Single battery and battery pack

Abstract

The invention discloses a single battery and a battery pack, and belongs to the technical field of battery packs. Comprising a shell, the shell comprises a side wall, the side wall is annularly arranged and forms a containing cavity in a surrounding mode, a first cavity opening is formed in one side, in the first direction, of the side wall, and the first cavity opening communicates with the containing cavity; the electrode assembly is arranged in the accommodating cavity and is electrically connected with the shell; the end cover assembly comprises a first pole and an insulating ring, the first pole is provided with a fixing part, the insulating ring is connected with the fixing part and sleeves the peripheral side of the first pole, the first pole covers the first cavity opening, the insulating ring is located between the first pole and the side wall, and the first pole is insulated from the side wall. The insulating ring is stably connected with the first pole through the fixing part, so that the double functions of sealing and conducting are integrated, a current collecting disc connected with the first pole is omitted, a current conduction path is simplified, the conduction internal resistance and the cost are reduced, and the energy conversion efficiency is improved on the basis of reducing the overall manufacturing cost of the single battery.

Description

Technical Field

[0001] This application belongs to the field of battery pack technology, specifically relating to a single cell battery and a battery pack. Background Technology

[0002] Currently, the application of cylindrical batteries in electric vehicles is a hot topic in the industry. The insulation and sealing of the positive terminal and the steel shell, as well as the design of the current flow area, are important structural designs of cylindrical batteries. The traditional method of insulation and sealing of the positive terminal and the steel shell of cylindrical power batteries is to use the positive terminal riveting method, that is, to use the riveting process of the positive terminal to make the insulating rubber ring nested between the terminal and the steel shell to achieve the functions of insulation and sealing.

[0003] However, the riveting process limits the cross-sectional area of ​​the electrode post. If the cross-sectional area of ​​the electrode post is designed to be too large, the force acting on the steel shell during riveting will be very large, and the steel shell is prone to deformation, leading to workpiece damage and low yield. In the industry, the maximum weldable area between the positive electrode post and the positive current collector using the riveting method is approximately 19.63 mm. 2 (A circular welding area with a diameter of 5mm) Taking a battery using traditional through-welding technology for positive and negative electrodes as an example, the DCR internal resistance limit can be as low as 2.0 milliohms, limiting the overcurrent capacity and thus restricting the battery's fast-charging performance. Meanwhile, the riveting process itself has certain disadvantages. For instance, because riveting requires applying increased stress, the insulating gasket inside the casing is prone to deformation or cracking, causing damage to the workpiece. Furthermore, due to the limited weldable area, welding between the electrode post and the core end face is not possible, meaning a current collector-less design cannot be achieved on the electrode post side, further hindering cost reduction. Summary of the Invention

[0004] The purpose of this application is to provide a single battery cell and a battery pack that can solve at least some of the above-mentioned problems.

[0005] To solve the above-mentioned technical problems, this application is implemented as follows: In a first aspect, embodiments of this application provide a single-cell battery having a first orientation, comprising: a housing, the housing including a sidewall, the sidewall being annularly arranged and surrounding a receiving cavity, the receiving cavity having a first opening at one end in the first orientation; an electrode assembly disposed in the receiving cavity, the electrode assembly being electrically connected to the housing; and an end cap assembly, the end cap assembly including a first electrode post and an insulating ring, the first electrode post having a fixing portion, the insulating ring surrounding the electrode post, the insulating ring being connected to the fixing portion and sleeved on the outer periphery of the first electrode post, the first electrode post sealing the first opening, the insulating ring being located between the first electrode post and the sidewall, and the first electrode post and the sidewall being insulated from each other by the insulating ring.

[0006] In this embodiment, the first electrode post itself acts as a traditional end cap, thus eliminating the need for an end cap, reducing the process flow, and lowering assembly complexity. The first electrode post has a fixing part that secures the insulating ring to it. An insulating connection is established between the first electrode post and the side wall of the housing, achieving insulation between the first electrode post and the housing and preventing short circuits. The insulating ring is connected to the fixing part and fitted onto the outer periphery of the first electrode post, eliminating the need for pressure fixation from the housing or additional insulating gaskets. The insulating ring fills the space between the first electrode post and the side wall of the housing. Through the cooperation of the insulating ring and the fixing part, insulation isolation between the first electrode post and the side wall is achieved, eliminating the need to apply additional compressive stress to the housing or the insulating ring. In this embodiment, the electrode assembly is electrically connected to the housing, and the first electrode post directly covers the first cavity opening and serves as the current output terminal.

[0007] In this embodiment, the first terminal post is no longer obstructed by a current collector and can be designed with a larger radial dimension R, increasing the current-carrying area. Simultaneously, the first terminal post seals the first cavity opening, with no additional obstruction structure on its outer periphery. This configuration results in a larger exposed area for the first terminal post, providing a larger welding area for external connections, reducing welding difficulty, improving welding reliability, and avoiding excessive contact resistance due to insufficient welding area. Furthermore, the insulating ring forms a stable connection with the first terminal post through a fixing part, rather than relying on squeezing the shell or insulating gasket for fixation. The insulating ring is positioned simply by the cooperation between the terminal post and the fixing part, without applying excessive clamping stress to the shell. This prevents deformation and cracking of the shell due to long-term stress, ensuring the sealing reliability of the shell to the cavity and extending the lifespan of the individual battery. The insulating ring is only subjected to the positioning force of the fixing part and does not need to bear additional compressive stress, preventing damage and aging of the insulating ring due to stress concentration, ensuring long-term insulation between the first terminal post and the shell, and reducing the risk of short circuits. An insulating ring is fitted around the outer periphery of the first electrode post, positioned between the first electrode post and the sidewall, forming a three-layer isolation structure of the first electrode post, insulating ring, and casing, with no gaps or contact blind spots. This completely blocks the electrical connection path between the first electrode post and the sidewall, avoiding internal short circuits and leakage problems in the single cell caused by conduction between the first electrode post and the casing, thus improving the safety performance of the single cell. The insulating ring also fills the gap between the electrode post and the casing, serving a sealing function to prevent electrolyte leakage within the cavity, ensuring a stable working environment for the electrode assembly, and further extending the cycle life of the single cell.

[0008] Optionally, in this embodiment, the insulating ring is threadedly connected to the sidewall; the single cell also has a circumferential direction, the fixing part includes a first limiting part, the first limiting part is disposed on the first electrode post, and the first limiting part is connected to the insulating ring, the first limiting part restricts the rotation of the insulating ring relative to the first electrode post in the circumferential direction.

[0009] Optionally, in this embodiment, the fixing part further includes a first support part, which is arranged in a ring shape and disposed on the outer periphery of the first pole post, and the first limiting part is disposed on the first support part; the insulating ring is located on the side of the first support part away from the electrode assembly.

[0010] Optionally, in this embodiment of the application, the outer peripheral side of the insulating ring is provided with a first limiting groove, at least a portion of the first limiting part is located in the first limiting groove, and the first limiting part is engaged with the side of the insulating ring away from the electrode assembly; the first limiting part is provided in multiples and is spaced apart along the circumferential direction.

[0011] Optionally, in this embodiment, the single cell further has a radial direction, which is perpendicular to the first direction; the outer peripheral side of the insulating ring is further provided with a first threaded portion, and the first limiting groove is located on the side of the first threaded portion closer to the electrode assembly in the first direction; the inner peripheral side of the sidewall is provided with a second threaded portion, which is threadedly connected to the first threaded portion, and the second threaded portion is spaced apart from either the first support portion or the first limiting portion.

[0012] Optionally, in this embodiment, the outer periphery of the insulating ring is further provided with a first stop portion, the first stop portion being located on the side of the first screw portion away from the first limiting groove in the first direction, and the first stop portion protruding radially away from the first electrode post; the inner periphery of the sidewall is further provided with a first stop portion, the first stop portion protruding radially away from the sidewall, the second screw portion being disposed on the first stop portion, and the first stop portion being spaced apart from either the first support portion or the first limiting portion; the first stop portion being located on the side of the first stop portion away from the electrode assembly in the first direction, and the first stop portion being limited and engaged with the first stop portion in the first direction.

[0013] Optionally, in this embodiment, the first stop portion is arranged in a ring along the circumferential direction; the first stop portion is arranged in a ring along the circumferential direction, or multiple first stop portions are provided, and multiple first stop portions are spaced apart along the circumferential direction.

[0014] Optionally, in this embodiment, the first electrode post and the sidewall are spaced apart in the radial direction, and the first electrode post, the insulating ring, the first stop portion and the sidewall cooperate to form a first groove, and the first groove is located on the side of the insulating ring away from the electrode assembly; the single cell also includes a sealing member, and the sealing member is accommodated in the first groove.

[0015] Optionally, in an embodiment of this application, the first stop portion and the sidewall are spaced apart in the radial direction to form an annular second groove, the second groove communicating with the first groove; the sealant is a sealant accommodated in the second groove and the first groove.

[0016] Optionally, in an embodiment of this application, the sidewall includes a first portion and a second portion connected in the first direction, the first stop portion is disposed in the first portion, and the wall thickness of the first portion is greater than the wall thickness of the second portion.

[0017] Optionally, in this embodiment, the first electrode post is provided with a welding groove on the side opposite to the electrode assembly, and the bottom wall of the welding groove is welded to the electrode assembly; the first electrode post is also provided with a fastening groove, which is located on the bottom wall of the welding groove, and the fastening groove is a blind groove, and the fastening groove is configured to cooperate with an auxiliary tool to rotate the first electrode post.

[0018] Optionally, in this embodiment, the receiving cavity further has a second opening, the second opening and the first opening being located on opposite sides of the receiving cavity along the first direction; the housing further includes a bottom wall, the bottom wall being connected to the side wall and sealing the second opening; the electrode assembly has a first tab and a second tab, the first tab being electrically connected to the first electrode post, and the second tab being electrically connected to the bottom wall.

[0019] Optionally, in this embodiment, the single cell further includes a current collector located between the bottom wall and the second electrode tab, the current collector being welded to both the bottom wall and the second electrode tab; and / or the side wall is cylindrical, the bottom wall has an injection hole that penetrates the bottom wall and communicates with the receiving cavity, the single cell further includes a sealing cap connected to the bottom wall and sealing the injection hole; and / or the bottom wall also has an explosion-proof groove, the explosion-proof groove being a blind groove located on the side of the bottom wall away from the electrode assembly.

[0020] Optionally, in this embodiment of the application, a battery pack is also provided, including the single battery cell as described above. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the exploded structure of a single battery cell in an embodiment of this application; Figure 2 This is a schematic diagram of the cross-sectional structure of a single battery cell in an embodiment of this application; Figure 3 This is an embodiment of the present application. Figure 2 Enlarged schematic diagram of the middle section structure; Figure 4This is an embodiment of the present application. Figure 3 Schematic diagram of the middle section; Figure 5 This is a schematic diagram of the structure of the first pole post in the embodiments of this application; Figure 6 This is a schematic diagram of the cross-sectional structure of the first pole post in an embodiment of this application; Figure 7 This is a schematic diagram of the insulating ring structure in an embodiment of this application; Figure 8 This is a schematic diagram of the cross-sectional structure of the insulating ring in an embodiment of this application; Figure 9 This is a schematic diagram of the shell structure in an embodiment of this application; Figure 10 This is a schematic diagram of the cross-sectional structure of the shell in an embodiment of this application.

[0022] Explanation of reference numerals in the attached figures: 10. Housing; 11. Side wall; 111. First part; 112. Second part; 12. Second threaded part; 13. First stop part; 14. Bottom wall; 141. Injection hole; 20. End cap assembly; 21. First pole post; 211. Welding groove; 212. Fastening groove; 213. Fixing part; 22. Insulating ring; 221. First limiting groove; 222. First threaded part; 223. First stop part; 23. First support part; 24. First limiting part; 30. Receiving cavity; 31. First cavity opening; 32. Second cavity opening; 40. First groove; 50. Seal; 60. Second groove; 70. Collector plate; 80. Sealing cover; 90. Electrode assembly; 91. First electrode tab; 92. Second electrode tab; Z, First direction; C, circumferential direction; R, radial direction. Detailed Implementation

[0023] 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, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0024] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such use of data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and the number of objects is not limited; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0025] The single battery and battery pack provided in this application will be described in detail below with reference to the accompanying drawings, through specific embodiments and application scenarios.

[0026] See Figures 1 to 10 This application provides a single-cell battery with a first direction Z, comprising: a housing 10, the housing 10 including a sidewall 11, the sidewall 11 being annularly arranged and surrounding a receiving cavity 30, the receiving cavity 30 having a first cavity opening 31 at one end in the first direction Z; an electrode assembly 90, the electrode assembly 90 being disposed in the receiving cavity 30 and electrically connected to the housing 10; and an end cap assembly 20, the end cap assembly 20 including a first electrode post 21 and an insulating ring 22, the first electrode post 21 having a fixing part 213, the insulating ring 22 being annularly arranged and surrounding the electrode post 21, the insulating ring 22 being connected to the fixing part 213 and sleeved on the outer periphery of the first electrode post 21, the first electrode post 21 sealing the first cavity opening 31, the insulating ring 22 being located between the first electrode post 21 and the sidewall 11, and the first electrode post 21 and the sidewall 11 being insulated from each other by the insulating ring 22.

[0027] In this embodiment, the first electrode post 21 itself acts as a traditional end cap, thus eliminating the need for an end cap, reducing the process flow, and lowering assembly complexity. The first electrode post 21 has a fixing part 213, which fixes the insulating ring 22 to the first electrode post 21. An insulating connection is formed between the first electrode post 21 and the side wall 11 of the housing 10, achieving insulation between the first electrode post 21 and the housing 10 and preventing short circuits. The insulating ring 22 is connected to the fixing part 213 and is fitted onto the outer periphery of the first electrode post 21, no longer relying on the housing 10 or additional insulating gaskets for compression fixation. The insulating ring 22 fills the space between the first electrode post 21 and the side wall 11 of the housing 10. Through the cooperation of the insulating ring 22 and the fixing part 213, insulation isolation between the first electrode post 21 and the side wall 11 is achieved, without applying additional compressive stress to the housing 10 or the insulating ring 22. In this embodiment, the electrode assembly 90 is directly electrically connected to the housing 10, and the first electrode post 21 directly covers the first cavity 31 and serves as the current output terminal.

[0028] In this embodiment, the first electrode post 21 is no longer obstructed by the current collector 70 connected to it, and a larger radial dimension R can be designed according to requirements, increasing the current flow area. Simultaneously, the first electrode post 21 directly faces the first cavity opening 31, with no additional obstruction structure on its outer periphery. This configuration results in a larger exposed area for the first electrode post 21, providing a larger welding area for external connections, reducing welding difficulty, improving welding reliability, and avoiding excessive contact resistance due to insufficient welding area. Furthermore, the insulating ring 22 forms a stable connection with the first electrode post 21 through the fixing part 213, rather than relying on squeezing the housing 10 or insulating gaskets for fixation. The insulating ring 22 can be positioned simply by the cooperation between the electrode post and the fixing part 213, without applying excessive clamping stress to the housing 10. This prevents deformation and cracking of the housing 10 due to long-term stress, ensuring the sealing reliability of the housing 10 to the receiving cavity 30 and extending the lifespan of the individual battery. The insulating ring 22 is only subjected to the positioning force of the fixing part 213 and does not need to bear additional compressive stress. This avoids damage and aging of the insulating ring 22 due to stress concentration, ensuring the long-term insulation effect between the first electrode post 21 and the shell and reducing the risk of short circuit. The insulating ring 22 is fitted onto the outer periphery of the first electrode post 21 and located between the first electrode post 21 and the side wall 11, forming a three-layer isolation structure of the first electrode post 21, the insulating ring 22, and the shell 10, without gaps or contact blind spots. This completely blocks the electrical connection path between the first electrode post 21 and the side wall 11, avoiding internal short circuits and leakage problems in the single cell caused by the first electrode post 21 being connected to the shell 10, thus improving the safety performance of the single cell. The insulating ring 22 also fills the gap between the electrode post and the shell 10, serving a sealing function to prevent electrolyte leakage in the receiving cavity 30, ensuring a stable working environment for the electrode assembly 90, and further extending the cycle life of the single cell.

[0029] Optionally, in this embodiment, the insulating ring 22 is connected to the sidewall 11 by a thread; the single cell also has a circumferential C, and the fixing part 213 includes a first limiting part 24, which is disposed on the first pole post 21 and connected to the insulating ring 22. The first limiting part 24 restricts the rotation of the insulating ring 22 relative to the first pole post 21 in the circumferential C.

[0030] In this embodiment, the outer circumferential surface of the insulating ring 22 is provided with external threads, and the inner sidewall of the first cavity 31 is provided with internal threads. The two are connected in a detachable and tight manner through threaded engagement, replacing the traditional interference fit or adhesive fixation. The first limiting part 24 can be a non-circular structure, such as a rectangular boss, flat part, spline, etc., and is adapted to the corresponding groove or hole on the inner wall of the insulating ring 22 to form a circumferential C anti-rotation fit, restricting the insulating ring 22 from rotating around the first pole post 21 in the circumferential C direction. The threaded connection has the characteristics of adjustable preload and surface contact sealing. The insulating ring 22 and the sidewall 11 are screwed together by threads, and the tightness of the fit can be adjusted by controlling the screw-in depth, and the thread profile can fill the fit gap. After the threads are screwed together, the insulating ring 22 and the inner wall of the sidewall 11 form a multi-turn threaded sealing surface, which can more effectively prevent electrolyte leakage in the receiving cavity 30 compared with the traditional interference fit, while isolating external moisture and impurities from entering, further ensuring the internal environmental stability of the single cell and extending the cycle life.

[0031] Furthermore, the threaded connection is a detachable assembly. If the position of the insulating ring 22 is found to be off during the assembly process, it can be loosened and adjusted and then tightened again without applying excessive assembly force, thus avoiding cracking of the insulating ring 22 due to excessive force and improving the assembly yield.

[0032] Furthermore, the threaded connection has self-locking properties, which can resist structural loosening caused by vibration and temperature changes during the charging and discharging process of a single battery, ensuring that the insulating ring 22 remains in a fixed position with the side wall 11 for a long time, and avoiding the risk of short circuit between the terminal and the housing 10 due to displacement of the insulating ring 22.

[0033] It should be noted that the limiting structure of the first limiting part 24 and the limiting structure of the insulating ring 22 forms a circumferential C constraint, preventing the insulating ring 22 from rotating around the axis of the first electrode post 21, directly locking the relative circumferential C position of the two. In practical applications, when a single cell is subjected to vibration or external impact, the insulating ring 22 may rotate circumferentially C with the first electrode post 21, causing the threaded connection with the side wall 11 to gradually loosen, damaging the seal and insulation. The first limiting part 24 can prevent such rotation, ensuring that the threaded connection remains in a pre-tightened state for a long time, avoiding seal failure. The circumferential C constraint can ensure that the insulating ring 22 is always in a precise isolated position, maintaining the stable insulation structure of the electrode post, insulating ring 22, and housing 10, reducing the risk of short circuit.

[0034] Optionally, in this embodiment, the fixing part 213 further includes a first support part 23, which is arranged in a ring shape and disposed on the outer periphery of the first pole post 21, and a first limiting part 24 is disposed on the first support part 23; the insulating ring 22 is located on the side of the first support part 23 away from the electrode assembly 90.

[0035] In this embodiment, the first support portion 23 is an annular structure, coaxially sleeved on the outer periphery of the first pole post 21, and the first limiting portion 24, such as a boss or a flat portion, is directly integrated into the annular wall of the first support portion 23. Together, they constitute the combined function of support and limiting of the fixing portion 213. The insulating ring 22 is located on the side of the first support portion 23 away from the electrode assembly 90, that is, along the first direction Z. The insulating ring 22 and the electrode assembly 90 are respectively located at the two ends of the first support portion 23, and the annular wall of the first support portion 23 can form a close fit support with the end face or inner wall of the insulating ring 22.

[0036] In this embodiment, the annular first support portion 23 is coaxially arranged with the first pole post 21, providing a stable axial (i.e., along the first direction Z) support surface for the insulating ring 22. Simultaneously, the first limiting portion 24 is integrated into the support portion, forming an integrated positioning system of support and limiting. During assembly, the insulating ring 22 can be directly referenced to the end face of the first support portion 23, avoiding assembly misalignment due to lack of support and preventing uneven insulation gaps and sealing failures caused by eccentricity. The annular support structure forms an annular contact surface with the end face of the insulating ring 22, rather than localized point or line contact. This evenly distributes the force borne by the insulating ring 22 during threaded connections or single-cell vibration to the first support portion 23, preventing localized stress concentration and cracking of the insulating ring 22 and extending the service life of the insulating component.

[0037] It should be noted that by integrating the first limiting part 24 into the annular first support part 23, there is no need to separately process the limiting structure on the first pole post 21, reducing the pole post processing steps. At the same time, the first support part 23 and the first pole post 21 are integrally formed, eliminating the need for additional assembly and improving production efficiency.

[0038] Furthermore, along the first direction Z, the first support portion 23 is located between the insulating ring 22 and the electrode assembly 90, forming a physical barrier. The support portion is a rigid annular structure, which can prevent the electrolyte in the receiving cavity 30 from penetrating towards the insulating ring 22. The receiving cavity 30, where the electrode assembly 90 is located, stores the electrolyte. The first support portion 23 can directly prevent the electrolyte from contacting the insulating ring 22, avoiding corrosion and aging of the insulating ring 22 material by the electrolyte, ensuring the long-term stable insulation performance of the insulating ring 22, and reducing the risk of short circuits due to insulation failure. Simultaneously, the insulating ring 22 and the electrode assembly 90 are separated by the first support portion 23, preventing axial interference between them, allowing for more sizing of the electrode assembly 90 (which is beneficial for increasing the capacity of a single battery cell). The first support portion 23 can form an auxiliary sealing surface with the end face of the insulating ring 22, combined with the threaded seal between the insulating ring 22 and the side wall 11, forming a double sealing structure, improving the sealing reliability of the single battery cell.

[0039] Optionally, in this embodiment of the application, the outer periphery of the insulating ring 22 is provided with a first limiting groove 221, at least a portion of the first limiting part 24 is located in the first limiting groove 221, and the first limiting part 24 is engaged with the side of the insulating ring 22 away from the electrode assembly 90; the first limiting part 24 is provided with a plurality of parts and is spaced apart along the circumferential direction C.

[0040] In this embodiment, the inner circumferential side of the insulating ring 22, that is, the side that fits against the first support portion 23, is provided with a first limiting groove 221. The shape and size of the limiting groove are perfectly matched with the first limiting portion 24, forming a fitted structure with a raised groove. Multiple first limiting portions 24 are evenly spaced along the circumferential direction C of the first support portion 23, such as 3, 4, or spaced at 90° or 120° intervals. Each first limiting portion 24 is at least partially embedded in the corresponding first limiting groove 221, achieving multi-point snap-fit ​​fixation.

[0041] In this embodiment, the first limiting part 24 is embedded in the first limiting groove 221 to form a rigid snap-fit, restricting the relative rotation of the insulating ring 22 and the first support part 23 in the circumferential direction C. This structure also serves as an assembly guide. Compared to a simple non-circular fit, the snap-fit ​​structure has a larger contact area and stronger constraint, resisting vibration, impact, or circumferential C torque during threaded assembly of a single battery cell. This prevents the insulating ring 22 from shifting, ensuring a long-term pre-tightened state between the insulating ring 22 and the threaded connection of the side wall 11, preventing seal failure. During assembly, the first limiting part 24 can be quickly inserted along the guide of the first limiting groove 221 without additional calibration of the circumferential C angle, reducing operational difficulty, improving assembly efficiency, and minimizing assembly errors. The snap-fit ​​fit makes the insulating ring 22 and the first support part 23 form an integral structure, rather than independent components, reducing relative displacement between them and preventing abnormal noise or wear caused by gaps after long-term use, thus extending the overall structural lifespan.

[0042] It should be noted that the multiple first limiting parts 24 are evenly distributed along the circumferential direction C, which can evenly transfer the circumferential force C of the insulating ring 22 to the first support part 23, rather than concentrating it at a single point. When the single cell is subjected to external impact or temperature change, causing the insulating ring 22 to deform circumferentially C, the multiple sets of first limiting parts 24 can simultaneously bear the force, distributing the stress load of each first limiting part 24, preventing a single first limiting part 24 from breaking or deforming due to excessive stress, and ensuring the long-term reliability of the first limiting structure.

[0043] It should also be noted that even if individual first limiting parts 24 experience slight failure due to processing errors or assembly problems, the remaining limiting parts can still perform their circumferential C-constraint function normally, avoiding the loss of overall limiting function, reducing the risk of single-cell battery scrap due to defects in a single part, and improving production yield.

[0044] Optionally, in this embodiment, the single cell also has a radial direction R, which is perpendicular to the first direction Z; the outer periphery of the insulating ring 22 is also provided with a first threaded portion 222, and the first limiting groove 221 is located on the side of the first threaded portion 222 in the first direction Z close to the electrode assembly 90; the inner periphery of the sidewall 11 is provided with a second threaded portion 12, which is threadedly connected to the first threaded portion 222, and the second threaded portion 12 is evenly spaced from either the first support portion 23 or the first limiting portion 24.

[0045] In this embodiment, the first threaded portion 222 on the outer periphery of the insulating ring 22 and the first limiting groove 221 on the inner periphery are arranged in layers along the first direction Z, and the first limiting groove 221 is located on the side of the first threaded portion 222 closer to the electrode assembly 90. The two do not overlap in the axial direction and are independent of each other. The second threaded portion 12 on the inner periphery of the sidewall 11 on the housing 10 is only threaded with the first threaded portion 222, and is axially spaced from the first support portion 23 and the first limiting portion 24. The three have no structural interference in the radial R and axial directions.

[0046] In this embodiment, the first threaded portion 222 and the first limiting groove 221 are layered vertically along the first direction Z, without occupying radial space R. During assembly, the insulating ring 22 can be first engaged with the limiting portion of the first support portion 23 through the first limiting groove 221, and then the insulating ring 22 can be rotated to engage the first threaded portion 222 with the second threaded portion 12, avoiding circumferential displacement of the insulating ring 22 during the threading process, thus greatly improving assembly efficiency and accuracy. The above-mentioned layered design makes the limiting and threading functions independent and do not interfere with each other. There is no need to worry about the torque during threading damaging the limiting portion, nor is there any need to worry about the limiting portion affecting the thread engagement depth, ensuring that both functions are stably performed.

[0047] Furthermore, the spacing between the second screw connection 12 and the first support portion 23 and the first limiting portion 24 serves to avoid short-circuit risks and assembly jamming. Specifically, the first support portion 23 and the first limiting portion 24 are integral with the first terminal post 21 and are all made of metal. The second screw connection 12 is located on the side wall 11 of the housing 10. The spacing prevents the two from contacting each other and forming a conductive path, completely avoiding the risk of internal short circuits in the single battery cell caused by metal contact and ensuring safety performance.

[0048] Optionally, in this embodiment, the outer periphery of the insulating ring 22 is further provided with a first stop portion 223. The first stop portion 223 is located on the side of the first screw portion 222 away from the first limiting groove 221 in the first direction Z, and the first stop portion 223 protrudes radially R toward the side away from the first pole post 21. The inner periphery of the sidewall 11 is further provided with a first stop portion 13. The first stop portion 13 protrudes radially R toward the side away from the sidewall 11. The second screw portion 12 is provided on the first stop portion 13, and the first stop portion 13 is spaced apart from either the first support portion 23 or the first limiting portion 24. The first stop portion 13 is located on the side of the first stop portion 223 away from the electrode assembly 90 in the first direction Z, and the first stop portion 13 is limited and engaged with the first stop portion 223 in the first direction Z.

[0049] In this embodiment, the outer periphery of the insulating ring 22 is provided with a first stop portion 223, which protrudes outward along the radial direction R. The inner periphery of the side wall 11 of the housing 10 is provided with a first stop portion 13, which protrudes inward along the radial direction R. The second screw portion 12 is directly machined on the inner wall of the first stop portion 13. The first stop portion 13 is spaced apart from the first support portion 23 and the first limiting portion 24, and is located on the side of the first stop portion 223 away from the electrode assembly 90 in the first direction Z. The two can form a limiting fit with axial end face contact.

[0050] In this embodiment, when the insulating ring 22 is screwed into the second screwed portion 12 via the first screwed portion 222, the first stop portion 223 moves axially with the insulating ring 22 until it comes into contact with the end face of the first stop portion 13, forming a rigid axial block that restricts the insulating ring 22 from being screwed in further. The axial limiting fit between the first stop portion 223 and the first stop portion 13 controls the screwing depth of the insulating ring 22, avoiding problems of excessively shallow or deep screwing due to differences in manual operation. Excessive shallow screwing leads to insufficient thread sealing and easy electrolyte leakage; excessive deep screwing compresses the insulating ring 22, causing it to deform and crack. The combination of these two features ensures the assembly consistency of all individual cells and improves product yield.

[0051] Furthermore, the first stop portion 223 and the first stop portion 13, after being fitted together, can withstand the axial vibration and impact loads of the individual battery, preventing the insulating ring 22 from loosening due to axial force, maintaining the pre-tightening force of the thread seal, ensuring no electrolyte leakage in the long term, and improving the service life of the individual battery. At the same time, the above-mentioned configuration eliminates the need for additional measurement or calibration of the screw depth during assembly. Assembly can be completed simply by rotating the insulating ring 22 until the stop portion and the stop portion are fitted together, reducing the skill requirements for operators and improving production efficiency.

[0052] Furthermore, the second screw-in portion 12 is directly disposed on the inner wall of the first stop portion 13, forming an integrated structure. Simultaneously, the first stop portion 13 maintains a physical distance from the first support portion 23 and the first limiting portion 24, with no contact whatsoever. This arrangement integrates the stop function and the screw-in function into the first stop portion 13, eliminating the need for separate machining of the stop structure and screw-in structure on the side wall 11. This simplifies the machining process of the housing 10, reduces manufacturing costs, and minimizes structural weaknesses in the side wall 11. The first stop portion 13 belongs to the side wall 11 of the housing 10, while the first support portion 23 and the first limiting portion 24 belong to the first terminal post 21. Their spaced arrangement prevents contact between the two, avoiding the formation of a conductive path and completely eliminating the risk of internal short circuits caused by metal contact, thus ensuring the safety performance of the individual battery cells.

[0053] It should be noted that the first stop portion 223 protrudes outward along the radial direction R, which can thicken the wall thickness of the corresponding position of the insulating ring 22, forming a local reinforcing rib structure. When the first stop portion 223 is in contact with the first stop portion 13, it will be subjected to axial compressive force. The radially protruding reinforcing structure can disperse this compressive force, preventing the insulating ring 22 from deforming due to excessive local stress, and ensuring the long-term positioning function of the stop portion. The protruding stop portion can enhance the overall rigidity of the insulating ring 22, reduce the circumferential contraction or expansion of the insulating ring 22 during the charging and discharging of a single battery, and prevent the increase of the thread sealing gap due to the deformation of the insulating ring 22, further ensuring the reliability of the seal.

[0054] Optionally, in the embodiments of this application, the first stop portion 13 is arranged in a ring along the circumferential direction C; the first stop portion 223 is arranged in a ring along the circumferential direction C, or there are multiple first stop portions 223, and the multiple first stop portions 223 are spaced apart along the circumferential direction C.

[0055] In this embodiment, the annular structure can form a full-circumferential C-face fit with the first stop portion 223, evenly distributing the axial limiting force throughout the entire circumferential C, avoiding deformation of the sidewall 11 or breakage of the stop portion due to force concentration in traditional local stop portions, thus ensuring long-term positioning stability. The second threaded portion 12 is machined on the inner wall of the annular stop portion, with a full-circumferential C-thread without gaps or misalignment, resulting in a tighter engagement with the first threaded portion 222 of the insulating ring 22, reducing the risk of electrolyte leakage caused by thread gaps; at the same time, the annular thread fit can resist circumferential C-torque, avoiding local thread wear and extending the life of the threaded structure.

[0056] Furthermore, the annular first stop portion 223 is integrally formed with the insulating ring 22, and the circumferential direction C is continuous. It can form a full-face fit with the annular first stop portion 13, and the contact area is much larger than that of the discrete stop portion. This allows the axial compressive force applied by the first stop portion 13 to be evenly transferred to the insulating ring 22, avoiding excessive local pressure that could cause the insulating ring 22 to crack, and extending the service life of the insulating ring 22. When the single cell is subjected to axial vibration or drop impact, the annular structure can simultaneously bear the load in the entire circumferential direction C, preventing the discrete stop portion from falling off due to excessive force at a single point, ensuring that the limiting function does not fail, further ensuring the pre-tightening state of the threaded seal, and preventing electrolyte leakage.

[0057] Furthermore, multiple stops are evenly distributed along the circumferential direction C, which, while ensuring the limiting function, reduces the amount of material used in the insulating ring 22, thereby reducing the overall weight and conforming to the design trend of lightweight single-cell batteries. Furthermore, the annular first stop portion 13 is circumferentially continuous (C), compatible with annular or multiple sets of spaced first stop portions 223. This allows for adaptation to different design requirements without altering the stop portion structure, satisfying diverse design needs. In practical applications, if the single battery cell requires high limiting stability, both the annular first stop portion 13 and the annular first stop portion 223 can be selected. If weight is a concern, both the annular first stop portion and multiple sets of spaced first stop portions 223 can be selected, eliminating the need to redevelop the housing 10 mold and reducing R&D and production costs.

[0058] Optionally, in this embodiment, the first electrode post 21 and the sidewall 11 are spaced apart in the radial direction R. The first electrode post 21, the insulating ring 22, the first stop portion 223 and the sidewall 11 cooperate to form a first groove 40, and the first groove 40 is located on the side of the insulating ring 22 away from the electrode assembly 90. The single cell also includes a sealing member 50, which is accommodated in the first groove 40.

[0059] In this embodiment, the radial R-space prevents the first electrode post 21 from directly contacting the sidewall 11, while providing the necessary annular space for the formation of the first groove 40. Based on the existing insulating ring 22, the radial R-space forms an air insulation layer. Even if the insulating ring 22 experiences partial failure due to aging or damage, the radial R-space can still block the conductive path, completely avoiding the short-circuit risk of the electrode post and the casing 10 conducting through, thus improving the safety redundancy of the single battery cell. Simultaneously, the radial R-space is a prerequisite for forming the first groove 40. If there is no space between the electrode post and the sidewall 11, a groove to accommodate the seal 50 cannot be formed, making subsequent sealing design impossible. This space provides a structural basis for strengthening the seal.

[0060] Furthermore, the first groove 40 is formed by multiple components to create an annular closed space, which can fix the circumferential C and axial position of the seal 50 and prevent the seal 50 from shifting. The annular groove provides a wrapping positioning for the seal 50. When the single cell is subjected to vibration, impact, or temperature changes, the seal 50 will not fall out of the first groove 40 or slide circumferentially C, ensuring that the sealing position remains stable and preventing seal failure caused by the displacement of the seal 50. The annular first groove 40 allows the seal 50 to form a multi-faceted fit with the terminal post, insulating ring 22, stop, and side wall 11, with a contact area much larger than that of a traditional single-plane seal, improving sealing efficiency. The elastic seal 50 is slightly compressed within the first groove 40, producing elastic deformation and filling the tiny gaps in the inner wall of the first groove 40, forming a composite sealing system of rigid structure and elastic seal.

[0061] Optionally, in this embodiment, the first stop portion 223 and the side wall 11 are spaced apart in the radial direction R to form an annular second groove 60, and the second groove 60 communicates with the first groove 40; the sealing member 50 is a sealant accommodated in the second groove 60 and the first groove 40.

[0062] In this embodiment, the first stop 223 and the sidewall 11 are radially spaced apart to form an annular second groove 60, and the second groove 60 and the first groove 40 are axially connected, together forming a continuous "L"-shaped extended accommodating space. The sealant 50 is a sealant, such as liquid silicone or epoxy resin. The sealant not only completely fills the first groove 40, but also fully accommodates the connected second groove 60. After curing, it tightly bonds with the groove walls of the first groove 40 and the groove walls of the second groove 60, forming an integral sealing structure that covers the gap and the end face of the insulating ring 22.

[0063] In this embodiment, after the second groove 60 and the first groove 40 are connected, the sealant can fill both simultaneously, thereby preventing electrolyte leakage and the intrusion of external impurities, and significantly improving the sealing reliability. Furthermore, the sealant is a liquid-curing material, which, compared to a solid sealing ring, can more flexibly fill irregular areas of the first groove 40 and the groove, such as tiny chamfers and gaps generated during component processing. After curing, it forms a seamless bond with the groove wall, avoiding the problem of loose fit caused by dimensional deviations in solid sealing rings, and further enhancing the sealing effect.

[0064] Optionally, in this embodiment of the application, the sidewall 11 includes a first portion 111 and a second portion 112 connected in the first direction Z, a first stop portion 13 is provided in the first portion 111, and the wall thickness of the first portion 111 is greater than the wall thickness of the second portion 112.

[0065] In this embodiment, the first part 111 needs to bear the first stop part 13, the second screw part 12 and the assembly force with the insulating ring 22. The thick-wall design can improve the structural rigidity and load-bearing capacity of this area. The second part 112 only needs to surround the electrode assembly 90, without the need for a complex assembly structure, and can adopt a thin-wall design.

[0066] In this embodiment, the above-mentioned arrangement enhances the deformation resistance of the first stop portion 13, preventing it from bending or breaking due to excessive force, thus ensuring the long-term stability of the limiting function. Simultaneously, the second portion 112 adopts a thin-walled design, reducing the overall material usage of the casing 10 while ensuring the strength of key structures, thereby lowering the weight and manufacturing cost of the individual battery and avoiding resource waste caused by a full-thickness design.

[0067] Optionally, in this embodiment, the first pole post 21 is provided with a welding groove 211 on the side away from the electrode assembly 90, and the bottom wall of the welding groove 211 is welded to the electrode assembly 90; the first pole post 21 is also provided with a fastening groove 212, which is located on the bottom wall of the welding groove 211, and the fastening groove 212 is a blind groove, and the fastening groove 212 is configured to cooperate with an auxiliary tool and rotate the first pole post 21.

[0068] In this embodiment, the electrode assembly 90 and the welding groove 211 are connected by through welding. The groove structure of the welding groove 211 can accommodate the welding point, preventing the welding part from protruding outward and affecting the assembly of other components. The first electrode post 21 is also provided with a fastening groove 212, which is formed on the bottom wall of the welding groove 211 and is a blind groove. It is understood that the fastening groove 212 does not penetrate the first electrode post 21. The cross-section of the fastening groove 212 can be hexagonal, cross-shaped, or slotted, etc. The fastening groove 212 is configured to cooperate with auxiliary tools, such as hex wrenches, screwdrivers, etc., to drive the first electrode post 21 to rotate around the axis through tool engagement, so as to complete the threaded assembly with the insulating ring 22.

[0069] Optionally, in this embodiment, the receiving cavity 30 further has a second cavity 32, the second cavity 32 and the first cavity 31 are respectively located on opposite sides of the receiving cavity 30 along the first direction Z; the housing 10 further includes a bottom wall 14, the bottom wall 14 is connected to the side wall 11 and closes the second cavity 32; the electrode assembly 90 has a first electrode tab 91 and a second electrode tab 92, the first electrode tab 91 is electrically connected to the first electrode post 21, and the second electrode tab 92 is electrically connected to the bottom wall 14.

[0070] In this embodiment, the sidewall 11 is further provided with a second cavity 32. The second cavity 32 and the first cavity 31 are located on opposite sides of the sidewall 11 along the first direction Z, and the second cavity 32 communicates with the receiving cavity 30, forming openings at both ends of the receiving cavity 30 in the axial direction. The housing 10 also has a bottom wall 14, which is connected to the sidewall 11 at the position corresponding to the second cavity 32 and completely seals the second cavity 32, so that the sidewall 11 and the bottom wall 14 together form a complete sealed receiving cavity 30 for accommodating the electrode assembly 90. The electrode assembly 90 has a first electrode tab 91 and a second electrode tab 92. The first electrode tab 91 is electrically connected to the first electrode post 21 by welding to the bottom wall of the welding groove 211, and the second electrode tab 92 is electrically connected by welding or abutting directly to the bottom wall 14, thus constructing the positive and negative current output paths of the single cell.

[0071] Optionally, in this embodiment, the single cell further includes a current collector 70, which is located between the bottom wall 14 and the second tab 92. The current collector 70 is welded to both the bottom wall 14 and the second tab 92. And / or the side wall 11 is cylindrical. The bottom wall 14 is provided with an injection hole 141, which penetrates the bottom wall 14 and communicates with the receiving cavity 30. The single cell also includes a sealing cap 80, which is connected to the bottom wall 14 and covers the injection hole 141. And / or the bottom wall 14 is also provided with an explosion-proof groove, which is a blind groove located on the side of the bottom wall 14 away from the electrode assembly 90.

[0072] In this embodiment, the current collector 70 is located between the bottom wall 14 and the second tab 92, and is welded to both, forming a conductive transition structure from the second tab 92 to the current collector 70 and then to the bottom wall 14. The current collector 70 can be circular in shape, with dimensions adapted to the inner side of the bottom wall 14, without interfering with the side wall 11. The side wall 11 is cylindrical in shape with a circular axial cross-section, making the receiving cavity 30 a cylindrical space that fits the shape of the wound electrode assembly 90, improving space utilization. The bottom wall 14 is provided with an injection hole 141, which penetrates the bottom wall 14 along the first direction Z, with one end connected to the receiving cavity 30 and the other end leading to the outside, for injecting electrolyte during single-cell assembly. The single-cell holder is also equipped with a sealing cap 80, which is fixed to the bottom wall 14 by welding, threaded connection, or interference fit, completely sealing the injection hole 141 to prevent electrolyte leakage. An explosion-proof groove is provided on the side of the bottom wall 14 away from the electrode assembly 90. The explosion-proof groove is a blind groove that does not penetrate the bottom wall 14. The cross-section of the explosion-proof groove heating groove can be "V", "U" or annular. The groove wall thickness is less than other areas of the bottom wall 14, forming a structurally weak area. The explosion-proof groove avoids the position of the liquid injection hole 141 and does not affect the assembly of the sealing cap 80.

[0073] Optionally, in this embodiment of the application, a battery pack is also provided, including the single battery cell as described above.

[0074] In this embodiment, the battery pack includes the single cell as described above, and also includes all the structural features and beneficial effects of the single cell, which will not be repeated here.

[0075] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. Furthermore, it should be noted that the scope of the methods and apparatuses in the embodiments of this application is not limited to performing functions in the order shown or discussed, but may also include performing functions substantially simultaneously or in the reverse order, depending on the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.

[0076] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this application.

Claims

1. A single-cell battery having a first orientation (Z), characterized in that, include: The housing (10) includes a sidewall (11) which is arranged in an annular shape and surrounds a receiving cavity (30). The receiving cavity (30) has a first cavity opening (31) at one end in the first direction (Z). An electrode assembly (90) is disposed in the receiving cavity (30) and electrically connected to the housing (10); End cap assembly (20), the end cap assembly (20) includes a first pole post (21) and an insulating ring (22). The first pole post (21) is provided with a fixing part (213). The insulating ring (22) is arranged around the pole post (21). The insulating ring (22) is connected to the fixing part (213) and fixed on the outer periphery of the first pole post (21). The first pole post (21) covers the first cavity (31). The insulating ring (22) is connected to the side wall (11) and located between the first pole post (21) and the side wall (11). The first pole post (21) and the side wall (11) are insulated from each other by the insulating ring (22).

2. The single-cell battery according to claim 1, characterized in that, The insulating ring (22) is connected to the side wall (11) by a thread; the single cell also has a circumferential (C) direction, the fixing part (213) includes a first limiting part (24), the first limiting part (24) is disposed on the first pole post (21), and the first limiting part (24) is connected to the insulating ring (22), the first limiting part (24) restricts the rotation of the insulating ring (22) relative to the first pole post (21) in the circumferential (C) direction.

3. The single-cell battery according to claim 2, characterized in that, The fixing part (213) further includes a first support part (23), which is arranged in a ring shape and located on the outer periphery of the first pole post (21), and the first limiting part (24) is located on the first support part (23); the insulating ring (22) is located on the side of the first support part (23) away from the electrode assembly (90).

4. The single-cell battery according to claim 3, characterized in that, The outer periphery of the insulating ring (22) is provided with a first limiting groove (221), at least a portion of the first limiting part (24) is located in the first limiting groove (221), and the first limiting part (24) is engaged with the side of the insulating ring (22) away from the electrode assembly (90). The first limiting part (24) is provided with a plurality of such parts and is spaced apart along the circumferential direction (C).

5. The single-cell battery according to claim 4, characterized in that, The single cell also has a radial direction (R), which is perpendicular to the first direction (Z); the outer periphery of the insulating ring (22) is also provided with a first screw connection (222), and the first limiting groove (221) is located on the side of the first screw connection (222) in the first direction (Z) close to the electrode assembly (90); The inner circumferential side of the sidewall (11) is provided with a second threaded part (12), which is threadedly connected to the first threaded part (222). The second threaded part (12) is evenly spaced from either the first support part (23) or the first limiting part (24).

6. The single-cell battery according to claim 5, characterized in that, The outer periphery of the insulating ring (22) is also provided with a first stop (223). The first stop (223) is located on the side of the first screw connection (222) away from the first limiting groove (221) in the first direction (Z), and the first stop (223) protrudes along the radial direction (R) towards the side away from the first pole post (21). The inner circumferential side of the sidewall (11) is also provided with a first stop portion (13), the first stop portion (13) protrudes along the radial direction (R) toward the side away from the sidewall (11), the second screw portion (12) is provided on the first stop portion (13), and the first stop portion (13) is spaced apart from either the first support portion (23) or the first limiting portion (24); The first stop portion (13) is located on the side of the first stop portion (223) near the electrode assembly (90) in the first direction (Z), and the first stop portion (13) is in a limiting engagement with the first stop portion (223) in the first direction (Z).

7. The single-cell battery according to claim 6, characterized in that, The first stop portion (13) is arranged in a ring along the circumferential direction (C); the first stop portion (223) is arranged in a ring along the circumferential direction (C), or there are multiple first stop portions (223), and multiple first stop portions (223) are spaced apart along the circumferential direction (C).

8. The single-cell battery according to claim 6, characterized in that, The first electrode post (21) and the side wall (11) are spaced apart in the radial direction (R). The first electrode post (21), the insulating ring (22), the first stop (223) and the side wall (11) cooperate to form a first groove (40), and the first groove (40) is located on the side of the insulating ring (22) away from the electrode assembly (90). The single cell also includes a seal (50), which is accommodated in the first groove (40).

9. The single-cell battery according to claim 8, characterized in that, The first stop (223) and the side wall (11) are spaced apart in the radial direction (R) and form an annular second groove (60), the second groove (60) communicating with the first groove (40); the seal (50) is a sealant contained in the second groove (60) and the first groove (40).

10. The single-cell battery according to claim 6, characterized in that, The sidewall (11) includes a first part (111) and a second part (112) connected in the first direction (Z), the first stop part (13) is provided in the first part (111), and the wall thickness of the first part (111) is greater than the wall thickness of the second part (112).

11. The single-cell battery according to any one of claims 1-10, characterized in that, The first electrode post (21) has a welding groove (211) on the side away from the electrode assembly (90), and the bottom wall of the welding groove (211) is welded to the electrode assembly (90); The first pole post (21) is also provided with a fastening groove (212), which is located on the bottom wall of the welding groove (211) and is a blind groove. The fastening groove (212) is configured to cooperate with an auxiliary tool and rotate the first pole post (21).

12. The single-cell battery according to claim 11, characterized in that, The receiving cavity (30) also has a second cavity (32), which is located on opposite sides of the receiving cavity (30) along the first direction (Z) and the first cavity (31) respectively; the housing (10) also includes a bottom wall (14), which is connected to the side wall (11) and closes the second cavity (32). The electrode assembly (90) has a first tab (91) and a second tab (92), the first tab (91) being electrically connected to the first post (21), and the second tab (92) being electrically connected to the bottom wall (14).

13. The single-cell battery according to claim 12, characterized in that, The single cell also includes a current collector (70), which is located between the bottom wall (14) and the second electrode (92). The current collector (70) is welded to both the bottom wall (14) and the second electrode (92); and / or The sidewall (11) is cylindrical, and the bottom wall (14) is provided with an injection hole (141). The injection hole (141) penetrates the bottom wall (14) and communicates with the receiving cavity (30). The single cell also includes a sealing cap (80), which is connected to the bottom wall (14) and seals the injection hole (141); and / or The bottom wall (14) is also provided with an explosion-proof groove, which is a blind groove, and the explosion-proof groove is located on the side of the bottom wall (14) away from the electrode assembly (90).

14. A battery pack, characterized in that, Including the single-cell battery as described in any one of claims 1-13.

Images