Single cell and battery pack

Abstract

The embodiment of the application provides a single battery and a battery pack, the single battery comprising: a shell; an electrode assembly arranged in the shell; a top cover assembly comprising a top cover sheet, a welding ring, a pole, a compression ring and an upper plastic, the top cover sheet being connected with the shell; the welding ring has a side plate arranged in a ring shape, the outer side of the ring of the side plate is arranged in a step shape and has a first side and a second side, the first side being located on the side away from the electrode assembly of the second side; the pole is sleeved on the inner side of the ring of the welding ring, the compression ring and the upper plastic are both sleeved on the outer side of the ring of the welding ring, the first side is closer to the pole than the second side, and the compression ring is welded with the first side, and the upper plastic is connected with the second side. The single battery in the application can avoid that the welding energy directly passes through the welding ring from the first side to damage the upper plastic connected with the second side, ensure the use performance of the upper plastic and the reliability of the top cover assembly, and improve the safety of the single 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] A battery typically consists of a casing, a cell, and a cover. The cell is housed inside the casing, and the cover is connected to the casing to secure the cell and seal the casing. The cover is also connected to the cell's tabs to allow current to flow.

[0003] In related technologies, the cover plate typically includes a welding ring, a pressure ring, and an upper plastic layer. The upper plastic layer is used to separate the terminal post from the cover plate, and the welding ring and pressure ring are welded together to fix the upper plastic layer. However, in existing cover plate structures, the welding energy during the welding connection between the welding ring and the pressure ring can easily damage the upper plastic layer, affecting its performance and assembly effect, and in severe cases, even affecting the battery's safety performance. Utility Model Content

[0004] This application aims to provide a single cell and a battery pack to solve the problem that welding the welding ring and the pressure ring of a single cell can easily damage the plastic.

[0005] To solve the above-mentioned technical problems, this application is implemented as follows:

[0006] In a first aspect, this application discloses a single-cell battery, said single-cell battery comprising:

[0007] case;

[0008] An electrode assembly, wherein the electrode assembly is disposed within the housing;

[0009] A top cover assembly, comprising a top cover plate, a welding ring, an electrode post, a pressure ring, and an upper plastic layer, wherein the top cover plate is connected to the housing;

[0010] The welding ring has a side plate arranged in a ring shape, the side plate passes through the top cover plate, the outer side of the ring of the side plate is stepped and has a first side and a second side, the first side being located on the side of the second side away from the electrode assembly;

[0011] The electrode post is sleeved inside the welding ring, and the pressure ring and the upper plastic are both sleeved outside the welding ring. The first side is closer to the electrode post than the second side, and the pressure ring is welded to the first side, while the upper plastic is connected to the second side.

[0012] Optionally, the top cover assembly further includes a heat insulation layer disposed between the upper plastic and the pressure ring.

[0013] Optionally, both the first side and the second side are circumferentially arranged around the side plate; the side plate also has a connecting surface, which connects the first side and the second side.

[0014] Optionally, the connecting surface is perpendicular to both the first side and the second side, a portion of the heat insulation layer is located between the pressure ring and the connecting surface, and another portion of the heat insulation layer is located between the pressure ring and the upper plastic.

[0015] Optionally, at least one of the side plate and the pressure ring is provided with a welding groove on the side opposite to the electrode assembly, the welding groove being used to accommodate solder.

[0016] Optionally, the welding groove is an annular groove; or, there are multiple welding grooves, which are spaced apart circumferentially along the side plate.

[0017] Optionally, the side plate is provided with a first welding groove on the side opposite to the electrode assembly, and the pressure ring is provided with a second welding groove on the side opposite to the electrode assembly. The second welding groove communicates with the first welding groove and forms the welding groove.

[0018] Optionally, the upper plastic includes a first isolation portion and a second isolation portion, the first isolation portion being disposed between the top cover sheet and the pressure ring, the second isolation portion being connected to the first isolation portion, and the second isolation portion being located between the top cover sheet and the second side surface;

[0019] The upper plastic also includes a third isolation portion, which is connected to the side of the first isolation portion away from the second isolation portion. The third isolation portion extends away from the electrode assembly, while the second isolation portion extends towards the electrode assembly. The third isolation portion is connected to the outer side of the pressure ring.

[0020] Optionally, the welding ring further includes a base plate connected to the side of the side plate facing the electrode assembly; the top cover assembly further includes an insulating ring and a sealing ring, the insulating ring being connected to the side of the top cover sheet facing the electrode assembly, a portion of the insulating ring being located between the top cover sheet and the base plate in the thickness direction of the top cover sheet, and another portion of the insulating ring being located outside the ring of the base plate; the sealing ring is disposed outside the ring of the side plate, and a portion of the sealing ring being located between the top cover sheet and the base plate, and another portion of the sealing ring being located between the top cover sheet and the side plate;

[0021] A first locking platform is provided on the outer periphery of the electrode post, and a second locking platform is provided on the inner side of the side plate. The second locking platform and the first locking platform are engaged in a positioning fit in the direction away from the electrode assembly.

[0022] Secondly, this application also discloses a battery pack, including: a housing, and a single battery cell as described above, wherein the single battery cell is disposed within the housing.

[0023] In this embodiment, the side plate of the welding ring passes through the top cover plate and has a first side and a second side forming a step. The pressure ring is sleeved on the outside of the welding ring and welded to the first side. The upper plastic is sleeved on the outside of the welding ring and connected to the second side. Since the first side is located on the side of the second side away from the electrode assembly and is closer to the electrode post than the second side, when the pressure ring is welded to the first side of the welding ring, it is offset from the upper plastic on the second side in the direction inside and outside the welding ring. This avoids the welding energy from directly passing through the welding ring from the first side and damaging the upper plastic connected to the second side, thus ensuring the performance of the upper plastic and the reliability of the top cover assembly, and improving the safety of the single cell.

[0024] 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

[0025] 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:

[0026] Figure 1 This is a schematic diagram of the structure of a single battery cell in an embodiment of this application;

[0027] Figure 2 This is an exploded view of a single cell in an embodiment of this application;

[0028] Figure 3 It is along Figure 1 A cross-sectional view of line A-A in the middle;

[0029] Figure 4 yes Figure 3 A magnified view of the corresponding top cover component;

[0030] Figure 5 yes Figure 4 An enlarged schematic diagram of section B shown in the middle circle;

[0031] Figure 6 This is a schematic diagram of the top cover assembly in an embodiment of this application;

[0032] Figure 7 This is an exploded view of the top cover assembly in an embodiment of this application;

[0033] Figure 8 This is a perspective sectional view of the welding ring in an embodiment of this application;

[0034] Figure 9 This is a perspective sectional view of the pressure ring in the embodiment of this application;

[0035] Figure 10 This is a perspective cross-sectional view of the plastic material in the embodiments of this application.

[0036] Figure label:

[0037] 10 - Top cover assembly, 11 - Top cover piece, 12 - Welding ring, 121 - Base plate, 122 - Side plate, 1221 - First side surface, 1222 - Second side surface, 1223 - Connecting surface, 1224 - First welding groove, 123 - Second locking platform, 13 - Pressure ring, 131 - Second welding groove, 14 - Upper plastic, 141 - First isolation part, 142 - Second isolation part, 143 - Third isolation part, 15 - Electrode post, 151 - First locking platform, 16 - Welding groove, 17 - Sealing ring, 18 - Insulating ring, 19 - Heat insulation layer, 20 - Housing, 21 - Receiving cavity, 30 - Electrode assembly, 31 - Cell body, 32 - Cell tab, X - First direction, Y - Second direction, Z - Third direction. Detailed Implementation

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] A battery typically includes a casing, a cell, and a cover. The casing has a cavity with an opening, the cell is housed within the cavity, and the cover is connected to the opening of the cavity to seal the casing. The battery cover typically includes a welding ring, a pressure ring, and an upper plastic layer. The upper plastic layer can be positioned between the terminals and the cover, either to isolate them or to allow them to conduct electricity, depending on the specific requirements. The welding ring is welded to the pressure ring to secure the upper plastic layer. However, in existing cover structure designs, the welding energy during the welding process between the welding ring and pressure ring can easily penetrate the plastic layer, damaging it and affecting its performance and assembly. In severe cases, this can even compromise the battery's safety.

[0043] Based on the above problems, this application provides a single-cell battery, such as... Figures 1-5 As shown, the single-cell battery includes a housing 20, an electrode assembly 30, and a top cover assembly 10. Wherein:

[0044] The housing 20 may be provided with a receiving cavity 21; the electrode assembly 30 is disposed within the receiving cavity 21 of the housing 20.

[0045] like Figure 6 , Figure 7As shown, the top cover assembly 10 includes a top cover plate 11, a welding ring 12, an electrode post 15, a pressure ring 13, and an upper plastic 14. The top cover plate 11 is connected to the housing 20 to close the receiving cavity 21. The welding ring 12 has a side plate 122 arranged in a ring shape, which passes through the top cover plate 11. The outer side of the ring of the side plate 122 is stepped and has a first side surface 1221 and a second side surface 1222. The first side surface 1221 is located on the side of the second side surface 1222 that is away from the electrode assembly 30. The electrode post 15 is sleeved on the inner side of the ring of the welding ring 12. The pressure ring 13 and the upper plastic 14 are both sleeved on the outer side of the ring of the welding ring 12. The first side surface 1221 is closer to the electrode post 15 than the second side surface 1222. The pressure ring 13 is welded to the first side surface 1221, and the upper plastic 14 is connected to the second side surface 1222.

[0046] In the embodiments of this application, such as Figure 1 As shown, the battery has a first direction X, a second direction Y, and a third direction Z that are perpendicular to each other. For example, the battery is a square battery, the first direction X is the height direction of the battery, the second direction Y is the length direction of the battery, and the third direction Z is the width direction of the battery.

[0047] Specifically, the casing 20 is the external structure of the battery, which can prevent the battery from being mechanically damaged, squeezed, impacted or corroded by the external environment. The casing 20 is provided with a receiving cavity 21, which has an opening. The electrode assembly 30 is disposed in the receiving cavity 21. The electrode assembly 30 includes a cell body 31 and a cell tab 32. The cell body 31, as the core structure of a single battery cell, realizes the charging and discharging function of the battery through an electrochemical reaction. The cell tab 32 serves as a bridge between the cell body 31 and the external circuit, and is responsible for conducting the current generated by the cell body 31 to the outside. The top cover assembly 10 is connected to the casing 20 and closes the opening of the receiving cavity 21.

[0048] It is understood that the battery cell body 31 includes a positive electrode plate, a negative electrode plate, and a separator. The positive electrode plate, separator, and negative electrode plate are stacked and wound in sequence. The battery cell tab 32 has two tabs, namely a positive tab and a negative tab. The positive tab is electrically connected to the positive electrode plate, and the negative tab is electrically connected to the negative electrode plate. This will not be described in detail.

[0049] In this embodiment, the top cover assembly 10 includes a top cover sheet 11, a welding ring 12, a terminal post 15, a pressure ring 13, and an upper plastic layer 14. The top cover sheet 11 is connected to the housing 20 and seals the receiving cavity 21. The cell tab 32 is connected to the terminal post 15 to conduct current to the outside of the individual battery cell. The welding ring 12 is used to assemble the terminal post 15 and the welding pressure ring 13. The welding ring 12 has a side plate 122 arranged in a ring shape. Figure 5 As shown, the side plate 122 passes through the top cover plate 11, as... Figure 8As shown, the outer side of the side plate 122 has a first side surface 1221 and a second side surface 1222. The first side surface 1221 is located on the side of the second side surface 1222 away from the electrode assembly 30 along the first direction X. The pole post 15 is generally a cylindrical structure, such as a circular, elliptical, or square column. The pole post 15 is sleeved on the inner side of the welding ring 12. Along the radial direction of the pole post 15, the first side surface 1221 is closer to the pole post 15 than the second side surface 1222, thus making the outer side of the side plate 122 stepped. The pressure ring 13 and the upper plastic 14 are both sleeved on the outer side of the welding ring 12, and the pressure ring 13 is welded to the first side surface 1221, and the upper plastic 14 is connected to the second side surface 1222.

[0050] In this embodiment, the side plate 122 of the welding ring 12 passes through the top cover plate 11 and has a first side 1221 and a second side 1222 forming a step. The pressure ring 13 is sleeved on the outside of the welding ring 12 and welded to the first side 1221. The upper plastic 14 is sleeved on the outside of the welding ring 12 and connected to the second side 1222. Since the first side 1221 is located on the side of the second side 1222 away from the electrode assembly 30, and the first side 1221 is closer to the electrode post 15 than the second side 1222, that is, along the radial direction of the welding ring 12, the first side 1221 and the second side 1222 are relatively offset. Therefore, when the pressure ring 13 is welded to the first side 1221 of the welding ring 12, the welding energy can be avoided from being directly conducted from the first side 1221 to the second side 1222 and damaging the upper plastic 14 connected to the second side 1222. This ensures the performance of the upper plastic 14 and the reliability of the top cover assembly 10, and improves the safety of the single battery.

[0051] In practical applications, the upper plastic 14 can be made of an insulating and heat-insulating material. Its insulating properties provide insulation between the electrode assembly 30 and the top cover plate 11. Simultaneously, its heat-insulating properties reduce the risk of welding energy penetrating the plastic 14, ensuring its reliability. For example, the upper plastic 14 may include at least one of a ceramic plate, epoxy resin plate, mica plate, or aerogel insulation plate. Of course, in other embodiments, the material of the upper plastic 14 can be adjusted to make it conductive, which will not be elaborated further.

[0052] It should be noted that, as Figure 1 , Figure 2 As shown, the battery includes a top cover plate 11 and two terminals 15, which are a positive terminal and a negative terminal, respectively. The two terminals 15 are spaced apart along the second direction Y. Correspondingly, there are also two welding rings 12, pressure rings 13 and upper plastic 14 in the top cover assembly 10. Each welding ring 12, pressure ring 13 and upper plastic 14 is sleeved on the outside of one terminal 15. This application uses one terminal 15 and welding rings 12, pressure rings 13 and upper plastic 14 as an example for illustration.

[0053] Optionally, the top cover assembly 10 also includes a heat insulation layer 19 disposed between the upper plastic 14 and the pressure ring 13.

[0054] By providing a heat insulation layer 19 between the upper plastic 14 and the pressure ring 13, welding energy can be further isolated to prevent the welding heat of the pressure ring 13 and the welding ring 12 from damaging the upper plastic 14, thereby ensuring the structural safety and reliability of the upper plastic 14.

[0055] like Figures 3-5 As shown, a single cell is shown along... Figure 1 A cross-sectional view of the AA line is shown, where the AA line is a cross-sectional line along the third direction Z of the single cell. The heat insulation layer 19 is disposed between the upper plastic 14 and the pressure ring 13 along the first direction X. In some embodiments, the heat insulation layer 19 is formed as an annular structure disposed along the outer periphery of the first side 1221, that is, the heat insulation layer 19 is continuously disposed along the outer periphery of the first side 1221. In this way, the pressure ring 13 and the welding ring 12 can be welded at any position on the outer periphery of the first side 1221, avoiding the heat insulation layer 19 failing to perform its heat insulation function due to misalignment of the welding position with the heat insulation layer 19. In other embodiments, multiple heat insulation layers 19 are disposed, and multiple heat insulation layers 19 are disposed at intervals along the outer periphery of the first side 1221. The pressure ring 13 and the welding ring 12 can be welded at the positions where the heat insulation layer 19 is disposed, thus saving heat insulation layer 19 material and reducing production costs. In specific applications, the heat insulation layer 19 can be a coating with heat insulation properties applied between the upper plastic 14 and the pressure ring 13, such as a ceramic coating. This application does not specifically limit the material type of the heat insulation layer 19.

[0056] Optionally, the first side 1221 and the second side 1222 are both arranged circumferentially around the side plate 122; the side plate 122 also has a connecting surface 1223, which connects the first side 1221 and the second side 1222.

[0057] The connecting surface 1223 includes an outer and an inner side that are radially opposite to each other along the pole post 15. The inner side of the connecting surface 1223 is connected to the bottom of the first side surface 1221, and the outer side of the connecting surface 1223 is connected to the top of the second side surface 1222. The connecting surface 1223 forms a stepped structure with the first side surface 1221 and the second side surface 1222, and has a stepped surface. During assembly, the pressure ring 13 can be placed on this stepped surface, thereby ensuring the positional stability of the pressure ring 13 and facilitating the welding operation between the pressure ring 13 and the welding ring 12. It can be understood that since the first side surface 1221 and the second side surface 1222 are both arranged circumferentially around the side plate 122, the connecting surface 1223 also forms an annular plane around the outer periphery of the first side surface 1221. In this way, the pressure ring 13 and the first side surface 1221 of the welding ring 12 can be welded at any position between them, which can avoid the welding energy passing through the welding ring 12 and damaging the upper plastic 14, greatly reducing the operation difficulty for the welding operator.

[0058] In this embodiment, the connecting surface 1223 is perpendicular to both the first side surface 1221 and the second side surface 1222. A portion of the heat insulation layer 19 is located between the pressure ring 13 and the connecting surface 1223, and another portion of the heat insulation layer 19 is located between the pressure ring 13 and the upper plastic 14. This effectively blocks the welding energy during the welding of the pressure ring 13 and the welding ring 12, protecting the safety and reliability of the upper plastic 14.

[0059] In some embodiments, the first side surface 1221 and the second side surface 1222 are arranged parallel to each other, and both the first side surface 1221 and the second side surface 1222 are perpendicular to the top cover plate 11. The connecting surface 1223 is perpendicular to both the first side surface 1221 and the second side surface 1222, that is, the connecting surface 1223 is arranged parallel to the top cover plate 11. The connecting surface 1223 has a certain width in the radial direction of the welding ring 12. In this way, the connecting surface 1223 can provide a certain support force for the pressure ring 13, thereby improving the tightness and reliability of the connection between the pressure ring 13 and the welding ring 12. When the pressure ring 13 and the welding ring 12 are welded, the welding energy is mainly transferred between the pressure ring 13 and the first side surface 1221. Since a part of the heat insulation layer 19 is also located between the pressure ring 13 and the connecting surface 1223, when the welding energy reaches the heat insulation layer 19, it is blocked by the heat insulation layer 19, thereby preventing the welding energy from continuing to be transferred to the upper plastic 14 along the connecting surface 1223, protecting the safety and reliability of the upper plastic 14.

[0060] like Figure 8As shown, along the radial direction of the welding ring 12, the width of the connecting surface 1223 is W, and the thickness of the side plate 122 at the second side surface 1222 is T, satisfying: T≥2W. By designing the relationship between the width of the connecting surface 1223 and the thickness of the side plate 122 at the second side surface 1222, the structural strength of the side plate 122 at the second side surface 1222 can be guaranteed. At the same time, it avoids the welding energy from passing through the first side surface 1221 and damaging the separator when the pressure ring 13 and the welding ring 12 are welded together, thereby improving the safety and reliability of the top cover assembly and the individual battery cells.

[0061] Optionally, at least one of the side plate 122 and the pressure ring 13 is provided with a welding groove 16 on the side opposite to the electrode assembly 30, the welding groove 16 being used to accommodate solder.

[0062] By providing a welding groove 16 on the side away from the electrode assembly 30 on at least one of the side plate 122 and the pressure ring 13, the welding groove 16 can accommodate the solder of the clamping part and the welding ring 12, and avoid the weld formed by welding from protruding from the upper surface of the pressure ring 13 and the side plate 122 of the welding ring 12, which would affect the overall height and appearance of the battery.

[0063] For example, in some embodiments, the welding groove 16 is disposed on the side plate 122 of the welding ring 12. Specifically, the welding groove 16 is disposed radially along the pole post 15 on the side plate 122 near the pressure ring 13. In this way, since the pressure ring 13 does not need to be provided with the welding groove 16, the structural integrity and strength of the pressure ring 13 can be better guaranteed, and the reliability of the entire top cover assembly 10 can be improved.

[0064] In other embodiments, the welding groove 16 is disposed on the pressure ring 13. Specifically, the welding groove 16 is disposed radially along the pole post 15 on the side of the pressure ring 13 near the side plate 122. Similarly, when the welding groove 16 is disposed only on the pressure ring 13, since the welding ring 12 does not need to be provided with the welding groove 16, the structural integrity and strength of the welding ring 12 can be better guaranteed, and the reliability of the entire top cover assembly 10 can also be improved.

[0065] In other embodiments, both the side plate 122 and the pressure ring 13 of the welding ring 12 are provided with welding grooves 16, and the welding grooves 16 on the side plate 122 and the pressure ring 13 are interconnected along the radial direction of the pole post 15. In this structure, the welding operation is performed at the intersection of the welding grooves 16 on the side plate 122 and the pressure ring 13. The solder can flow more smoothly to both sides into the welding grooves 16 on the side plate 122 and the pressure ring 13, ensuring that the solder can fully fill the welding area, reducing solder accumulation, helping to reduce the solder height, and further preventing the solder from protruding from the top surface of the pressure ring 13 and the welding ring 12 along the first direction X.

[0066] In some optional embodiments of this application, the welding groove 16 is an annular groove. This annular groove design allows welding operations to be performed at any position along the circumference of the welding groove 16, improving welding flexibility and convenience. Furthermore, this structure allows for continuous welding operations along the circumference of the welding groove 16, ultimately forming a continuous annular weld within the annular groove, thus enhancing the welding strength between the pressure ring 13 and the welding ring 12. The welding groove 16 can be an annular groove located on the top of the pressure ring 13, or it can be an annular groove formed on the top of the top plate of the welding ring 12; this application does not specifically limit this.

[0067] In some alternative embodiments of this application, there are multiple welding grooves 16, which are spaced apart circumferentially along the side plate 122. It is understood that the welding grooves 16 are formed because a portion of the structure of the pressure ring 13 and / or welding ring 12 is removed, which to some extent reduces the structural strength of the individual component. The multiple welding grooves 16 spaced apart circumferentially along the side plate 12 mean that welding grooves 16 are not formed at certain circumferential locations of the pressure ring 13 and / or welding ring 12. This reduces the adverse effects of forming welding grooves 16 on the structural strength and ensures structural stability.

[0068] like Figures 3-5 ,as well as Figure 8 , Figure 9 As shown in the embodiment of this application, a first welding groove 1224 is provided on the side of the side plate 122 away from the electrode assembly 30, and a second welding groove 131 is provided on the side of the pressure ring 13 away from the electrode assembly 30. The second welding groove 131 communicates with the first welding groove 1224 to form a welding groove 16.

[0069] Specifically, the first welding groove 1224 is an L-shaped groove located on the side plate 122 away from the top surface of the electrode assembly 30 along the first direction X, and radially located on the outer side of the side plate 122. The second welding groove 131 is an L-shaped groove located on the pressure ring 13 away from the top surface of the electrode assembly 30 along the first direction X, and radially located on the inner side of the pressure ring 13. The first welding groove 1224 and the second welding groove 131 together form a U-shaped welding groove 16. In this structure, the welding operation is performed at the intersection of the first welding groove 1224 and the second welding groove 131. The solder can flow more smoothly to both sides into the first welding groove 1224 and the second welding groove 131, ensuring that the solder can fully fill the welding area, improving the bonding strength of the two after welding, reducing solder accumulation, helping to reduce the solder height, and further preventing the solder from protruding from the top surface of the pressure ring 13 and the welding ring 12 along the first direction X.

[0070] Optionally, the upper plastic 14 includes a first isolation portion 141 and a second isolation portion 142. The first isolation portion 141 is disposed between the top cover plate 11 and the pressure ring 13, and the second isolation portion 142 is connected to the first isolation portion 141 and is located between the top cover plate 11 and the second side surface 1222. The upper plastic 14 also includes a third isolation portion 143. The third isolation portion 143 is connected to the side of the first isolation portion 141 away from the second isolation portion 142. The third isolation portion 143 extends in a direction away from the electrode assembly 30, and the second isolation portion 142 extends in a direction close to the electrode assembly 30. The third isolation portion 143 is connected to the outer side of the pressure ring 13.

[0071] like Figure 10 As shown, the second isolation portion 142, the first isolation portion 141, and the third isolation portion 143 are connected end to end and arranged at an angle. The first isolation portion 141 is located between the second isolation portion 142 and the third isolation portion 143. The second isolation portion 142 and the third isolation portion 143 are respectively connected to both sides of the first isolation portion 141 along the width direction. The second isolation portion 142 extends along the first direction X towards the side closer to the electrode assembly 30, and the third isolation portion 143 extends along the first direction X towards the side farther from the electrode assembly 30. That is, the second isolation portion 142 and the third isolation portion 143 extend in opposite directions along the thickness direction of the first isolation portion 141.

[0072] In this embodiment, the first isolation portion 141 can isolate the top cover plate 11 from the pressure ring 13, and the second isolation portion 142 can isolate the top cover plate 11 from the welding ring 12, thereby separating the top cover plate 11 from the pressure ring 13 and the welding ring 12, and ensuring the insulation between the pressure ring 13, the welding ring 12 and the top cover plate 11; the third isolation portion 143 extends from the first isolation portion 141 toward the side away from the electrode assembly 30, and the first isolation portion 141 and the third isolation portion 143 form an L-shaped structure, which wraps around the outer side and bottom surface of the pressure ring 13, thereby enhancing the insulation protection between the top cover plate 11 and the pressure ring 13.

[0073] Optionally, the welding ring 12 further includes a base plate 121, which is connected to the side of the side plate 122 facing the electrode assembly 30. The top cover assembly 10 also includes an insulating ring 18 and a sealing ring 17. The insulating ring 18 is connected to the side of the top cover plate 11 facing the electrode assembly 30. A portion of the insulating ring 18 is located between the top cover plate 11 and the base plate 121 in the thickness direction of the top cover plate 11, and another portion of the insulating ring 18 is located outside the ring of the base plate 121. The sealing ring 17 is located outside the ring of the side plate 122, and a portion of the sealing ring 17 is located between the top cover plate 11 and the base plate 121, while another portion of the sealing ring 17 is located between the top cover plate 11 and the side plate 122.

[0074] By providing a sealing ring 17 on the outer side of the side plate 122 of the welding ring 12, with one part of the sealing ring 17 located between the top cover plate 11 and the bottom plate 121, and the other part located between the top cover plate 11 and the side plate 122, the welding ring 12 can be insulated from the top cover plate 11. This effectively prevents electrolyte or other substances inside the battery from leaking to the outside, and also prevents external moisture or impurities from entering the battery, thereby improving the battery's sealing performance. Furthermore, the welding ring 12 is connected to the bottom plate 121 and the side plate 122, and forms a connection and support with the top cover plate 11 through the sealing ring 17, enhancing the structural stability between the welding ring 12 and the top cover plate 11. The insulating ring 18 further improves the insulation effect between the welding ring 12 and the top cover plate 11.

[0075] Optionally, a lower plastic sheet is provided on the lower side of the top cover plate 11. The lower plastic sheet is fixed to the top cover plate 11. The lower plastic sheet is provided with perforations to allow at least one of the electrode tabs and electrode posts 15 to pass through and to achieve electrical connection between the electrode tabs and electrode posts 15, such as welding.

[0076] Optionally, a first locking platform 151 is provided on the outer periphery of the electrode post 15, and a second locking platform 123 is provided on the inner side of the ring of the side plate 122. The second locking platform 123 and the first locking platform 151 are engaged in a positioning fit in the direction away from the electrode assembly 30.

[0077] It is understandable that, since the outer periphery of the terminal post 15 is provided with a first retaining plate 151 and the inner side of the side plate 122 is provided with a second retaining plate 123, the limiting cooperation between the first retaining plate 151 and the second retaining plate 123 can ensure that the terminal post 15 and the welding ring 12 are in a relatively stable state, thereby preventing the terminal post 15 from loosening or shifting due to vibration during battery use, and improving the safety and reliability of the single battery cell.

[0078] In summary, the single-cell battery provided in this application embodiment may include at least the following advantages:

[0079] In this embodiment, the side plate of the welding ring passes through the top cover plate and has a first side and a second side forming a step. The pressure ring is sleeved on the outside of the welding ring and welded to the first side. The upper plastic is sleeved on the outside of the welding ring and connected to the second side. Since the first side is located on the side of the second side away from the electrode assembly and is closer to the electrode post than the second side, when the pressure ring is welded to the first side of the welding ring, it is offset from the upper plastic on the second side in the direction inside and outside the welding ring. This avoids the welding energy from directly passing through the welding ring from the first side and damaging the upper plastic connected to the second side, thus ensuring the performance of the upper plastic and the reliability of the top cover assembly, and improving the safety of the single cell.

[0080] This application also provides a battery pack, including: a housing, and a single battery cell as described above, the housing having a mounting cavity in which the single battery cell is disposed.

[0081] Specifically, there can be multiple individual cells, which can be arranged in different directions to form an array of battery packs. The housing provides support and protection for the battery packs. It should be noted that in this embodiment, the structure of the individual cell is the same as that of any of the individual cells in the above embodiments, and its beneficial effects are similar, so it will not be described again here.

[0082] 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.

[0083] 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, include: Shell (20); Electrode assembly (30), the electrode assembly (30) being disposed within the housing (20); Top cover assembly (10), the top cover assembly (10) includes a top cover piece (11), a welding ring (12), a pole post (15), a pressure ring (13) and an upper plastic (14), the top cover piece (11) being connected to the housing (20); The welding ring (12) has a side plate (122) arranged in an annular shape. The side plate (122) passes through the top cover plate (11). The outer side of the side plate (122) is stepped and has a first side (1221) and a second side (1222). The first side (1221) is located on the side of the second side (1222) away from the electrode assembly (30). The pole post (15) is sleeved on the inner side of the welding ring (12), the pressure ring (13) and the upper plastic (14) are both sleeved on the outer side of the welding ring (12), the first side (1221) is closer to the pole post (15) than the second side (1222), and the pressure ring (13) is welded to the first side (1221), and the upper plastic (14) is connected to the second side (1222).

2. The single-cell battery according to claim 1, characterized in that, The top cover assembly (10) also includes a heat insulation layer (19) disposed between the upper plastic (14) and the pressure ring (13).

3. The single-cell battery according to claim 2, characterized in that, The first side (1221) and the second side (1222) are both arranged circumferentially around the side plate (122); the side plate (122) also has a connecting surface (1223), which is connected between the first side (1221) and the second side (1222).

4. The single-cell battery according to claim 3, characterized in that, The connecting surface (1223) is perpendicular to both the first side surface (1221) and the second side surface (1222). A portion of the heat insulation layer (19) is located between the pressure ring (13) and the connecting surface (1223), and another portion of the heat insulation layer (19) is located between the pressure ring (13) and the upper plastic (14).

5. The single-cell battery according to any one of claims 1 to 4, characterized in that, At least one of the side plate (122) and the pressure ring (13) is provided with a welding groove (16) on the side opposite to the electrode assembly (30), the welding groove (16) being used to accommodate solder.

6. The single-cell battery according to claim 5, characterized in that, The welding groove (16) is an annular groove; or, there are multiple welding grooves (16), and the multiple welding grooves (16) are arranged at intervals along the circumference of the side plate (122).

7. The single-cell battery according to claim 5, characterized in that, The side plate (122) is provided with a first welding groove (1224) on the side away from the electrode assembly (30), and the pressure ring (13) is provided with a second welding groove (131) on the side away from the electrode assembly (30). The second welding groove (131) communicates with the first welding groove (1224) and forms the welding groove (16).

8. The single-cell battery according to any one of claims 1 to 4, characterized in that, The upper plastic (14) includes a first isolation part (141) and a second isolation part (142). The first isolation part (141) is disposed between the top cover plate (11) and the pressure ring (13). The second isolation part (142) is connected to the first isolation part (141) and is located between the top cover plate (11) and the second side surface (1222). The upper plastic (14) also includes a third isolation portion (143), which is connected to the side of the first isolation portion (141) away from the second isolation portion (142). The third isolation portion (143) extends away from the electrode assembly (30), and the second isolation portion (142) extends towards the electrode assembly (30). The third isolation portion (143) is connected to the outer side of the pressure ring (13).

9. The single-cell battery according to any one of claims 1 to 4, characterized in that, The welding ring (12) further includes a base plate (121) connected to the side plate (122) facing the electrode assembly (30); the top cover assembly (10) further includes an insulating ring (18) and a sealing ring (17), the insulating ring (18) being connected to the side of the top cover plate (11) facing the electrode assembly (30), a portion of the insulating ring (18) being located between the top cover plate (11) and the base plate (121) in the thickness direction of the top cover plate (11), and another portion of the insulating ring (18) being located outside the ring of the base plate (121); the sealing ring (17) is disposed outside the ring of the side plate (122), and a portion of the sealing ring (17) being located between the top cover plate (11) and the base plate (121), and another portion of the sealing ring (17) being located between the top cover plate (11) and the side plate (122); A first locking platform (151) is provided on the outer periphery of the electrode post (15), and a second locking platform (123) is provided on the inner side of the side plate (122). The second locking platform (123) and the first locking platform (151) are engaged in a positional engagement in the direction away from the electrode assembly (30).

10. A battery pack, characterized in that, include: The housing, and the single battery cell according to any one of claims 1 to 9, wherein the single battery cell is disposed in the housing.

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