess 23.

[0065] like Figure 5 Or such as Figure 11 As shown, in some embodiments, the thickness L1 of the protrusion 31 at the second connecting portion 311 is greater than the thickness L5 of the first connecting portion 22. For example, L5 = 1 mm, L1 = 3 mm. Along the thickness direction of the first connecting portion 22, the welding portion 20 extends from the side of the first connecting portion 22 away from the protrusion 31 to the second connecting portion 311 and extends into the interior of the protrusion 31. The weld penetration of the welding portion 20 is less than the thickness L1 of the protrusion 31 at the second connecting portion 311. This arrangement can prevent burn-through during laser welding, which would affect the electrode assembly 8 below the current collector 3.

[0066] In one embodiment of this application, please refer to Figures 22 to 26 In the illustrated embodiment, a stepped structure 313 is provided at the outer edge of the protrusion 31. It is understood that, along the thickness direction of the manifold 3, the height of the stepped structure 313 is lower than the height of the second connecting portion 311. In this embodiment, the bottom surface of the first sealing member 4 in the thickness direction abuts against the stepped surface of the stepped structure 313, and the top surface of the first sealing member 4 in the thickness direction abuts against the bottom surface of the second recess 23, as shown. Figure 22 As shown. In this embodiment, the thickness of the first sealing member 4 can be no less than the distance between the step surface of the step structure 313 and the bottom surface of the second recess 23. Then, after the second connecting part 311 is welded to the first connecting part 22, the first sealing member 4 is pressed by the step surface of the step structure 313 and the bottom surface of the second recess 23, thereby squeezing the first sealing member 4 to rebound and form a seal.

[0067] In another embodiment of this application, please refer to Figures 17 to 21 In the illustrated embodiment, a stepped structure 313 is provided at the outer edge of the protrusion 31. It is understood that, along the thickness direction of the manifold 3, the height of the stepped structure 313 is lower than the height of the second connecting portion 311. An annular groove 231 is provided around the first connecting portion 22 in the second recess 23. It is understood that the annular groove 231 is a groove-shaped structure located inside the second recess 23 and surrounding the first connecting portion 22. In this embodiment, the width of the annular groove 231 is at least sufficient to accommodate the first sealing member 4. The bottom surface of the first sealing member 4 in the thickness direction abuts against the stepped surface of the stepped structure 313, and the top surface of the first sealing member 4 in the thickness direction abuts against the bottom of the annular groove 231, as shown. Figure 17As shown. The thickness of the first sealing element 4 can be no less than the distance between the bottom of the annular groove 231 and the step surface of the stepped structure 313, so that the first sealing element 4 can be pressed between the bottom of the annular groove 231 and the step surface of the stepped structure 313. Then, after the second connecting part 311 is welded to the first connecting part 22, the first sealing element 4 is pressed and subjected to force, thereby squeezing the first sealing element 4 to rebound and form a seal.

[0068] In this embodiment, such as Figure 17 As shown, the top surface of the first sealing member 4 in the thickness direction is higher than the mating surface of the second connecting part 311 and the first connecting part 22, and the bottom surface of the first sealing member 4 in the thickness direction is lower than the mating surface of the second connecting part 311 and the first connecting part 22. This ensures that the two surfaces of the first sealing member 4 in the thickness direction are not on the same plane as the mating surface, preventing electrolyte from entering the mating interface and causing leakage.

[0069] In another embodiment of this application, please refer to Figures 1 to 5 Or please refer to Figures 6 to 11 Or refer to Figures 12 to 16 In the illustrated embodiment, a third recess 310 is provided on the side of the protrusion 31 facing the first connecting portion 22. It can be understood that the third recess 310 is a groove structure formed by the indentation of the surface of the protrusion 31 facing the electrode terminal 2. A second connecting portion 311 is formed at the bottom of the third recess 310, and the first connecting portion 22 is accommodated in the third recess 310, with the bottom of the third recess 310 abutting against the bottom surface of the first connecting portion 22. In some embodiments, the groove depth L2 of the third recess 310 may be consistent with the thickness L5 of the first connecting portion 22.

[0070] like Figures 1 to 5 In the illustrated embodiment, the second recess 23 has an annular groove 231 surrounding the first connecting portion 22. The first sealing member 4 is disposed in the annular groove 231 and abuts against the bottom of the annular groove 231 and the top surface of the protrusion 31. The protrusion 31 forms an annular platform 312 around the outer side of the third recess 310. The annular platform 312 is at least partially accommodated within the annular groove 231. The bottom surface of the first sealing member 4 in the thickness direction abuts against the platform surface of the annular platform 312, and the top surface of the first sealing member 4 in the thickness direction abuts against the bottom of the annular groove 231. The width of the annular groove 231 is at least sufficient to accommodate the first sealing member 4. In this embodiment, as... Figure 5 As shown, the welding part 20 and the first sealing element 4 are not on the same plane, which can reduce the impact of the high temperature of welding on the first sealing element 4. After the first connecting part 22 and the second connecting part 311 are assembled, the thickness L3 of the first sealing element 4 is greater than the distance between the top surface of the annular platform 312 and the bottom of the annular groove 231, so that after the second connecting part 311 is welded to the first connecting part 22, the first sealing element 4 is pressed by the bottom of the annular groove 231 and the top of the annular platform 312, thereby squeezing the first sealing element 4 to rebound and form a seal.

[0071] like Figure 5 As shown, in this embodiment, along the radial direction of the manifold 3, the maximum diameter of the outer edge of the first recess 21 is L6. The maximum diameter L6 of the outer edge of the first recess 21 can also be understood as the maximum inner diameter between the inner walls of the annular groove 231. The groove width of the third recess 310 is L7, satisfying L6 < L7, so that the first recess 21 can be accommodated in the third recess 310 and meet the welding area requirements of the first connecting part 22 and the second connecting part 311. The depth L4 of the first recess 21 extending into the third recess 310 is less than the sum of the height of the annular platform 312 and the thickness of the first sealing member 4, so that the first connecting part 22 and the second connecting part 311 can fit together seamlessly without affecting the welding effect. At the same time, it ensures that after the second connecting part 311 is welded to the first connecting part 22, the first sealing member 4 is pressed by the bottom of the annular groove 231 and the top of the annular platform 312, thereby squeezing and rebounding to form a seal. The maximum diameter of the outer edge of the protrusion 31 is L8, and the minimum outer diameter between the outer groove walls of the second recess 23 is L9, satisfying L8 < L9, so that the protrusion 31 can be accommodated in the second recess 23. Furthermore, the difference between the outer and inner diameters of the first sealing member 4, L10 (i.e., the width of the first sealing member 4), is not less than the difference between the minimum outer diameter L9 of the outer groove wall of the annular groove 231 and the maximum inner diameter L6 of the inner groove wall. This ensures that the first sealing member 4 can be securely clamped within the annular groove 231 and will not fall off.

[0072] In another embodiment of this application, please refer to Figures 6 to 11 In the illustrated embodiment, a truncated ring 312 is formed around the outer side of the third recess 310 on the protrusion 31. A stepped structure 313 is provided on the outer side of the truncated ring 312. At least a portion of the truncated ring 312 and the stepped structure 313 are accommodated within an annular groove 231. The bottom surface of the first sealing member 4 in the thickness direction abuts against the stepped surface of the stepped structure 313 and the platform surface of the truncated ring 312, and the top surface of the first sealing member 4 in the thickness direction abuts against the bottom of the annular groove 231. Thus, the first sealing member 4 seals the protrusion 31 and the welding portion 20 of the electrode terminal 2.

[0073] In this embodiment, such as Figure 9 As shown, the longitudinal section of the first sealing element 4 can be inverted L-shaped. The bottom of the first sealing element 4 abuts against the stepped structure 313 and the annular platform 312, and the top of the first sealing element 4 abuts against the bottom of the annular groove 231. In this embodiment, the first sealing element 4 can be divided into two connected parts, one part being pressed between the stepped structure 313 and the bottom of the annular groove 231, and the other part being pressed between the annular platform 312 and the bottom of the annular groove 231. Therefore, as Figure 11As shown, the height L3 of the portion of the first sealing member 4 pressed between the bottom of the annular platform 312 and the groove 231 is not less than the distance between the bottom of the annular platform 312 and the groove 231. Similarly, the height of the portion of the first sealing member 4 pressed between the step structure 313 and the bottom of the groove 231 is not less than the distance between the step structure 313 and the bottom of the groove 231. This ensures that after the second connecting part 311 is welded to the first connecting part 22, the first sealing member 4 is pressed down by the bottom of the groove 231, the annular platform 312, and the top of the step structure 313, causing it to rebound and form a seal. The difference L10 between the outer diameter and the inner diameter of the first sealing member 4, i.e., the width of the first sealing member 4, is not less than the difference between the minimum outer diameter L9 of the outer groove wall and the maximum inner diameter L6 of the inner groove wall of the annular groove 231. This ensures that the first sealing member 4 can be securely clamped within the annular groove 231 and will not fall off.

[0074] In some other embodiments, please refer to Figures 12 to 16 In the illustrated embodiment, the protrusion 31 forms an annular platform 312 around the outer side of the third recess 310. A stepped structure 313 is provided on the outer side of the annular platform 312. At least a portion of the annular platform 312 and the stepped structure 313 are accommodated within the annular groove 231. The bottom surface of the first sealing member 4 in the thickness direction abuts against the stepped surface of the stepped structure 313, and the top surface of the first sealing member 4 in the thickness direction abuts against the bottom of the annular groove 231. In this embodiment, the thickness of the first sealing member 4 is not less than the distance between the stepped structure 313 and the bottom of the annular groove 231, so that after the second connecting part 311 is welded to the first connecting part 22, the first sealing member 4 is pressed and subjected to force by the bottom of the annular groove 231 and the top of the stepped structure 313, thereby squeezing the first sealing member 4 to rebound and form a seal.

[0075] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A cylindrical battery, characterized by comprising: include: Shell (1); Electrode assembly (8) is disposed within the housing (1); Electrode terminal (2), insulatedly connected to the housing (1), the electrode terminal (2) includes a first recess (21), at least a portion of the bottom of the first recess (21) forms a first connection portion (22); The current collector (3) includes a body portion (30) and a protrusion (31) provided on the side of the body portion (30) facing the first connecting portion (22). At least a portion of the top of the protrusion (31) forms a second connecting portion (311). The first connecting portion (22) and the second connecting portion (311) are welded to form a weld portion (20). A first sealing member (4) is provided between the electrode terminal (2) and the protrusion (31) and around the weld portion (20).

2. The cylindrical battery according to claim 1, characterized by, The electrode terminal (2) further includes a second recess (23), which is disposed on the side of the electrode terminal (2) facing the current collector (3). The projection of the second recess (23) in the thickness direction of the electrode terminal (2) covers the projection of the first recess (21) in the thickness direction of the electrode terminal (2). The protrusion (31) is at least partially accommodated in the second recess (23) and the second connecting portion (311) is in contact with the first connecting portion (22). The first sealing member (4) is disposed around the welding portion (20) between the bottom of the second recess (23) and the top of the protrusion (31).

3. The cylindrical battery according to claim 2, characterized by The thickness of the protrusion (31) at the second connecting portion (311) is greater than the thickness of the first connecting portion (22). Along the thickness direction of the first connecting portion (22), the welding portion (20) extends from the side of the first connecting portion (22) away from the protrusion (31) to the second connecting portion (311) and extends into the interior of the protrusion (31).

4. The cylindrical battery according to claim 2 or 3, characterized by, A third recess (310) is provided on the side of the protrusion (31) facing the first connecting portion (22). The second connecting portion (311) is formed at the bottom of the third recess (310). The first connecting portion (22) is accommodated in the third recess (310), and the bottom of the third recess (310) is in contact with the bottom surface of the first connecting portion (22). The second recess (23) is provided with an annular groove (231) around the first connecting part (22), and the first sealing member (4) is provided in the annular groove (231) and abuts between the bottom of the annular groove (231) and the top surface of the protrusion (31).

5. The cylindrical battery according to claim 4, characterized by The protrusion (31) forms an annular platform (312) around the outside of the third recess (310). The annular platform (312) is at least partially accommodated in the annular groove (231). The bottom surface of the first seal (4) in the thickness direction abuts against the platform surface of the annular platform (312), and the top surface of the first seal (4) in the thickness direction abuts against the bottom of the annular groove (231).

6. The cylindrical battery according to claim 4, wherein The protrusion (31) forms an annular platform (312) around the outer side of the third recess (310). A stepped structure (313) is provided on the outer side of the annular platform (312). At least a portion of the annular platform (312) and the stepped structure (313) are accommodated within the annular groove (231). The bottom surface of the first sealing member (4) in the thickness direction abuts against the stepped surface of the stepped structure (313) and the platform surface of the annular platform (312). The top surface of the first sealing member (4) in the thickness direction abuts against the bottom of the annular groove (231). Alternatively, The protrusion (31) forms an annular platform (312) around the outer side of the third recess (310). A stepped structure (313) is provided on the outer side of the annular platform (312). At least a portion of the annular platform (312) and the stepped structure (313) are accommodated in the annular groove (231). The bottom surface of the first sealing member (4) in the thickness direction abuts against the stepped surface of the stepped structure (313), and the top surface of the first sealing member (4) in the thickness direction abuts against the bottom of the annular groove (231).

7. The cylindrical battery according to claim 3, wherein A stepped structure (313) is provided on the outer edge of the protrusion (31), the bottom surface of the first sealing member (4) in the thickness direction abuts against the stepped surface of the stepped structure (313), and the top surface of the first sealing member (4) in the thickness direction abuts against the bottom surface of the second recess (23).

8. The cylindrical battery according to claim 7, characterized by The second recess (23) is provided with an annular groove (231) around the first connecting part (22). The bottom surface of the first sealing member (4) in the thickness direction abuts against the step surface of the step structure (313), and the top surface of the first sealing member (4) in the thickness direction abuts against the bottom of the annular groove (231).

9. The cylindrical battery according to claim 8, characterized by The top surface of the first sealing member (4) in the thickness direction is higher than the contact surface between the second connecting part (311) and the first connecting part (22), and the bottom surface of the first sealing member (4) in the thickness direction is lower than the contact surface between the second connecting part (311) and the first connecting part (22).

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

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