Sealing assembly, top cover and power battery

Abstract

The application relates to the technical field of power batteries, and provides a sealing assembly, a top cover and a power battery. The sealing assembly comprises a sealing main body, a sealing ring sleeved on the sealing main body, and an end cover arranged at one end of the sealing main body, at least part of the sealing main body is inserted into a first through hole, the sealing ring can seal a first gap between the sealing main body and a hole wall of the first through hole; and the end cover is welded to the hole wall of a second through hole and can seal a second gap between the end cover and the hole wall of the second through hole. The sealing assembly can form a first-level sealing on the first through hole through the sealing ring, the end cover is welded to the hole wall of the second through hole, a second-level sealing can be formed on the second through hole, the two-level sealing can better seal a liquid injection hole on a battery shell, the sealing quality can be improved, the safety and reliability of the power battery application can be improved, the sealing main body, the end cover and the sealing ring are integrated, and the assembly process can be effectively simplified.

Description

Technical Field

[0001] This application relates to the field of power battery technology, and in particular to a sealing assembly. This application also relates to a top cover using the sealing assembly, and a power battery using the top cover. Background Technology

[0002] In typical battery designs, filler plugs and filler caps are often used to seal the filler holes in the battery structure.

[0003] In the production of power batteries, the injection hole plug needs to be inserted into the injection hole using a plugging device. After plugging, the injection hole cap needs to be assembled, and then welding is performed. This process requires three steps, and the plugging and injection hole cap assembly processes each require separate equipment. This increases the production line's workflow, equipment investment, and the number of steps, which inevitably has a certain impact on the production line's yield. Utility Model Content

[0004] In view of this, this application aims to provide a sealing component to simplify the assembly process and ensure sealing quality.

[0005] To achieve the above objectives, the technical solution of this application is implemented as follows: A sealing assembly for sealing a liquid injection hole on a battery housing, the liquid injection hole including a first through hole and a second through hole that are connected, the diameter of the first through hole being smaller than the diameter of the second through hole, and the second through hole being arranged on a side close to the outside of the battery housing; The sealing assembly includes a sealing body, a sealing ring fitted onto the sealing body, and an end cap disposed at one end of the sealing body; the sealing body and the end cap are integrally formed. At least a portion of the sealing body is inserted into the first through hole, and the sealing ring is capable of sealing the first gap between the sealing body and the wall of the first through hole; the end cap is welded to the wall of the second through hole, and is capable of sealing the second gap between the end cap and the wall of the second through hole.

[0006] Furthermore, there are multiple sealing rings, which are arranged at axial intervals along the first through hole.

[0007] Furthermore, the wall of the second through hole is frustum-shaped, and the smaller diameter end of the second through hole is arranged close to the first through hole; The end cap has an outer peripheral wall that conforms to the wall of the second through hole, and the outer peripheral wall and the wall of the second through hole are fitted together.

[0008] Furthermore, the end cap can be completely embedded in the second through hole, and the outer peripheral wall includes a first outer peripheral wall and a second outer peripheral wall connected together; The first outer peripheral wall is arranged near the end of the end cap facing away from the sealing body, and the inclination angle of the first outer peripheral wall is smaller than the inclination angle of the second outer peripheral wall.

[0009] Furthermore, a first groove is formed on the end cap, the first groove is recessed toward the side where the sealing body is located, and the first groove is arranged circumferentially around the end cap.

[0010] Compared with related technologies, this application has the following advantages: (1) The sealing assembly described in this application can form a primary seal for the first through hole by setting a sealing ring on the sealing body, and can form a secondary seal for the second through hole by welding the end cap to the hole wall of the second through hole. The two-level seals work together to better seal the liquid injection hole on the battery shell, which can improve the sealing quality and improve the safety and reliability of the power battery application. The sealing assembly integrates the sealing body, end cap and sealing ring into one piece, which can effectively simplify the assembly process. The end cap can be assembled during the plugging process, which can save the end cap assembly equipment and assembly process, and also helps to improve the production line yield.

[0011] (2) Multiple sealing rings are arranged at axial intervals along the first through hole, which is equivalent to setting up multiple sealing defenses. When a sealing ring fails due to long-term use, wear, aging or abnormal pressure, the other sealing rings can still play a sealing role, thereby greatly reducing the risk of leakage, improving the reliability of the sealing assembly, and ensuring that the sealing assembly can effectively prevent electrolyte leakage under various working conditions.

[0012] (3) The wall of the second through hole is frustum-shaped and has a smaller diameter. One end is close to the first through hole. The outer peripheral wall of the end cap is set to conform to the wall of the second through hole and fits and connects with the wall of the second through hole. With this structure, during the assembly of the sealing assembly, the second through hole can restrict the installation configuration of the sealing assembly in its own axial direction, which is conducive to the tight fit between the outer peripheral wall of the end cap and the wall of the second through hole, thus ensuring a better sealing effect.

[0013] (4) The end cap can be fully embedded in the second through hole, which helps to ensure the surface of the end cap is flat and the end cap is not easily hit by external objects, which helps to ensure the sealing effect of the battery casing. The outer peripheral wall includes the first outer peripheral wall and the second outer peripheral wall connected together. The inclination angle of the first outer peripheral wall is smaller than that of the second outer peripheral wall, which can accommodate more solder, which helps to improve the welding quality and welding yield of the end cap and the battery casing.

[0014] (5) A first groove is formed on the end cap and the first groove is arranged around the circumference of the end cap. After the sealing component is assembled into the injection hole, the part of the end cap with the first groove can produce a certain plastic deformation, which can withstand a certain extrusion force and help ensure that the outer peripheral wall of the end cap and the hole wall of the second through hole are tightly fitted. At the same time, it can also prevent stress concentration to a certain extent, which helps to ensure the welding quality and welding yield of the end cap and the battery shell.

[0015] Another object of this application is to provide a top cover for sealing the opening of the main body of the battery casing, the top cover having the liquid injection hole, the liquid injection hole being sealed by the sealing assembly described above.

[0016] Furthermore, the top cover includes a top cover body and a lower plastic part disposed on one side of the top cover body, and the liquid injection hole is located on the top cover body; The lower plastic part is provided with a second groove corresponding to the injection hole. The second groove is recessed towards the side opposite to the top cover body. The bottom wall of the second groove is provided with multiple openings. The projection of the injection hole on the bottom wall is staggered with the openings.

[0017] Furthermore, the bottom wall of the second groove is stepped and includes a first bottom wall, a second bottom wall, and a connecting wall that connects the first bottom wall and the second bottom wall together. In the thickness direction of the top cover, the first bottom wall is arranged near the injection hole relative to the second bottom wall. In the length direction of the top cover, the second bottom wall is arranged near the end of the top cover relative to the first bottom wall, and the second bottom wall is arranged directly opposite the injection hole.

[0018] Furthermore, the lower plastic is provided with a first protrusion, which protrudes to the side away from the top cover body, and the lower plastic abuts against the electrode assembly inside the battery casing through the first protrusion.

[0019] The top cover of this application has the same beneficial effects as the aforementioned sealing assembly compared to the prior art. In addition, a second groove is provided on the lower plastic of the top cover, and the projection of the liquid injection hole on the bottom wall of the second groove is misaligned with the opening on the bottom wall, which can prevent the liquid injection pressure from damaging the electrode assembly inside the battery casing during liquid injection.

[0020] Furthermore, the bottom wall of the second groove is stepped and includes a first bottom wall, a second bottom wall, and a connecting wall. In the injection hole, the electrolyte can enter the battery casing not only through the opening on the second bottom wall but also through the opening on the first bottom wall, which increases the drainage path and improves the drainage effect during the injection process. The stepped bottom wall can also improve the structural strength of the bottom wall of the second groove to a certain extent, thereby effectively preventing the deformation of the bottom wall of the second groove during the vacuuming process, allowing for smooth vacuuming and improving the vacuuming effect.

[0021] The second bottom wall, relative to the end of the first bottom wall near the top cover, can reduce the space occupied by the second groove within the battery casing to a certain extent, thus facilitating the arrangement of the tabs. The first protrusion can abut against the electrode assembly inside the battery casing, effectively preventing the electrode assembly from shaking within the battery casing. It can also better prevent the tabs from blocking the openings in power batteries, thereby improving the safety and reliability of power battery applications.

[0022] Meanwhile, another objective of this application is to provide a power battery whose battery casing includes a top cover as described above.

[0023] The power battery of this application has the same beneficial effects as the aforementioned top cover compared to the prior art, and will not be repeated here. Attached Figure Description

[0024] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings: Figure 1 This is an exemplary structural diagram of the power battery described in an embodiment of this application; Figure 2 This is an exemplary cross-sectional view of the power battery described in an embodiment of this application; Figure 3 for Figure 2 Enlarged view of section A; Figure 4 This is an exemplary structural diagram of the sealing assembly described in an embodiment of this application; Figure 5 for Figure 4 A structural diagram from another perspective; Figure 6 This is an exemplary structural diagram of the top cover described in an embodiment of this application; Figure 7 for Figure 6 A structural diagram from another perspective; Figure 8 for Figure 6A structural diagram from another perspective; Figure 9 For along Figure 8 Sectional view of the middle BB line; Figure 10 for Figure 9 Enlarged view of section C; Figure 11 for Figure 10 A structural diagram in another embodiment; Figure 12 for Figure 11 A structural diagram from another perspective; Figure 13 for Figure 3 A structural diagram in another embodiment.

[0025] Explanation of reference numerals in the attached figures: 1. Power battery; 101. Main body of the housing; 102. Top cover; 103. Electrode assembly; 104. Electrode post; 105. Explosion-proof valve; 1021. Top cover body; 1022. Lower plastic; 10211, Injection hole; 10211a, First through hole; 10211b, Second through hole; 10211c, Second protrusion; 10222, Second groove; 10222a, Opening; 10222b, First protrusion; 10222c, First bottom wall; 10222d, Second bottom wall; 10222e, Connecting wall; 2. Sealing components; 201. Sealing body; 202. End cap; 203. Sealing ring; 204. Sealing gasket; 2021, First groove; 2022, Outer peripheral wall; 2022a, First outer peripheral wall; 2022b, Second outer peripheral wall; m, first gap; n, second gap. Detailed Implementation

[0026] To make the technical solution and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0027] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0028] Furthermore, it should be noted that in the description of this application, if terms such as "upper," "lower," "inner," or "outer" appear, indicating orientation or positional relationship, these are based on the orientation or positional relationship shown in the accompanying drawings and 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 on this application. In addition, if terms such as "first" or "second" appear, they are also used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0029] Furthermore, in the description of this application, unless otherwise expressly defined, the terms "installation," "connection," "joining," and "connector" 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 in light of the specific circumstances.

[0030] In this application, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which 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. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0031] The present application will now be described in detail through exemplary embodiments. However, it should be understood that, without further description, elements, structures, and features in one embodiment may be advantageously incorporated into other embodiments.

[0032] An embodiment of the first aspect of this application provides a sealing component that, by improving its structure, simplifies the assembly process of the sealing component, thereby helping to ensure product qualification rate and sealing effect.

[0033] In related technologies, during the design process of power batteries, a plug and a cap for the injection hole are often used to seal the injection hole of the battery structure.

[0034] In the production process of power batteries, the injection hole plug needs to be inserted into the injection hole using a plugging device. After plugging, the injection hole cap needs to be assembled, and then welding is performed. This processing requires three steps, and the plugging process and the injection hole cap assembly process each require separate equipment, which increases the production line flow and equipment investment. At the same time, the large number of steps will inevitably have a certain impact on the yield of the production line.

[0035] In view of this, in order to overcome the shortcomings of the related technology, the sealing component 2 in this embodiment is used to seal the liquid injection hole 10211 on the battery casing, combined with Figures 2 to 5 As shown, in terms of overall design, the sealing assembly 2 includes a sealing body 201, a sealing ring 203 fitted onto the sealing body 201, and an end cap 202 located at one end of the sealing body 201. The sealing body 201 and the end cap 202 are integrally formed, for example, by a casting process.

[0036] To better understand the sealing component 2 in this embodiment, please refer to the following: Figure 1 and Figure 2 A brief description of the structure of power battery 1 is provided.

[0037] The power battery 1 mainly includes a battery casing and an electrode assembly 103 disposed in a cavity within the battery casing. The battery casing includes a casing body 101 and a top cover 102, which together form a cavity in which the electrode assembly 103 is installed.

[0038] The top cover 102 mainly includes a top cover body 1021 and a lower plastic 1022 disposed on the side of the top cover body 1021 facing the pole assembly 103. The structure and material of the top cover body 1021 and the lower plastic 1022 can refer to relevant technologies.

[0039] In this embodiment, the sealing component 2 seals the injection hole 10211, which is specifically located on the top cover body 1021. Figure 3 As shown, the injection hole 10211 includes a first through hole 10211a and a second through hole 10211b that are connected. The diameter of the first through hole 10211a is smaller than the diameter of the second through hole 10211b, and the second through hole 10211b is arranged on the side close to the outside of the battery casing.

[0040] At least a portion of the sealing body 201 is inserted into the first through hole 10211a, and the sealing ring 203 can seal the first gap m between the sealing body 201 and the wall of the first through hole 10211a; the end cap 202 is welded to the wall of the second through hole 10211b, and can seal the second gap n between the end cap 202 and the wall of the second through hole 10211b. It should be noted that the diameter of the sealing body 201 is slightly smaller than the diameter of the second through hole 10211b.

[0041] In a preferred embodiment, the sealing plug body in this example, axially along the second through hole 10211b, refers to Figure 3In the middle, the upper part of the sealing body 201 protrudes upward outside the second through hole 10211b, and the lower part of the sealing body 201 protrudes downward outside the second through hole 10211b, so as to ensure the sealing effect of the second through hole 10211b.

[0042] It should be noted that, in a preferred embodiment, both the first through hole 10211a and the second through hole 10211b are cylindrical, and the sealing body 201 is also cylindrical. A groove is provided on the outer wall of the sealing body 201, arranged circumferentially around it. The aforementioned sealing ring 203 is embedded in the groove. During the insertion of the sealing body 201 into the first through hole 10211a, the sealing ring 203 is effectively prevented from shifting, and the sealing ring 203 and the wall of the first through hole 10211a are interference-fitted.

[0043] In one example, the cross-section of the groove is semi-circular, and the cross-section of the sealing ring 203 is circular, so that the sealing ring 203 is firmly and reliably installed on the sealing body 201, and the sealing body 201 with the sealing ring 203 fitted on it can be easily inserted into the first through hole 10211a. It should be understood that, according to actual needs, the cross-sectional shape of the groove and the cross-sectional shape of the sealing ring 203 can be changed.

[0044] The sealing assembly 2 described in this application, by providing a sealing ring 203 on the sealing body 201, can form a primary seal for the first through hole 10211a. By welding the end cap 202 to the hole wall of the second through hole 10211b, a secondary seal can be formed for the second through hole 10211b. The cooperation of the two seals can better seal the liquid injection hole 10211 on the battery casing, thereby improving the sealing quality and enhancing the safety and reliability of the power battery 1 application.

[0045] In addition, the sealing assembly 2 integrates the sealing body 201, end cap 202 and sealing ring 203 into one unit, which can effectively simplify the assembly process. The end cap 202 can be assembled during the plugging process, which can save the assembly equipment and assembly process of the end cap 202, and also help improve the yield of the production line.

[0046] To improve the sealing effect, in some exemplary embodiments, there are multiple sealing rings 203, which are arranged at axial intervals along the first through hole 10211a.

[0047] In this embodiment, multiple sealing rings 203 are arranged at axial intervals along the first through hole 10211a, which is equivalent to setting up multiple sealing defenses. When one sealing ring 203 fails to seal due to long-term use, wear, aging, or abnormal pressure, the other sealing rings 203 can still play a sealing role, thereby greatly reducing the risk of leakage, improving the reliability of the entire sealing assembly 2, and ensuring that the sealing assembly 2 can effectively prevent electrolyte leakage under various operating conditions.

[0048] To improve the sealing effect, refer to Figure 3 As shown, in some exemplary embodiments, the wall of the second through hole 10211b is frustoconical, and the smaller diameter end of the second through hole 10211b is arranged close to the first through hole 10211a. The end cap 202 has an outer peripheral wall 2022 conforming to the wall of the second through hole 10211b, and the outer peripheral wall 2022 is fitted and connected to the wall of the second through hole 10211b.

[0049] Here, the wall of the second through hole 10211b is frustoconical with a smaller diameter end close to the first through hole 10211a. The outer peripheral wall 2022 of the end cap 202 is conformed to the wall of the second through hole 10211b and fits and connects with the wall of the second through hole 10211b. With this structure, during the assembly of the sealing assembly 2, the second through hole 10211b can restrict the installation configuration of the sealing assembly 2 in its own axial direction, which is conducive to the tight fit of the outer peripheral wall 2022 of the end cap 202 and the wall of the second through hole 10211b, thus ensuring a better sealing effect.

[0050] Continue to refer to Figure 3 As shown, in some exemplary embodiments, the end cap 202 can be fully embedded in the second through hole 10211b, and the outer peripheral wall 2022 includes a first outer peripheral wall 2022a and a second outer peripheral wall 2022b connected together; the first outer peripheral wall 2022a is arranged near the end of the end cap 202 facing away from the sealing body 201, and the inclination angle of the first outer peripheral wall 2022a is smaller than the inclination angle of the second outer peripheral wall 2022b.

[0051] It should be noted that the inclination angle of the first outer peripheral wall 2022a mentioned here refers to the angle between the first outer peripheral wall 2022a on one side and the axial centerline of the sealing body 201 on the longitudinal section of the sealing body 201. The inclination angle of the second outer peripheral wall 2022b refers to the angle between the second outer peripheral wall 2022b on one side and the axial centerline of the sealing body 201 on the longitudinal section of the sealing body 201.

[0052] In the above embodiment, the end cap 202 can be completely embedded in the second through hole 10211b, which helps to ensure the surface of the end cap 202 is flat and the end cap 202 is not easily impacted by external objects, thus ensuring a good seal for the battery casing. The outer peripheral wall 2022 includes a first outer peripheral wall 2022a and a second outer peripheral wall 2022b connected together. The inclination angle of the first outer peripheral wall 2022a is smaller than that of the second outer peripheral wall 2022b, which can accommodate more solder, thus improving the welding quality and welding yield of the end cap 202 and the battery casing.

[0053] Depend on Figures 3 to 5 As shown, in some exemplary embodiments, the end cap 202 is formed with a first groove 2021, which is recessed toward the side where the sealing body 201 is provided, and the first groove 2021 is arranged circumferentially around the end cap 202.

[0054] Here, a first groove 2021 is formed on the end cap 202, and the first groove 2021 is arranged around the circumference of the end cap 202. After the sealing component 2 is assembled into the injection hole 10211, the part of the end cap 202 with the first groove 2021 can undergo a certain plastic deformation, which can withstand a certain extrusion force and help ensure that the outer peripheral wall 2022 of the end cap 202 and the hole wall of the second through hole 10211b are tightly fitted. At the same time, it can also prevent stress concentration to a certain extent, which helps to ensure the welding quality and welding yield of the end cap 202 and the battery casing.

[0055] It is worth noting that, regarding the sealing component 2 of this embodiment, based on the above exemplary embodiments, in specific implementation, as a preferred embodiment, it is still composed of... Figures 1 to 5 As shown, it may include, for example, a sealing body 201, a sealing ring 203 disposed on the sealing body 201, and an end cap 202 disposed at one end of the sealing body 201; the sealing body 201 and the sealing ring 203 are integrally formed.

[0056] At least a portion of the sealing body 201 is inserted into the first through hole 10211a, and the sealing ring 203 can seal the first gap m between the sealing body 201 and the hole wall of the first through hole 10211a; the end cap 202 is welded to the hole wall of the second through hole 10211b, and can seal the second gap n between the end cap 202 and the hole wall of the second through hole 10211b.

[0057] In the preferred embodiment of the sealing component 2 above, the specific settings and arrangements of the sealing ring 203, end cap 202, sealing body 201, etc. can still be referred to the descriptions in the above exemplary embodiments. Furthermore, in this preferred embodiment, the beneficial effects brought about by the design of the sealing ring 203, end cap 202, and sealing body 201, etc., can also be referred to the descriptions in the above exemplary embodiments.

[0058] In one example, in order to allow the sealing body 201 to be smoothly inserted into the first through hole 10211a, the following is still referred to Figure 3 As shown, a guide portion is provided at the end of the sealing body 201 away from the end cap 202, that is, at the end of the sealing body 201 that is first inserted into the first through hole 10211a. Specifically, the guide portion is a chamfer or rounded corner provided at the end of the sealing body 201, so that the sealing body 201 can be smoothly inserted into the first through hole 10211a, thereby improving assembly efficiency.

[0059] The sealing component 2 of this application simplifies the structure of the injection port seal. The end cap 202 and the sealing plug body are integrally formed. In the injection port sealing stage, after the sealing component 2 is inserted into place, only laser welding is required.

[0060] In related technologies, during the electrolyte injection process of power battery 1, the injection volume is generally large, and power battery 1 is generally injected multiple times, with the injection pressure gradually reduced, to prevent the electrolyte from overflowing from the injection hole 10211 onto the surface of the top cover 102, thereby preventing the overflowing electrolyte from affecting the welding quality.

[0061] After electrolyte injection is completed, the inside of the power battery 1 is evacuated, and then the sealing assembly 2 is sealed. During the evacuation process, the tabs of the electrode assembly 103 are affected by the negative pressure inside the cell, which may cause the tabs to block the opening 10222a on the lower plastic 1022. The opening 10222a here refers to the opening 10222a on the lower plastic 1022 that facilitates the entry of electrolyte into the internal cavity of the battery casing. Once the tabs block the opening 10222a on the lower plastic 1022, it will affect the negative pressure and the efficiency and effectiveness of the vacuum process.

[0062] In view of this, the second aspect of the present application relates to a top cover 102 for sealing the opening of the housing body 101 in the battery housing, the top cover 102 having an injection hole 10211, the injection hole 10211 being sealed by the sealing assembly 2 as described above.

[0063] The top cover 102 of this application, by applying the aforementioned sealing component 2, can better ensure the sealing performance of the battery casing, thereby improving the safety and reliability of the power battery 1 application.

[0064] like Figures 6 to 9 As shown, in some exemplary embodiments, the top cover 102 includes a top cover body 1021 and a lower plastic 1022 disposed on one side of the top cover body 1021, with an injection hole 10211 located on the top cover body 1021. The structures of the top cover body 1021 and the lower plastic 1022 can both refer to the structures in the related art.

[0065] In detail, in this application, the injection hole 10211 is arranged near one end of the top cover 102 along the length of the top cover 102, and an electrode post 104 is provided on the top cover 102 near the other end of the top cover 102.

[0066] like Figure 9 and Figure 10 As shown, the lower plastic 1022 has a second groove 10222 at the location corresponding to the injection hole 10211. The second groove 10222 is recessed towards the side facing away from the top cover body 1021. The bottom wall of the second groove 10222 has multiple openings 10222a. The projection of the injection hole 10211 on the bottom wall is staggered with the openings 10222a.

[0067] In this embodiment, a second groove 10222 is provided on the lower plastic 1022 of the top cover 102, and the projection of the injection hole 10211 on the bottom wall of the second groove 10222 is misaligned with the opening 10222a on the bottom wall, which can prevent the injection pressure from damaging the electrode assembly 103 inside the battery casing during injection.

[0068] In some exemplary embodiments, the bottom wall of the second groove 10222 is stepped and includes a first bottom wall 10222c, a second bottom wall 10222d, and a connecting wall 10222e that connects the first bottom wall 10222c and the second bottom wall 10222d together.

[0069] In detail, the second groove 10222 includes an inner groove and an outer groove that are connected. The depth of the inner groove is less than the depth of the outer groove. The outer groove is arranged corresponding to the injection hole 10211. The bottom wall of the inner groove forms a first bottom wall 10222c, and the bottom wall of the outer groove forms a second bottom wall 10222d.

[0070] In a preferred embodiment, along the length of the top cover 102, the first bottom wall 10222c is arranged near the injection hole 10211 relative to the second bottom wall 10222d, and along the length of the top cover 102, the second bottom wall 10222d is arranged near the end of the top cover 102 relative to the first bottom wall 10222c, and the second bottom wall 10222d is arranged directly opposite the injection hole 10211.

[0071] In the above embodiment, the bottom wall of the second groove 10222 is stepped and includes a first bottom wall 10222c, a second bottom wall 10222d, and a connecting wall 10222e. In the injection hole 10211, the electrolyte can enter the battery housing not only through the opening 10222a on the second bottom wall 10222d, but also through the opening 10222a on the first bottom wall 10222c, which increases the drainage path and improves the drainage effect during the injection process.

[0072] In a preferred embodiment, both the first bottom wall 10222c and the second bottom wall 10222d are provided with multiple openings 10222a. Due to the limitation of the electrolyte filling speed, the added battery fluid can enter the receiving cavity of the battery casing through the openings 10222a on the second bottom wall 10222d, and can also enter the receiving cavity of the battery casing simultaneously through the openings 10222a on the first bottom wall 10222c and the second bottom wall 10222d.

[0073] Furthermore, the stepped bottom wall can improve the structural strength of the bottom wall of the second groove 10222 to a certain extent, thereby effectively preventing deformation of the bottom wall of the second groove 10222 during the vacuuming process, allowing for smooth vacuuming and improving the vacuuming effect. The second bottom wall 10222d, relative to the end of the first bottom wall 10222c near the top cover 102, can reduce the space occupied by the second groove 10222 within the battery casing, thus facilitating the arrangement of the electrode tabs.

[0074] In one example, there are multiple openings 10222a, and multiple openings 10222a are provided on both the first bottom wall 10222c and the second bottom wall 10222d, which can better disperse the impact force on the electrode assembly 103 during the liquid injection process. The shape of the opening 10222a is preferably circular, but other shapes can also be used, such as square, triangular, rhomboid, or irregular shapes.

[0075] like Figure 11 and Figure 12 As shown, in some exemplary embodiments, the lower plastic 1022 is provided with a first protrusion 10222b, which protrudes to the side away from the top cover body 1021, and the lower plastic 1022 abuts against the electrode assembly 103 inside the battery housing through the first protrusion 10222b.

[0076] Here, the first protrusion 10222b can abut against the electrode assembly 103 inside the battery casing, which can effectively prevent the electrode assembly 103 from shaking inside the battery casing. At the same time, it can also better prevent the tab from blocking the opening 10222a. When applied to the power battery 1, it helps to improve the safety and reliability of the power battery 1 application.

[0077] In a preferred embodiment, the first protrusion 10222b is annular and made of a thin plate. Specifically, the first protrusion 10222b is arranged circumferentially around the second bottom wall 10222d, which can better abut against the electrode assembly 103. It should be noted that the first protrusion 10222b can be annular or made of a thin plate to form other shapes. It should be noted that the thin plate and the opening 10222a are staggered, as long as it does not affect the liquid injection.

[0078] To ensure welding quality, in some exemplary embodiments, such as Figure 13 As shown, a second protrusion 10211c is provided on the bottom wall of the second through hole 10211b. The second protrusion 10211c is annular and is arranged circumferentially around the first through hole 10211a.

[0079] In the above embodiment, the second protrusion 10211c can, to a certain extent, prevent electrolyte from entering the outer area of ​​the second protrusion 10211c during the electrolyte filling process, thereby reducing contamination of the hole wall of the second through hole 10211b. This helps to ensure the welding quality of the end cap 202 and the top cap body 1021, thus ensuring the sealing effect of the sealing assembly 2 on the injection hole 10211.

[0080] Meanwhile, the embodiments of the third aspect of this application relate to a power battery 1, which includes a top cover 102 for the battery casing as described above.

[0081] In one example, such as Figure 2 As shown, the housing body 101 has openings at both the top and bottom, and each opening is sealed with a top cover 102. Each top cover 102 has a terminal post 104, and one of the top covers 102 has an injection hole 10211. At the same time, an explosion-proof valve 105 is provided on one side of the housing body 101 to facilitate the arrangement of the power battery 1 in the battery pack.

[0082] Still refer to Figure 13 As shown, in a preferred embodiment, an annular sealing gasket 204 is provided between the end cap 202 and the bottom wall of the second through hole 10211b, which can seal the gap between the end cap 202 and the bottom wall of the second through hole 10211b.

[0083] Here, the bottom wall of the second through hole 10211b is the plane that transitions between the first through hole 10211a and the second through hole 10211b. Adding a sealing gasket 204 between the end cap 202 and the bottom wall of the second through hole 10211b can add an extra seal and improve the sealing effect of the sealing assembly 2.

[0084] It should be noted that in this application, the sealing ring 203 and the sealing gasket 204 are made of materials such as rubber and silicone. The sealing gasket 204 can be fixed to one end of the bottom wall of the end cap 202 facing the second through hole 10211b by means of adhesive bonding, so as to facilitate the assembly of the sealing assembly 2.

[0085] The above descriptions are merely some embodiments of this application and are not intended to limit this application. The technical features or structures in the foregoing different embodiments can be arbitrarily combined to form other specific technical solutions as needed. For those skilled in the art, this application can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of this application should be included within the protection scope of the claims of this application.

Claims

1. A sealing assembly for sealing a liquid injection hole on a battery casing, characterized in that: The injection hole includes a first through hole and a second through hole that are connected to each other. The diameter of the first through hole is smaller than the diameter of the second through hole, and the second through hole is arranged on the side close to the outside of the battery casing. The sealing assembly includes a sealing body, a sealing ring fitted onto the sealing body, and an end cap disposed at one end of the sealing body; the sealing body and the end cap are integrally formed. At least a portion of the sealing body is inserted into the first through hole, and the sealing ring is capable of sealing the first gap between the sealing body and the wall of the first through hole; the end cap is welded to the wall of the second through hole, and is capable of sealing the second gap between the end cap and the wall of the second through hole.

2. The sealing assembly according to claim 1, characterized in that: There are multiple sealing rings, and the multiple sealing rings are arranged at axial intervals along the first through hole.

3. The sealing assembly according to claim 1, characterized in that: The wall of the second through hole is frustum-shaped, and the smaller diameter end of the second through hole is arranged close to the first through hole; The end cap has an outer peripheral wall that conforms to the wall of the second through hole, and the outer peripheral wall and the wall of the second through hole are fitted together.

4. The sealing assembly according to claim 3, characterized in that: The end cap can be completely embedded in the second through hole, and the outer peripheral wall includes a first outer peripheral wall and a second outer peripheral wall connected together; The first outer peripheral wall is arranged near the end of the end cap facing away from the sealing body, and the inclination angle of the first outer peripheral wall is smaller than the inclination angle of the second outer peripheral wall.

5. The sealing assembly according to any one of claims 1-4, characterized in that: The end cap has a first groove formed therein, the first groove is recessed toward the side where the sealing body is located, and the first groove is arranged circumferentially around the end cap.

6. A top cover for sealing an opening in the main body of a battery casing, characterized in that, The top cover is provided with the injection hole, which is sealed by a sealing component as described in any one of claims 1-5.

7. The top cover according to claim 6, characterized in that: The top cover includes a top cover body and a lower plastic part disposed on one side of the top cover body, and the liquid injection hole is located on the top cover body; The lower plastic part is provided with a second groove corresponding to the injection hole. The second groove is recessed towards the side opposite to the top cover body. The bottom wall of the second groove is provided with multiple openings. The projection of the injection hole on the bottom wall is staggered with the openings.

8. The top cover according to claim 7, characterized in that: The bottom wall of the second groove is stepped and includes a first bottom wall, a second bottom wall, and a connecting wall that connects the first bottom wall and the second bottom wall together. In the thickness direction of the top cover, the first bottom wall is arranged near the injection hole relative to the second bottom wall. In the length direction of the top cover, the second bottom wall is arranged near the end of the top cover relative to the first bottom wall, and the second bottom wall is arranged directly opposite the injection hole.

9. The top cover according to claim 7, characterized in that: The lower plastic is provided with a first protrusion, which protrudes to the side away from the top cover body, and the lower plastic abuts against the electrode assembly inside the battery casing through the first protrusion.

10. A power battery, characterized in that: The battery casing of the power battery includes a top cover as described in any one of claims 6-9.

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