CN220382200U

CN220382200U - Sealing end plate of battery, battery cell and battery pack

Info

Publication number: CN220382200U
Application number: CN202321952421.5U
Authority: CN
Inventors: 王贝
Original assignee: Chuneng New Energy Co Ltd
Current assignee: Chuneng New Energy Co Ltd
Priority date: 2023-07-21
Filing date: 2023-07-21
Publication date: 2024-01-23
Anticipated expiration: 2033-07-21

Abstract

The embodiment of the utility model provides a sealing end plate of a battery, a battery cell and a battery pack. The sealing end plate of the battery comprises an end plate body. The end plate body can be covered at the opening of the shell, the end plate body is provided with a liquid injection hole and an air exhaust hole, and the air exhaust hole is used for exhausting redundant gas in the battery when the pressure in the battery exceeds a threshold value so as to keep the pressure in the battery in a preset range. Thus, the sealing end plate according to the embodiment of the utility model has the advantage of improving the cycle life of the cell and improving the stability of the electrochemical performance of the cell.

Description

Sealing end plate of battery, battery cell and battery pack

Technical Field

The utility model relates to the technical field of battery manufacturing, in particular to a sealing end plate of a battery, a battery cell with the sealing end plate and a battery pack.

Background

Energy conservation and emission reduction are key factors for sustainable development of the automobile industry, and electric vehicles become an important component for sustainable development due to the advantages of energy conservation and environmental protection. Battery technology is an important factor in the development of electric vehicles. The lithium ion battery has the advantages of high stored energy density, high rated voltage, low self-discharge rate, strong adaptability to high and low temperatures, long service life and the like, and is applied to the industry of electric vehicles. In the process of manufacturing lithium ion batteries, the formation of the battery plays a critical role in the performance of the battery.

In the related art, only the liquid injection hole is arranged on the battery cell shell, namely only the corresponding liquid injection channel is arranged, so that no matter negative pressure injection, equal pressure injection or high pressure injection is carried out, a negative pressure environment is required to be formed in the battery cavity. Negative pressure can be taken out the air in the electric core, helps eliminating the bubble in the pole piece, but negative pressure environment not only can lead to the casing to collapse to probably, annotate the liquid in-process moreover, the inside atmospheric pressure of battery case gradually rises and can form the bubble around the R angle of pole piece again, and this bubble is difficult to take out in the formation in later stage, causes the pole piece black spot easily, influences holistic performance and the life of battery.

Disclosure of Invention

The present utility model aims to solve at least one of the technical problems in the related art to some extent. To this end, embodiments of the present utility model provide a sealing end plate for a pool. The sealing end plate has the advantages of prolonging the cycle life of the battery and improving the stability of the electrochemical performance of the battery.

The embodiment of the utility model also provides a battery cell.

The embodiment of the utility model also provides a battery pack.

The sealing end plate of the battery of the embodiment of the utility model comprises an end plate body.

The end plate body can be covered at the opening of the shell, the end plate body is provided with a liquid injection hole and an air exhaust hole, and the air exhaust hole is used for exhausting redundant gas in the battery when the pressure in the battery exceeds a threshold value so as to keep the pressure in the battery in a preset range.

Meanwhile, because the shell has certain hardness, the problem of bulge and collapse easily occurs when the shell is subjected to overpressure or negative pressure. According to the battery sealing end plate, the liquid injection hole and the air exhaust hole are formed in the end plate body at the same time, and redundant gas in the shell can be timely exhausted through the air exhaust hole in the liquid injection process, so that the problem of overpressure in the shell is prevented. Meanwhile, the arranged air suction and exhaust holes further prevent bubbles from being formed around the R angle of the pole piece due to gradual rising of air pressure in the battery shell in the liquid injection process, and further avoid the problem of black spots. The black spots can cause poor electrode interface state, so that poor consistency among battery electrode groups causes too fast local capacity degradation, and the cycle life of the battery is seriously influenced. Therefore, the sealing end plate of the battery provided by the embodiment of the utility model is beneficial to forming a uniform negative electrode solid electrolyte interface film (SEI film) and a positive electrode passivation film (CEI film), so that the interface impedance of the battery is effectively reduced, the stability of the electrochemical performance of the battery is further improved, and the cycle life of the battery is prolonged.

In addition, the exhaust hole can timely exhaust the gas in the exhaust hole, so that the uniformity of the liquid injection speed is guaranteed.

Therefore, the battery cell with the sealing end plate of the battery of the embodiment of the utility model has the advantages of helping to prolong the cycle life of the battery and improving the stability of the electrochemical performance of the battery.

In some embodiments, the aperture of the liquid injection hole is larger than the aperture of the gas extraction hole.

In some embodiments, the liquid injection hole comprises a containing hole section and a communicating hole section which are sequentially arranged along the thickness direction of the sealing end plate, the diameter of the containing hole section is larger than that of the communicating hole section, the containing hole section and the communicating hole section form a step part at a connecting position, and the communicating hole section is communicated with the inside of the battery.

In some embodiments, the depth of the receiving hole section is 1/3-1/2 of the thickness of the end plate body.

In some embodiments, each of the receiving bore section and the communication bore section is an oblong bore; the distance D1 between the containing hole section and the communicating hole section in the length direction of the oblong hole is 1.5mm-10mm; the distance D2 between the containing hole section and the communicating hole section in the width direction of the oblong hole is 1.5mm-10mm.

In some embodiments, the aperture of the communication hole segment has a length D3, D3/D1 of 2-3, and the aperture of the communication hole segment has a width D4, D4/D2 of 2-4.

In some embodiments, the sealing end plate of the battery further comprises a unidirectional air film layer, and the unidirectional air film layer covers the air exhaust hole so as to seal and exhaust redundant air after air exhaust is finished;

in some embodiments, the sealing end plate of the battery comprises an explosion-proof valve, a valve port is arranged on the end plate body, the explosion-proof valve is arranged on the valve port, and the explosion-proof valve is arranged at a distance from the liquid filling hole and the air discharging hole;

in some embodiments, the end plate body provided with the vent hole has a boss portion on a side facing the inside of the battery.

The battery cell of the embodiment of the utility model can comprise an electric core, a shell and the sealing end plate of the battery, wherein the end plate body can be covered at the opening of the shell so as to form a containing cavity, and the electric core is arranged in the containing cavity.

In some embodiments, the housing has a first side and a second side disposed adjacent or opposite, the first side having an opening, the end plate body covering the opening, the second side having a post mounting hole.

The battery pack of the embodiment of the utility model can comprise a battery box and a plurality of battery cells.

Drawings

Fig. 1 is a schematic diagram showing the assembly of a battery cell, a liquid injection device and a suction device according to an embodiment of the present utility model.

Fig. 2 is a perspective view of the sealing end plate, priming device, and pumping device of an embodiment of the present utility model mated.

Fig. 3 is a cross-sectional view of the sealing end plate, priming device, and pumping device of an embodiment of the present utility model mated.

Fig. 4 is a cross-sectional view of a seal end plate according to an embodiment of the present utility model.

FIG. 5 is a cross-sectional view of a pour spout according to an embodiment of the present utility model.

Reference numerals:

a battery cell 100; a priming device 200; a suction device 300; needle tip 301; an airway tube 302;

a seal end plate 10; a housing 20; a first side 201; a second side 202; a post mounting hole 203;

an end plate body 1;

a liquid injection hole 11; a receiving hole section 111; a communication hole section 112;

an exhaust hole 12;

a valve port 13;

a boss portion 14;

an explosion-proof valve 2.

Detailed Description

Reference will now be made in detail to embodiments of the present utility model, examples of which are illustrated in the accompanying drawings. The embodiments described below by referring to the drawings are illustrative and intended to explain the present utility model and should not be construed as limiting the utility model.

The sealing end plate 10, the battery cell 100, and the battery pack of the battery according to the embodiment of the present utility model are described below with reference to fig. 1 to 5.

The sealing end plate 10 of the battery of the embodiment of the utility model includes an end plate body 1.

The end plate body 1 can be covered at the opening of the shell 20, the end plate body 1 is provided with a liquid injection hole 11 and an air exhaust hole 12, and the air exhaust hole 12 is used for exhausting redundant gas in the battery when the pressure in the battery exceeds a threshold value so as to keep the pressure in the battery in a preset range. The predetermined range may be, for example, -30 Kpa-10 Kpa. The predetermined range is changed by the change of the size and the material of the housing 20. Therefore, the battery is normally charged and discharged in a circulating way, and the safety problem caused by expansion of the battery is avoided. Air in the battery shell and the battery core can be pumped out through the air pumping holes 12, and air pumping in the battery core is beneficial to bonding between the positive electrode and the diaphragm and bonding between the negative electrode and the diaphragm, so that the quality of battery formation is improved.

Meanwhile, since the housing 20 itself has a certain hardness, the problem of swelling and collapsing easily occurs when the housing 20 is subjected to overpressure or negative pressure. According to the battery sealing end plate 10 provided by the embodiment of the utility model, the liquid injection hole 11 and the air exhaust hole 12 are simultaneously arranged on the end plate body 1, and in the liquid injection process, redundant gas in the shell 20 can be timely exhausted through the air exhaust hole 12, so that the problem of overpressure in the shell 20 is prevented. Meanwhile, the arranged air suction and exhaust hole 12 further prevents air bubbles from being formed around the R angle of the pole piece due to gradual increase of air pressure in the battery shell 20 in the liquid injection process, so that the problem of black spots is avoided. The black spots can cause poor electrode interface state, so that poor consistency among battery electrode groups causes too fast local capacity degradation, and the cycle life of the battery is seriously influenced. Therefore, the sealing end plate 10 of the battery of the embodiment of the utility model is beneficial to forming a uniform anode solid electrolyte interface film (SEI film) and a positive electrode passivation film (CEI film), so that the interface impedance of the battery is effectively reduced, the stability of the electrochemical performance of the battery is further improved, and the cycle life of the battery is prolonged.

In addition, the arranged air suction and exhaust holes 12 can timely exhaust the air in the air suction and exhaust holes, so that the uniformity of the liquid injection speed is ensured.

Accordingly, the battery cell 100 having the sealing end plate 10 of the battery of the embodiment of the present utility model has advantages of contributing to an improvement in the cycle life of the battery and an improvement in the stability of the electrochemical performance of the battery.

Alternatively, the liquid injection hole 11 and the gas suction hole 12 may be provided in plural.

The sealing end plate 10 is used as a sealing structure for the open end of the battery case, and the sealing end plate 10 covers the opening of the case 20 to isolate the internal environment of the battery cell 100 from the external environment. Without limitation, the shape of the sealing end plate 10 may be adapted to the shape of the housing 20 to fit the housing 20. However, unlike the conventional cover plate structure, the sealing end plate 10 of the battery of the present utility model does not require lower plastic and a post.

Alternatively, the sealing end plate 10 may be made of a material having a certain hardness and strength (such as an aluminum alloy), and the sealing end plate 10 is not easy to deform when being extruded and collided, so that the formed battery cell 100 can have a higher structural strength, and the safety performance can be improved.

The aperture of the liquid injection hole 11 is larger than that of the air suction hole 12.

According to the battery sealing end plate 10 provided by the embodiment of the utility model, the aperture of the liquid injection hole 11 is larger than that of the air exhaust hole 12, so that the liquid injection speed can be improved, and the air in the shell 20 is driven out through the injected electrolyte during negative pressure liquid injection, so that the window opening surface of the air exhaust hole 12 is reduced. Thus, the sealing end plate 10 is advantageous in improving the sealing performance of the battery.

As shown in fig. 3 and 4, the liquid injection hole 11 is a stepped hole including a receiving hole section 111 and a communicating hole section 112 which are sequentially provided in the thickness direction of the sealing end plate 10, the diameter of the receiving hole section 111 is larger than that of the communicating hole section 112, the receiving hole section 111 and the communicating hole section 112 form a stepped portion at the junction, and the communicating hole section 112 communicates with the inside of the battery.

According to the battery sealing end plate 10 provided by the embodiment of the utility model, the liquid injection hole 11 is divided into the containing hole section 111 and the communicating hole section 112 which are sequentially arranged along the thickness direction of the sealing end plate 10, the diameter of the containing hole section 111 is larger than that of the communicating hole section 112, when the liquid injection pipe of the liquid injection device 200 is inserted into the liquid injection hole of the battery during liquid injection, the liquid injection pipe can penetrate into the containing hole section 111, one end of the liquid injection pipe is abutted against the step part, and a certain degree of deformation can be generated under the action of external force, so that the sealing effect of the position is ensured. This seal end plate 10 further improves the sealing performance at the time of liquid injection.

The depth of the receiving hole section 111 is 1/3-1/2 of the thickness of the end plate body 1. That is, the ratio of the depth of the receiving hole section 111 to the thickness of the end plate body 1 is 1/3 to 1/2.

According to the battery sealing end plate 10 provided by the embodiment of the utility model, the depth of the accommodating hole section 111 is controlled to be 1/3-1/2 of the thickness of the end plate body 1, so that the problem of poor sealing stability caused by too small thickness of the end plate body 1 at the liquid injection hole 11 due to too large depth of the accommodating hole section 111 can be avoided. Meanwhile, the problem that the liquid leakage easily occurs during liquid injection because the depth of the accommodating hole section 111 is too small and the inner wall of the accommodating hole section 111 cannot limit the liquid injection pipe of the liquid injection device 200 is avoided.

As shown in fig. 5, each of the receiving hole section 111 and the communicating hole section 112 is an oblong hole, and a distance D1 between the receiving hole section 111 and the communicating hole section 112 in the length direction of the oblong hole is 1.5mm to 10mm; the distance D2 between the receiving hole section 111 and the communicating hole section 112 in the width direction of the oblong hole is 1.5mm-10mm. Width of the stepped surface formed by the aperture gap between the receiving hole section 111 and the communicating hole section 112.

According to the battery sealing end plate 10 provided by the embodiment of the utility model, the distance D1 between the accommodating hole section 111 and the communicating hole section 112 in the length direction of the oblong hole is controlled to be 1.5-10 mm, and the distance D2 between the accommodating hole section 111 and the communicating hole section 112 in the width direction of the oblong hole is controlled to be 1.5-10 mm. The problem that the battery pole piece is damaged due to the fact that the liquid injection pipe is inserted into the battery due to the fact that the width of the step surface is too small and the liquid injection pipe cannot be blocked is avoided. In addition, the width of the step surface is too small, and the problem of difficult sealing after liquid injection exists. Thus, the sealing end plate 10 has the advantages of being convenient for sealing and avoiding mistaken damage to the pole piece during liquid injection.

Alternatively, the circle centers of the accommodating hole section 111 and the communicating hole section 112 may coincide, and the space between the inner wall surface of the accommodating hole section 111 and the inner wall surface of the communicating hole section 112 is 1.5mm-10mm.

The aperture length of the communication hole section 112 is D3, D3/D1 is 2-3, the aperture width of the communication hole section 112 is D4, and D4/D2 is 2-4. That is, the ratio of D3 to D1 is 2-3, and the ratio of D4 to D2 is 2-4.

The sealing end plate 10 of the battery of the embodiment of the present utility model further includes a unidirectional air film layer (not shown) that covers the air extraction holes 12 to remove the excess air inside the case 20 after the air extraction is completed during formation or use.

During the use of the battery cell 100, the battery can be charged and discharged in a circulating manner, and gas is continuously generated until the battery cell expands, and the use performance and the safety performance of the battery cell 100 can be affected by excessive gas generated in the battery cell. The sealing end plate 10 of the battery in the embodiment of the utility model can further discharge the gas generated in the discharging process through the unidirectional air film layer arranged on the air suction hole 12. Thus, the sealing end plate 10 has an advantage of improving the battery service performance.

As shown in fig. 1, 3 and 4, the end plate body 1 is provided with an explosion-proof valve 2, the end plate body 1 is provided with a valve port 13, the explosion-proof valve 2 is arranged on the valve port 13, and the explosion-proof valve 2 is arranged at a distance from the liquid injection hole 11 and the air exhaust hole.

For example, the front-to-back direction shown in fig. 1.

Further, the explosion-proof valve 2 may be disposed between the liquid filling hole 11 and the gas suction hole 12.

Alternatively, the diameter of the vent is 2mm-3mm.

The end plate body 1 provided with the gas exhaust hole 12 has a boss portion 14 on the side facing the inside of the battery. So as to be inserted into the suction hole 12 using the suction device 300. Illustratively, the aspiration device 300 may include a needle tip 301 and an airway tube 302 in communication with each other, the needle tip 301 being disposed through the aspiration orifice 12. The length of the needle tip 301 is adapted to the thickness of the boss portion 14.

Alternatively, the boss portion 14 may be formed by press-fitting the end plate body 1 downward as shown in fig. 1.

The battery cell 100 of the embodiment of the present utility model includes a battery cell, a case 20, and a sealing end plate 10 of the battery according to any one of the above, the end plate body 1 being capable of being covered at an opening of the case 20 so as to form a receiving cavity in which the battery cell is disposed.

Therefore, the battery cell 100 of the embodiment of the present utility model has advantages of improving the cycle life of the battery and improving the stability of the electrochemical performance of the battery.

The sealing end plate 10 and the housing 20 may be integrated, and specifically, the sealing end plate 10 and the housing 20 may form a common connection surface before other components are put into the housing, and when the interior of the housing 20 needs to be sealed, the sealing end plate 10 is covered on the housing 20. The housing 20 may be of various shapes and sizes, such as rectangular parallelepiped, cylindrical, hexagonal prism, etc. In particular, the shape of the housing 20 may be determined according to the specific shape and size of the cell assembly. The material of the housing 20 may be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., which is not particularly limited in the embodiments of the present application.

As shown in fig. 1, the housing 20 has a first side 201 and a second side 202 disposed adjacently or oppositely, the first side 201 has an opening, the end plate body 1 covers the opening, and the second side 202 has a pole mounting hole 203. It will be appreciated that the post is not provided on the seal end plate 10.

In the battery cell 100 according to the embodiment of the utility model, the problem of interference between the polar post and the liquid injection hole 11 and the air exhaust hole 12 during the arrangement is avoided by placing the polar post and the sealing end plate 10 at two sides of the casing 20.

The battery pack of the embodiment of the present utility model may include a battery case and a plurality of battery cells 100 of any one of the above.

Therefore, the battery pack of the embodiment of the utility model has the advantages of prolonging the cycle life of the battery and improving the stability of the electrochemical performance of the battery.

In the battery pack, the number of the battery cells 100 may be plural, and the plurality of battery cells 100 may be connected in series, parallel, or series-parallel, where series-parallel refers to that the plurality of battery cells 100 are connected in both series and parallel. The battery cell 100 may be in the shape of a cylinder, a flat body, a rectangular parallelepiped, or other shapes, etc. The battery pack may further include other structures, for example, the battery may further include a bus bar member for making electrical connection between the plurality of battery cells 100.

In the description of the present utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings are merely for convenience in describing the present utility model and simplifying the description, and do not indicate or imply that the device or element being referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present utility model.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present utility model, the meaning of "plurality" means at least two, for example, two, three, etc., unless specifically defined otherwise.

In the present utility model, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; may be mechanically connected, may be electrically connected or may be in communication with each other; either directly or indirectly, through intermediaries, or both, may be in communication with each other or in interaction with each other, unless expressly defined otherwise. The specific meaning of the above terms in the present utility model can be understood by those of ordinary skill in the art according to the specific circumstances.

In the present utility model, unless expressly stated or limited otherwise, a first feature "up" or "down" a second feature may be the first and second features in direct contact, or the first and second features in indirect contact via an intervening medium. Moreover, a first feature being "above," "over" and "on" a second feature may be a first feature being directly above or obliquely above the second feature, or simply indicating that the first feature is level higher than the second feature. The first feature being "under", "below" and "beneath" the second feature may be the first feature being directly under or obliquely below the second feature, or simply indicating that the first feature is less level than the second feature.

For purposes of this disclosure, the terms "one embodiment," "some embodiments," "example," "a particular example," 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 utility model. In this specification, schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, the different embodiments or examples described in this specification and the features of the different embodiments or examples may be combined and combined by those skilled in the art without contradiction.

While embodiments of the present utility model have been shown and described above, it will be understood that the above embodiments are illustrative and not to be construed as limiting the utility model, and that variations, modifications, alternatives and variations may be made to the above embodiments by one of ordinary skill in the art within the scope of the utility model.

Claims

1. A sealing end plate of a battery, comprising: an end plate body, a connecting rod and a connecting rod,

2. The sealed end plate of claim 1, wherein the liquid injection hole has a larger pore diameter than the gas extraction hole.

3. The sealing end plate of a battery according to claim 2, wherein the liquid injection hole comprises a receiving hole section and a communicating hole section which are sequentially arranged in a thickness direction of the sealing end plate, a diameter of the receiving hole section is larger than that of the communicating hole section, a step part is formed at a connecting position of the receiving hole section and the communicating hole section, and the communicating hole section can communicate with the inside of the battery.

4. A sealing end plate for a battery according to claim 3, wherein the depth of the receiving hole section is 1/3-1/2 of the thickness of the end plate body.

5. The sealing end plate of the battery according to claim 3, wherein each of the receiving hole section and the communication hole section is an oblong hole; the distance D1 between the containing hole section and the communicating hole section in the length direction of the oblong hole is 1.5mm-10mm; the distance D2 between the containing hole section and the communicating hole section in the width direction of the oblong hole is 1.5mm-10mm.

6. The sealing end plate of claim 5, wherein the aperture of the communication hole section has a length D3, D3/D1 of 2-3, and the aperture of the communication hole section has a width D4, D4/D2 of 2-4.

7. The sealed end plate of the battery according to claim 1, further comprising a unidirectional gas film layer that covers the gas extraction holes so as to seal and extract surplus gas after the gas extraction is completed;

and/or, the liquid injection device further comprises an explosion-proof valve, wherein a valve port is arranged on the end plate body, the explosion-proof valve is arranged on the valve port, and the explosion-proof valve is arranged at intervals with the liquid injection hole and the exhaust hole;

and/or a boss part is arranged on one side of the end plate body provided with the air suction hole, which faces the inside of the battery.

8. A battery cell comprising a cell, a housing, and a sealed end plate of the battery of any one of claims 1-7, the end plate body covering at an opening of the housing to form a receiving cavity, the cell being disposed within the receiving cavity.

9. The battery cell of claim 8, wherein the housing has first and second sides disposed adjacent or opposite each other, the first side having an opening, the end plate body covering the opening, the second side having a post mounting hole.

10. A battery pack comprising a battery box and a plurality of battery cells according to any one of claims 8 or 9.