CN222813924U - Battery and battery pack - Google Patents

Abstract

The utility model provides a battery and a battery pack, wherein the battery comprises a battery core, a shell, a top cover, a sealing nail and a sealing sheet, wherein the top cover is provided with a liquid injection hole which is communicated with each other, the top cover is connected with the shell, the top cover and the shell jointly define a cavity, the battery core is arranged in the cavity, the sealing nail comprises an inserting part and a pressing part, the inserting part is arranged in the liquid injection hole, the pressing part is connected to one end of the inserting part far away from the battery core, the pressing part is positioned outside the cavity, the inserting part penetrates through the sealing sheet, the sealing sheet is positioned outside the cavity, and the pressing part and the top cover clamp the sealing sheet. Because the sealing sheet is pressed on the top cover by the pressing part of the sealing nail, the sealing sheet is not easy to run, which is beneficial to improving the welding quality between the sealing sheet and the top cover, thereby improving the sealing effect of the sealing sheet and the sealing nail on the liquid injection hole.

Description

Battery and battery pack

Technical Field

The utility model relates to the technical field of batteries, in particular to a battery and a battery pack.

Background

In the production process of the battery, electrolyte needs to be injected into the battery through the electrolyte injection hole of the top cover, and after the electrolyte injection is completed, the electrolyte injection hole needs to be sealed. At present, a common mode of sealing the liquid injection hole is that a sealing nail is inserted into the liquid injection hole, then a sealing sheet is covered above the sealing nail, and finally the sealing sheet is welded with the top cover. However, in the process of welding the sealing sheet, the sealing sheet is liable to incline, shift, etc., and the actual position of the sealing sheet may deviate from the ideal position. This can affect the quality of the seal and the top cap (e.g., cold joint, flash joint, etc.) and thus the sealing effect on the fill hole.

Disclosure of utility model

The present utility model aims to solve at least one of the technical problems existing in the prior art. Therefore, the utility model provides a battery, wherein the sealing sheet is clamped by the sealing nail and the top cover, and the sealing sheet is not easy to incline, deviate and the like.

The utility model also provides a battery pack comprising the battery.

The battery comprises a battery core, a shell, a top cover, a sealing nail and a sealing sheet, wherein the top cover is provided with a liquid injection hole which is communicated with each other, the top cover is connected with the shell, a cavity is defined by the top cover and the shell together, the battery core is arranged in the cavity, the sealing nail comprises an inserting portion and a pressing portion, the inserting portion is arranged in the liquid injection hole, the pressing portion is connected to one end of the inserting portion, which is far away from the battery core, the pressing portion is located outside the cavity, the inserting portion penetrates through the sealing sheet, the sealing sheet is located outside the cavity, and the sealing sheet is clamped by the pressing portion and the top cover.

The battery according to the embodiment of the first aspect of the utility model has at least the advantage that the sealing sheet is less likely to shift or tilt due to the sealing sheet being sandwiched by the nip portion and the top cover (or the sealing sheet being pressed against the top cover by the nip portion). Therefore, the sealing piece is not easy to deviate when being welded with the top cover, which is beneficial to improving the welding quality between the sealing piece and the top cover, thereby improving the sealing effect of the sealing piece and the sealing nail on the liquid injection hole.

According to some embodiments of the utility model, the sealing plate is sealingly connected to the top cover, and the press-fit portion is sealingly connected to the sealing plate, so that the sealing nail and the sealing plate seal the pouring hole.

According to some embodiments of the utility model, the sealing piece is made of metal, the sealing piece is welded with the top cover, the pressing portion is made of plastic, and the pressing portion is connected with the sealing piece in a hot melting mode.

According to some embodiments of the utility model, the sealing spike has a melting point of not less than 120 ℃ and not greater than 200 ℃.

According to some embodiments of the utility model, the sealing sheet is provided with a receiving groove in which the nip is disposed, with a gap between an outer peripheral edge of the nip and a side wall of the receiving groove.

According to some embodiments of the utility model, the sealing sheet is provided with a receiving groove, an opening of the receiving groove is arranged on the top surface of the sealing sheet, the pressing part is arranged in the receiving groove, and the bottom surface of the pressing part is attached to the bottom wall of the receiving groove.

According to some embodiments of the utility model, the top surface of the nip is flush with the top surface of the sealing sheet or the top surface of the nip is lower than the top surface of the sealing sheet.

According to some embodiments of the utility model, the sealing piece further comprises an anti-falling portion, the anti-falling portion has elasticity, the anti-falling portion is located in the cavity, the anti-falling portion and the pressing portion are respectively connected to two ends of the plug-in portion, one end, close to the plug-in portion, of the anti-falling portion is an abutting end, the outer diameter of the abutting end is larger than the aperture of the liquid injection hole, and one side surface, facing the cavity, of the top cover abuts against the end face of the abutting end.

According to some embodiments of the utility model, the diameter of the anti-drop portion gradually decreases from an end of the anti-drop portion near the nip portion to an end of the anti-drop portion remote from the nip portion.

A battery pack according to an embodiment of the second aspect of the present utility model includes the battery of the embodiment of the first aspect.

The beneficial effects of the battery pack according to the second aspect of the present utility model are the same as those of the battery according to the first aspect, and are not described here.

Additional aspects and advantages of the utility model will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the utility model.

Drawings

The utility model is further described with reference to the accompanying drawings and examples, in which:

Fig. 1 is a schematic view of a battery according to an embodiment of the present utility model;

FIG. 2 is a schematic view of a seal assembly according to one embodiment of the present utility model;

FIG. 3 is a cross-sectional view of the seal assembly;

FIG. 4 is a schematic illustration of the mating relationship between the seal assembly and the cap in one embodiment;

FIG. 5 is a schematic illustration of the mating relationship between the seal assembly and the cap in another embodiment;

FIG. 6 is a cross-sectional view of the seal staple;

fig. 7 is a cross-sectional view of a sealing plate.

Reference numerals:

100-battery, 101-shell, 102-positive terminal, 103-top cover, 104-mounting groove, 105-sealing component, 106-negative terminal, 107-sealing piece, 108-sealing nail and 109-liquid injection hole;

201-a pressing part, 202-an inserting part and 203-an anti-falling part;

301-receiving slots, 302-through holes.

Detailed Description

Embodiments of the present utility model are described in detail below, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements or elements having like or similar functions throughout. The embodiments described below by referring to the drawings are illustrative only and are not to be construed as limiting the utility model.

In the description of the present utility model, it should be understood that references to orientation descriptions such as upper, lower, front, rear, left, right, etc. are based on the orientation or positional relationship shown in the drawings, are merely for convenience of description of the present utility model and to simplify the description, and do not indicate or imply that the apparatus or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus should not be construed as limiting the present utility model.

In the description of the present utility model, the meaning of a number is one or more, the meaning of a number is two or more, and greater than, less than, exceeding, etc. are understood to exclude the present number, and the meaning of a number is understood to include the present number. The description of the first and second is for the purpose of distinguishing between technical features only and should not be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated or implicitly indicating the precedence of the technical features indicated.

In the description of the present utility model, unless explicitly defined otherwise, terms such as arrangement, installation, connection, etc. should be construed broadly and the specific meaning of the terms in the present utility model can be reasonably determined by a person skilled in the art in combination with the specific contents of the technical scheme.

Fig. 1 shows a battery 100 according to an embodiment of the present utility model, the battery 100 comprising a housing 101, a top cover 103, a sealing assembly 105 and a cell (the cell is not shown in the drawings). The battery 100 shown in fig. 1 has a rectangular parallelepiped shape, and in other embodiments, not shown, the battery 100 may be provided as a cylindrical battery.

The housing 101 is hollow inside, the top of the housing 101 is provided with an opening, the top cover 103 is connected with the housing 101 and the top cover 103 is mounted at the opening. The top cover 103 and the housing 101 together define a chamber (the space defined by the lower side surface of the top cover 103 and the inner surface of the housing 101 together is a chamber), and the battery cell is disposed in the chamber. That is, the cells are located inside the housing 101 and below the top cover 103. In order to improve the structural strength of the battery 100, the top cover 103 and the case 101 may be made of a metal material such as aluminum alloy, steel, or the like. Accordingly, the top cover 103 and the housing 101 may be connected by welding. The battery cell can be a winding type battery cell or a lamination type battery cell. Battery 100 also includes a positive terminal 102 and a negative terminal 106. The top end of the positive electrode terminal 102 and the top end of the negative electrode terminal 106 are exposed out of the cavity, the bottom end of the positive electrode terminal 102 and the bottom end of the negative electrode terminal 106 are located in the cavity, the positive electrode lug of the battery cell is electrically connected with the bottom end of the positive electrode terminal 102, and the negative electrode lug of the battery cell is electrically connected with the bottom end of the positive electrode terminal 102. The positive electrode terminal 102 and the negative electrode terminal 106 are used for connection with conductive members such as wires and bus bars.

The cap 103 is provided with a pouring hole 109 (as shown in fig. 4), and the pouring nozzle can pour the electrolyte from the pouring hole 109 into the chamber in the case where the pouring hole 109 is not blocked. And after the filling is completed, the sealing assembly 105 seals the filling hole 109, thereby preventing the electrolyte from leaking out of the chamber and preventing water and dust of the external environment from entering the chamber.

As shown in fig. 2, the seal assembly 105 includes a seal pin 108 and a seal tab 107. As shown in fig. 3, the seal pin 108 includes a socket portion 202 and a press-fit portion 201. As shown in fig. 4, the insertion portion 202 is provided in the pouring hole 109, thereby blocking the pouring hole 109. To enhance the blocking effect of the insertion portion 202, the outer peripheral surface of the insertion portion 202 may be bonded to the wall of the liquid injection hole 109. Further, the insertion portion 202 penetrates the sealing piece 107. The pressing portion 201 is connected to an end of the plugging portion 202 away from the battery cell, that is, the pressing portion 201 is connected to a top end of the plugging portion 202. The nip 201 is located outside the chamber, the sealing sheet 107 is also located outside the chamber, and the nip 201 and the top cover 103 sandwich the sealing sheet 107 together.

In fig. 4, the chamber is not specifically shown, and if the reference is made to fig. 4, the chamber is actually located below the bottom surface of the top cover 103. Since the nip 201 is located above the bottom surface of the top cover 103, the nip 201 is located outside the chamber.

The "the nip 201 and the top cover 103 together hold the sealing sheet 107" can also be regarded as the nip 201 pressing the sealing sheet 107 against the top cover 103. Since the sealing sheet 107 is sandwiched (or pressed against the top cover 103 by the pressing portion 201), the sealing sheet 107 is less likely to be displaced or inclined. Therefore, the sealing sheet 107 is not easy to deviate when being welded with the top cover 103, which is beneficial to improving the welding quality between the sealing sheet 107 and the top cover 103, thereby improving the sealing effect of the sealing sheet 107 and the sealing nail 108 on the liquid injection hole 109.

For the manufactured battery 100, the sealing sheet 107 is sealingly connected with the top cover 103, and the pressing portion 201 is also sealingly connected with the sealing sheet 107, so that the sealing nail 108 and the sealing sheet 107 seal the liquid injection hole 109, preventing the electrolyte from leaking out of the chamber, and preventing water and dust of the external environment from entering the chamber. In some embodiments, the material of the sealing piece 107 may be metal, and the sealing piece 107 is welded to the top cover 103, so as to achieve a sealed connection between the sealing piece 107 and the top cover 103. More specifically, the weld between the peripheral edge of the sealing plate 107 and the top cover 103 may be a complete circle. The sealing nail 108 is made of plastic, and the pressing part 201 of the sealing nail 108 is connected with the sealing piece 107 in a hot melting way, so that the sealing connection between the pressing part 201 and the sealing piece 107 is realized. Of course, in other embodiments not shown, the sealing connection between the pressing portion 201 and the sealing piece 107 may be achieved by bonding, or a sealing ring is provided between the pressing portion 201 and the sealing piece 107, or if the sealing nail 108 is made of metal, the pressing portion 201 and the sealing piece 107 may be welded to each other to achieve sealing.

For embodiments in which the sealing sheet 107 is of metal and the sealing nail 108 is of plastic, the term "heat-fusible connection of the bonding portion 201 to the sealing sheet 107" means that at least a portion of the bonding portion 201 is melted by heat and then solidified, and the re-solidified bonding portion 201 is connected to the sealing sheet 107 and fixed to each other. The molten plastic may fill or seal the gap between the nip 201 and the sealing sheet 107, thereby achieving a seal. Therefore, the heat-fusible connection between the pressing portion 201 and the sealing sheet 107 means that the sealing between the pressing portion 201 and the sealing sheet 107 is not required by other parts (for example, a seal ring), the number of parts of the battery 100 is small, and the production difficulty and cost of the battery 100 are low. In addition, heat generated when the sealing sheet 107 is welded to the top cover 103 may be transferred to the pressing portion 201, and this heat may melt the pressing portion 201, and when the welding is completed, the pressing portion 201 is not heated, and the pressing portion 201 is cooled and solidified, thereby achieving fixation between the pressing portion 201 and the sealing member. Therefore, after the sealing sheet 107 is welded, the heat-fusible joint between the bonding portion 201 and the sealing sheet 107 can be achieved by cooling the bonding portion 201, and a step of connecting the bonding portion 201 and the sealing sheet 107 is not required to be separately provided. That is, the welding process of the sealing sheet 107 and the melting process of the pressing portion 201 are overlapped in time, and both are performed simultaneously, and the heat-fusion connection of the pressing portion 201 and the sealing sheet 107 is advantageous in improving the production efficiency of the battery 100.

In some embodiments, the sealing spike 108 itself may also act as an explosion-proof valve, and the battery 100 does not need to be provided with an additional explosion-proof valve, which is also beneficial for reducing the cost of the battery 100. When the battery 100 is internally short-circuited or thermally out-controlled, a large amount of high-temperature gas is generated in the chamber, the sealing nail 108 is melted by heat, and the sealing of the sealing nail 108 to the liquid injection hole 109 is broken. The breaking of the seal of the sealing nail 108 against the pouring hole 109 includes at least one of (1) the sealing nail 108 itself having a hole after the sealing nail 108 is melted and (2) the sealing nail 108 having a gap between the sealing nail 108 and both the sealing piece 107 and the top cover 103 after the sealing nail 108 is melted. After the seal of the sealing nail 108 to the liquid injection hole 109 is broken, the high-temperature gas can be rapidly discharged from the liquid injection hole 109 to the outside of the chamber. In this way, the pressure inside the battery 100 decreases, and the risk of explosion of the battery 100 decreases.

In some embodiments, the melting point of the sealing spike 108 may be no less than 120 ℃ and no greater than 200 ℃, primarily to make the sealing spike 108 suitable as an explosion-proof valve. If the melting point of the sealing nail 108 is less than 120 ℃, the melting point of the sealing nail 108 is too low, and the critical temperature of the battery 100 for venting is low, which is detrimental to maintaining long-term operation of the battery 100. If the melting point of the sealing nail 108 is greater than 200 ℃, the melting point of the sealing nail 108 is too high, the critical temperature at which the sealing of the sealing nail 108 to the liquid injection hole 109 is broken is too high, the critical temperature at which the battery 100 is vented is high, and the risk of explosion of the battery 100 is high. In addition, the melting point of the seal nail 108 is not more than 200 ℃ and it is also advantageous to melt the nip 201 by the heat generated when the seal sheet 107 is welded. If the melting point of the seal nail 108 is greater than 200 ℃, the melting point of the nip 201 is too high, and it is difficult for the heat generated when the seal sheet 107 is welded to melt the nip 201, so that it is difficult to synchronously achieve the melting of the nip 201 during the welding of the seal sheet 107. In order to make the melting point of the sealing nail 108 not less than 120 ℃ and not more than 200 ℃, the material of the sealing nail 108 may be Polyethylene (PE), polyvinyl chloride (PVC), polypropylene (PP), polystyrene (PS), etc., and of course, the sealing nail 108 may be made of other materials besides the above-listed plastics, so long as the melting point thereof is within the above-mentioned temperature range, so that the sealing nail 108 can be used as an explosion-proof valve.

As shown in fig. 7, the sealing sheet 107 is provided with a receiving groove 301 and a through hole 302, the tip of the through hole 302 is provided at the bottom wall of the receiving groove 301, and the opening of the receiving groove 301 is provided at the top surface of the sealing sheet 107. The plug portion 202 is disposed in the through hole 302, the pressing portion 201 is disposed in the accommodating groove 301, and the bottom surface of the pressing portion 201 is attached to the bottom wall of the accommodating groove 301. The receiving groove 301 may receive at least a portion of the nip 201, reducing the portion of the nip 201 protruding above the top surface of the sealing sheet 107, thereby improving the flatness of the top of the sealing assembly 105. To further improve the flatness of the top of the seal assembly 105, the top surface of the nip 201 is flush with the top surface of the sealing sheet 107 or the top surface of the nip 201 is lower than the top surface of the sealing sheet 107. The receiving groove 301 may also act as a fool-proof, thereby reducing the risk of the sealing flap 107 being put back. Further, in some embodiments, there is a gap between the peripheral edge of the nip 201 and the side wall of the accommodation groove 301. This arrangement leaves the receiving groove 301 with enough space to receive the melted plastic of the nip 201, preventing the plastic from spilling out of the receiving groove 301 and even onto the top cover 103.

As shown in fig. 4, in some embodiments, the "the pressing portion 201 and the top cover 103 sandwich the sealing piece 107" is specifically that the bottom surface of the pressing portion 201 abuts against the bottom wall of the accommodation groove 301, and the top surface of the top cover 103 abuts against the bottom surface of the sealing piece 107. The top surface of the top cover 103 is welded to the sealing plate 107.

In other embodiments, as shown in fig. 5, the top cover 103 may be provided with a mounting groove 104, and the sealing piece 107 is disposed in the mounting groove 104. The mounting groove 104 can locate the sealing piece 107 to facilitate assembly between the sealing piece 107 and the top cover 103. For the embodiment shown in fig. 5, the "pressing portion 201 and the top cover 103 sandwich the sealing piece 107" is specifically that the bottom surface of the pressing portion 201 abuts against the bottom wall of the accommodation groove 301, and the bottom wall of the mounting groove 104 of the top cover 103 abuts against the bottom surface of the sealing piece 107. Furthermore, the bottom wall and/or the side walls of the mounting groove 104 are used for welding with the sealing piece 107.

As shown in fig. 6, the sealing nail 108 further includes a drop-off prevention portion 203, the drop-off prevention portion 203 and the pressing portion 201 are respectively connected to two ends of the plugging portion 202, and the drop-off prevention portion 203 is located in the cavity (the drop-off prevention portion 203 is located below the bottom surface of the top cover 103). The drop-off prevention portion 203 has elasticity so that the drop-off prevention portion 203 passes through the liquid injection hole 109 and enters into the chamber. For example, the drop-off preventing portion 203 may be made of plastic having elasticity. One end of the anti-drop portion 203, which is close to the insertion portion 202, is an abutment end, which is a tip of the anti-drop portion 203 in fig. 6. The outer diameter of the abutting end is larger than the aperture of the liquid injection hole 109, and one side surface of the top cover 103 facing the cavity abuts against the end face of the abutting end, namely the bottom surface of the top cover 103 abuts against the top surface of the abutting end. The anti-drop portion 203 corresponds to a barb structure, and the abutting end and the top cover 103 abut against each other to prevent the sealing nail 108 from moving outwards, so that the sealing nail 108 is prevented from being completely separated from the liquid injection hole 109, and the sealing effect of the sealing nail 108 on the liquid injection hole 109 is improved. In addition, as shown in fig. 4, the anti-drop portion 203 and the pressing portion 201 clamp the sealing sheet 107 and the top cover 103 together, and the anti-drop portion 203 can prevent the sealing nail 108 from moving outward, so the sealing nail 108 is not easy to loosen, and the pressing portion 201 can press the sealing sheet 107, preventing the sealing sheet 107 from deviating.

In some embodiments, the diameter (outer diameter) of the anti-drop portion 203 gradually decreases from an end of the anti-drop portion 203 near the nip portion 201 to an end of the anti-drop portion 203 away from the nip portion 201. Taking fig. 6 as an example, the diameter of the drop-off preventing portion 203 gradually decreases from the top end of the drop-off preventing portion 203 to the bottom end of the drop-off preventing portion 203. This facilitates insertion of the drop-off preventing portion 203 into the pouring orifice 109 and through the pouring orifice 109. More specifically, the drop-off prevention portion 203 may have a truncated cone shape.

The dimensions of the sealing spike 108 and the sealing piece 107 are described again below.

In some embodiments, the anti-drop portion 203 is in a truncated cone shape, the pressing portion 201 and the inserting portion 202 are both in a cylindrical shape, the sealing piece 107 is in a cylindrical shape, and the receiving groove 301 is a circular groove. In other embodiments, however, the sealing spike 108 and the sealing plate 107 may be provided in other shapes, not illustrated herein. As shown in FIG. 6, the diameter of the pressing portion 201 is B, the diameter of the insertion portion 202 is C, and the area of the pressing portion 201 for pressing the sealing piece 107 is positively correlated with the difference between B and C, and B and C satisfy that B-C is not less than 0.5mm in order for the pressing portion 201 to stably press the sealing piece 107. The maximum diameter of the drop-off prevention portion 203 is F, the minimum diameter of the drop-off prevention portion 203 is E, and the height of the drop-off prevention portion 203 is K. E may be equal to C, and F is greater than C and less than B, K satisfying 1.2 mm.ltoreq.K.ltoreq.10 mm. The specific value of K is adjusted according to the cell between the bottom surface of the top cover 103 and the cell, as long as the anti-drop part 203 does not squeeze the cell and causes the cell to be damaged. The included angle between the top surface and the side surface of the anti-falling part 203 is alpha, and alpha is more than or equal to 30 degrees. In the process that the anti-falling part 203 passes through the liquid injection hole 109, the hole wall of the liquid injection hole 109 can squeeze the anti-falling part 203, so that the anti-falling part 203 is contracted towards the central axis of the anti-falling part, and alpha is more than or equal to 30 degrees, so that the anti-falling part 203 is conveniently contracted when passing through the liquid injection hole 109, and the anti-falling part 203 conveniently passes through the liquid injection hole 109.

As shown in FIG. 7, the outside diameter of the sealing plate 107 is A, and B < A.ltoreq.50 mm. The thickness of the sealing sheet 107 (i.e., the height of the sealing sheet 107) is J, the thickness of the accommodating groove 301 (i.e., the height of the accommodating groove 301) is H, and H.gtoreq.0.5J. As shown in fig. 5, the diameter of the accommodation groove 301 is larger than the diameter of the nip 201, and the difference between the diameter of the accommodation groove 301 and the diameter of the nip 201 is 2D. After the bottom surface of the pressing portion 201 is bonded to the bottom wall of the accommodating groove 301, the difference in height between the bottom surface of the sealing piece 107 and the top surface of the drop-preventing portion 203 is G, which should be not smaller than the thickness of the portion where the top cover 103 is sandwiched.

The battery 100 in any of the above embodiments may be applied to a battery pack, which may include a case and a plurality of batteries 100, the batteries 100 being disposed in the case, and the plurality of batteries 100 in the case being connected in series with each other. The battery pack can provide power for the electric automobile.

In the description of the present utility model, the descriptions of the terms "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present utility model. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Claims (10)

1. A battery, comprising:

A battery cell;

a housing;

The top cover is provided with mutually communicated liquid injection holes, the top cover is connected with the shell, the top cover and the shell jointly define a cavity, and the battery cell is arranged in the cavity;

The sealing nail comprises an inserting part and a pressing part, the inserting part is arranged in the liquid injection hole, the pressing part is connected to one end, far away from the battery cell, of the inserting part, and the pressing part is positioned outside the cavity;

The sealing piece, the grafting portion runs through the sealing piece, the sealing piece is located outside the cavity, pressfitting portion with the top cap centre gripping the sealing piece.

2. The battery of claim 1, wherein the sealing sheet is sealingly connected to the top cover and the press-fit portion is sealingly connected to the sealing sheet such that the sealing nail and the sealing sheet seal the liquid injection hole.

3. The battery of claim 2, wherein the sealing plate is made of metal, the sealing plate is welded to the top cover, the pressing portion is made of plastic, and the pressing portion is connected to the sealing plate by hot melting.

4. The battery of claim 1, wherein the sealing pin has a melting point of not less than 120 ℃ and not greater than 200 ℃.

5. A battery according to claim 3, wherein the sealing sheet is provided with a receiving groove, the nip portion is provided in the receiving groove, and a gap is provided between an outer peripheral edge of the nip portion and a side wall of the receiving groove.

6. The battery according to claim 1, wherein the sealing sheet is provided with a receiving groove, an opening of the receiving groove is provided at a top surface of the sealing sheet, the nip portion is provided in the receiving groove, and a bottom surface of the nip portion is fitted to a bottom wall of the receiving groove.

7. The battery of claim 6, wherein a top surface of the nip portion is flush with a top surface of the sealing sheet or a top surface of the nip portion is lower than a top surface of the sealing sheet.

8. The battery according to claim 1, wherein the sealing sheet further comprises an anti-falling portion, the anti-falling portion has elasticity, the anti-falling portion is located in the cavity, the anti-falling portion and the pressing portion are respectively connected to two ends of the plugging portion, one end of the anti-falling portion, which is close to the plugging portion, is an abutting end, the outer diameter of the abutting end is larger than the aperture of the liquid injection hole, and one side surface of the top cover, which faces the cavity, is abutted with the end face of the abutting end.

9. The battery according to claim 8, wherein a diameter of the drop-off preventing portion gradually decreases from an end of the drop-off preventing portion near the nip portion to an end of the drop-off preventing portion remote from the nip portion.

10. Battery pack, characterized in that it comprises a battery according to any one of claims 1 to 9.