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 the electrode assembly is electrically connected with the shell; the end cover assembly comprises a first pole and an insulating ring, the first pole is electrically connected with the electrode assembly, the insulating ring is connected with the first pole and the side wall, the first pole is insulated from the side wall, and the first pole covers and seals the first cavity opening. In the embodiment of the invention, the arrangement of the first pole integrates the dual functions of covering and sealing the accommodating cavity and conducting output, 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] The application belongs to the technical field of single batteries, and particularly relates to a single battery and a battery pack. BACKGROUND

[0002] At present, the application of cylindrical single batteries in power automobiles is an industry hotspot, and the insulation sealing and overcurrent area design of the positive pole and the steel shell are important structure designs of the cylindrical single battery. The traditional insulation sealing mode of the positive pole and the steel shell of the cylindrical power single battery adopts a positive pole riveting mode, that is, the riveting process of the positive pole is used to embed an insulation rubber ring between the positive pole and the steel shell, so as to realize the insulation and sealing functions.

[0003] However, the riveting process limits the cross-sectional area of the positive pole. If the cross-sectional area of the positive pole is designed to be too large, the force acting on the steel shell is large during riveting, and the steel shell is easily deformed under stress, which causes damage to the workpiece, has a low yield rate, and the limit of the weldable area of the positive pole and the positive pole current collector plate in the industry can be about 19.63 mm2 (a circular welding area with a diameter of 5 mm). Taking a single battery with a traditional positive and negative penetration welding process as an example, the limit of the DCR internal resistance can be 2.0 milliohms, and the overcurrent capacity is limited, which limits the fast charging performance of the single battery. At the same time, the riveting process itself has certain disadvantages, such as, due to the large stress applied during riveting, the insulation gasket in the shell is easily deformed or cracked under stress, which causes damage to the workpiece. At the same time, based on the limited weldable area, the welding mode between the positive pole and the winding core end face cannot be realized, that is, the positive pole side cannot be designed without a current collector plate, and the cost cannot be further reduced. SUMMARY

[0004] The purpose of the embodiments of the application is to provide a single battery and a battery pack, which can solve at least part of the above problems.

[0005] In order to solve the above technical problems, the application is implemented as follows: In a first aspect, the embodiments of the application provide a single battery having a first direction, comprising: a shell, the shell comprising a side wall, the side wall being arranged in a ring shape and surrounding a containing cavity, the containing cavity having a first cavity opening at one end in the first direction; an electrode assembly, the electrode assembly being arranged in the containing cavity, the electrode assembly being electrically connected with the shell; a cover assembly, the cover assembly comprising a first pole and an insulation ring, the first pole being electrically connected with the electrode assembly, the insulation ring being arranged around the first pole, and the insulation ring being connected with the first pole and the side wall, the first pole and the side wall being insulated through the insulation ring, and the first pole covering the first cavity opening.

[0006] In this embodiment, the end cap assembly includes a first electrode post and an insulating ring. The first electrode post functions as a cover plate, not only as an electrode post but also as a seal for the first cavity opening. It is also insulated from the housing sidewall by the insulating ring. This design eliminates the current collector in traditional structures, making the first electrode post an integrated component for current conduction and cavity sealing. Furthermore, one end of the first electrode post is directly electrically connected to the electrode assembly, while the other end serves as the end cap body, sealing the cavity opening. Without the structural limitations of an additional current collector post, its dimensions can be flexibly designed according to actual current requirements, such as increasing the cross-sectional area to expand the welding contact area with external components. Moreover, the insulating ring provides insulation between the first electrode post and the housing sidewall, while simultaneously fixing their positions. This eliminates the need for excessive clamping force on the housing or insulating gasket to achieve a seal, avoiding the stress-based sealing design logic of traditional structures. The housing sidewall is annularly arranged to form a cavity, where the electrode assembly is located and directly electrically connected to the housing, forming a stable current loop foundation without interfering with the conduction path of the first electrode post.

[0007] Understandably, in the single-cell battery of this application embodiment, the first terminal post integrates the dual functions of sealing the receiving cavity and conducting output, eliminating the need for a traditional current collector. This reduces the material and assembly costs of single-cell battery production, simplifies the current conduction path, effectively reduces internal resistance, and thus reduces internal resistance loss and improves energy conversion efficiency while lowering the overall manufacturing cost of the single-cell battery. Furthermore, since the first terminal post is freed from the structural limitations of an additional current collector, its size can be flexibly designed according to actual needs. This allows for increased current-carrying area to meet fast-charging requirements, improving current throughput per unit time. It also enhances welding stability with external circuits by expanding the welding area, reducing contact resistance and significantly optimizing the fast-charging performance of the single-cell battery, avoiding overheating or performance limitations caused by insufficient current capacity.

[0008] Furthermore, the insulating ring achieves insulation and sealing between the first electrode and the side wall of the casing, eliminating the need to apply excessive stress to the casing or insulating gasket as in traditional structures. This design effectively avoids the risk of casing deformation and cracking due to excessive stress, while also preventing the insulating gasket from being damaged or failing to seal due to stress compression, thus significantly improving the structural stability and service life of the single cell.

[0009] In addition, the insulating ring ensures the insulation between the first terminal and the casing, eliminating the risk of leakage between them, further improving the electrical safety of the single cell, and avoiding energy loss or safety accidents caused by insulation failure.

[0010] Optionally, in this embodiment of the application, the housing further includes a first support portion, which is connected to the side wall and located within the receiving cavity. The first support portion is arranged in a ring shape. The insulating ring is connected to the side wall through the first support portion. In the first direction, the insulating ring is located on the side of the first support portion near the first cavity opening, and at least a portion of the electrode assembly is located on the side of the first support portion away from the first cavity opening.

[0011] Optionally, in this embodiment, the single cell also has a circumferential direction; the insulating ring is threadedly connected to the first electrode post, and the housing further includes a first limiting part, which is disposed on at least one of the side wall and the first support part, and the first limiting part is used to restrict the rotation of the insulating ring in the circumferential direction.

[0012] Optionally, in this embodiment, the first limiting part is disposed on the first supporting part, the first limiting part is located on the side of the first supporting part away from the side wall, and the first limiting part is bent relative to the first supporting part, and the first limiting part abuts against the side of the insulating ring facing the first pole post.

[0013] Optionally, in an embodiment of this application, the insulating ring is provided with a first limiting groove, the first limiting groove is provided on the side of the insulating ring facing the electrode assembly, at least a portion of the first limiting part is located in the first limiting groove and abuts against the groove wall of the first limiting groove; and / or, the first limiting part is provided with a plurality of portions and is spaced apart along the circumferential direction.

[0014] Optionally, in this embodiment, the single cell further has a radial direction, which is perpendicular to the first direction; the inner circumferential side of the insulating ring is provided with a first threaded portion and a first stop portion, the first threaded portion is provided on the side of the first stop portion away from the electrode assembly, the first stop portion is provided on the side of the first limiting groove away from the electrode assembly, and the first stop portion protrudes along the radial direction toward the first electrode post; the outer circumferential side of the first electrode post is provided with a second threaded portion, the side of the second threaded portion facing the electrode assembly is provided with a first stop portion, the second threaded portion is threadedly connected to the first threaded portion, and the first stop portion and the first stop portion are in a limiting engagement in the first direction.

[0015] Optionally, in an embodiment of this application, a second stop portion is provided on the outer periphery of the first electrode post. The second stop portion is disposed on the side of the second screw portion away from the electrode assembly. The second stop portion protrudes in the radial direction away from the first electrode post and abuts against the insulating ring in the first direction.

[0016] Optionally, in this embodiment, the second stop portion is arranged in a ring shape, and the second stop portion and the insulating ring are spaced apart in the radial direction, forming a first groove between the second stop portion, the insulating ring and the sidewall; the single cell also includes a sealing member, which is accommodated in the first groove.

[0017] Optionally, in this embodiment, the insulating ring is provided with a groove, the groove is located on the side of the insulating ring away from the electrode assembly, and the groove communicates with the first groove; the sealant is a sealant, and the sealant is accommodated in the first groove and the groove.

[0018] 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.

[0019] Optionally, in this embodiment, the receiving cavity further has a second opening in the first direction, 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.

[0020] 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.

[0021] Secondly, in this application embodiment, a single-cell battery pack is also provided, including the single-cell battery as described above. Attached Figure Description

[0022] 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 2Enlarged schematic diagram of the middle section structure; Figure 4 This 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.

[0023] Explanation of reference numerals in the attached figures: 10. Housing; 11. Side wall; 111. First cavity opening; 112. Second cavity opening; 12. First support part; 13. First limiting part; 14. Bottom wall; 141. Injection hole; 20. End cap assembly; 21. First pole post; 211. Second screw connection part; 212. First stop part; 213. Second stop part; 214. Welding groove; 215. Fastening groove; 22. Insulating ring; 221. First limiting groove; 222. First screw connection part; 223. First stop part; 224. Groove; 30. Receiving cavity; 40. First groove; 50. Seal; 60. Collector plate; 70. Sealing cover; 80. Electrode assembly; 81. First electrode tab; 82. Second electrode tab; Z, First direction; C, circumferential direction; R, radial direction. Detailed Implementation

[0024] 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.

[0025] 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.

[0026] The following detailed description, in conjunction with the accompanying drawings, of the individual battery cells and battery packs provided in this application through specific embodiments and application scenarios, will be provided in detail.

[0027] See Figures 1 to 10 The embodiments of this application provide a single-cell battery having 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 opening 111 on one side of the first direction Z; an electrode assembly 80, the electrode assembly 80 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 being electrically connected to the electrode assembly 80, the insulating ring 22 being disposed around the first electrode post 21, and the insulating ring 22 being connected to the first electrode post 21 and the sidewall 11, the first electrode post 21 and the sidewall 11 being insulated from each other by the insulating ring 22, and the first electrode post 21 sealing the first opening 111.

[0028] In this embodiment, the end cap assembly 20 includes a first electrode post 21 and an insulating ring 22. The first electrode post 21 functions as a cover plate, serving not only as an electrode post but also sealing the first cavity opening 111. It forms an insulated connection with the side wall 11 of the housing 10 via the insulating ring 22. This design eliminates the need for a current collector 60 connected to the first electrode post 21 in traditional structures, making the first electrode post 21 an integrated component for current conduction and cavity sealing. Furthermore, one end of the first electrode post 21 is directly electrically connected to the electrode assembly 80, while the other end serves as the end cap body sealing the cavity. Without the structural limitations of an additional current collector 60, its dimensions can be flexibly designed according to actual current requirements, such as increasing the cross-sectional area to expand the welding contact area with external components. Furthermore, the insulating ring 22 achieves insulation isolation between the first electrode post 21 and the side wall 11 of the housing 10. Simultaneously, the insulating ring 22's connecting effect fixes their positions, eliminating the need for excessive clamping force on the housing 10 or insulating gaskets to achieve a seal, thus avoiding the stress-based sealing design logic of traditional structures. The side wall 11 of the housing 10 forms a ring-shaped cavity 30, within which the electrode assembly 80 is located and directly electrically connected to the housing 10, forming a stable current loop foundation without interfering with the conduction path of the first electrode post 21.

[0029] Understandably, in the single-cell battery of this application embodiment, the first terminal 21 integrates the dual functions of sealing the receiving cavity 30 and conducting output, eliminating the need for the current collector 60 connected to the first terminal 21. This reduces the material cost and assembly process cost of the single-cell battery production, simplifies the current conduction path, effectively reduces the conduction internal resistance, and thus reduces internal resistance loss and improves energy conversion efficiency while reducing the overall manufacturing cost of the single-cell battery. Furthermore, since the first terminal 21 is freed from the structural limitations of the additional current collector 60, its size can be flexibly designed according to actual needs. This allows for increased current-carrying area to meet fast-charging requirements, improving the current-carrying capacity per unit time. It also enhances welding stability with external circuits by expanding the welding area, reducing contact resistance and significantly optimizing the fast-charging performance of the single-cell battery, avoiding overheating or performance limitations caused by insufficient current-carrying capacity.

[0030] Furthermore, the insulating ring 22 achieves insulation and sealing between the first electrode post 21 and the side wall 11 of the housing 10, eliminating the need to apply excessive stress to the housing 10 or insulating gasket as in traditional structures. This design effectively avoids the risk of deformation and cracking of the housing 10 due to excessive stress, while also preventing the insulating gasket from being damaged or failing to seal due to stress compression, thus significantly improving the structural stability and service life of the single cell.

[0031] In addition, the insulating ring 22 ensures the insulation between the first terminal 21 and the casing 10, eliminates the risk of leakage between them, further improves the electrical safety of the single battery, and avoids energy loss or safety accidents caused by insulation failure.

[0032] Optionally, in this embodiment, the housing 10 further includes a first support portion 12, which is connected to the side wall 11 and located within the receiving cavity 30. The first support portion 12 is arranged in a ring shape. An insulating ring 22 is connected to the side wall 11 through the first support portion 12. In the first direction Z, the insulating ring 22 is located on the side of the first support portion 12 near the first cavity opening 111, and at least a portion of the electrode assembly 80 is located on the side of the first support portion 12 away from the first cavity opening 111.

[0033] In this embodiment, the first support portion 12 is directly connected to the annular sidewall 11 of the housing 10, and is entirely located within the receiving cavity 30 formed by the sidewall 11. It is also annular in shape, forming a ring-shaped support structure within the receiving cavity 30. The insulating ring 22, in addition to connecting the first electrode post 21 to the sidewall 11 of the housing 10, is also connected to the first support portion 12. In the first direction Z of the single battery cell, the insulating ring 22 is located on the side of the first support portion 12 closest to the first cavity opening 111, forming a fixed, vertical connection between the two. At least a portion of the electrode assembly 80 is located on the side of the first support portion 12 away from the first cavity opening 111. That is, the first support portion 12 separates the electrode assembly 80 from the insulating ring 22 and the first electrode post 21 near the cavity opening in different areas within the receiving cavity 30, forming an axial spatial partition.

[0034] In this embodiment, the first support portion 12, connected to the insulating ring 22, provides additional annular support for the insulating ring 22. It also provides upward support along the first direction Z, preventing uneven stress and swaying issues that might occur if the insulating ring 22 relies solely on its connection to the sidewall 11. Simultaneously, the annular support structure evenly distributes the pressure from the first pole post 21 on the insulating ring 22, further ensuring the structural integrity of the insulating ring 22 during long-term use and reducing the risk of insulation failure due to displacement or deformation of the insulating ring 22. Furthermore, the first support portion 12 forms an axial partition within the receiving cavity 30, confining at least a portion of the electrode assembly 80 to a region away from the first cavity opening 111. On the one hand, this prevents the electrode assembly 80 from shifting towards the first cavity opening 111 during the assembly or use of a single battery cell, preventing accidental contact with the insulating ring 22 and the first electrode post 21, thus ensuring electrical safety. On the other hand, the annular first support portion 12 can provide a slight circumferential C-shaped limit to the electrode assembly 80, reducing the shaking of the electrode assembly 80 caused by external factors such as vibration, and lowering the probability of damage to the internal structure of the electrode assembly 80.

[0035] Furthermore, the first support portion 12 connects the sidewall 11 and the insulating ring 22, forming an additional force transmission channel from the sidewall 11 to the insulating ring 22. When the single cell is subjected to external impact or internal pressure changes, the first support portion 12 can share some of the force, avoiding stress concentration at the connection between the sidewall 11 and the insulating ring 22, while reducing the direct pressure of the insulating ring 22 on the electrode assembly 80, further improving the impact resistance and long-term stability of the entire single cell structure.

[0036] Optionally, in this embodiment of the application, the single cell also has a circumferential C; the insulating ring 22 is connected to the first terminal post 21 by a thread, and the housing 10 also includes a first limiting part 13, which is disposed in at least one of the side wall 11 and the first support part 12, and the first limiting part 13 is used to limit the rotation of the insulating ring 22 in the circumferential C.

[0037] In this embodiment, the insulating ring 22 and the first pole post 21 are fixedly assembled through threaded engagement, replacing possible snap-fit ​​or interference fit connection methods. This threaded connection structure is located within the mating area of ​​the first pole post 21 and the insulating ring 22, and does not affect the connection between the insulating ring 22 and the side wall 11 or the first support portion 12. The first limiting portion 13 is provided at least once in either the side wall 11 or the first support portion 12. In practical applications, the first limiting portion 13 may be in the shape of a protrusion or boss, and its position corresponds to the circumferential C edge of the insulating ring 22, enabling it to form a circumferential C engaging or abutting fit with the insulating ring 22, thereby restricting the rotation of the insulating ring 22 in the circumferential C direction. This embodiment does not limit this aspect. The insulating ring 22 is connected to the first pole post 21 by a thread, and has a potential tendency to rotate in the circumferential direction C. On the other hand, the first limiting part 13 of the housing 10 forms a circumferential C constraint on the insulating ring 22 from the outside. The two work together to build a dual fixing structure of threaded connection and circumferential C limiting, while not destroying the positional stability and insulation function of the insulating ring 22 in the first direction Z.

[0038] In practical applications, to prevent the threads of the insulating ring 22 and the first terminal 21 from loosening and to ensure connection reliability, the aforementioned double fixing structure is adopted. Because the insulating ring 22 and the first terminal 21 are threaded together, during the assembly, transportation, or use of a single battery cell, external factors such as vibration and impact can easily cause the threads to loosen circumferentially (C-direction). The first limiting part 13 can effectively restrict the circumferential rotation (C-direction) of the insulating ring 22, fundamentally preventing relative rotation at the thread engagement point. This avoids connection failure between the first terminal 21 and the insulating ring 22 due to thread loosening, thereby ensuring the sealing performance of the first terminal 21 and the stability of current conduction.

[0039] Furthermore, the circumferential C-rotation of the insulating ring 22 can not only cause the threads to loosen, but may also cause its mating position with the side wall 11 and the first support 12 to shift, damaging the sealing surface and insulation gap between the insulating ring 22 and these components. The first limiting part 13 can also limit the circumferential C-rotation of the insulating ring 22, ensuring that the insulating ring 22 is always in the preset assembly position, keeping the sealing contact surface with the side wall 11 and the first support 12 intact, and maintaining the insulation gap with the first pole post 21 and the housing 10 within the design range, effectively avoiding problems such as insulation failure caused by the displacement of the insulating ring 22.

[0040] It should also be noted that the threaded connection facilitates the rapid assembly of the insulating ring 22 and the first terminal post 21, eliminating the need for complex tools or high-precision interference fit control. Simultaneously, the first limiting part 13 provides a circumferential C positioning reference for the insulating ring 22 during assembly, eliminating the need for repeated adjustments to the circumferential C angle of the insulating ring 22, thus achieving precise assembly. This simplifies the assembly process, reduces operational difficulty, minimizes connection errors, and improves the production efficiency and product quality consistency of individual cells.

[0041] Optionally, in this embodiment, the first limiting part 13 is disposed on the first support part 12. The first limiting part 13 is located on the side of the first support part 12 away from the side wall 11, and the first limiting part 13 is bent relative to the first support part 12. The first limiting part 13 abuts against the side of the insulating ring 22 facing the first pole post 21.

[0042] In this embodiment, the first limiting part 13 is disposed in the inner edge region of the first support part 12, rather than in the outer region near the side wall 11 of the housing 10, so that the limiting part can directly act on the inner side of the insulating ring 22, avoiding structural interference with the side wall 11. Specifically, the first limiting part 13 does not extend in a plane with the first support part 12, but adopts a relatively bent structural design, such as bending at a certain angle towards the insulating ring 22. The free end after bending directly forms physical contact with the surface of the insulating ring 22, and the contact surface mainly acts on the circumferential C-side surface or axial end surface of the insulating ring 22, which can construct circumferential C-rotation constraint through hard contact.

[0043] In this embodiment, the first limiting part 13 is positioned away from the side wall 11, avoiding processing and assembly conflicts with the side wall 11 of the housing 10, protecting the structural integrity of the side wall 11, and also reserving sufficient space for the sealing gap between the insulating ring 22 and the side wall 11. This eliminates the need to compress the sealing area to accommodate the limiting structure, indirectly ensuring the sealing effect between the insulating ring 22 and the side wall 11. Simultaneously, the contact after bending is a line contact or a small-area contact. Compared to a surface-to-surface contact limiting structure, this places lower requirements on the flatness of the insulating ring 22 surface, reducing the processing accuracy and assembly tolerance requirements for the insulating ring 22 and the limiting part, and minimizing limiting failure problems caused by tolerance mismatch. Finally, the first limiting part 13 engages with the insulating ring 22 by abutting with its bent end rather than by completely wrapping it. The contact area is relatively small, and the contact force is concentrated on the circumferential C-side of the insulating ring 22. This avoids wear or indentation on the surface of the insulating ring 22 due to large-area contact. In particular, it protects the sealing surface accuracy of the insulating ring 22 in conjunction with the first pole post 21 and the first support part 12, reduces the risk of sealing failure caused by contact of the limiting structure, and extends the functional life of the insulating ring 22.

[0044] Optionally, in this embodiment of the application, the insulating ring 22 is provided with a first limiting groove 221, the first limiting groove 221 is provided on the side of the insulating ring 22 facing the electrode assembly 80, at least a portion of the first limiting part 13 is located in the first limiting groove 221 and abuts against the groove wall of the first limiting groove 221; and / or, the first limiting part 13 is provided with a plurality of parts and is spaced apart along the circumferential direction C.

[0045] In this embodiment, the first limiting groove 221 is located on the side of the insulating ring 22 facing the electrode assembly 80, that is, below the insulating ring 22 and away from the first cavity 111. At least part of the structure of the first limiting part 13, such as the bent free end, is embedded in the first limiting groove 221 and forms a tight abutment with the groove wall of the first limiting groove 221, such as the circumferential C groove wall or the radial R groove wall, to construct a fitting limiting structure of the protrusion and the groove 224.

[0046] Furthermore, the first limiting part 13 is not a single setting, but multiple settings are provided, and all the first limiting parts 13 are evenly spaced along the circumferential direction C of the first support part 12, for example, 3 or 4, spaced at 90° or 120° intervals. This embodiment does not limit the specific setting and can be determined according to the actual situation. Each first limiting part 13 independently forms abutment or fits with the insulating ring 22 or the first limiting groove 221, together forming a multi-point constraint system in the circumferential direction C.

[0047] In practical applications, compared to simply having the bent end abut against the surface of the insulating ring 22, the fitting structure of the first limiting groove 221 and the first limiting part 13 can form a dual constraint of circumferential C-shaped anti-rotation and radial R-shaped anti-displacement: the circumferential C-groove wall directly blocks the rotation of the limiting part, preventing the insulating ring 22 from shifting circumferentially due to vibration. The radial R-groove wall restricts the insulating ring 22 from shifting in the radial direction, preventing the threaded connection between the insulating ring 22 and the first pole post 21 from loosening due to radial R-shaped misalignment, thus completely eliminating sealing failure or poor conductivity caused by loose threads. Specifically, the axial groove wall of the first limiting groove 221, i.e., the upper groove wall, can form an axial abutment with the first limiting part 13, restricting the displacement of the insulating ring 22 in the first direction Z. This prevents the insulating ring 22 from shifting towards the first cavity 111, avoiding separation from the sealing surface of the first electrode post 21 and ensuring a sealing effect. It also prevents the insulating ring 22 from shifting towards the electrode assembly 80, avoiding compression of the electrode assembly 80 and causing deformation or damage to its internal structure. No additional axial fixing components are needed, simplifying the structure while improving assembly accuracy. Furthermore, the first limiting groove 221 can serve as a positioning base during assembly. By aligning the first part with the first groove 40 and pressing it during assembly, the circumferential C and axial positioning of the insulating ring 22 can be completed. There is no need to repeatedly calibrate the angle and position, greatly reducing the difficulty of assembly operations. At the same time, the guiding nature of the interlocking structure can reduce jamming during assembly, increase assembly speed, and thus improve the production efficiency of single cells.

[0048] In this embodiment, the arrangement of multiple first limiting portions 13 can evenly distribute the force generated when the insulating ring 22 rotates or the stress from external impacts to each first limiting portion 13, preventing a single first limiting portion 13 from bending, breaking, or deforming due to concentrated force. Simultaneously, multi-point force application reduces localized pressure on the insulating ring 22, preventing cracks or wear caused by excessive force at a single point, and extending the service life of the insulating ring 22 and the first support portion 12. Even if individual first limiting portions 13 are accidentally damaged, such as breaking at the bent end, the remaining first limiting portions 13 can still continue to provide circumferential C-shaped constraint, preventing the overall limiting function from being lost due to the failure of a single first limiting portion 13. This significantly improves the structure's resilience and ensures the long-term stable operation of the individual battery cells.

[0049] Optionally, in this embodiment, the single cell further has a radial direction R, which is perpendicular to the first direction Z; the inner circumferential side of the insulating ring 22 is provided with a first threaded portion 222 and a first stop portion 223, the first threaded portion 222 is located on the side of the first stop portion 223 away from the electrode assembly 80, the first stop portion 223 is located on the side of the first limiting groove 221 away from the electrode assembly 80, and the first stop portion 223 protrudes along the radial direction R towards the first electrode post 21; the outer circumferential side of the first electrode post 21 is provided with a second threaded portion 211, and the side of the second threaded portion facing the electrode assembly 80 is provided with a first stop portion 212, the second threaded portion 211 is threadedly connected to the first threaded portion 222, and the first stop portion 212 and the first stop portion 223 are in a limiting engagement in the first direction Z.

[0050] In this embodiment, the inner circumferential side of the insulating ring 22 is provided with a first threaded portion 222 and a first stop portion 223. Viewed from the first direction Z, the first threaded portion 222 is located on the side of the first stop portion 223 away from the electrode assembly 80, that is, closer to the first cavity 111. The first stop portion 223 is provided on the side of the first limiting groove 221 away from the electrode assembly 80, and the first stop portion 223 protrudes along the radial direction R towards the first pole post 21, forming a protruding structure facing the center of the radial direction R, which can cooperate with the outer circumferential structure of the first pole post 21.

[0051] Furthermore, a second threaded portion 211 and a first stop portion 212 are provided on the outer periphery of the first pole post 21, that is, on the side near the insulating ring 22. The second threaded portion 211 and the first threaded portion 222 form a threaded connection to achieve a fixed assembly of the two. The first stop portion 212 forms a limiting engagement with the first stop portion 223 of the insulating ring 22 in the first direction Z, that is, the two abut against each other in the axial direction to limit the axial relative displacement between the first pole post 21 and the insulating ring 22.

[0052] In this embodiment, the first stop portion 223 of the insulating ring 22 and the first stop portion 212 of the first pole post 21 form a rigid abutment in the first direction Z. When the first pole post 21 is threadedly engaged with the first threaded portion 222 of the insulating ring 22 through the second screw portion 211, as the engagement depth increases, the first stop portion 212 will eventually abut against the first stop portion 223, preventing further engagement. The above arrangement can adjust the axial assembly depth of the first pole post 21 and the insulating ring 22, avoiding deformation of the insulating ring 22 due to excessive engagement, or loose sealing surface contact due to insufficient engagement, thus ensuring assembly consistency and structural integrity.

[0053] Furthermore, the axial limiting fit between the first stop portion 223 and the first stop portion 212 compensates for the insufficient fixation of the threaded connection in the first direction Z. The threaded connection mainly resists circumferential rotation C, while the contact structure of the two can directly withstand axial forces, such as external tension or internal pressure of the first electrode post 21, preventing the first electrode post 21 from loosening or shifting in the axial direction, thereby preventing the sealing surface of the first electrode post 21 from separating from the insulating ring 22 and the threaded connection from loosening, significantly improving the long-term stability of the connection between the two.

[0054] Furthermore, the first stop portion 223 protrudes radially towards the first electrode post 21, and its mating surface with the first stop portion 212 not only provides axial restraint but also provides a certain degree of support in the radial direction. When a single battery cell is subjected to radial impact or vibration, the first stop portion 223 and the first stop portion 212 can share part of the radial force, preventing the entire radial force from being borne by the threaded engagement of the first threaded portion 222 and the second threaded portion 211. This reduces wear or deformation of the threaded teeth, protects the integrity of the threaded structure, and extends the service life of the threaded connection.

[0055] Optionally, in this embodiment, a second stop portion 213 is provided on the outer periphery of the first pole post 21. The second stop portion 213 is disposed on the side of the second screw portion 211 away from the electrode assembly 80. The second stop portion 213 protrudes in the radial direction R away from the first pole post 21 and abuts against the insulating ring 22 in the first direction Z.

[0056] In this embodiment, a second stop portion 213 is also provided on the outer periphery of the first electrode post 21. From an axial position perspective, the second stop portion 213 is located on the side of the second screw connection portion 211 away from the electrode assembly 80, that is, closer to the first cavity opening 111 than the second screw connection portion 211. The second stop portion 213 protrudes radially R in a direction away from the first electrode post 21, which is opposite to the direction of the first stop portion 223 protruding towards the first electrode post 21. The second stop portion 213 directly abuts against the corresponding end face of the insulating ring 22 in the first direction Z, that is, the end face of the insulating ring 22 near the first cavity opening 111.

[0057] In this embodiment, the second stop portion 213213 and the first stop portion 212212 are located on both sides of the second screw portion 211. The second stop portion 213 is on the side away from the electrode assembly 80, and the first stop portion 212 is on the side closer to the electrode assembly 80, and both form axial contact with the insulating ring 22. The second stop portion 213 abuts against the end face of the insulating ring 22 near the first cavity opening 111, and the first stop portion 212 abuts against the first stop portion 223 of the insulating ring 22. The above arrangement avoids the problem of the first pole post 21 coming out of the cavity opening or going too deep into the cavity due to axial force. Compared with a single stop structure, the limiting stability is greatly improved.

[0058] Optionally, in this embodiment, the second stop portion 213 is arranged in a ring shape, and the second stop portion 213 and the insulating ring 22 are spaced apart in the radial direction R. A first groove 40 is formed between the second stop portion 213, the insulating ring 22 and the side wall 11; the single cell also includes a sealing member 50, which is accommodated in the first groove 40.

[0059] In this embodiment, the second stop portion 213 is arranged in a ring shape and is spaced apart from the insulating ring 22 in the radial direction R, meaning that the two do not contact each other in the radial direction R, and there is an annular gap. The aforementioned gap, combined with the side wall 11, causes the second stop portion 213, the insulating ring 22, and the side wall 11 to form an annular first groove 40. The cross-section of the first groove 40 can be U-shaped and continuously distributed along the circumferential direction C. The single cell is also equipped with a sealing element 50, such as sealant, which is completely contained within the first groove 40 and is tightly fitted with the groove wall of the first groove 40, that is, with the radial inner side wall of the second stop portion 213, the radial outer side wall of the insulating ring 22, and the radial inner side wall of the side wall 11, without any obvious gap.

[0060] In this embodiment, the sealing element 50 within the first groove 40 fits tightly against the groove wall, forming an annular sealing barrier at the gaps. This prevents electrolyte or gas inside the single battery from leaking out through the first cavity opening 111, while also preventing external moisture and dust from entering the receiving cavity 30. The aforementioned sealing element 50, together with the existing seal between the insulating ring 22 and the first terminal post 21, forms a double seal, significantly improving the leak-proof, waterproof, and dustproof capabilities of the single battery, making it particularly suitable for use in high-humidity and harsh environments.

[0061] Furthermore, the annular first groove 40 provides precise accommodating space for the seal 50, restricting its displacement in the circumferential direction (C), axial direction, and radial direction (R). This prevents the seal 50 from detaching or shifting due to vibration or temperature changes in the individual battery cells, ensuring that the seal 50 always maintains a tight fit with the groove wall. In addition, the seal 50 not only blocks the flow of liquids and gases but also isolates external corrosive substances, such as salts and chemical reagents, from contact with the insulating ring 22 and sidewall 11, reducing structural damage to these components caused by corrosion, such as rusting of the sidewall 11 and aging of the insulating ring 22. At the same time, the seal 50 also buffers the radial friction (R) between the second stop portion 213 and the insulating ring 22 and sidewall 11, preventing wear caused by long-term friction and further protecting the integrity of the internal structure.

[0062] Optionally, in this embodiment, the insulating ring 22 is provided with a groove 224, which is located on the side of the insulating ring 22 away from the electrode assembly 80, and the groove 224 communicates with the first groove 40; the sealing member 50 is a sealant, which is contained in the first groove 40 and the groove 224.

[0063] In this embodiment, the insulating ring 22 is provided with a groove 224. The groove 224 is located on the side of the insulating ring 22 away from the electrode assembly 80, that is, on the same end face that abuts against the second stop portion 213, and the groove 224 is distributed in a ring shape along the circumferential direction C. The radial dimension R of the groove 224 matches the first groove 40, so that the groove 224 and the first groove 40 are connected in the axial direction, and the two together form a continuous "L"-shaped or "T"-shaped extended accommodating space. The sealing element 50 is a sealant, which can be liquid silicone, epoxy resin, etc. The sealant not only completely fills the first groove 40, but also fully accommodates in the connected groove 224. After curing, it is tightly bonded to the groove wall of the first groove 40 and the groove wall of the groove 224, forming an integral sealing structure that covers the gap and the groove 224 on the end face of the insulating ring 22.

[0064] In this embodiment, after the groove 224 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 224, 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.

[0065] Optionally, in this embodiment, the first pole post 21 is provided with a welding groove 214 on the side away from the electrode assembly 80, and the bottom wall of the welding groove 214 is welded to the electrode assembly 80; the first pole post 21 is also provided with a fastening groove 215, which is located on the bottom wall of the welding groove 214, and the fastening groove 215 is a blind groove, and the fastening groove 215 is configured to cooperate with an auxiliary tool and rotate the first pole post 21.

[0066] In this embodiment, the electrode assembly 80 and the welding groove 214 are connected by through welding. The groove structure of the welding groove 214 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 215, which is formed on the bottom wall of the welding groove 214 and is a blind groove. It is understood that the fastening groove 215 does not penetrate the first electrode post 21. The cross-section of the fastening groove 215 can be hexagonal, cross-shaped, or slotted, etc. The fastening groove 215 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.

[0067] Optionally, in this embodiment, the receiving cavity 30 further has a second cavity 112 in the first direction Z, and the second cavity 112 and the first cavity 111 are respectively located on opposite sides of the receiving cavity 30 in the first direction Z; the housing 10 further includes a bottom wall 14, which is connected to the side wall 11 and closes the second cavity 112; the electrode assembly 80 has a first electrode tab 81 and a second electrode tab 82, the first electrode tab 81 is electrically connected to the first electrode post 21, and the second electrode tab 82 is electrically connected to the bottom wall 14.

[0068] In this embodiment, the sidewall 11 is further provided with a second cavity 112. The second cavity 112 and the first cavity 111 are located on opposite sides of the sidewall 11 along the first direction Z, and the second cavity 112 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 112 and completely seals the second cavity 112, so that the sidewall 11 and the bottom wall 14 together form a complete sealed receiving cavity 30 for accommodating the electrode assembly 80. The electrode assembly 80 has a first tab 81 and a second tab 82. The first tab 81 is electrically connected to the first electrode post 21 by welding to the bottom wall of the welding groove 214, and the second tab 82 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.

[0069] Optionally, in this embodiment, the single cell further includes a current collector 60, which is located between the bottom wall 14 and the second tab 82. The current collector 60 is welded to both the bottom wall 14 and the second tab 82. 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 70, 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 80.

[0070] In this embodiment, the current collector 60 is located between the bottom wall 14 and the second tab 82, and is welded to both, forming a conductive transition structure from the second tab 82 to the current collector 60 and then to the bottom wall 14. The current collector 60 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 section, making the receiving cavity 30 a cylindrical space that fits the shape of the wound electrode assembly 80, 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 70, 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 80. 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 70.

[0071] Secondly, in this application embodiment, a single-cell battery pack is also provided, including the single-cell battery as described above.

[0072] In this embodiment, the single-cell battery pack includes the single-cell battery as described above, and also includes all the structural features and beneficial effects of the single-cell battery, which will not be repeated here.

[0073] 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.

[0074] 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 opening (111) at one end in the first direction (Z). An electrode assembly (80) is disposed in the receiving cavity (30) and is 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 electrically connected to the electrode assembly (80), the insulating ring (22) is arranged around the first pole post (21), and the insulating ring (22) is connected to 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), and the first pole post (21) covers the first cavity (111).

2. The single-cell battery according to claim 1, characterized in that, The housing (10) further includes a first support (12), which is connected to the side wall (11) and located in the receiving cavity (30). The first support (12) is arranged in a ring shape. The insulating ring (22) is connected to the sidewall (11) via the first support (12). In the first direction (Z), the insulating ring (22) is located on the side of the first support (12) near the first cavity (111), and at least a portion of the electrode assembly (80) is located on the side of the first support (12) away from the first cavity (111).

3. The single-cell battery according to claim 2, characterized in that, The single cell also has a circumferential (C) orientation; the insulating ring (22) is threadedly connected to the first electrode post (21), and the housing (10) further includes a first limiting part (13), which is disposed on at least one of the side wall (11) and the first support part (12), and the first limiting part (13) is used to limit the rotation of the insulating ring (22) in the circumferential (C) orientation.

4. The single-cell battery according to claim 3, characterized in that, The first limiting part (13) is provided on the first support part (12). The first limiting part (13) is located on the side of the first support part (12) away from the side wall (11), and the first limiting part (13) is bent relative to the first support part (12). The first limiting part (13) abuts against the side of the insulating ring (22) facing the first pole post (21).

5. The single-cell battery according to claim 4, characterized in that, The insulating ring (22) is provided with a first limiting groove (221), the first limiting groove (221) is provided on the side of the insulating ring (22) facing the electrode assembly (80), and at least a portion of the first limiting part (13) is located in the first limiting groove (221) and abuts against the groove wall of the first limiting groove (221). And / or, the first limiting part (13) is provided with a plurality of such parts and is spaced apart along the circumferential direction (C).

6. The single-cell battery according to claim 5, characterized in that, The single cell also has a radial direction (R), which is perpendicular to the first direction (Z); the inner circumferential side of the insulating ring (22) is provided with a first screw portion (222) and a first stop portion (223), the first screw portion (222) is located on the side of the first stop portion (223) away from the electrode assembly (80), the first stop portion (223) is located on the side of the first limiting groove (221) away from the electrode assembly (80), and the first stop portion (223) protrudes along the radial direction (R) towards the first electrode post (21); The outer periphery of the first pole post (21) is provided with a second threaded part (211), and the second threaded part (211) is provided with a first stop part (212) on the side facing the electrode assembly (80). The second threaded part (211) is threadedly connected to the first threaded part (222), and the first stop part (212) and the first stop part (223) are engaged in a stop cooperation in the first direction (Z).

7. The single-cell battery according to claim 6, characterized in that, The outer periphery of the first pole post (21) is provided with a second stop portion (213). The second stop portion (213) is located on the side of the second screw portion (211) away from the electrode assembly (80). The second stop portion (213) protrudes in the radial direction (R) away from the first pole post (21). The second stop portion (213) abuts against the insulating ring (22) in the first direction (Z).

8. The single-cell battery according to claim 7, characterized in that, The second stop portion (213) is arranged in a ring shape, and the second stop portion (213) and the insulating ring (22) are spaced apart in the radial direction (R). A first groove (40) is formed between the second stop portion (213), the insulating ring (22) and the side wall (11); the single cell also includes a sealing member (50), which is accommodated in the first groove (40).

9. The single-cell battery according to claim 8, characterized in that, The insulating ring (22) is provided with a groove (224), the groove (224) is located on the side of the insulating ring (22) away from the electrode assembly (80), and the groove (224) communicates with the first groove (40); the sealing element (50) is a sealant, and the sealant is contained in the first groove (40) and the groove (224).

10. The single-cell battery according to any one of claims 1-9, characterized in that, The first electrode post (21) has a welding groove (214) on the side away from the electrode assembly (80), and the bottom wall of the welding groove (214) is welded to the electrode assembly (80); The first pole post (21) is also provided with a fastening groove (215), which is located on the bottom wall of the welding groove (214), and the fastening groove (215) is a blind groove. The fastening groove (215) is configured to cooperate with an auxiliary tool and rotate the first pole post (21).

11. The single-cell battery according to claim 10, characterized in that, The receiving cavity (30) also has a second opening (112) in the first direction (Z), the second opening (112) and the first opening (111) are respectively located on opposite sides of the receiving cavity (30) along the first direction (Z); the housing (10) also includes a bottom wall (14), the bottom wall (14) is connected to the side wall (11) and closes the second opening (112). The electrode assembly (80) has a first tab (81) and a second tab (82), the first tab (81) being electrically connected to the first post (21), and the second tab (82) being electrically connected to the bottom wall (14).

12. The single-cell battery according to claim 11, characterized in that, The single cell also includes a current collector (60), which is located between the bottom wall (14) and the second electrode (82). The current collector (60) is welded to both the bottom wall (14) and the second electrode (82); 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 battery also includes a sealing cap (70), 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 (80).

13. A battery pack, characterized in that, Including the single cell battery as described in any one of claims 1-12.

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