CN217589180U

CN217589180U - Power battery top cover and power battery

Info

Publication number: CN217589180U
Application number: CN202221146090.1U
Authority: CN
Inventors: 邹旭晨
Original assignee: Wuhan Chuneng New Energy Co ltd
Current assignee: Wuhan Chuneng New Energy Co ltd
Priority date: 2022-05-12
Filing date: 2022-05-12
Publication date: 2022-10-14
Anticipated expiration: 2032-05-12

Abstract

The utility model provides a power battery top cover and a power battery, which comprises a cover plate and a lower plastic part, wherein the top surface of the cover plate is provided with a liquid injection hole, the lower plastic part is provided with a cavity corresponding to the liquid injection hole, and a containing cavity is formed between the cavity and the cover plate; the explosion-proof assembly comprises a fixing piece and a plunger piece, a flow channel communicated with the accommodating cavity is arranged on the cavity, a through mounting hole is formed in the center of the fixing piece, and the diameter of the mounting hole is gradually reduced from top to bottom; plunger spare, for the rubber material, the setting is in the mounting hole, when being ordered about by external force, can follow the mounting hole inner wall and upwards slide to form the clearance that is linked together with flow channel between plunger spare and the mounting hole. The utility model discloses a be in the same place explosion-proof valve subassembly and notes liquid hole integration, need not to set up explosion-proof valve opening alone, can effectively deal with the battery and cross to fill and explosion-proof, avoided simultaneously electrolyte to pour into liquid back and splash to the explosion-proof membrane through explosion-proof valve opening and cause the explosion-proof membrane subassembly to damage.

Description

Power battery top cap and power battery

Technical Field

The utility model relates to a power battery technical field especially relates to a power battery top cap and power battery.

Background

The current power battery (such as lithium ion battery) needs continuous charging and discharging in the use process, and can cause overcharging, and because a large amount of gas is generated inside the battery during overcharging, the hidden danger of explosion exists, so an explosion-proof valve structure is arranged on a top cover of the power battery to perform pressure relief protection on the power battery.

The top surface of a top cover of the existing power battery is provided with a liquid injection hole and an explosion-proof hole, an explosion-proof valve and an attached explosion-proof membrane assembly are arranged in the explosion-proof hole, and because the top cover is provided with a plurality of holes and is provided with an upward opening, dust and foreign matters are easily accumulated in the holes, and meanwhile, the explosion-proof membrane is easy to age and damage after being used for a long time.

In addition, the liquid injection hole is close to the explosion-proof valve hole, certain pressure is left in the battery shell after liquid injection is completed, and electrolyte is easy to splash into the explosion-proof valve hole when the liquid injection nozzle is withdrawn, so that the explosion-proof membrane assembly is corroded.

SUMMERY OF THE UTILITY MODEL

In view of this, the utility model provides a power battery top cap and power battery solves and annotates the liquid hole on the current power battery top cap and is nearer apart from explosion-proof valve hole, and it causes the problem of explosion-proof membrane subassembly damage to splash to the explosion-proof membrane after the electrolyte is annotated easily to take place.

The technical scheme of the utility model is realized like this:

on one hand, the utility model provides a power battery top cover, it includes the apron and fixes the lower plastic part that sets up in the apron bottom surface, the apron top surface is provided with annotates the liquid hole, the lower plastic part is sunken downwards and is formed with the cavity corresponding to annotating the liquid hole, be formed with between cover plate and the cavity and hold the chamber;

the explosion-proof component comprises a fixing piece and a plunger piece, wherein the fixing piece is arranged in the accommodating cavity, a flow channel communicated with the accommodating cavity is arranged on the cavity, a through mounting hole is formed in the center of the fixing piece, and the diameter of the mounting hole is gradually reduced from top to bottom;

plunger spare, for the rubber material, the setting is in the mounting hole, when being ordered about by external force, can follow the mounting hole inner wall and upwards slide to form the clearance that is linked together with flow channel between plunger spare and the mounting hole.

On above-mentioned technical scheme's basis, it is preferred, the plunger piece is the round platform form, the degree of depth that highly is less than the mounting hole of plunger piece, the bottom of plunger piece is higher than the bottom of mounting hole, and the top of plunger piece is less than the top of mounting hole, and the plunger piece is interference fit with the junction of mounting hole, and the interference loading volume is 0.2mm-0.5mm.

On the basis of the technical scheme, preferably, a vertically downward liquid injection channel is formed in the center of the top surface of the plunger piece, and the thickness from the bottom end of the liquid injection channel to the bottom surface of the plunger piece is 0.5-2 mm.

Further, preferably, the aperture of the liquid injection hole is smaller than that of the top of the mounting hole, a separation baffle is horizontally and fixedly arranged in the liquid injection hole, the separation baffle is formed by heat sealing of rubber/AL/LDPE, the thickness of the separation baffle is 0.5mm-1mm, and a cutting seam is arranged at the center of the separation baffle.

On the basis of the technical scheme, preferably, a sharp part for puncturing the separation baffle is vertically and fixedly arranged on the top surface of the plunger piece.

Further, preferably, the top surface of the cover plate is provided with a sensing element for detecting the spike part.

In one embodiment, the flow channel penetrates through the bottom surface of the cavity and is coaxial with the mounting hole.

As another embodiment, the peripheral wall of the cavity is provided with a plurality of notches communicated with the accommodating cavity, the bottom surface of the accommodating cavity is provided with a plurality of supporting ribs, the supporting ribs are arranged at intervals, the fixing part is arranged on the supporting ribs, one end of each supporting rib, which is close to the side wall of the accommodating cavity, is provided with an abutting part for limiting the side wall of the fixing part, and the flow channel is formed between the supporting ribs and communicated with the notches.

Preferably, a sealing ring is arranged between the top surface of the fixing piece and the bottom surface of the cover plate, and the sealing ring is sleeved outside the mounting hole.

On the other hand, the utility model also provides a power battery, which comprises the power battery top cover; the battery also comprises a battery shell and a battery cell arranged in the battery shell.

The utility model discloses following beneficial effect has for prior art:

(1) The utility model discloses a power battery top cap, through set up the cavity on moulding down, and correspond with annotating the liquid hole, set up between cavity and the apron and hold the chamber, set up explosion-proof assembly holding the intracavity, when power battery overcharges, electrolyte in the battery releases a large amount of gas, the inside atmospheric pressure of battery risees, gaseous promotion plunger piece upwards slides along the mounting hole on the mounting, make and form the clearance between plunger piece and the mounting hole, thereby make the inside gaseous following flow path of battery and flow through above-mentioned clearance, and discharge through annotating the liquid hole, thereby keep the pressure difference unanimous inside and outside the battery, play explosion-proof purpose, can wear plunger piece to annotate liquid syringe needle thorn through annotating the liquid hole simultaneously and annotate liquid, electrolyte can flow into the battery case through flow path in vivo, thereby realize that electrolyte adds, the utility model discloses a valve subassembly with annotate the liquid hole is integrated together, need not to set up the valve opening alone, it causes explosion-proof assembly to damage to splash to annotate explosion-proof membrane subassembly through explosion-proof valve opening after having avoided electrolyte to annotating liquid. Meanwhile, the number of parts is reduced, the cost is reduced, and meanwhile, the battery overcharge and explosion prevention can be effectively dealt with;

(2) A vertically downward liquid injection channel is formed in the center of the top surface of the plunger piece, so that a liquid injection needle can easily penetrate through the plunger piece, and liquid injection is carried out on the battery;

(3) By arranging the separation blocking piece at the liquid injection hole and arranging the cutting seam at the center of the separation blocking piece, when explosion-proof pressure relief and electrolyte injection operation are not influenced, dust impurities can be prevented from falling into the mounting hole to pollute a liquid injection channel on the plunger piece;

(4) The spine part is arranged on the top surface of the plunger part, so that the plunger part can slide upwards along the mounting hole in the pressure relief process of the battery, and the spine part is used for piercing the separation block piece, so that on one hand, the gas release in the battery shell is accelerated, on the other hand, whether the battery is overcharged or not can be known in time, the power battery can be stopped in time, and the maintenance or the replacement can be carried out, and the potential safety hazard caused by continuous use can be avoided;

(5) The sensing element for detecting the spine part is arranged on the top surface of the cover plate, the sensing element can be connected with the power battery control system, when the sensing element detects the spine part, the battery is in an over-inflated and inflated state, the control system can automatically cut off the charging and discharging of the battery, and the safety accident caused by the continuous charging and discharging of the power battery is avoided;

(6) Set up the support rib through making the mounting with holding chamber bottom to set up the breach on the cavity periphery wall, make flow channel and the breach intercommunication that forms between the support rib, when carrying out the electrolyte filling, annotate liquid needle and pierce post plug member after, can be blockked by the cavity bottom surface, it is internal that electrolyte can flow into the battery case through flow channel and breach, avoids annotating that liquid needle pierces and causes electric core to puncture in the battery case.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the description below are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

Fig. 1 is a schematic perspective view of a top cover of a power battery disclosed by the present invention;

fig. 2 is an exploded schematic view of a power battery top cover disclosed by the present invention;

fig. 3 is a schematic plan structure view of the top cover of the power battery disclosed by the present invention;

FIG. 4 is a schematic plan view of the first embodiment at A in FIG. 3;

FIG. 5 is a schematic plan view of the second embodiment at A in FIG. 3;

the attached drawings are as follows:

1. a cover plate; 2. a plastic part is put; 11. a liquid injection hole; 21. a cavity; 211. an accommodating chamber; 3. an explosion-proof assembly; 31. a fixing member; 32. a plunger member; 4. a flow channel; 311. mounting holes; 321. a liquid injection channel; 5. separating sheets; 51. cutting a seam; 322. a spike portion; 6. an inductive element; 212. a notch; 213. a support rib; 214. a holding portion; 7. and (5) sealing rings.

Detailed Description

The technical solutions of the embodiments of the present invention will be described clearly and completely below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts all belong to the protection scope of the present invention.

As shown in figure 1, combine fig. 2-4, the embodiment of the utility model discloses a power battery top cap, mould a 2 including apron 1 and fixed setting under 1 bottom surface of apron, apron 1 is used for cooperating with the battery casing, as the shutoff piece with electric core encapsulation in the battery casing to play the effect of installation utmost point post. The top surface of the cover plate 1 is provided with a liquid injection hole 11 for injecting electrolyte into the battery cell in the battery shell. In order to adapt to the structure of the square aluminum-shell battery, the cover plate 1 is in a strip shape, is made of aluminum, and can be made of other metal materials.

The lower plastic part 2 is made of plastic materials and used for electrically isolating the cover plate 1 from the battery core. The lower plastic part 2 and the cover plate 1 can be riveted or welded.

All set up explosion-proof valve hole on traditional top cap annotating liquid hole 11 one side for install explosion-proof valve membrane subassembly, because explosion-proof valve hole is close to annotates liquid hole 11, leave certain pressure in annotating liquid completion back battery case, cause electrolyte to splash to explosion-proof valve hole easily when annotating the liquid mouth and withdraw from, cause the corruption to explosion-proof membrane subassembly.

Therefore, the present embodiment improves the structure of the existing top cover to solve the above technical problems.

Specifically, in the present embodiment, a cavity 21 corresponding to the liquid filling hole 11 is formed by recessing the lower plastic part 2 downward, and an accommodating cavity 211 is formed between the cavity 21 and the cover plate 1, specifically, the accommodating cavity 211 is disposed in the cavity 21, and the top opening thereof is connected to the bottom surface of the cover plate 1.

In order to realize the explosion-proof purpose, the embodiment is provided with the explosion-proof assembly 3, specifically, the explosion-proof assembly 3 includes a fixing member 31 and a plunger member 32, wherein the fixing member 31 is disposed in the accommodating cavity 211, a flow channel 4 communicated with the accommodating cavity 211 is disposed on the cavity 21, by disposing the flow channel 4, gas or liquid can enter the accommodating cavity 211 along the flow channel 4, a through mounting hole 311 is disposed in the center of the fixing member 31, and the diameter of the mounting hole 311 is gradually reduced from top to bottom. In this embodiment, the outer contour of the fixing member 31 may be a cubic column or a cylinder, and the cross section of the mounting hole 311 is circular.

The plunger member 32, made of rubber, is disposed in the mounting hole 311, and when being driven by an external force, can slide upwards along the inner wall of the mounting hole 311, so that a gap communicating with the flow passage 4 is formed between the plunger member 32 and the mounting hole 311. In this embodiment, the plunger member 32 is in a circular truncated cone shape, the height of the plunger member 32 is smaller than the depth of the mounting hole 311, the bottom end of the plunger member 32 is higher than the bottom end of the mounting hole 311, the top end of the plunger member 32 is lower than the top end of the mounting hole 311, the joint of the plunger member 32 and the mounting hole 311 is in interference fit, and the interference fit amount is 0.2mm-0.5mm. The interference is set to ensure that a certain connecting force exists between the plunger member 32 and the mounting hole 311, but when the plunger member 32 is subjected to a lifting force, the plunger member 32 can be pushed to slide.

In order to cooperate with the plunger 32, the fixing member 31 of this embodiment is preferably made of metal or hard plastic, and the connection between different materials has a large friction coefficient, and in the initial state, because the plunger 32 is made of rubber, it has a certain elastic deformation, and it can avoid the plunger 32 from falling off from the mounting hole 311 by interference fit with the fixing member 31 made of hard material.

Adopt above-mentioned technical scheme, through set up cavity 21 on moulding piece 2 under, and correspond with annotating liquid hole 11, cavity 211 is held in the setting between cavity 21 and the apron 1, set up explosion-proof subassembly 3 in holding the cavity 211, when power battery overcharge, electrolyte in the battery releases a large amount of gas, the inside atmospheric pressure of battery risees, gaseous promotion plunger piece 32 upwards slides along mounting hole 311 on the mounting 31, make and form the clearance between plunger piece 32 and the mounting hole 311, thereby make the inside gaseous following flow path 4 of battery and flow through above-mentioned clearance, and discharge through annotating liquid hole 11, thereby keep the pressure difference unanimous inside and outside the battery, play explosion-proof purpose, can pierce plunger piece 32 with annotating the notes liquid syringe needle and carry out notes liquid through annotating liquid hole 11 simultaneously, electrolyte can flow into the battery casing through flow path 4, thereby realize that electrolyte adds, the utility model discloses an explosion-proof valve subassembly is in the same place with annotating liquid hole 11 integration together, need not to set up the valve opening alone, caused explosion-proof damage to annotate on the explosion-proof membrane subassembly through splashing after having avoided electrolyte. Simultaneously, reduced spare part figure, reduced the cost, simultaneously can effectual reply battery overcharge and explosion-proof.

Because plunger piece 32 has certain thickness, the liquid injection needle need exert great power to pierce plunger piece 32 completely, the handling difficulty, simultaneously in the puncture process, still can produce stronger tight fit power with plunger piece 32 and mounting hole 311 extrusion back for battery case's gas can't be with plunger piece 32 jack-up. Therefore, in the embodiment, the liquid injection channel 321 is opened vertically downwards at the center of the top surface of the plunger member 32, and the thickness from the bottom end of the liquid injection channel 321 to the bottom surface of the plunger member 32 is 0.5mm-2mm. Make things convenient for the notes liquid needle to easily pierce plunger piece 32 to the implementation annotates the liquid to the battery, has also avoided at the puncture in-process, produces stronger tight-fitting power with plunger piece 32 and mounting hole 311 extrusion back.

Since the liquid injection hole 11 is used for adding the electrolyte into the battery case, and is used for pressure relief during explosion protection, the liquid injection hole 11 is formed as a circular hole with a certain diameter on the cover plate 1, but during the use of the battery, external dust and impurities can fall into the mounting hole 311 through the liquid injection hole 11 and enter the liquid injection channel 321, and when the liquid injection needle is inserted into the liquid injection channel 321 for injection, the dust can pollute the electrolyte.

Therefore, the scheme adopted by the embodiment is as follows: the diameter of the liquid injection hole 11 is set to be smaller than that of the top of the mounting hole 311 so as to prevent the fixing piece 31 from being separated from the mounting hole 311, a separation blocking piece 5 is horizontally and fixedly arranged in the liquid injection hole 11, the separation blocking piece 5 is formed by rubber/AL/LDPE through heat sealing, the thickness of the separation blocking piece is 0.5mm-1mm, and a cutting seam 51 is arranged at the center of the separation blocking piece 5. By adopting the technical scheme, when the explosion-proof pressure relief and electrolyte injection operation are not influenced, dust and impurities can be prevented from falling into the mounting hole 311 to pollute the injection channel 321 on the plunger piece 32. Because the separation blocking piece 5 is made of rubber or aluminum foil, has certain elasticity, is thin and easy to puncture, the cutting seam 51 can be opened to facilitate air exhaust or liquid injection and can be closed automatically, and dust can be blocked conveniently.

Owing to having seted up the kerf 51 on separating the separation blade 5, when the pressure release, gaseous can be followed and is discharged in kerf 51, at this moment, can not see plunger piece 32 and whether sliding in mounting hole 311, and then can't know whether the battery releases the pressure, after the pressure release, plunger piece 32 can fall owing to the dead weight, nevertheless can't keep closely cooperating with mounting hole 311, continue to use power battery this moment, and can cause the weeping problem because of the leakproofness is bad, seriously influence power battery's safe handling.

Therefore, the scheme adopted by the embodiment is as follows: a piercing portion 322 for piercing the separation blade 5 is vertically and fixedly provided on the top surface of the plunger member 32. In the process of releasing the pressure of the battery, the plunger piece 32 slides upwards along the mounting hole 311, the spine part 322 can be used for easily puncturing the separation baffle 5, on one hand, the pressure can be released quickly, and on the other hand, after the separation baffle is punctured, whether the battery is overcharged or not can be timely known, so that the power battery can be timely stopped, and the maintenance or the replacement can be realized, thereby avoiding the potential safety hazard caused by the continuous use. In this embodiment, one or more of the spikes 322 are provided, and when one spike 322 is provided, the spike 322 may be an annular spike wall coaxial with the injection channel 321 or a separate spike. When provided in plurality, the spike 322 is a plurality of individual spikes that are equally spaced about the central axis of the injection channel 321 on the top surface of the plunger member 32.

The top surface of the cover plate 1 is provided with a sensing element 6 for detecting the spike 322. The inductive element 6 can be connected with a power battery control system, when the inductive element 6 detects the spine 322, the battery is in an over-inflated and inflated state, the control system can automatically cut off the charging and discharging of the battery, and the safety accident caused by the continuous charging and discharging of the power battery is avoided. In the present embodiment, the sensing element 6 is a proximity switch or a touch sensor.

Referring to fig. 4, as some embodiments, the flow channel 4 penetrates the bottom surface of the cavity 21 and is coaxial with the mounting hole 311. With this arrangement, at the time of pressure relief, the gas in the battery case enters the accommodation chamber 211 upward through the flow channel 4, flows along the gap between the fixing member 31 and the mounting hole 311, and is discharged through the slit 51.

In the above embodiment, in the process of injecting liquid, the liquid injection needle penetrates through the cutting slit 51 and the liquid injection channel 321 and pierces through the plunger member 32, and the liquid injection needle penetrates downward through the flow channel 4 on the cavity 21 and enters into the battery shell, thereby implementing the injection of the electrolyte.

Based on the above embodiments, when the injection needle penetrates into the battery case, the injection needle may have a risk of piercing the battery cell, and therefore, as shown in fig. 2 and 5, as another embodiment, in this embodiment, as another embodiment, a plurality of notches 212 communicating with the accommodating cavity 211 are provided on the outer peripheral wall of the cavity 21, a plurality of support ribs 213 are provided on the bottom surface of the accommodating cavity 211, the plurality of support ribs 213 are arranged at intervals, the fixing member 31 is provided on the support ribs 213, one end of the support ribs 213 close to the side wall of the accommodating cavity 211 is provided with a holding portion 214 for limiting the side wall of the fixing member 31, by providing the support ribs 213, the fixing member 31 can be supported, so that the fixing member 31 forms a flow channel 4 with the bottom of the accommodating cavity 211 through the support ribs 213, and meanwhile, the holding portion 214 can limit the fixing member 31 in the horizontal direction, thereby preventing the fixing member 31 from moving horizontally in the accommodating cavity 211, at this time, the diameter of the accommodating cavity 211 is greater than the outer diameter of the fixing member 31, by providing the holding portion 214, the fixing member 31 can be fixed at the center of the fixing member 211, so that a gap exists between the fixing member 31 and the electrolyte can prevent the electrolyte from flowing into the battery cell from penetrating into the battery case, thereby preventing the electrolyte from flowing through the notch 212. Meanwhile, when explosion-proof decompression is performed, the gas in the battery case firstly enters the accommodating cavity 211 through the notches 212 and then enters the mounting hole 311 through the flow channel 4 between the plurality of supporting ribs 213 at the bottom of the fixing member 31, thereby pushing the plunger member 32 to slide upward.

Preferably, a sealing ring 7 is arranged between the top surface of the fixing member 31 and the bottom surface of the cover plate 1, and the sealing ring 7 is sleeved outside the mounting hole 311. It is possible to establish a sealed connection between the fixing member 31 and the lid plate 1, to improve airtightness, and to prevent the electrolyte from leaking out of the above-mentioned gap.

The embodiment also discloses a power battery, which comprises the power battery top cover; the battery also comprises a battery shell and a battery core arranged in the battery shell. Through the top cover structure, liquid can be injected or replenished to the battery cell in the battery shell.

The utility model discloses a theory of operation is:

when power battery overcharges, the electrolyte in the battery releases a large amount of gases, the inside atmospheric pressure of battery risees, gaseous promotion plunger piece 32 upwards slides along mounting hole 311 on the mounting 31, make and form the clearance between plunger piece 32 and the mounting hole 311, thereby make the inside gaseous following flow path 4 of battery and flow through above-mentioned clearance, and discharge through annotating liquid hole 11, thereby keep the pressure differential unanimous inside and outside the battery, play explosion-proof purpose, can pierce plunger piece 32 with annotating the liquid syringe needle through annotating liquid hole 11 simultaneously and annotate liquid, electrolyte can flow into in the battery case through flow path 4, thereby realize that electrolyte adds, the utility model discloses a be in the same place explosion-proof valve subassembly and annotate liquid hole 11 are integrated, need not to set up explosion-proof valve hole alone, has avoided electrolyte to annotate the liquid back and has splashed to cause explosion-proof membrane subassembly to damage on the explosion-proof membrane subassembly through explosion-proof valve hole. Simultaneously, reduced spare part figure, reduced the cost, simultaneously can effectual reply battery overcharge and explosion-proof.

The above description is only a preferred embodiment of the present invention, and should not be taken as limiting the invention, and any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A power battery top cover comprises a cover plate (1) and a lower plastic part (2) fixedly arranged on the bottom surface of the cover plate (1), wherein a liquid injection hole (11) is formed in the top surface of the cover plate (1), a cavity (21) corresponding to the liquid injection hole (11) is formed in the downward depression of the lower plastic part (2), and an accommodating cavity (211) is formed between the cavity (21) and the cover plate (1);

the method is characterized in that: also comprises an explosion-proof assembly (3), wherein the explosion-proof assembly (3) comprises a fixed piece (31) and a plunger piece (32),

the fixing piece (31) is arranged in the accommodating cavity (211), the cavity (21) is provided with a flow channel (4) communicated with the accommodating cavity (211), the center of the fixing piece (31) is provided with a through mounting hole (311), and the diameter of the mounting hole (311) is gradually reduced from top to bottom;

the plunger piece (32) is made of rubber materials, is arranged in the mounting hole (311), and can slide upwards along the inner wall of the mounting hole (311) when being driven by external force, so that a gap communicated with the flow channel (4) is formed between the plunger piece (32) and the mounting hole (311).

2. The power battery top cap of claim 1, wherein: plunger spare (32) are the round platform form, and the degree of depth that highly is less than mounting hole (311) of plunger spare (32), the bottom of plunger spare (32) is higher than the bottom of mounting hole (311), and the top of plunger spare (32) is less than the top of mounting hole (311), and plunger spare (32) are interference fit with mounting hole (311) department of being connected, and the interference loading volume is 0.2mm-0.5mm.

3. The power battery top cap of claim 1, wherein: the plunger piece (32) is characterized in that a vertical downward liquid injection channel (321) is formed in the center of the top surface of the plunger piece (32), and the thickness from the bottom end of the liquid injection channel (321) to the bottom surface of the plunger piece (32) is 0.5-2 mm.

4. The power cell header of claim 3, wherein: annotate the aperture of liquid hole (11) and be less than mounting hole (311) top aperture, annotate the fixed separation blade (5) that is provided with of level in liquid hole (11), separate separation blade (5) and form for being heat-seal by rubber/AL/LDPE, thickness is 0.5mm-1mm, separates that separation blade (5) center department is provided with joint-cutting (51).

5. The power cell header of claim 4, wherein: the top surface of the plunger piece (32) is vertically and fixedly provided with a sharp part (322) for puncturing the separation blocking piece (5).

6. The power cell header of claim 5, wherein: and the top surface of the cover plate (1) is provided with a sensing element (6) for detecting the spine part (322).

7. The power battery top cover of claim 1, wherein: the flow channel (4) penetrates through the bottom surface of the cavity (21) and is coaxial with the mounting hole (311).

8. The power battery top cover of claim 1, wherein: the outer peripheral wall of the cavity (21) is provided with a plurality of notches (212) communicated with the accommodating cavity (211), the bottom surface of the accommodating cavity (211) is provided with a plurality of supporting ribs (213), the supporting ribs (213) are arranged at intervals, the fixing piece (31) is arranged on the supporting ribs (213), one end, close to the side wall of the accommodating cavity (211), of each supporting rib (213) is provided with a butting part (214) used for limiting the side wall of the fixing piece (31), and the flow channel (4) is formed between the supporting ribs (213) and communicated with the notches (212).

9. The power battery top cover of claim 1, wherein: a sealing ring (7) is arranged between the top surface of the fixing piece (31) and the bottom surface of the cover plate (1), and the sealing ring (7) is sleeved outside the mounting hole (311).

10. A power battery, characterized by comprising the power battery top cover as claimed in any one of claims 1 to 9; the battery also comprises a battery shell and a battery core arranged in the battery shell.