A single battery and a battery pack

Abstract

This application provides a single-cell battery and a battery pack. The single-cell battery includes: a housing having a receiving cavity; a top cover plate connected to the housing and having tab holes; an electrode assembly connected to the side of the top cover plate away from the receiving cavity; and an electrode core assembly including an electrode core body and tabs. The electrode core body is disposed within the receiving cavity, the tabs are connected to the electrode core body and include a first connecting surface, the tabs at least partially passing through the tab holes, and the first connecting surface is connected to the electrode core assembly. The single-cell battery also has a first projection plane perpendicular to a second direction and / or a third direction, and the orthographic projection of the first connecting surface onto the first projection plane lies within the orthographic projection of the top cover plate onto the first projection plane. In this application embodiment, on the one hand, more space is freed up on the side of the top cover plate closest to the receiving cavity to improve the energy density of the single-cell battery; on the other hand, the overall height of the single-cell battery is effectively controlled, which is beneficial for reducing the overall size of the single-cell battery.

Description

Technical Field

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

[0002] In a single battery cell, the electrode core is the core energy storage component, and its size is closely related to the energy density of the single battery cell.

[0003] However, due to the trend of miniaturization of batteries and the limitation of battery installation space, it is difficult to increase the height of a single battery cell, which limits the increase in the size of the electrode core and, to some extent, restricts the improvement of the energy density of a single battery cell. Summary of the Invention

[0004] This application aims to provide a single-cell battery and a battery pack that at least solves the problem of insufficient energy density of single-cell batteries.

[0005] To solve the above-mentioned technical problems, this application is implemented as follows: In a first aspect, embodiments of this application propose a single-cell battery having a first direction, a second direction, and a third direction that are perpendicular to each other, wherein the single-cell battery includes: The housing has a receiving cavity, and one end of the receiving cavity has an opening along the first direction; A top cover plate is connected to the housing and seals the opening, and includes a first side and a second side that are opposite to each other along the first direction. The first side is disposed opposite to the receiving cavity. The top cover plate is provided with an electrode hole that penetrates the first side and the second side along the first direction. The pole assembly is connected to the first side of the top cover plate; The electrode assembly includes an electrode body and an electrode tab. The electrode body is disposed within the receiving cavity, and the electrode tab is connected to the end of the electrode body near the opening. The electrode tab includes a first connecting surface, and the electrode tab at least partially passes through the electrode tab hole. The first connecting surface is connected to the electrode post assembly. The single battery cell also has a first projection plane perpendicular to the second direction or the third direction. The orthographic projection of the first connecting surface onto the first projection plane is the first projection, and the orthographic projection of the top cover onto the first projection plane is the second projection. The first projection is located within the second projection.

[0006] Optionally, the pole assembly includes a pole body and a pole ring. The pole ring is connected to the first side of the top cover plate. The pole ring has an inner ring surface. The pole body is disposed inside the pole ring and has an outer circumferential surface. The outer circumferential surface is welded to the inner ring surface.

[0007] Optionally, the pole body has a first half-groove, which is located on the side of the pole body away from the top cover plate along the first direction. The pole ring has a second half-groove, which is located on the side of the pole ring away from the top cover plate along the first direction. The first half-groove and the second half-groove together form a welding groove. The weld mark formed by welding the pole body and the pole ring is contained in the welding groove and located at the junction of the first half-groove and the second half-groove.

[0008] Optionally, the pole body includes a first part and a second part, the first part is connected to the first connecting surface of the pole tab, the second part is connected to the side of the first part away from the pole tab, and the second part protrudes from the first part along the second direction and the third direction, and the second part and the first part enclose to form the first half-groove.

[0009] Optionally, the electrode core body has a first upper surface close to the top cover plate, and the distance between the bottom wall of the welding groove and the first upper surface is greater than the distance between the first side of the top cover plate and the first upper surface.

[0010] Optionally, the single cell further includes an upper plastic layer and a sealing ring, wherein the upper plastic layer and the sealing ring are respectively connected to both sides of the electrode ring along the first direction; Along the radial direction of the pole ring, both the sealing ring and the upper plastic are located on the inner ring surface of the pole ring away from the pole body.

[0011] Optionally, the single cell also has a second projection plane perpendicular to the first direction, the orthographic projection of the inner ring surface of the electrode ring along the first direction in the second projection plane is a third projection, the orthographic projection of the hole wall of the electrode ear hole along the first direction in the second projection plane is a fourth projection, and the third projection is located within the fourth projection.

[0012] Optionally, the outer peripheral surface is provided with a first limiting part, and the inner ring surface is provided with a second limiting part. The first limiting part and the second limiting part are in concave-convex cooperation to limit the pole body along the first direction.

[0013] Optionally, the first limiting portion is located on the side of the second limiting portion that is close to the receiving cavity along the first direction.

[0014] Optionally, the top cover includes a main body and a recessed portion, the main body being disposed around the recessed portion, the recessed portion sinking toward the receiving cavity along the first direction and defining a recessed groove, and the pole assembly being at least partially received in the recessed groove and connected to the recessed portion.

[0015] Optionally, the single battery cell further includes a welding ring, an upper plastic layer, and a sealing ring. The sealing ring connects the terminal assembly and the top cover plate. The upper plastic layer is disposed around the outer periphery of the terminal assembly, and the welding ring is disposed around the outer periphery of the upper plastic layer. The welding ring, the upper plastic and the sealing ring are all located at least partially within the sink and are connected to the top cover plate.

[0016] Secondly, embodiments of this application propose a battery pack comprising any of the individual batteries described above.

[0017] In this embodiment, the electrode post assembly is connected to the first side of the top cover plate, and the tab in the electrode core assembly is at least partially inserted through the tab hole on the top cover plate. The first connecting surface of the tab is connected to the electrode post assembly. Since the first projection of the first connecting surface in the first projection plane is located at the second projection of the top cover plate in the first projection plane, on the one hand, the position of the connecting surface of the tab and the electrode post assembly along the first direction is not lower than the second side surface of the top cover plate, thereby freeing up more space on the side of the top cover plate close to the receiving cavity. Therefore, the height of the electrode core body in the receiving cavity can be increased to improve the energy density of the single battery. On the other hand, the position of the connecting surface of the tab and the electrode post assembly along the first direction is not higher than the first side surface of the top cover plate. In this way, while increasing the energy density of the single battery, the overall height of the single battery is effectively controlled by controlling the position of the connecting surface, avoiding the increase in the height of the single battery due to the excessively high position of the electrode post assembly and the tab connecting surface. This can help reduce the overall size of the single battery and improve the layout flexibility of the single battery in the battery pack or electrical equipment.

[0018] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0019] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a partial cross-sectional view of a single cell in an embodiment of this application; Figure 2 yes Figure 1 Enlarged diagram of section A in the middle; Figure 3 This is a schematic diagram of the structure of the pole piece and pole ring at one angle in an embodiment of this application; Figure 4 This is a schematic diagram of the pole piece and pole ring at another angle in an embodiment of this application; Figure 5 This is a schematic diagram of the top cover sheet in an embodiment of this application.

[0020] Reference numerals: 10-Housing, 101-Receiving cavity, 20-Electrode core assembly, 21-Electrode core body, 22-Electrode tab, 221-First connecting surface, 30-Top cover assembly, 31-Top cover piece, 311-Electrode tab hole, 312-Main body, 313-Recessed part, 32-Electrode post assembly, 321-Electrode post body, 3211-Outer peripheral surface, 32111-First limiting part, 3212-First half-groove, 3213-First part, 3214-Second part, 322-Electrode post ring, 3221-Inner ring surface, 32211-Second limiting part, 3222-Second half-groove, 323-Welding groove, 3231-Groove bottom wall, 33-Upper plastic, 34-Sealing ring, 35-Welding ring, 36-Lower plastic, 37-Insulating layer, X-First direction, Y-Second direction, Z-Third direction. Detailed Implementation

[0021] The embodiments of this application will now be described in detail. Examples of these embodiments are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0022] The terms "first" and "second" in the specification and claims of this application may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise stated, "multiple" means two or more. Furthermore, "and / or" in the specification and claims indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0023] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0024] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0025] In a single battery cell, the electrode core is the core energy storage component, and its size is closely related to the energy density of the single battery cell.

[0026] However, due to the trend of miniaturization of batteries and the limitation of battery installation space, it is difficult to increase the height of a single battery cell, which limits the increase in the size of the electrode core and, to some extent, restricts the improvement of the energy density of a single battery cell.

[0027] To further improve the energy density of a single battery cell, this application proposes a single battery cell. The single battery cell in this application embodiment has three perpendicular directions: a first direction X, a second direction Y, and a third direction Z. (Refer to...) Figure 1 A partial cross-sectional view of a single cell in an embodiment of this application is shown, with reference to... Figure 2 , showed Figure 1 An enlarged diagram of part A in the middle, as shown below. Figure 1 , Figure 2 As shown, the single-cell battery in this application includes: a housing 10 having a receiving cavity 101, one end of which has an opening along a first direction X; a top cover 31 connected to the housing 10 and sealing the opening, and including a first side and a second side opposite to each other along the first direction X, the first side being disposed opposite to the receiving cavity 101, and the top cover 31 having a tab hole 311 extending through the first side and the second side along the first direction X; a terminal post assembly 32 connected to the first side of the top cover 31; and a core assembly 20 including a core body 21 and a tab 22. The main body 21 is disposed within the receiving cavity 101. A tab 22 is connected to the end of the main body 21 near the opening. The tab 22 includes a first connecting surface 221, and at least partially passes through the tab hole 311. The first connecting surface 221 is connected to the electrode post assembly 32. The individual battery cell also has a first projection plane perpendicular to either the second direction Y or the third direction Z. The orthographic projection of the first connecting surface 221 onto the first projection plane is the first projection, and the orthographic projection of the top cover 31 onto the first projection plane is the second projection. The first projection is located within the second projection. For example, in... Figure 2 In the diagram, the plane indicated by S1 is the first projection plane, the projection indicated by A1 is the first projection, and the projection range indicated by A2 is the second projection.

[0028] In this embodiment, the pole post assembly 32 is connected to the first side of the top cover plate 31. The pole tab 22 in the pole core assembly 20 is at least partially inserted through the pole tab hole 311 on the top cover plate 31, and the first connecting surface 221 of the pole tab 22 is connected to the pole post assembly 32. Since the first projection of the first connecting surface 221 in the first projection plane is located at the second projection of the top cover plate 31 in the first projection plane, on the one hand, the position of the connecting surface between the pole tab 22 and the pole post assembly 32 along the first direction X is not lower than the second side surface of the top cover plate 31, thereby freeing up more space on the side of the top cover plate 31 close to the receiving cavity 101. The height of the electrode core body 21 inside the cavity 101 can be increased to improve the energy density of the single battery. On the other hand, the position of the connection surface between the tab 22 and the terminal assembly 32 along the first direction X is not higher than the first side surface of the top cover plate 31. In this way, while increasing the energy density of the single battery, the overall height of the single battery is effectively controlled by controlling the position of the connection surface. This avoids the increase in the height of the single battery caused by the connection surface between the terminal assembly 32 and the tab 22 being too high. This can help reduce the overall size of the single battery and improve the layout flexibility of the single battery in the battery pack or electrical equipment.

[0029] In the embodiments of this application, a single cell has a first direction X, a second direction Y, and a third direction Z that are perpendicular to each other. The first direction X is the height direction of the single cell, the second direction Y is the length direction of the single cell, and the third direction Z is the width direction of the single cell.

[0030] Specifically, the casing 10, serving as the main frame of the single battery cell, is typically made of steel or aluminum. It provides mechanical strength to the single battery cell, preventing damage to the internal core assembly 20 from external impacts or vibrations. The core assembly 20 is housed within the receiving cavity 101 of the casing 10 and includes a core body 21 and tabs 22. The core body 21, formed by winding or stacking positive electrode plates, negative electrode plates, and a separator, is the core component of the single battery cell, responsible for electrochemical reactions, energy storage, and release. The tabs 22 are connected to the core body 21 and are used to conduct current from inside the core body 21. The tab 22 is provided with a first connecting surface 221. The tab 22 is at least partially inserted through the tab hole 311 of the top cover plate 31 and connected to the terminal assembly 32 through the first connecting surface 221, so as to conduct current to the outside of the single battery through the terminal assembly 32. There are two tabs 22, namely a positive tab 22 and a negative tab 22. In this embodiment, the positive tab 22 and the negative tab 22 are arranged at intervals along the second direction Y. The two tabs 22 have the same structure. Correspondingly, two tab holes 311 are opened on the top cover plate 31, and the tab holes 311 are arranged one-to-one with the tabs 22. The top cover plate 31 is a metal structure and is connected to the housing 10 by welding or snap-fitting to seal the opening of the housing 10's receiving cavity 101. The terminal post assembly 32 is connected to the first side of the top cover plate 31 in the top cover assembly 30, forming a closed, stable and safe internal environment together with the top cover assembly 30 and the housing 10 to prevent moisture and dust from entering, and to effectively prevent electrolyte leakage, ensuring the safety of the single battery during charging and discharging.

[0031] It should be understood that, in this embodiment, the electrode assembly 32 is disposed on the first side of the top cover plate 31. Therefore, the tab 22 needs to pass through the tab hole 311 of the top cover plate 31 from the second side of the top cover plate 31 to connect with the electrode assembly 32 through the first connecting surface 221. In the first projection plane perpendicular to the second direction Y and / or the third direction Z, if the first projection formed by the first connecting surface 221 is lower than the lowest point of the second projection formed by the top cover plate 31, it means that the electrode assembly 32 is at least partially located on the second side of the top cover plate 31, that is, the electrode assembly 32 occupies the space of the receiving cavity 101 of the housing 10. This will compress the layout space of the electrode core body 21 and reduce the energy density of the single battery. If the first projection formed by the first connecting surface 221 is higher than the highest point of the second projection formed by the top cover plate 31, it means that the electrode assembly 32 protrudes completely from the top cover plate 31 along the first direction X, thereby increasing the overall height of the single battery, which is not conducive to the miniaturization design of the single battery. Therefore, by controlling the first projection position formed by the first connecting surface 221 within the second projection formed by the top cover plate 31, the above two problems are solved at the same time. While improving the energy density of the single battery, the height of the single battery is also effectively controlled, thereby ensuring the battery pack's range performance and optimizing the battery pack's spatial layout.

[0032] Optionally, the pole assembly 32 includes a pole body 321 and a pole ring 322. The pole ring 322 is connected to the first side of the top cover plate 31. The pole ring 322 is provided with an inner ring surface 3221. The pole body 321 is disposed inside the ring of the pole ring 322 and is provided with an outer peripheral surface 3211. The outer peripheral surface 3211 is welded to the inner ring surface 3221.

[0033] In this embodiment, the electrode post 321 is welded to the inner circumferential surface of the electrode post ring 322 via its outer surface. That is, the electrode post 321 and the electrode post ring 322 are separate structures and are welded during the assembly stage of the single cell. It can be understood that with this separate structure of the electrode post assembly 32, the electrode post 321 and the electrode post ring 322 can be processed and produced separately. The structural design of the electrode post 321 and the electrode post ring 322 can be more flexible, so as to adapt to the structure of the tab 22, the top cover plate 31 or the sealing ring 34 respectively, ensuring the compactness of the internal structure of the single cell, improving the space utilization rate and reducing the assembly difficulty.

[0034] Specifically, the electrode post 321 is the main component for conducting current generated in the electrode core 21 of the single cell. The lower surface of the electrode post 321 is connected to the first connecting surface 221 of the tab 22, and the upper surface of the electrode post 321 can be used to connect a busbar or connecting piece. The electrode post ring 322 serves as a welding and sealing carrier in the electrode post assembly 32, and is sleeved on the outer periphery of the electrode post 321 and welded to the electrode post 321. Since the electrode post ring 322 is an independent structure, it can be made of the same or different materials as the electrode post 321.

[0035] Optionally, the single cell also includes an upper plastic 33 and a sealing ring 34, the upper plastic 33 and the sealing ring 34 being respectively connected to both sides of the terminal ring 322 along the first direction X; along the radial direction of the terminal ring 322, the sealing ring 34 and the upper plastic 33 are both located on the side of the inner ring surface 3221 of the terminal ring 322 away from the terminal body 321.

[0036] In practical applications, a sealing ring 34 is provided between the lower part of the terminal ring 322 and the top cover plate 31 to seal the individual battery cells. A welding ring 35 is provided above the terminal ring 322 and connected to the top cover plate 31 to fix the terminal ring 322. An upper plastic 33 is provided between the welding ring 35 and the terminal ring 322 to achieve insulation between the terminal ring 322 and the welding ring 35. During assembly, the terminal body 321 and the tab 22 can be welded first, then the sealing ring 34 is placed on the top cover plate 31, and then the terminal ring 322 is sleeved on the outer periphery of the terminal body 321. The upper plastic 33 and the welding ring 35 are then sleeved on the top of the terminal ring 322. The welding ring 35 is welded to the top cover plate 31 to form a whole.

[0037] In this embodiment, by placing the sealing ring 34 and the upper plastic 33 on the side of the inner ring surface 3221 of the pole post ring 322 away from the pole post body 321, a clearance space is formed on the inner side of the pole post ring 322, which avoids obstruction of the pole post body 321, facilitates welding operations between the pole post body 321 and the pole post ring 322, and ensures the feasibility and convenience of welding operations.

[0038] Optionally, the pole piece 321 has a first half-groove 3212, which is located on the side of the pole piece 321 away from the top cover plate 31 along the first direction X. The pole piece ring 322 has a second half-groove 3222, which is located on the side of the pole piece ring 322 away from the top cover plate 31 along the first direction X. The first half-groove 3212 and the second half-groove 3222 together form a welding groove 323. The weld mark formed by welding the pole piece 321 and the pole piece ring 322 is contained in the welding groove 323 and is located at the junction of the first half-groove 3212 and the second half-groove 3222.

[0039] In this embodiment, the electrode post 321 and the electrode ring 322 are welded together, and the first half-groove 3212 of the electrode post 321 and the second half-groove 3222 of the electrode ring 322 enclose a welding groove 323. Thus, the bottom wall 3231 of the welding groove 323 is actually lower than the upper surfaces of the electrode post 321 and the electrode ring 322, allowing the welding operation to be performed within the welding groove 323, facilitating positioning during the welding operation and improving welding accuracy. When the electrode post 321 and the electrode ring 322 are welded together, after welding... A weld mark will be formed at the junction of the first half-groove 3212 and the second half-groove 3222. The welding energy passes through the gap between the two, which can make the groove wall of the first half-groove 3212 and the groove wall of the second half-groove 3222 tightly bonded, ensuring the welding strength. Since the weld mark will have a certain thickness, the welding groove 323 in this embodiment can also be used to accommodate the weld mark, preventing the weld mark from protruding from the upper surface of the pole post 321 and the pole post ring 322, and preventing any adverse effects that may be caused to the fit of other upper structures.

[0040] like Figure 3 , Figure 4As shown, the first half-groove 3212 is formed on the outer peripheral surface 3211 of the pole post 321, with the groove opening of the first half-groove 3212 facing the pole post ring 322 and the side away from the top cover plate 31. The second half-groove 3222 is formed on the inner peripheral surface of the pole post ring 322, with the groove opening of the second half-groove 3222 facing the pole post 321 and the side away from the top cover plate 31. When the outer peripheral surface 3211 of the pole post 321 is welded to the inner ring surface 3221 of the pole post ring 322, the groove opening of the first half-groove 3212 is connected to the groove opening of the second half-groove 3222. The first half-groove 3212 and the second half-groove 3222 enclose to form a welding groove 323. The bottom wall 3231 of the first half-groove 3212 and the bottom wall 3231 of the second half-groove 3222 are located on the same plane to ensure the flatness of the bottom wall 3231 of the welding groove 323 formed by the two.

[0041] Optionally, the pole body 321 includes a first part 3213 and a second part 3214. The first part 3213 is connected to the first connecting surface 221 of the pole tab 22, and the second part 3214 is connected to the side of the first part 3213 away from the pole tab 22. The second part 3214 protrudes from the first part 3213 along the second direction Y and the third direction Z. The second part 3214 and the first part 3213 enclose each other to form a first semi-groove 3212.

[0042] Specifically, the first part 3213 is located on the side of the electrode post 321 closer to the tab 22, and the second part 3214 is located on the side of the electrode post 321 away from the tab 22. The area of ​​the second part 3214 is smaller than that of the first part 3213, and the second part 3214 is located at the center of the first part 3213. The peripheral wall of the second part 3214 and the top wall of the first part 3213 form an L-shaped first semi-groove 3212. In practical applications, the second part 3214 is used to connect to structures such as busbars or connecting pieces to conduct the current of the single cell. The first part 3213 and the second part 3214 can be manufactured separately and then connected together by welding or bonding. When the two are bonded together, the bonding medium needs to be a material with conductive properties, such as conductive adhesive, to ensure that the current received by the first part 3213 from the tab 22 can be smoothly transmitted to the second part 3214. Alternatively, the first part 3213 and the second part 3214 can also be an integrally formed structure, and this application embodiment does not specifically limit this.

[0043] It is understandable that by designing the electrode post 321 into a first part 3213 and a second part 3214 with different shapes, and manufacturing the first part 3213 and the second part 3214 separately, the first part 3213 and the second part 3214 can be made of different materials to obtain different properties. This facilitates connection and cooperation with different materials and structures, thereby improving connection strength, enhancing conductivity, or saving material costs. For example, in this application, the first part 3213 of the electrode post 321 is used to connect with the electrode tab 22, and the first part 3213 is made of copper. The second part 3214 is used to connect with the busbar or connecting piece, and is made of aluminum.

[0044] like Figure 2 As shown, the core body 21 has a first upper surface close to the top cover plate 31, and the distance between the bottom wall 3231 of the welding groove 323 and the first upper surface is greater than the distance between the first side of the top cover plate 31 and the first upper surface.

[0045] It should be noted that the first upper surface of the core body 21 is not necessarily a plane, such as... Figure 2 As shown, along the third direction Z, the middle position of the upper surface of the electrode core body 21 is higher, and the two sides are lower. The height of the bottom wall 3231 of the welding groove 323 and the height of the first side of the top cover plate 31 are relative to the highest position of the first upper surface of the electrode core body 21, based on the single cell being upright (the casing 10 is below and the top cover assembly 30 is above). This height is to illustrate the relative positional relationship between the bottom wall 3231 of the welding groove 323 and the first side of the top cover plate 31, and does not represent the dimensions of the relevant structures themselves. Specifically, as shown... Figure 2 As shown, the distance between the bottom wall 3231 of the welding groove 323 and the first upper surface relative to the first upper surface of the electrode core body 21 is shown as H1, and the distance between the first side of the top cover plate 31 and the first upper surface is shown as H2.

[0046] In this embodiment, since the height of the bottom wall 3231 of the welding groove 323 is higher than the height of the first side of the top cover plate 31, the welding operation is carried out entirely on the top cover plate 31. The welding component (such as the welding gun) does not need to pass through the tab hole 311 on the top cover plate 31, thereby avoiding interference of the top cover plate 31 with the welding operation in the welding groove 323, and also avoiding damage to the structure of the top cover plate 31 by the welding component during the welding operation, thereby ensuring welding quality and product yield.

[0047] Optionally, the single cell also has a second projection plane perpendicular to the first direction X. The orthographic projection of the inner ring surface 3221 of the electrode ring 322 along the first direction X into the second projection plane is a third projection, and the orthographic projection of the hole wall of the electrode tab 311 along the first direction X into the second projection plane is a fourth projection. The third projection is located within the fourth projection. Wherein, in Figure 1 In the diagram, the plane indicated by S2 is the second projection plane, the projection range indicated by A3 is the third projection, and the projection range indicated by A4 is the fourth projection.

[0048] In practical applications, since the welding operation is performed at the junction of the inner ring surface 3221 of the electrode ring 322 and the outer peripheral surface 3211 of the electrode body 321, the welding energy is downward during welding. If the fourth projection is located within the third projection, the top cover sheet 31 may be deformed or shifted due to the welding energy, affecting the structural reliability of the top cover assembly 30 and thus adversely affecting the safety of the single battery cell. In this embodiment, the height direction of the inner ring surface 3221 extends along the first direction X. In the second projection plane perpendicular to the first direction X, the shape of the third projection formed by the inner ring surface 3221 of the electrode ring 322 on the second projection plane is the same as the shape formed by the inner ring surface 3221 of the electrode ring 322. The shape of the fourth projection formed by the hole wall of the tab hole 311 on the second projection plane is the same as the shape of the tab hole 311. The third projection is located within the fourth projection, which means that the inner ring surface 3221 is completely located within the range of the tab hole 311. In this way, when welding the inner ring surface 3221 of the pole ring 322 to the outer peripheral surface 3211 of the pole body 321, there is no need to consider the damage of welding energy to the top cover plate 31, which reduces the welding difficulty and avoids the welding energy from acting directly downward to the top cover plate 31, ensuring the stability of the structure and position of the top cover plate 31 and further ensuring the welding quality.

[0049] Optionally, the outer peripheral surface 3211 is provided with a first limiting part 32111, and the inner ring surface 3221 is provided with a second limiting part 32211. The first limiting part 32111 and the second limiting part 32211 are in concave-convex cooperation to limit the pole body 321 along the first direction X.

[0050] Specifically, the first limiting part 32111 protrudes from the outer peripheral surface 3211 along the second direction Y and / or the third direction Z and extends toward the pole ring 322. The second limiting part 32211 protrudes from the inner ring surface 3221 along the second direction Y and / or the third direction Z and extends toward the pole body 321. When the pole body 321 and the pole ring 322 are welded together, the first limiting part 32111 and the second limiting part 32211 are arranged along the first direction X to limit the pole body 321 in the first direction X. In this embodiment, the limiting cooperation of the first limiting part 32111 and the second limiting part 32211 limits the pole body 321, which facilitates the initial positioning of the pole body 321 during installation and ensures the installation effect. In some embodiments, the second limiting portion 32211 of the pole ring 322 is located above the first limiting portion 32111 of the pole body 321, that is, the pole ring 322 cooperates with the pole body 321 and presses down on the pole body 321. In other embodiments, the second limiting portion 32211 of the pole ring 322 is located below the first limiting portion 32111 of the pole body 321, that is, the pole ring 322 cooperates with the pole body 321 and supports the pole body 321. The positional relationship between the first limiting portion 32111 and the second limiting portion 32211 in the first direction X is not specifically limited in the embodiments of this application.

[0051] For example, in an embodiment of this application, the first limiting portion 32111 is located on the side of the second limiting portion 32211 near the receiving cavity 101 along the first direction X. Figure 3 As shown, the first limiting part 32111 is a limiting protrusion, and the second limiting part 32211 is a limiting groove. The limiting protrusion is at least partially accommodated in the limiting groove. In this way, the top wall of the limiting groove can abut against the top wall of the limiting protrusion to restrict the movement of the limiting protrusion upward along the first direction X. This achieves the limiting of the movement of the electrode ring 322 on the electrode body 321 away from the receiving cavity 101 along the first direction X. Under this limiting and matching structure, during the assembly of a single battery cell, the electrode body 321 can be effectively prevented from detaching upward from the electrode ring 322, improving the convenience of assembly operation and ensuring the assembly effect.

[0052] In practical applications, the terminal post 321 can be placed above the core assembly 20 and welded to the tab 22. Then, the terminal post ring 322 is assembled above the top cover plate 31. At this time, the second limiting part 32211 of the terminal post ring 322 is located above the first limiting part 32111 of the terminal post 321, limiting the terminal post 321 and preventing it from moving freely or even coming off the terminal post ring 322 during subsequent assembly steps. In addition, during the use of a single battery cell, the second limiting part 32211 can also provide a continuous limiting force to the first limiting part 32111, controlling the terminal post 321 to be tightly connected to the first connecting surface 221 of the tab 22 at a preset position, ensuring a reliable connection between the terminal post 321 and the tab 22.

[0053] like Figure 5 As shown, the top cover plate 31 includes a main body portion 312 and a recessed portion 313. The main body portion 312 is disposed around the recessed portion 313. The recessed portion 313 sinks towards the receiving cavity 101 along the first direction X and defines a recessed groove. The pole post assembly 32 is at least partially accommodated in the recessed groove and connected to the recessed portion 313.

[0054] Specifically, in this embodiment, the top cover 31 includes two recessed portions 313. A tab hole 311 is opened on the recessed portion 313 and is located at the center of the recessed portion 313. A space for accommodating the electrode ring 322 is formed around the tab hole 311. In this embodiment, when the recessed portion 313 is recessed towards the receiving cavity 101 along the first direction X, the surface height of the first side of the recessed portion 313 is reduced. Thus, when at least part of the electrode assembly 32 (e.g., the electrode ring 322) is accommodated in the recess and connected to the recessed portion 313, the height of the upper surface of the electrode assembly 32 relative to the bottom surface of the housing 10 is reduced, that is, the overall height of the single battery cell is reduced, which is in line with the current trend of high energy density in batteries.

[0055] Optionally, the single cell also includes a welding ring 35, an upper plastic 33, and a sealing ring 34. The sealing ring 34 is connected between the terminal assembly 32 and the top cover plate 31. The upper plastic 33 is disposed around the outer periphery of the terminal assembly 32, and the welding ring 35 is disposed around the outer periphery of the upper plastic 33. The welding ring 35, the upper plastic 33, and the sealing ring 34 are all at least partially located in the sink and connected to the top cover plate 31.

[0056] Specifically, the top cover plate 31, welding ring 35, upper plastic 33, and sealing ring 34 are all part of the top cover assembly 30 in the single cell. The top cover plate 31 is connected to the housing 10 and seals the opening of the housing 10's receiving cavity 101. The welding ring 35, upper plastic 33, and sealing ring 34 are connected to the side of the top cover plate 31 away from the receiving cavity 101 to achieve the sealing and insulation performance of the top cover assembly 30. The sealing ring 34 is connected between the terminal ring 322 and the top cover plate 31 to ensure the sealing of the receiving cavity 101. The upper plastic 33 is connected to the side of the terminal ring 322 away from the sealing ring 34, and the welding ring 35 is connected to the side of the upper plastic 33 away from the terminal ring 322. The upper plastic 33 is used to insulate between the welding ring 35 and the terminal ring 322. The welding ring 35 is located at the top of the top cover assembly 30 and is used to weld to the top cover plate 31 to fix the upper plastic 33, terminal ring 322, and sealing ring 34 between the welding ring 35 and the top cover plate 31, ensuring the structural stability of the top cover assembly 30. In practical applications, an insulating layer 37 can also be provided above the welding ring 35. The insulating layer 37 covers the upper surface of the welding ring 35 and the top cover plate 31 to isolate the external environment from the welding ring 35 and the top cover plate 31, preventing the welding ring 35 and the top cover plate 31 from contacting other live parts and causing a short circuit in the single battery. The insulating layer 37 can be an insulating varnish (such as epoxy resin), insulating tape, or an insulating coating (such as a ceramic coating).

[0057] Understandably, when a recessed portion 313 is provided on the top cover plate 31, the recessed portion 313 can not only support the terminal assembly 32 (such as the terminal ring 322), but also support structures such as the welding ring 35, the upper plastic 33, and the sealing ring 34. Since the welding ring 35, the upper plastic 33, and the sealing ring 34 in the top cover assembly 30 are all at least partially located in the recessed groove of the recessed portion 313, the height of the upper surface of the welding ring 35 located at the top is reduced, which also effectively controls the height of the single cell.

[0058] In addition, in this embodiment, the top cover assembly 30 also includes a lower plastic 36, which is connected to the second side of the top cover sheet 31. The lower plastic 36 is insulating and is used to insulate the top cover sheet 31 from the electrode core body 21.

[0059] In summary, the single-cell battery provided in this application embodiment may include at least the following advantages: In this embodiment, the pole post assembly 32 is connected to the first side of the top cover plate 31. The pole tab 22 in the pole core assembly 20 is at least partially inserted through the pole tab hole 311 on the top cover plate 31, and the first connecting surface 221 of the pole tab 22 is connected to the pole post assembly 32. Since the first projection of the first connecting surface 221 in the first projection plane is located at the second projection of the top cover plate 31 in the first projection plane, on the one hand, the position of the connecting surface between the pole tab 22 and the pole post assembly 32 along the first direction X is not lower than the second side surface of the top cover plate 31, thereby freeing up more space on the side of the top cover plate 31 close to the receiving cavity 101. The height of the electrode core body 21 inside the cavity 101 can be increased to improve the energy density of the single battery. On the other hand, the position of the connection surface between the tab 22 and the terminal assembly 32 along the first direction X is not higher than the first side surface of the top cover plate 31. In this way, while increasing the energy density of the single battery, the overall height of the single battery is effectively controlled by controlling the position of the connection surface. This avoids the increase in the height of the single battery caused by the connection surface between the terminal assembly 32 and the tab 22 being too high. This can help reduce the overall size of the single battery and improve the layout flexibility of the single battery in the battery pack or electrical equipment.

[0060] This application also provides a battery pack comprising any of the aforementioned individual batteries.

[0061] It should be noted that in the embodiments of this application, the structure of the single cell is the same as that of the single cell in any of the above embodiments, and its beneficial effects are similar, so they will not be described in detail here.

[0062] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0063] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A single-cell battery, characterized in that, The single cell includes three mutually perpendicular directions: a first direction (X), a second direction (Y), and a third direction (Z). The housing (10) has a receiving cavity (101) with an opening at one end along the first direction (X); The top cover (31) is connected to the housing (10) and covers the opening, and includes a first side and a second side opposite to each other along the first direction (X). The first side is disposed opposite to the receiving cavity (101). The top cover (31) is provided with an ear hole (311) that passes through the first side and the second side along the first direction (X). The pole assembly (32) is connected to the first side of the top cover plate (31); And the electrode core assembly (20), including an electrode core body (21) and an electrode tab (22), wherein the electrode core body (21) is disposed within the receiving cavity (101), the electrode tab (22) is connected to one end of the electrode core body (21) near the opening, the electrode tab (22) includes a first connecting surface (221), the electrode tab (22) is at least partially inserted through the electrode tab hole (311), and the first connecting surface (221) is connected to the electrode post assembly (32); wherein, The single cell also has a first projection plane perpendicular to the second direction (Y) or the third direction (Z), the orthographic projection of the first connecting surface (221) onto the first projection plane is the first projection, the orthographic projection of the top cover (31) onto the first projection plane is the second projection, and the first projection is located within the second projection.

2. The single-cell battery according to claim 1, characterized in that, The pole assembly (32) includes a pole body (321) and a pole ring (322). The pole ring (322) is connected to the first side of the top cover plate (31). The pole ring (322) is provided with an inner ring surface (3221). The pole body (321) is located inside the pole ring (322) and is provided with an outer peripheral surface (3211). The outer peripheral surface (3211) is welded to the inner ring surface (3221).

3. The single-cell battery according to claim 2, characterized in that, The pole post (321) has a first half-groove (3212), which is located on the side of the pole post (321) away from the top cover plate (31) along the first direction (X). The pole post ring (322) has a second half-groove (3222), which is located on the side of the pole post ring (322) away from the top cover plate (31) along the first direction (X). The first half-groove (3212) and the second half-groove (3222) together form a welding groove (323). The weld mark formed by welding the pole post (321) and the pole post ring (322) is contained in the welding groove (323) and located at the junction of the first half-groove (3212) and the second half-groove (3222).

4. The single-cell battery according to claim 3, characterized in that, The pole body (321) includes a first part (3213) and a second part (3214). The first part (3213) is connected to the first connecting surface (221) of the pole tab (22). The second part (3214) is connected to the side of the first part (3213) away from the pole tab (22). The second part (3214) protrudes from the first part (3213) along the second direction (Y) and the third direction (Z). The second part (3214) and the first part (3213) enclose each other to form the first semi-groove (3212).

5. The single-cell battery according to claim 3, characterized in that, The core body (21) has a first upper surface close to the top cover plate (31), and the distance between the bottom wall (3231) of the welding groove (323) and the first upper surface is greater than the distance between the first side of the top cover plate (31) and the first upper surface.

6. The single-cell battery according to claim 2, characterized in that, The single cell also includes an upper plastic (33) and a sealing ring (34), wherein the upper plastic (33) and the sealing ring (34) are respectively connected to both sides of the electrode ring (322) along the first direction (X); Along the radial direction of the pole ring (322), the sealing ring (34) and the upper plastic (33) are both located on the side of the inner ring surface (3221) of the pole ring (322) away from the pole body (321).

7. The single-cell battery according to claim 2, characterized in that, The single cell also has a second projection plane perpendicular to the first direction (X), the inner ring surface (3221) of the electrode ring (322) is projected in the second projection plane along the first direction (X) as a third projection, the hole wall of the electrode hole (311) is projected in the second projection plane along the first direction (X) as a fourth projection, and the third projection is located within the fourth projection.

8. The single-cell battery according to claim 2, characterized in that, The outer peripheral surface (3211) is provided with a first limiting part (32111), and the inner ring surface (3221) is provided with a second limiting part (32211). The first limiting part (32111) and the second limiting part (32211) are in concave-convex cooperation to limit the pole body (321) along the first direction (X).

9. The single-cell battery according to claim 8, characterized in that, The first limiting part (32111) is located on the side of the second limiting part (32211) along the first direction (X) close to the receiving cavity (101).

10. The single-cell battery according to any one of claims 1 to 9, characterized in that, The top cover (31) includes a main body (312) and a recessed portion (313). The main body (312) is disposed around the recessed portion (313). The recessed portion (313) sinks toward the receiving cavity (101) along the first direction (X) and defines a recessed groove. The pole post assembly (32) is at least partially received in the recessed groove and connected to the recessed portion (313).

11. The single-cell battery according to claim 10, characterized in that, The single cell also includes a welding ring (35), an upper plastic layer (33), and a sealing ring (34). The sealing ring (34) is connected between the terminal assembly (32) and the top cover plate (31). The upper plastic layer (33) is disposed around the outer periphery of the terminal assembly (32), and the welding ring (35) is disposed around the outer periphery of the upper plastic layer (33). The welding ring (35), the upper plastic (33) and the sealing ring (34) are all located at least partially within the sink and are connected to the top cover plate (31).

12. A battery pack, characterized in that, Includes the single-cell battery as described in any one of claims 1 to 11.

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