Battery monomer

Abstract

The utility model relates to a battery monomer. The battery monomer comprises a shell, a sealing nail and a locking piece, the shell is provided with a first wall, a liquid injection hole is formed in the first wall, and the inner circumferential surface of the liquid injection hole is sunken to form a containing groove; the sealing nail comprises a sealing part; the sealing part is matched with the liquid injection hole in an inserted mode, and the outer circumferential face of the sealing part is attached to the inner circumferential face of the liquid injection hole. Wherein the outer peripheral surface of the sealing part is sunken to form a mounting hole; the locking piece comprises an elastic part and a first limiting part, and the elastic part is arranged in the mounting hole; the elastic part is provided with a first end, and the first limiting part is limited between the first end of the elastic part and the containing groove. Compared with laser welding sealing, the battery can be disassembled, so that the electrolyte can be supplemented or replaced, and the service life of the battery is prolonged; the sealing structure is used for replacing a welding mode, so that the production cost caused by welding defects can be reduced, and the reliability and the production efficiency are higher.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to a battery monomer. Background Art

[0002] During the production of lithium-ion batteries, electrolyte is injected through the injection hole. The injection hole is generally sealed by first pressing the sealing particles and then by laser welding the sealing aluminum sheet. When the sealing particles are used to pre-seal the injection hole, there is no limiting structure in the injection hole, so the sealing particles will fall into the battery. When the sealing aluminum sheet is used to laser weld the injection hole, on the one hand, the residual electrolyte in the injection hole causes welding explosion points during welding, affecting the welding quality and sealing effect, and is very likely to leak. On the other hand, the battery consumes electrolyte continuously during use, resulting in a decrease in battery capacity. The above-mentioned sealing method is inconvenient to disassemble, and therefore the electrolyte cannot be replaced or replenished. The battery capacity cannot be replenished, and the service life is reduced. Utility Model Content

[0003] To this end, the technical problem to be solved by the present invention is to overcome the technical difficulties in the existing technology of the battery filling hole sealing structure, which has the risk of glue nails falling off and leakage, and the inconvenience of replacing or replenishing the electrolyte, and to provide a battery cell that optimizes the sealing effect, can be disassembled and assembled to replenish the electrolyte, and extends the service life.

[0004] In order to solve the above technical problems, the present invention provides a battery cell, which includes:

[0005] The housing has a first wall, wherein the first wall is provided with a liquid injection hole, and the inner circumference of the liquid injection hole is concave to form a receiving groove;

[0006] The sealing nail includes a sealing portion and a locking piece; the sealing portion is plugged into the liquid injection hole, and the outer circumferential surface of the sealing portion is arranged in contact with the inner circumferential surface of the liquid injection hole; wherein the outer circumferential surface of the sealing portion is recessed to form a mounting hole; the locking piece includes an elastic portion and a first limiting portion, and the elastic portion is arranged in the mounting hole; the elastic portion has a first end, and the first limiting portion is limited between the first end of the elastic portion and the accommodating groove.

[0007] In one embodiment of the present invention, the mounting hole includes a first orifice formed on the outer peripheral surface of the sealing portion, the first limiting portion and the mounting hole are slidably fitted, and a portion of the first limiting portion is limited in the mounting hole by the first orifice.

[0008] In one embodiment of the present invention, the mounting hole extends along a first direction and passes through the sealing portion; the locking member also includes a second limiting portion, and the second limiting portion and the first limiting portion are respectively arranged on both sides of the first direction of the elastic portion; the elastic portion has a second end arranged away from the first end, and the second limiting portion is limited between the second end of the elastic portion and the accommodating groove.

[0009] In one embodiment of the present invention, the mounting hole also includes a second orifice formed on the outer peripheral surface of the sealing portion, and the first orifice and the second orifice are arranged relative to each other along a first direction; the second limiting portion and the mounting hole are slidingly matched, and a portion of the second limiting portion is limited in the mounting hole by the second orifice.

[0010] In one embodiment of the present invention, the first limiting portion and the second limiting portion are both spherical structures; the diameter of the first limiting portion is larger than the diameter of the first orifice; the diameter of the second limiting portion is larger than the diameter of the second orifice.

[0011] In one embodiment of the present invention, the accommodating groove is formed by extending around the liquid injection hole; or, the accommodating groove includes more than two sub-grooves, and the more than two sub-grooves are distributed at intervals along the circumference of the liquid injection hole.

[0012] In one embodiment of the present invention, a groove is formed on a side of the first wall away from the battery cell, and the injection hole is arranged at the bottom of the groove; the sealing nail also includes a covering part fixedly connected to the sealing part, the covering part is accommodated in the groove, and the covering part is in contact with the bottom of the groove.

[0013] In one embodiment of the present invention, the bottom of the groove is provided with an annular groove arranged around the injection hole, and the inner annular surface of the annular groove, the hole wall of the injection hole and the groove bottom of the groove constitute an annular protrusion; the inner annular surface of the annular groove is provided with a first thread; the covering part is provided with a connecting part, the connecting part is provided with a connecting hole, and the hole wall of the connecting hole is provided with a second thread; the annular protrusion and the connecting hole are connected by threaded cooperation of the first thread and the second thread.

[0014] In one embodiment of the present invention, a sealing ring is provided between the covering portion and the bottom of the groove.

[0015] In one embodiment of the present invention, a first chamfer is provided at one end of the liquid injection hole away from the battery core.

[0016] The above technical solution of the utility model has the following beneficial effects compared with the prior art:

[0017] Compared with the sealing structure of the existing battery filling hole, the battery cell described in the present invention has a sealing pin and a filling hole that can be matched to achieve positioning and disassembly, thereby preventing the sealing pin from falling into the battery and facilitating multiple replenishments of the electrolyte. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to make the content of the utility model easier to understand, the utility model is further described in detail below based on the specific embodiments of the utility model in conjunction with the accompanying drawings, wherein:

[0019] Figure 1 This is a schematic structural diagram of the first wall of the housing in a preferred embodiment of the present invention;

[0020] Figure 2 for Figure 1 An enlarged schematic diagram of the middle injection hole;

[0021] Figure 3 for Figure 2 A cross-sectional view of the injection hole shown;

[0022] Figure 4 This is a top view of the first wall after the sealing nails are assembled in the preferred embodiment of the present invention;

[0023] Figure 5 for Figure 4 A cross-sectional view of the first wall along the AA direction;

[0024] Figure 6 for Figure 5 A magnified schematic diagram of point B in the middle;

[0025] Figure 7 This is a structural diagram of a sealing nail in a preferred embodiment of the present utility model;

[0026] Figure 8 This is a side view of the sealing pin and the locking member in the preferred embodiment of the present utility model;

[0027] Figure 9 for Figure 8 Cross-sectional view along CC direction;

[0028] Figure 10 for Figure 9 Schematic diagram of the structure of the middle sealing nail part;

[0029] Figure 11 for Figure 10 An enlarged schematic diagram of the first orifice in FIG.

[0030] Explanation of the reference numerals in the specification: 1. First wall; 11. Groove; 2. Liquid injection hole; 21. Accommodating groove; 3. Sealing pin; 31. Sealing portion; 3101. Mounting hole; 3102. First orifice; 3103. Second orifice; 32. Covering portion; 4. Locking member; 41. Elastic portion; 42. First limiting portion; 43. Second limiting portion; 51. First thread; 52. Second thread; 6. Sealing ring; 71. First chamfer; 72. Second chamfer. DETAILED DESCRIPTION

[0031] The present invention will be further described below with reference to the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it. However, the embodiments are not intended to limit the present invention.

[0032] Example

[0033] Reference Figures 1 to 11 As shown, the utility model provides a battery cell, which includes a shell, and a first wall 1 of the shell is provided with an injection hole 2; the battery cell also includes a sealing nail 3 for sealing the injection hole 2; the utility model changes the sealing structure of the injection hole 2 so that the sealing structure can be installed or disassembled, which is convenient for replenishing electrolyte into the shell and extending the service life of the battery; in addition, compared with the laser welding sealing method, the sealing structure of the utility model does not require welding processing, can avoid waste caused by welding defects, reduce production costs, improve sealing yield, and prevent electrolyte leakage.

[0034] For this purpose, refer to Figure 6 As shown, the sealing nail 3 includes a sealing portion 31 and a locking member 4; the liquid injection hole 2 passes through the first wall 1 of the shell along its axial direction, and the liquid injection hole 2 is connected to the space inside the shell that contains the electrolyte. The inner circumferential surface of the liquid injection hole 2 is recessed to form a receiving groove 21, and the receiving groove 21 is recessed on the inner circumferential surface of the liquid injection hole 2 along the axial direction away from the liquid injection hole 2. The sealing nail 3 includes a sealing portion 31, and the sealing portion 31 and the liquid injection hole 2 are plugged into each other, and the outer circumferential surface of the sealing portion 31 is fitted with the inner circumferential surface of the liquid injection hole 2 to form a seal. The outer circumferential surface of the sealing portion 31 is recessed to form a mounting hole 3101, and the mounting hole 3101 is recessed on the outer circumferential surface of the sealing portion 31 along the axial direction away from the sealing portion 31. The locking member 4 is fixed to the sealing pin 3. The locking member 4 includes an elastic portion 41 and a first limiting portion 42. The elastic portion 41 is arranged in the mounting hole 3101. The elastic portion has a first end. The first limiting portion 42 is limited between the first end of the elastic portion 41 and the accommodating groove 21. The sealing portion 31 and the liquid injection hole 2 are detachably connected in a manner that the first limiting portion 42 is limited between the first end of the elastic portion 41 and the accommodating groove 21, thereby realizing the locking of the sealing pin 3.

[0035] In this embodiment, the position of the first limiting portion 42 can be controlled by the deformation of the elastic portion 41. Specifically, when the sealing nail 3 needs to be inserted, a portion of the sealing portion 31 of the sealing nail 3 is first inserted into the injection hole 2. At this time, at least a portion of the first limiting portion 42 protrudes from the outer peripheral surface of the sealing portion 31. The sealing portion 31 of the sealing nail 3 is further controlled to be inserted into the injection hole 2, so that the first limiting portion 42 is forced to squeeze the elastic portion 41, and then the first limiting portion 42 and the elastic portion 41 are completely accommodated in the mounting hole 3101, and then the sealing portion 31 of the sealing nail 3 is further controlled to be inserted into the injection hole 2. Until the mounting hole 3101 and the accommodating groove 21 are facing each other, at this time, under the action of the elastic part 41, part of the first limiting part 42 is pushed into the accommodating groove 21, thereby limiting the sealing nail 3 and preventing the sealing nail 3 from falling easily; and when the sealing nail 3 needs to be removed, it is necessary to first apply force to pull up the sealing part 31, and at this time the first limiting part 42 can be forced to squeeze the elastic part 41, so that the first limiting part 42 and the elastic part 41 are completely accommodated in the mounting hole 3101, and then continue to pull up the sealing part 31 until the sealing part 31 is completely separated from the injection hole 2.

[0036] In some embodiments, the shell includes an outer shell and an end cover. The end cover can be designed as a first wall. This end cover is not only provided with a liquid injection hole, but also with components such as a pole and an explosion-proof valve; of course, the side wall or bottom wall constituting the outer shell can also be designed as the first wall.

[0037] In some embodiments, the installation hole 3101 is provided to provide an accommodation space for the locking member 4. The installation hole 3101 can be designed as either a blind hole structure or a through hole structure, depending on the specific installation design requirements.

[0038] When the mounting hole 3101 is configured as a blind hole, the mounting hole 3101 has an open end and a closed end. The open end of the mounting hole 3101 forms a first aperture 3102 on the outer circumferential surface of the sealing portion 31. The elastic portion 41 has a first end and a second end disposed away from the first end. The elastic portion 41 is disposed within the mounting hole 3101, with the second end of the elastic portion 41 abutting against the closed end of the mounting hole 3101. Alternatively, the second end of the elastic portion 41 abuts against the closed end of the mounting hole 3101 via the second limiting portion 43; the first end of the elastic portion 41 abuts against the first limiting portion 42.

[0039] In addition, in order to make the installation of the sealing part 31 more secure, when the mounting hole 3101 is a blind hole, a plurality of mounting holes 3101 are provided, and the plurality of mounting holes 3101 are arranged at intervals around the axis of the sealing part 31. Correspondingly, a plurality of locking members 4 are also provided, and the plurality of locking members 4 are arranged at intervals around the axis of the sealing part 31, and the locking members 4 and the mounting holes 3101 are in a one-to-one correspondence.

[0040] When the mounting hole 3101 is set as a through hole, refer to Figure 9 and Figure 10 As shown, the mounting hole 3101 forms a first opening 3102 and a second opening 3103 on the outer peripheral surface of the sealing portion 31, which are arranged opposite each other along the axis thereof. The locking member 4 includes an elastic portion 41, a first limiting portion 42, and a second limiting portion 43. The elastic portion 41 has a first end and a second end disposed away from the first end, and is disposed within the mounting hole 3101. The second limiting portion 43 is limited between the second end of the elastic portion 41 and the receiving groove 21. The first limiting portion 42 is limited between the first end of the elastic portion 41 and the receiving groove 21. By designing that both the first limiting portion 42 and the second limiting portion 43 are accommodated in the receiving groove 21, the installation of the sealing portion 31 is more secure.

[0041] Furthermore, in order to facilitate the installation of the limiting portion of the locking member 4 into the accommodating groove 21, the accommodating groove 21 can be designed to extend around the injection hole 2, that is, the accommodating groove 21 is annular, or the accommodating groove 21 can be designed to include more than two sub-grooves, and the more than two sub-grooves are distributed at intervals along the circumference of the injection hole 2.

[0042] Furthermore, in order to facilitate installation, the first end of the elastic part 41 can be designed to be connected to the first limiting part 42, and the second end of the elastic part 41 can be connected to the second limiting part 43; it should be noted that the elastic part 41 can be a spring or a block structure made of elastic material.

[0043] Furthermore, the mounting hole 3101 is arranged on the outer peripheral surface of the sealing portion 31, and the mounting hole 3101 extends along a first direction, and a non-zero angle is formed between the first direction and the axial direction of the injection hole. Specifically, the angle between the first direction and the axial direction of the injection hole is 45° to 90°. Specifically in this embodiment, the angle between the first direction and the axial direction of the injection hole is 90°. This design facilitates the processing of the mounting hole 3101.

[0044] In some embodiments, the installation hole 3101 is provided not only to provide an accommodation space for the locking member 4 , but also to provide a guide for the limiting portion of the locking member 4 .

[0045] When the mounting hole on the sealing portion 31 and the accommodating groove 21 on the liquid injection hole 2 are not arranged opposite each other, and the locking piece on the sealing portion 31 is located in the liquid injection hole 2, the limiting portion and the elastic portion 41 are both accommodated in the mounting hole 3101, and the elastic portion 41 is in a compressed state. When the mounting hole on the sealing portion 31 and the accommodating groove 21 on the liquid injection hole 2 are opposite each other, the limiting portion is pushed by the elastic portion 41. Therefore, if the mounting hole and the limiting portion are slidingly matched, the limiting portion will move under the guidance of the mounting hole, thereby ensuring that at least part of the limiting portion is accurately installed in the accommodating groove 21.

[0046] Thus, the first limiting portion 42 and the mounting hole 3101 are designed to slide together; further, the second limiting portion 43 and the mounting hole 3101 are designed to slide together.

[0047] In some embodiments, the installation hole 3101 is provided not only to provide an accommodation space for the locking member 4 and to provide a guiding function for the limiting portion of the locking member 4, but also to provide a limiting function for the installation of the limiting portion of the locking member 4.

[0048] The mounting hole 3101 includes a first opening 3102 formed on the outer circumferential surface of the sealing portion 31 and a channel communicating with the first opening 3102 . A portion of the first limiting portion 42 is designed to be limited within the mounting hole 3101 by the first opening 3102 .

[0049] Specifically, the portion of the first limiting portion 42 that is limited in the mounting hole 3101 by the first hole 3102 is the first mounting portion. The size of the first mounting portion is larger than the size of the first hole 3102, and the first mounting portion and the channel are slidably matched.

[0050] When installing the first limiting portion 42 and the sealing portion 31, it is necessary to first utilize the specific elasticity of the sealing portion 31 itself to deform the first orifice 3102 to achieve the purpose of expanding the size of the first orifice 3102, so that the first mounting portion of the first limiting portion 42 can be installed into the mounting hole 3101 from the enlarged first orifice 3102, and then the first orifice 3102 is deformed and reset to achieve the purpose of limiting the first mounting portion of the first limiting portion 42 in the mounting hole 3101.

[0051] Furthermore, the mounting hole 3101 also includes a second orifice 3103 formed on the outer peripheral surface of the sealing portion 31 , and a channel connects the second orifice 3103 and the first orifice 3102 . A portion of the second limiting portion 42 is designed to be limited in the mounting hole 3101 by the first orifice 3102 .

[0052] Specifically, the portion of the second limiting portion 42 that is limited in the mounting hole 3101 by the second orifice 3103 is the second mounting portion. The size of the second mounting portion is larger than the size of the second orifice 3103, and the second mounting portion and the channel are slidably matched.

[0053] When installing the second limiting portion 42 and the sealing portion 31, it is necessary to first utilize the specific elasticity of the sealing portion 31 itself to deform the second orifice 3103 to achieve the purpose of expanding the size of the second orifice 3103, so that the second mounting portion of the second limiting portion 42 can be installed into the mounting hole 3101 from the enlarged second orifice 3103, and then the second orifice 3103 is deformed and reset to achieve the purpose of limiting the second mounting portion of the second limiting portion 43 in the mounting hole 3101.

[0054] Specifically in this embodiment, see Figures 9-11 The first limiting portion 42 and the second limiting portion 43 are both spherical structures. In order to adapt to the first limiting portion 42 and the second limiting portion 43, the cross-section of the channel of the mounting hole is designed to be circular, and the first orifice 3102 and the second orifice 3103 are designed to be circular, and the diameter of the first limiting portion 42 is larger than the diameter of the first orifice 3102; the diameter of the second limiting portion 43 is larger than the diameter of the second orifice 3103.

[0055] Among them, since the first limiting part 42 and the second limiting part 43 are both spherical structures, the first limiting part 42 and the second limiting part 43 can rotate on their own, making the sealing part 31 and the injection hole 2 plug-in smoother, and also making the first limiting part 42 and the second limiting part 43 easier to retract into the mounting hole 3101 when subjected to external force.

[0056] It should be noted that the spheres of the first limiting portion 42 and the second limiting portion 43 can be set to be the same or different in diameter. When the diameters of the spheres on both sides are different, the accommodating groove 21 can be configured as sub-grooves with different slot widths to accommodate the spheres. Preferably, the spheres of the first limiting portion 42 and the second limiting portion 43 have the same diameter.

[0057] It should also be noted that the hole wall of the mounting hole 3101 for connecting to the first hole 3102 and the hole wall of the mounting hole 3101 for connecting to the second hole 3103 can be set as an arc surface to avoid damaging the ball while allowing the ball to slide in the mounting hole 3101. Preferably, refer to Figure 11 As shown, the connection between the two side openings of the mounting hole 3101 can be set as a simulated spherical structure to match the spheres on both sides of the elastic part 41. In addition, the cross section of the accommodating groove 21 can also be set to be arc-shaped so as to better fit the spherical structure.

[0058] In some embodiments, in order to be able to replenish the battery after it has been used for a period of time, specifically, referring to Figures 1 to 3 As shown, the first wall 1 of the shell is recessed toward the inside of the shell in the thickness direction on one side surface away from the battery cell inside the shell, forming a groove 11; the injection hole 2 is arranged at the bottom of the groove 11; the sealing nail 3 also includes a covering part 32 fixedly connected to the sealing part 31, the covering part 32 is accommodated in the groove 11, and the covering part 32 is in contact with the bottom of the groove 11.

[0059] In this embodiment, the cover portion 32 made of the same material as the sealing portion 31 is used to replace the existing sealing aluminum nails, so that the battery can be replenished after being used for a period of time.

[0060] It should be noted that, for the convenience of manufacturing, the covering portion 32 and the sealing portion 31 are integrally formed.

[0061] Furthermore, in order to achieve a better sealing effect of the covering part 32, the bottom of the groove 11 is provided with an annular groove arranged around the injection hole 2, and the inner annular surface of the annular groove, the hole wall of the injection hole 2 and the groove bottom of the groove 11 form an annular protrusion; the covering part 32 is provided with a connecting part, the connecting part is annular, and the inner annular surface of the connecting part forms a connecting hole, the annular protrusion and the connecting hole are plugged in, and the inner annular surface of the annular groove and the inner annular surface of the connecting part contact to form a seal, and the outer annular surface of the annular groove and the outer annular surface of the connecting part contact to form a seal.

[0062] Furthermore, to further secure the connection between the covering portion 32 and the first wall, the inner annular surface of the annular groove is provided with a first thread 51, and the inner annular surface of the connecting portion is provided with a second thread 52. The annular protrusion and the connecting hole are connected by threaded engagement of the first thread 51 and the second thread 52. Of course, the connecting hole and the annular protrusion may also be provided with other connection methods, and are not limited thereto.

[0063] Further, refer to Figure 6 As shown, in order to further improve the sealing effect, a sealing ring 6 is provided between the cover portion 32 and the bottom of the groove 11, and the material of the sealing ring 6 is set to elastic rubber; the sealing ring 6 is an "O"-shaped sealing ring located between the connecting hole and the annular protrusion, which is used to further improve the airtightness, prevent the electrolyte or its volatile gas from diffusing and leaking, and prevent moisture, gas and impurities in the air from entering the shell.

[0064] In some embodiments, in order to facilitate the insertion of the sealing part 31 into the liquid injection hole 2, a first chamfer 71 is provided at the end of the liquid injection hole 2 away from the battery cell, and / or a second chamfer 72 is provided at the end of the sealing part 31 away from the covering part 32. The first chamfer 71 and the second chamfer 72 serve as a guide, which facilitates the insertion of the sealing part 31 into the liquid injection hole 2, reduces the difficulty of assembly, and improves the assembly efficiency.

[0065] The working principle of the battery cell of the present invention is as follows:

[0066] When installing the sealing pin 3, it is necessary to first control the sealing part 31 to be partially inserted into the liquid injection hole 2. When the connecting part is to be installed into the annular groove, it is necessary to control the sealing pin to rotate so that the sealing part 31 can be rotated and inserted, so that the connecting part and the annular protrusion are threadedly connected.

[0067] Among them, during the insertion process of the sealing part 31, the first limiting part 42 and the second limiting part 43 first begin to shrink along the axial direction of the mounting hole due to hitting the first chamfer 71, and then the first limiting part 42 and the second limiting part 43 will hit the inner circumference of the liquid injection hole 2 and are all accommodated in the mounting hole 3101 along the axial direction of the mounting hole. Afterwards, because the first limiting part 42 and the second limiting part 43 are both spherical structures, the first limiting part 42 and the second limiting part 43 both roll with the inner circumference of the liquid injection hole 2. Finally, due to the accommodating groove 21 set on the inner circumference of the liquid injection hole 2 and under the action of the elastic part 41, part of the first limiting part 42 and part of the second limiting part 43 are pushed into the accommodating groove 21, thereby achieving the purpose of locking the sealing nail.

[0068] The utility model facilitates repeated replenishment or replacement of electrolyte in the shell through the detachable arrangement of the sealing nail 3, thereby extending the service life of the battery cell.

[0069] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will appreciate that other variations or modifications based on the above descriptions are possible. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A battery cell, characterized in that: include, The housing comprises a first wall (1), wherein the first wall (1) is provided with a liquid injection hole (2), and the inner peripheral surface of the liquid injection hole (2) is recessed to form a receiving groove (21); A sealing nail (3) comprises a sealing portion (31) and a locking member (4); the sealing portion (31) is plugged into and matched with the liquid injection hole (2), and the outer peripheral surface of the sealing portion (31) is arranged in contact with the inner peripheral surface of the liquid injection hole (2); wherein the outer peripheral surface of the sealing portion (31) is recessed to form a mounting hole (3101); the locking member (4) comprises an elastic portion (41) and a first limiting portion (42), and the elastic portion (41) is arranged in the mounting hole (3101); the elastic portion (41) has a first end, and the first limiting portion (42) is limited between the first end of the elastic portion (41) and the accommodating groove (21).

2. The battery cell according to claim 1, wherein: The mounting hole (3101) includes a first orifice (3102) formed on the outer peripheral surface of the sealing portion (31), the first limiting portion (42) and the mounting hole (3101) are slidably fitted, and a portion of the first limiting portion (42) is limited in the mounting hole (3101) by the first orifice (3102).

3. The battery cell according to claim 2, wherein: The mounting hole (3101) extends along a first direction and passes through the sealing portion (31); the locking member (4) further comprises a second limiting portion (43), wherein the second limiting portion (43) and the first limiting portion (42) are respectively arranged on both sides of the elastic portion (41) in the first direction; the elastic portion (41) has a second end arranged away from the first end, and the second limiting portion (43) is limited between the second end of the elastic portion (41) and the accommodating groove (21).

4. The battery cell according to claim 3, wherein: The mounting hole (3101) further comprises a second orifice (3103) formed on the outer peripheral surface of the sealing portion (31), the first orifice (3102) and the second orifice (3103) being arranged relative to each other along a first direction; the second limiting portion (43) and the mounting hole (3101) are slidably fitted, and a portion of the second limiting portion (43) is limited within the mounting hole (3101) by the second orifice (3103).

5. The battery cell according to claim 4, characterized in that: The first limiting portion (42) and the second limiting portion (43) are both spherical structures; the diameter of the first limiting portion (42) is larger than the diameter of the first orifice (3102); and the diameter of the second limiting portion (43) is larger than the diameter of the second orifice (3103).

6. The battery cell according to any one of claims 1 to 5, characterized in that: The accommodating groove (21) is formed by extending around the liquid injection hole (2); or, the accommodating groove (21) includes more than two sub-grooves, and the more than two sub-grooves are distributed at intervals along the circumference of the liquid injection hole (2).

7. The battery cell according to any one of claims 1 to 5, characterized in that: A groove (11) is formed on a side of the first wall (1) away from the battery cell, and the injection hole (2) is arranged at the bottom of the groove (11); the sealing nail (3) also includes a covering portion (32) fixedly connected to the sealing portion (31), the covering portion (32) is accommodated in the groove (11), and the covering portion (32) is in contact with the bottom of the groove (11).

8. The battery cell according to claim 7, characterized in that: The bottom of the groove (11) is provided with an annular groove arranged around the injection hole (2), and the inner annular surface of the annular groove, the hole wall of the injection hole (2) and the groove bottom of the groove (11) constitute an annular protrusion; the inner annular surface of the annular groove is provided with a first thread (51); the covering portion (32) is provided with a connecting portion, the connecting portion is provided with a connecting hole, and the hole wall of the connecting hole is provided with a second thread (52); the annular protrusion and the connecting hole are connected by threaded cooperation of the first thread (51) and the second thread (52).

9. The battery cell according to claim 8, characterized in that: A sealing ring (6) is provided between the covering portion (32) and the bottom of the groove (11).

10. The battery cell according to any one of claims 1 to 5, characterized in that: A first chamfer (71) is provided at one end of the liquid injection hole (2) away from the battery core.

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