Battery injection structure, power battery, battery pack and electric vehicle

Abstract

The present application discloses a battery injection structure, a power battery, a battery pack and an electric vehicle, wherein at least a portion of the battery injection structure is disposed in the injection hole of the battery top cover, and the battery injection structure includes: a welding ring disposed on the side of the injection hole away from the battery cell, the side wall of the welding ring being fixedly connected to the side wall of the injection hole, and at least one pressure relief hole being disposed on the welding ring; a moving part, wherein the moving part is disposed on the side of the injection hole close to the battery cell, and the moving part abuts against the side wall of the injection hole, the welding ring, the moving part and the side wall of the injection hole enclose a cavity, and the pressure relief hole is connected to the cavity; a sealing ring, wherein the sealing ring is disposed between the side wall of the moving part and the side wall of the injection hole; an elastic part, wherein the two ends of the elastic part are respectively connected to the welding ring and the moving part, and the elastic part can extend or shorten along a preset direction to drive the moving part to move in a direction away from or close to the welding ring. The present application realizes repeated injection and repeated pressure relief of the battery injection structure by arranging the elastic part, thereby improving the service life of the power battery.

Description

Technical Field

[0001] The present application relates to the technical field of battery top covers, and in particular to a battery liquid injection structure, a power battery, a battery pack and an electric vehicle. Background Art

[0002] Existing power battery top covers typically seal the liquid injection port with a rubber plug, which is then welded to the top cover with aluminum nails. While this sealing method completely seals the injection port, it only allows for a single injection. If electrolyte needs to be added later, it cannot be added, forcing the entire battery to be scrapped, resulting in losses.

[0003] At the same time, the existing battery top cover is explosion-proof by setting an explosion-proof plate. When the internal pressure of the battery is too high, the explosion-proof plate is used to blast to release the pressure and avoid battery explosion. However, once the explosion-proof plate explodes due to overpressure, it must be replaced.

[0004] Therefore, there is an urgent need to provide a battery filling structure, power battery, battery pack and electric vehicle. The filling holes and explosion-proof plates in the existing technology cannot be reused, resulting in a technical problem of a short battery top cover life. Summary of the Invention

[0005] The present application provides a battery liquid injection structure, a power battery, a battery pack and an electric vehicle, aiming to solve the technical problem in the prior art that the liquid injection hole and the explosion-proof plate cannot be reused, resulting in a short life of the battery top cover.

[0006] In a first aspect, the present application provides a battery liquid injection structure, at least a portion of which is disposed within a liquid injection hole of a battery top cover, the battery liquid injection structure comprising:

[0007] A welding ring, the welding ring is arranged on a side of the liquid injection hole away from the battery core, the side wall of the welding ring is fixedly connected to the side wall of the liquid injection hole, and at least one pressure relief hole is provided on the welding ring;

[0008] a moving member, the moving member being disposed on a side of the liquid injection hole close to the battery core, and the moving member abutting against a side wall of the liquid injection hole, the welding ring, the moving member, and the side wall of the liquid injection hole enclosing a cavity, and the at least one pressure relief hole being in communication with the cavity;

[0009] A sealing ring, the sealing ring being arranged between a side wall of the moving part and a side wall of the liquid injection hole;

[0010] An elastic member, wherein both ends of the elastic member are respectively connected to the welding ring and the moving member, and the elastic member can be extended or shortened along a preset direction to drive the moving member to move in a direction away from or close to the welding ring.

[0011] In a possible implementation of the present application, both ends of the elastic member are fixedly connected or detachably connected to the welding ring and the movable member respectively.

[0012] In a possible implementation of the present application, the welding ring includes a first threaded hole opened on the welding ring, the movable part includes a second threaded hole opened on the fixed ring, and the elastic part includes an elastic part body and a first threaded portion and a second threaded portion respectively threadedly connected to the first threaded hole and the second threaded hole.

[0013] In a possible implementation of the present application, the welding ring also includes a first welding ring body and a second welding ring body fixedly connected to the first welding ring body, the second welding ring body is arranged on a side of the first welding ring body close to the moving part, and the first threaded hole is opened on the second welding ring body.

[0014] In a possible implementation of the present application, the moving part also includes a first moving part body and a second moving part body fixedly connected to the first moving part body, the second moving part body is arranged on a side of the first moving part body close to the welding ring, and the second threaded hole is opened on the second moving part body.

[0015] In a possible implementation of the present application, the movable part also includes a through hole opened on the first movable part body, the welding ring also includes a third welding ring body fixedly connected to the second welding ring body, the elastic part is wrapped around the third welding ring body, and the third welding ring body passes through the through hole.

[0016] In a possible implementation of the present application, a sliding seal is provided between the third welding ring body and the through hole.

[0017] In a possible implementation of the present application, the elastic member is a spring.

[0018] In a possible implementation of the present application, the welding ring includes a guide groove, the movable member includes a sliding portion, the sliding portion is arranged in the guide groove, the two ends of the elastic member are respectively connected to the sliding portion and the guide groove, and the sliding portion can slide along the guide groove to drive the movable member to move in a direction away from or close to the welding ring.

[0019] In a possible implementation of the present application, the welding ring includes a blind hole, the movable part includes an extending shaft, the extending shaft extends into the blind hole, the two ends of the elastic part are respectively connected to the extending shaft and the inner wall of the blind hole, and the extending shaft can slide along the inner wall of the blind hole to drive the movable part to move in a direction away from or close to the welding ring.

[0020] In a possible implementation of the present application, the injection hole includes a first sub-injection hole and a second sub-injection hole connected to the first sub-injection hole, the welding ring is fixedly connected to the side wall of the first sub-injection hole, and the movable part abuts against the side wall of the second sub-injection hole; the battery top cover includes a first surface and a second surface arranged opposite to each other, and along the direction from the first surface to the second surface, the diameter of the first sub-injection hole gradually decreases, the diameter of the second sub-injection hole is the same, and the minimum diameter of the first sub-injection hole is the same as the diameter of the second sub-injection hole.

[0021] In a possible implementation of the present application, the welding ring includes a top surface, and the top surface is located at the same height as the first surface.

[0022] In a possible implementation of the present application, the top cover includes a first top cover and a second top cover fixedly connected to the first top cover on a side away from the moving part, the injection hole passes through the first top cover and the second top cover, the second top cover includes a third surface away from the side of the first top cover, the welding ring includes a top surface away from the moving part, and the top surface and the third surface are at the same height.

[0023] In a possible implementation of the present application, the distance between the first surface and the third surface is less than or equal to 10 mm.

[0024] In a possible implementation of the present application, the outer wall of the moving part is provided with a groove for accommodating a sealing ring, one end of the sealing ring abuts against the groove, and the other end of the sealing ring abuts against the side wall of the liquid injection hole.

[0025] In a second aspect, the present application further provides a power battery, comprising a battery liquid injection structure, wherein the battery liquid injection structure is the battery liquid injection structure in any of the above-mentioned implementations.

[0026] In a third aspect, the present application further provides a battery pack, comprising a battery liquid injection structure, wherein the battery liquid injection structure is the battery liquid injection structure in any of the above-mentioned implementation methods.

[0027] In a third aspect, the present application also provides an electric vehicle, comprising a battery injection structure, wherein the battery injection structure is the battery injection structure in any of the above-mentioned implementations.

[0028] Compared with the prior art, the present application sets an elastic part. When liquid needs to be injected into the battery, the liquid is injected through the pressure relief hole set on the welding ring. As the amount of injected liquid increases, the pressure on the movable part becomes greater and greater. The movable part drives the elastic part to move in the direction close to the battery cell until the cavity is connected to the interior of the battery. The liquid is injected into the battery through the pressure relief hole and the cavity to achieve liquid injection. When the liquid injection is completed, the movable part is reset under the drive of the elastic part to achieve repeated liquid injection. When a large air pressure is generated inside the battery, the movable part drives the elastic part to move in the direction close to the welding ring until the cavity is connected to the interior of the battery. The gas flows out to the outside of the battery through the cavity and the pressure relief hole to achieve pressure relief. When the pressure relief is completed, the movable part is reset under the drive of the elastic part to achieve repeated pressure relief. Therefore, the battery liquid injection structure of the present application can achieve repeated pressure relief and repeated liquid injection, thereby improving the service life of the battery top cover. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0030] Figure 1 Schematic diagram of the battery injection structure provided in an embodiment of the present application;

[0031] Figure 2 Schematic diagram of the structure of the welding ring provided in the embodiment of the present application;

[0032] Figure 3 It is a structural diagram of the moving part provided in the embodiment of the present application;

[0033] Figure 4 is a bottom view of a welding ring provided in an embodiment of the present application;

[0034] Figure 5 is a top view of the moving part provided in an embodiment of the present application;

[0035] Figure 6 This is a structural diagram of a movable connection method between a welding ring and a moving part provided in an embodiment of the present application;

[0036] Figure 7 This is a structural diagram of another movable connection method between the welding ring and the moving part provided in an embodiment of the present application;

[0037] Figure 8 This is a schematic structural diagram of the liquid injection hole provided in an embodiment of the present application;

[0038] Figure 9This is another structural diagram of the battery injection structure provided in the embodiment of the present application.

[0039] Figure 10 This is a schematic diagram of the structure of the battery liquid injection structure provided in an embodiment of the present application during liquid injection;

[0040] Figure 11 It is a structural schematic diagram of the battery liquid injection structure provided in an embodiment of the present application during pressure relief. DETAILED DESCRIPTION

[0041] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without making creative efforts are within the scope of protection of this application.

[0042] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the said features. In the description of the present application, "multiple" means two or more, unless otherwise clearly and specifically defined.

[0043] In this application, the word "exemplary" is used to mean "serving as an example, illustration, or illustration." Any embodiment described in this application as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. The following description is given to enable any person skilled in the art to implement and use the present application. In the following description, details are listed for the purpose of explanation. It should be understood that one of ordinary skill in the art can recognize that the present application can be implemented without using these specific details. In other instances, well-known structures and processes are not elaborated in detail to avoid obscuring the description of the present application with unnecessary details. Therefore, the present application is not intended to be limited to the embodiments shown, but is consistent with the widest scope consistent with the principles and features disclosed in this application.

[0044] The embodiments of the present application provide a battery liquid injection structure, a power battery, a battery pack and an electric vehicle, which are described in detail below.

[0045] like Figure 1 As shown in FIG. 1 , a battery liquid injection structure provided in an embodiment of the present application is provided. At least a portion of the battery liquid injection structure 10 is disposed in the liquid injection hole 21 of the battery top cover 20 . The battery liquid injection structure 10 includes:

[0046] The welding ring 100 is arranged on the side of the liquid injection hole away from the battery cell. The side wall of the welding ring 100 is fixedly connected to the side wall of the liquid injection hole 21, and at least one pressure relief hole 101 is provided on the welding ring 100;

[0047] The movable member 200 is disposed on a side of the liquid injection hole close to the battery cell, and the movable member 200 abuts against the side wall of the liquid injection hole 21. The welding ring 100, the movable member 200 and the side wall of the liquid injection hole 21 enclose a cavity 201, and the at least one pressure relief hole 101 is in communication with the cavity 201;

[0048] The sealing ring 300 is provided between the side wall of the moving member 200 and the side wall of the liquid injection hole 21;

[0049] The elastic member 400 has two ends connected to the welding ring 100 and the moving member 200 respectively. The elastic member 400 can be extended or shortened along a preset direction to drive the moving member 200 to move away from or close to the welding ring 100.

[0050] In the embodiment of the present application, an elastic member 400 is provided. When liquid needs to be injected into the battery, the liquid is injected through the pressure relief hole 101 provided on the welding ring 100. As the amount of injected liquid increases, the pressure on the movable member 200 becomes greater and greater. The movable member 200 drives the elastic member 400 to move toward the direction close to the battery cell. The elastic member 400 stretches along a preset direction until the cavity 201 is connected with the interior of the battery. The liquid flows into the interior of the battery through the pressure relief hole 101 and the cavity 201 to achieve liquid injection. When the liquid injection is completed, the movable member 200 is reset under the drive of the elastic member 400 to achieve repeated liquid injection. When a high air pressure is generated inside the battery, the movable part 200 drives the elastic part 400 to move toward the welding ring 100, and the elastic part 400 shortens along the preset direction until the cavity 201 is connected with the interior of the battery. The gas flows out to the outside of the battery through the cavity 201 and the pressure relief hole 101 to achieve pressure relief. When the pressure relief is completed, the movable part 200 is reset under the drive of the elastic part 400 to achieve repeated pressure relief. The battery liquid injection structure 10 of the embodiment of the present application can achieve repeated pressure relief and repeated liquid injection, thereby improving the service life of the battery top cover 20.

[0051] It should be understood that the number of the pressure relief holes 101 can be one or more, which is not limited here and can be adjusted according to actual needs.

[0052] Furthermore, in some embodiments of the present application, both ends of the elastic member 400 are fixedly connected or detachably connected to the welding ring 100 and the moving member 200 .

[0053] The two ends of the elastic member 400 can be connected to the welding ring 100 and the moving member 200 by welding. Through the above arrangement, the connection between the two ends of the elastic member 400 and the welding ring 100 and the moving member 200 is stable and reliable.

[0054] Preferably, both ends of the elastic member 400 are detachably connected to the welding ring 100 and the movable member 200. With the above arrangement, the elastic member 400 can be replaced in time when damaged without having to replace the welding ring 100 and the movable member 200 at the same time, further improving the life of the battery injection structure 10.

[0055] Specifically, if Figure 1 、 Figure 4 and Figure 5 As shown, the welding ring 100 includes a first threaded hole 110 opened on the welding ring 100, the movable part 200 includes a second threaded hole 210 opened on the fixed ring 200, and the elastic part 400 includes an elastic part body 410 and a first threaded portion (not shown in the figure) and a second threaded portion (not shown in the figure) threadedly connected to the first threaded hole 110 and the second threaded hole 210 respectively.

[0056] It should be understood that the center lines of the first threaded hole 110 and the second threaded hole 210 coincide with each other.

[0057] It should be noted that the above-mentioned threaded connection is only one of the detachable connection methods between the two ends of the elastic member 400 and the welding ring 100 and the movable member 200. In some embodiments of the present application, the two ends of the elastic member 400 and the welding ring 100 and the movable member 200 can be detachably connected through a snap-fit connection method.

[0058] Furthermore, if Figure 2 As shown, the welding ring 100 also includes a first welding ring body 120 and a second welding ring body 130 fixedly connected to the first welding ring body 120 . The second welding ring body 130 is arranged on a side of the first welding ring body 120 close to the moving part 200 , and the first threaded hole 110 is opened on the second welding ring body 130 .

[0059] Through the above arrangement, the elastic member 400 can be threadedly connected to the welding ring 100 while ensuring the strength of the welding ring 100, thereby avoiding the situation where the welding ring 100 at the first threaded hole 110 is easily damaged when only the first welding ring body 120 is provided and the first threaded hole 110 is opened on it, thereby improving the reliability of the welding ring 100.

[0060] Furthermore, if Figure 3As shown, the moving member 200 also includes a first moving member body 220 and a second moving member body 230 fixedly connected to the first moving member body 220. The second moving member body 230 is arranged on a side of the first moving member body 210 close to the welding ring 100, and the second threaded hole 210 is opened on the second moving member body 230.

[0061] Through the above-mentioned setting, the strength of the moving part 200 can be guaranteed while the threaded connection between the elastic part 400 and the moving part 200 is achieved, avoiding the situation when only the first moving part body 220 is set and the second threaded hole 210 is opened on it, which causes the moving part 200 at the second threaded hole 210 to be easily damaged, thereby improving the reliability of the moving part 200.

[0062] It should be noted that, in order to simplify the manufacturing process and reduce costs, in some embodiments of the present application, the second welding ring body 130 and the second moving member body 230 are hexagonal nuts. This arrangement eliminates the need for threaded holes in the second welding ring body 130 and the second moving member body 230, allowing standard parts to be used directly, thus reducing costs.

[0063] Furthermore, if Figure 3 As shown, the outer wall of the moving member 200 is provided with a groove 240 for accommodating the sealing ring 300 , one end of the sealing ring 300 abuts against the groove 240 , and the other end of the sealing ring 300 abuts against the side wall of the liquid injection hole 21 .

[0064] Furthermore, if Figure 1 and Figure 5 As shown, the moving part 200 also includes a through hole 221 opened on the first moving part body 220, and the welding ring 100 also includes a third welding ring body 140 fixedly connected to the second welding ring body 130, and the elastic part 400 is wound around the outside of the third welding ring body 140, and the third welding ring body 140 passes through the through hole 221.

[0065] Through the above arrangement, the third welding ring body 140 can provide guidance for the movement of the moving part 200, preventing the moving part 200 from moving in a direction deviating from the preset direction, resulting in the moving part 200 being unable to reset or not being in the original position when reset.

[0066] It should be understood that in order to prevent the extension or contraction of the elastic member 400 from being affected, the width of the third welding ring body 140 is smaller than the width of the elastic member 400 .

[0067] To prevent battery leakage caused by the third welding ring body moving along the through hole 221, in some embodiments of the present application, a sliding seal is provided between the third welding ring body 140 and the through hole 221. The provision of the sliding seal not only enables the third welding ring body 140 to move along the through hole 221, providing a guide, but also prevents the technical problem of battery leakage caused by the third welding ring body 140 moving along the through hole 221.

[0068] Furthermore, in some embodiments of the present application, the elastic member 400 is a spring. This is because, when the elastic member 400 is a spring, springs with different elastic coefficients can be selected according to different needs, which has strong applicability and low cost.

[0069] It should be understood that the manner in which the welding ring 100 and the moving member 200 can be movably connected is not limited to the above manner. In some embodiments of the present application, for example, Figure 6 As shown, the welding ring 100 includes a guide groove 1001, and the movable member 200 includes a sliding portion 2001, which is arranged in the guide groove 1001. The two ends of the elastic member 400 are respectively connected to the guide groove 1001 and the sliding portion 2001. The sliding portion 2001 can slide along the guide groove 1001 to drive the movable member 200 to move in a direction away from or close to the welding ring 100.

[0070] The working principle of the battery injection structure 10 in the above embodiment is as follows: when the battery needs to be injected with liquid, the liquid is injected through the pressure relief hole 101 provided on the welding ring 100. As the amount of injected liquid increases, the pressure on the movable part 200 becomes greater and greater, and the sliding part 2001 drives it to move in a direction away from the welding ring 100. A gap appears between the movable part 200 and the injection hole 21, that is, the cavity 201 is connected to the interior of the battery, and the liquid flows into the interior of the battery through the pressure relief hole 101 and the cavity 201 to achieve injection. When the injection is completed, the movable part 200 is reset under the drive of the elastic part 400 to achieve repeated injection. When a large air pressure is generated inside the battery, the sliding part 2001 moves in a direction close to the welding ring 100, and a gap appears between the moving part 200 and the liquid injection hole 21, that is, the cavity 201 is connected to the inside of the battery, and the gas flows out to the outside of the battery through the cavity 201 and the pressure relief hole 101 to achieve pressure relief. When the pressure relief is completed, the moving part 200 is reset under the drive of the elastic part 400 to achieve repeated pressure relief. The battery liquid injection structure 10 of the embodiment of the present application can achieve repeated pressure relief and repeated liquid injection, thereby improving the service life of the battery top cover 20.

[0071] In some embodiments of the present application, Figure 7As shown, the welding ring 100 includes a blind hole 1002, and the movable member 200 includes an extended shaft 2002. The extended shaft 2002 extends into the blind hole 1002. The ends of the elastic member 400 are respectively connected to the extended shaft 2002 and the inner wall of the blind hole 1002. The extended shaft 2002 can slide along the inner wall of the blind hole 1002 to drive the movable member 2000 to move away from or toward the welding ring 100. The working principle of this embodiment is the same as that of the above embodiment and will not be repeated here.

[0072] Furthermore, if Figure 8 As shown, the injection hole 21 includes a first sub-injection hole 211 and a second sub-injection hole 212 connected to the first sub-injection hole 211, the welding ring 100 is fixedly connected to the side wall of the first sub-injection hole 211, and the movable part 200 abuts against the side wall of the second sub-injection hole 212; the battery top cover 20 includes a first surface 22 and a second surface 23 arranged opposite to each other, and along the direction from the first surface 22 to the second surface 23, the diameter of the first sub-injection hole 211 gradually decreases, the diameter of the second sub-injection hole 212 is the same, and the minimum diameter of the first sub-injection hole 211 is the same as the diameter of the second sub-injection hole 212.

[0073] With the above arrangement, when injecting liquid, the liquid flow path outside the liquid injection hole 21 can be avoided, and at the same time, it can also be beneficial to the installation of the moving part 200 and the sealing ring 300.

[0074] At the same time, by setting the diameter of the second sub-injection hole 212 that abuts the moving part 200 to remain unchanged, the sealing ability of the sealing ring 300 on the injection hole structure 10 can be improved, avoiding air leakage and liquid leakage when the battery injection structure 10 is not working, and further improving the safety and reliability of the battery injection structure 10.

[0075] Furthermore, in order to prevent the second sub-injection hole 212 from interfering with or damaging the sealing ring 300 when the moving part 200 is reset from the side away from the welding ring 100, in some embodiments of the present application, the side of the second sub-injection hole 212 away from the welding ring 100 is rounded.

[0076] Similarly, in order to avoid interference or damage to the sealing ring 300 at the connection between the second sub-injection hole 212 and the first sub-injection hole 211 when the moving part is reset from the side close to the welding ring 100, in some embodiments of the present application, the connection between the first sub-injection hole 211 and the second sub-injection hole 212 is chamfered.

[0077] Furthermore, if Figure 1 and Figure 8 As shown, one end of the sealing ring 300 abuts against the groove 240 of the moving member 200 , and the other end of the sealing ring 300 abuts against the side wall of the second sub-liquid injection hole 212 .

[0078] Among them, such as Figure 1 As shown, the welding ring 100 is disposed on a side close to the first surface 22 , and the moving member 200 is disposed on a side close to the second surface 23 .

[0079] like Figure 1 As shown, in some embodiments of the present application, the welding ring 100 includes a top surface 102 away from the moving part 200, and the top surface 102 is at the same height as the first surface 22. Through the above arrangement, the aesthetics of the battery top cover 20 can be improved.

[0080] like Figure 9 As shown, in some embodiments of the present application, the top cover 20 includes a first top cover 24 and a second top cover 25 fixedly connected to the first top cover 24 away from the side of the moving member 200, the injection hole 21 runs through the first top cover 24 and the second top cover 25, the second top cover 25 includes a third surface 26 away from one side of the first top cover 24, and the top surface 102 and the third surface 26 are located at the same height. Through the above-mentioned arrangement, the area of the cavity 201 formed by the injection hole 21, the welding ring 100 and the moving member 200 can be increased. By increasing the area of the cavity 201, the length of the elastic member 400 to be extended or shortened can be increased, thereby improving the efficiency of the injection or pressure relief.

[0081] Through the above arrangement, when the battery liquid injection structure 10 is not injecting liquid or relieving pressure, the sealing of the liquid injection hole 21 can be ensured to avoid leakage, thereby improving the reliability of the battery liquid injection structure 10.

[0082] Furthermore, in some embodiments of the present application, Figure 9 As shown, the distance between the first surface 22 and the third surface 26 is less than or equal to 10 mm.

[0083] The above arrangement ensures the assembly performance of the battery top cover 20. Specifically, the above arrangement prevents interference between the second top cover 25 and other components of the power battery or battery module due to excessive spacing between the first surface 22 and the third surface 26 during assembly of the power battery or assembly of the power battery into a battery module, thereby preventing poor assembly performance.

[0084] like Figure 10 As shown, when the battery needs to be injected with liquid, the liquid is injected through the pressure relief hole 101 provided on the welding ring 100. As the amount of injected liquid increases, the pressure on the movable part 200 becomes greater and greater. The movable part 200 drives the elastic part 400 to move toward the direction close to the interior of the battery. The elastic part 400 stretches along the preset direction, and a gap appears between the movable part 200 and the injection hole 21, that is, the cavity 201 is connected with the interior of the battery, and the liquid flows into the interior of the battery through the pressure relief hole 101 and the cavity 201 to realize injection. When the injection is completed, the movable part 200 is reset under the drive of the elastic part 400 to realize repeated injection.

[0085] like Figure 11 As shown, when a large air pressure is generated inside the battery, the movable part 200 drives the elastic part 400 to move toward the direction close to the welding ring 100, and the elastic part 400 shortens along the preset direction. A gap appears between the movable part 200 and the liquid injection hole 21, that is, the cavity 201 is connected to the interior of the battery, and the gas flows out to the outside of the battery through the cavity 201 and the pressure relief hole 101 to achieve pressure relief. When the pressure relief is completed, the movable part 200 is reset under the drive of the elastic part 400 to achieve repeated pressure relief. The battery liquid injection structure 10 of the embodiment of the present application can achieve repeated pressure relief and repeated liquid injection, thereby improving the service life of the battery top cover 20.

[0086] In a second aspect, an embodiment of the present application further provides a power battery, which includes a battery liquid injection structure 10 , and the battery liquid injection structure 10 is the battery liquid injection structure 10 in any of the above embodiments.

[0087] In a third aspect, an embodiment of the present application further provides a battery pack, which includes a battery liquid injection structure 10, and the battery liquid injection structure 10 is the battery liquid injection structure 10 in any of the above embodiments.

[0088] In a fourth aspect, an embodiment of the present application further provides an electric vehicle, which includes a battery liquid injection structure 10 , and the battery liquid injection structure 10 is the battery liquid injection structure 10 in any of the above embodiments.

[0089] To sum up, in the embodiment of the present application, an elastic part 400 is provided. When liquid needs to be injected into the battery, the liquid is injected through the pressure relief hole 101 provided on the welding ring 100. As the amount of injected liquid increases, the pressure on the movable part 200 becomes greater and greater. The movable part 200 drives the elastic part 400 to move toward the direction close to the battery cell. The elastic part 400 stretches along the preset direction until the cavity 201 is connected with the interior of the battery. The liquid flows into the interior of the battery through the pressure relief hole 101 and the cavity 201 to achieve liquid injection. When the liquid injection is completed, the movable part 200 is reset under the drive of the elastic part 400 to achieve repeated liquid injection. When a high air pressure is generated inside the battery, the movable part 200 drives the elastic part 400 to move toward the direction close to the welding ring 100, and the elastic part 400 shortens along the preset direction until the cavity 201 is connected with the interior of the battery, and the gas flows out to the outside of the battery through the cavity 201 and the pressure relief hole 101, thereby achieving pressure relief. When the pressure relief is completed, the movable part 200 is reset under the drive of the elastic part 400, thereby achieving repeated pressure relief. The battery liquid injection structure 10 of the embodiment of the present application can achieve repeated pressure relief and repeated liquid injection, thereby improving the service life of the battery top cover 20; and, by passing through the third welding ring body 140 through the through hole 221 of the movable part 200, a guide is provided for the movement of the movable part 200, thereby achieving the technical effect of improving the reliability of the battery liquid injection structure 10.

[0090] In the above embodiments, the description of each embodiment has its own focus. For parts not described in detail in a particular embodiment, please refer to the detailed description of other embodiments above and will not be repeated here. In specific implementations, the above units or structures can be implemented as independent entities or in any combination as the same entity or multiple entities, and will not be repeated here.

[0091] The above is a detailed introduction to a battery liquid injection structure, a power battery, a battery pack and an electric vehicle provided in the embodiments of the present application. Specific examples are used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the structure and core ideas of the present application. At the same time, for those skilled in the art, according to the ideas of the present application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A battery injection structure, characterized in that: At least part of the battery liquid injection structure is arranged in the liquid injection hole of the battery top cover, and the battery liquid injection structure includes: A welding ring, the welding ring is arranged on a side of the liquid injection hole away from the battery core, the side wall of the welding ring is fixedly connected to the side wall of the liquid injection hole, and at least one pressure relief hole is provided on the welding ring; a moving member, the moving member being disposed on a side of the liquid injection hole close to the battery core, the moving member abutting against a side wall of the liquid injection hole, the welding ring, the moving member, and the side wall of the liquid injection hole enclosing a cavity, the at least one pressure relief hole being in communication with the cavity; A sealing ring, the sealing ring being arranged between a side wall of the moving part and a side wall of the liquid injection hole; An elastic member, wherein both ends of the elastic member are respectively connected to the welding ring and the movable member, and the elastic member extends in a direction close to the battery cell under liquid pressure to drive the movable member to move in a direction away from the welding ring for injecting liquid into the battery; the elastic member shortens in a direction away from the battery to drive the movable member to move in a direction close to the welding ring for repeatedly injecting liquid into the battery.

2. The battery liquid injection structure according to claim 1, characterized in that: Two ends of the elastic member are respectively fixedly connected or detachably connected to the welding ring and the moving member.

3. The battery liquid injection structure according to claim 2, characterized in that: The welding ring includes a first threaded hole opened on the welding ring, the movable member includes a second threaded hole opened on the fixed ring, and the elastic member includes an elastic member body and a first threaded portion and a second threaded portion respectively threadedly connected to the first threaded hole and the second threaded hole.

4. The battery liquid injection structure according to claim 3, characterized in that: The welding ring further includes a first welding ring body and a second welding ring body fixedly connected to the first welding ring body. The second welding ring body is arranged on a side of the first welding ring body close to the moving part. The first threaded hole is opened on the second welding ring body.

5. The battery liquid injection structure according to claim 4, characterized in that: The moving part further includes a first moving part body and a second moving part body fixedly connected to the first moving part body. The second moving part body is arranged on a side of the first moving part body close to the welding ring. The second threaded hole is opened on the second moving part body.

6. The battery liquid injection structure according to claim 5, characterized in that: The moving part further includes a through hole opened on the first moving part body, the welding ring further includes a third welding ring body fixedly connected to the second welding ring body, the elastic part is wound around the third welding ring body, and the third welding ring body passes through the through hole.

7. The battery liquid injection structure according to claim 6, characterized in that: A sliding seal is provided between the third welding ring body and the through hole.

8. The battery liquid injection structure according to claim 1, characterized in that: The elastic member is a spring.

9. The battery liquid injection structure according to claim 1, characterized in that: The welding ring includes a guide groove, and the movable member includes a sliding portion, which is arranged in the guide groove. Both ends of the elastic member are respectively connected to the sliding portion and the guide groove. The sliding portion can slide along the guide groove to drive the movable member to move in a direction away from or close to the welding ring.

10. The battery liquid injection structure according to claim 1, characterized in that: The welding ring includes a blind hole, and the movable member includes an extending shaft, which extends into the blind hole. The two ends of the elastic member are respectively connected to the extending shaft and the inner wall of the blind hole. The extending shaft can slide along the inner wall of the blind hole to drive the movable member to move in a direction away from or close to the welding ring.

11. The battery liquid injection structure according to claim 1, characterized in that: The injection hole includes a first sub-injection hole and a second sub-injection hole connected to the first sub-injection hole, the welding ring is fixedly connected to the side wall of the first sub-injection hole, and the movable part abuts against the side wall of the second sub-injection hole; the battery top cover includes a first surface and a second surface arranged opposite to each other, and along the direction from the first surface to the second surface, the diameter of the first sub-injection hole gradually decreases, the diameter of the second sub-injection hole is the same, and the minimum diameter of the first sub-injection hole is the same as the diameter of the second sub-injection hole.

12. The battery liquid injection structure according to claim 11, characterized in that: The welding ring includes a top surface away from the moving part, and the top surface is located at the same height as the first surface.

13. The battery liquid injection structure according to claim 11, characterized in that: The top cover includes a first top cover and a second top cover fixedly connected to the first top cover on a side away from the moving part, the injection hole passes through the first top cover and the second top cover, the second top cover includes a third surface away from the side of the first top cover, and the welding ring includes a top surface away from the moving part, and the top surface and the third surface are located at the same height.

14. The battery liquid injection structure according to claim 13, characterized in that: A distance between the first surface and the third surface is less than or equal to 10 mm.

15. The battery liquid injection structure according to claim 1, characterized in that: The movable member is further provided with a groove for accommodating the sealing ring. One end of the sealing ring abuts against the groove, and the other end of the sealing ring abuts against the side wall of the liquid injection hole.

16. A power battery, characterized in that: The battery liquid injection structure comprises the battery liquid injection structure according to any one of claims 1 to 15.

17. A battery pack, characterized in that: The battery liquid injection structure comprises the battery liquid injection structure according to any one of claims 1 to 15.

18. An electric vehicle, characterized in that: The battery liquid injection structure comprises the battery liquid injection structure according to any one of claims 1 to 15.

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