Battery top cover and battery

Abstract

The utility model provides a battery top cover and a battery, and belongs to the technical field of new energy batteries. The battery top cover comprises a cover body, the cover body is provided with a pole hole, an anti-explosion valve hole and a liquid injection hole, the liquid injection hole is a counterbore and comprises a blind hole section connected with the top of the cover body and a through hole section connected with the bottom of the cover body, the bottom of the blind hole section is provided with peripheral side through holes communicated with the two sides of the cover body, and the peripheral side through holes are strip-shaped and are arranged in the radial direction of the through hole section. By adopting the battery top cover, the problem of low yield of battery products caused by defects of a battery liquid injection hole structure and a liquid injection mode in the prior art can be solved.

Description

Technical Field

[0001] The utility model relates to the technical field of new energy batteries, and particularly relates to a battery top cover and a battery. Background Art

[0002] At present, with the rapid development of electric vehicles, the research and application of electric vehicles have received increasing attention. The battery pack composed of new energy batteries such as lithium batteries, as the power source of electric vehicles, is an important part of electric vehicles. Lithium batteries usually consist of structures such as battery cells, top covers, and shells. When assembling lithium batteries, the battery cells are usually first installed on the top cover and then inserted into the shell, and then the top cover and the shell are buckled. The top cover is usually provided with a liquid injection hole for facilitating the injection of electrolyte into the battery cells. After the lithium battery is injected with electrolyte, an inert gas such as helium is usually filled into the shell, and then a sealed aluminum sheet is used to seal the liquid injection hole.

[0003] In the related art, in order to ensure the injection speed and the infiltration effect of the electrolyte, a negative pressure injection method is often used. That is, during the normal injection process, the inside of the battery shell is usually evacuated before injection, so that the inside of the shell is in a negative pressure state, and then the electrolyte is sucked into the shell through the negative pressure to complete the injection process.

[0004] With the injection method in the related art, since the negative pressure inside the sealed battery shell is difficult to control, the explosion-proof valve patch disposed beside the liquid injection hole and also communicating with the outside of the top cover and the inside of the shell is easily sucked flat and damaged. And when the injected electrolyte is excessive, the electrolyte is easily ejected from the liquid injection hole to the explosion-proof valve patch due to excessive internal air pressure, and then penetrates through the breathing hole to contaminate the explosion-proof valve, affecting the yield of battery products. Summary of the Utility Model

[0005] The embodiment of the utility model provides a battery top cover and a battery, which can solve the problem of low yield of battery products caused by the defects of the battery liquid injection hole structure and injection method in the prior art. The technical solution is as follows:

[0006] In a first aspect, the embodiment of the utility model provides a battery top cover, including: a cover body, on which a pole hole, an explosion-proof valve hole, and a liquid injection hole are provided. The liquid injection hole is a countersunk hole, including a blind hole section connected to the top of the cover body and a through hole section connected to the bottom of the cover body. A circumferential through hole communicating with both sides of the cover body is opened at the bottom of the blind hole section. The circumferential through hole is strip-shaped and arranged along the radial direction of the through hole section.

[0007] Optionally, the width of the circumferential through hole is smaller than the diameter of the through hole section.

[0008] Optionally, two circumferential through holes are provided, and the two circumferential through holes are symmetrically arranged with respect to the through hole section.

[0009] Optionally, the top diameter of the blind hole section is larger than the bottom diameter.

[0010] Optionally, the length of the circumferential through hole at the top of the cover body is greater than the length at the bottom of the cover body.

[0011] Optionally, it further includes a bottom plastic part, which is arranged at the bottom of the cover body, and the bottom plastic part is provided with a liquid injection opening corresponding to the liquid injection hole, a pole column opening corresponding to the pole column hole, and a ventilation hole corresponding to the explosion-proof valve hole.

[0012] Optionally, a positioning protrusion communicating with the through hole section is arranged at the bottom of the cover body, and a positioning part matching the positioning protrusion is arranged on the bottom plastic part. The positioning part includes a positioning groove on one side of the bottom plastic part and a liquid injection protrusion protruding from the other side of the bottom plastic part. The liquid injection opening communicates with the bottom of the positioning groove and the liquid injection protrusion.

[0013] Optionally, a plurality of liquid distribution holes communicating with the bottom of the positioning groove and the liquid injection protrusion are arranged on the positioning part, and the plurality of liquid distribution holes are arranged at equal angular intervals around the liquid injection opening.

[0014] Optionally, the bottom plastic part is provided in multiple sections.

[0015] In a second aspect, a battery includes the battery top cover described in the first aspect above.

[0016] The beneficial effects brought by the technical solution provided by the embodiments of the present invention at least include:

[0017] When injecting liquid into a battery using this battery top cover, a different liquid injection method from the prior art is adopted. First, the liquid injection nozzle is matched with the liquid injection hole. The liquid injection nozzle will be closely matched with the conventional blind hole section and through hole section in the liquid injection hole, while the circumferential through hole remains in communication with the outside. At this time, the electrolyte can be injected into the battery housing from one side of the liquid injection nozzle with a certain pressure. As the liquid injection progresses, the gas inside the battery housing can be released to the external air through the circumferential through hole under pressure, so that the air pressure inside the battery housing is in balance with the external air pressure during the battery liquid injection process. Since the negative pressure treatment process such as evacuating the inside of the battery housing is cancelled, while reducing the difficulty of the entire liquid injection process, there is no need to worry about the influence of the internal negative pressure magnitude on the explosion-proof valve piece of the explosion-proof valve hole causing deformation. Further, when the injected electrolyte is excessive, under the air pressure balance of the circumferential through hole, the air pressure inside the battery housing will not cause the electrolyte to splash out due to excessive air pressure, thereby avoiding the electrolyte spraying onto the explosion-proof valve during the liquid injection process and when the liquid injection nozzle is separated after the liquid injection is completed, effectively solving the problem of low yield of battery products caused by the defects of the battery liquid injection hole structure and liquid injection method in the prior art. Description of the Drawings

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for use in the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0019] Figure 1 It is a three-dimensional structural schematic diagram of the top surface of the battery top cover provided by an embodiment of the present invention;

[0020] Figure 2 It is a partial structural schematic diagram of the liquid injection hole provided by an embodiment of the present invention;

[0021] Figure 3 It is a three-dimensional structural schematic diagram of the bottom surface of the battery top cover provided by an embodiment of the present invention;

[0022] Figure 4 It is a partial structural schematic diagram of the bottom surface of the cover body provided by an embodiment of the present invention;

[0023] Figure 5 It is a three-dimensional structural schematic diagram of the bottom plastic part provided by an embodiment of the present invention;

[0024] Figure 6 It is a structural schematic diagram of the sealing aluminum sheet provided by an embodiment of the present invention.

[0025] In the figure: 1 - cover body; 2 - bottom plastic part; 3 - sealing aluminum sheet; 11 - pole post hole; 12 - explosion-proof valve hole; 13 - liquid injection hole; 14 - positioning protrusion; 21 - liquid injection opening; 22 - pole post opening; 23 - ventilation hole; 24 - positioning part; 31 - lug; 131 - blind hole section; 132 - through hole section; 133 - circumferential through hole; 241 - positioning groove; 242 - liquid injection protrusion; 243 - liquid distribution hole. Specific Embodiments

[0026] To make the purpose, technical solutions, and advantages of the present invention clearer, the following will further describe the embodiments of the present invention in detail in conjunction with the drawings.

[0027] Figure 1 It is a three-dimensional structural schematic diagram of the top surface of the battery top cover provided by an embodiment of the present invention; Figure 2 It is a partial structural schematic diagram of the liquid injection hole provided by an embodiment of the present invention; Figure 3 It is a three-dimensional structural schematic diagram of the bottom surface of the battery top cover provided by an embodiment of the present invention; Figure 4 It is a partial structural schematic diagram of the bottom surface of the cover body provided by an embodiment of the present invention; Figure 5It is a schematic three-dimensional structure diagram of the bottom plastic part provided by the embodiment of the present utility model; Figure 6 It is a schematic structure diagram of the sealing aluminum sheet provided by the embodiment of the present utility model. As Figures 1 to 6 shown, the embodiment of the present utility model provides a battery top cover, including a cover body 1. Among them, a pole hole 11, an explosion-proof valve hole 12, and a liquid injection hole 13 are provided on the cover body 1. The liquid injection hole 13 is a countersunk hole, including a blind hole section 131 connected to the top of the cover body 1 and a through hole section 132 connected to the bottom of the cover body 1. A circumferential through hole 133 communicating with both sides of the cover body 1 is opened at the bottom of the blind hole section 131. The circumferential through hole 133 is strip-shaped and arranged along the radial direction of the through hole section 132.

[0028] In the embodiment of the present utility model, the pole hole 11 and the explosion-proof valve hole 12 on the cover body 1 are respectively used to assemble structures such as poles and explosion-proof valve sheets on a conventional battery cover plate. On this basis, the liquid injection hole structure on the cover body of the traditional battery top cover is optimized. On the basis of using a countersunk hole-shaped liquid injection hole 13 on the cover body 1, the lower through hole section 132 with a smaller diameter is processed into a special shape, and a strip-shaped through hole communicating with it is added radially outward along the through hole section 132, that is, the circumferential through hole 133. The circumferential through hole penetrates the opposite two side surfaces of the cover body 1 in the thickness direction. Among them, the width of the circumferential through hole 133 should be smaller than the diameter of the through hole section 132 itself to avoid affecting the cooperation between the liquid injection nozzle and the liquid injection hole 13 during the liquid injection process and causing sliding into the circumferential through hole 133, ensuring the assembly stability during the liquid injection process. Correspondingly, when injecting liquid into a battery using this battery top cover, a liquid injection method different from the prior art can be adopted. First, the liquid injection nozzle is matched with the liquid injection hole 13. The liquid injection nozzle will be closely matched with the conventional blind hole section 131 and through hole section 132 in the liquid injection hole 13, while the circumferential through hole 133 remains in communication with the outside. At this time, the electrolyte can be injected into the battery housing from one side of the liquid injection nozzle with a certain pressure. As the liquid injection progresses, the gas inside the battery housing can be released to the external air through the circumferential through hole 133, so that the air pressure inside the battery housing is in balance with the external air pressure during the battery liquid injection process. Since the negative pressure treatment process such as vacuum pumping inside the battery housing is cancelled, while reducing the difficulty of the entire liquid injection process, there is no need to worry about the influence of the internal negative pressure magnitude on the explosion-proof valve sheet of the explosion-proof valve hole 12 causing deformation. Further, when the injected electrolyte is excessive, the air pressure inside the battery housing will not cause the electrolyte to splash out due to excessive air pressure under the air pressure balance of the circumferential through hole 133, thereby avoiding the electrolyte spraying onto the explosion-proof valve during the liquid injection process and when the liquid injection nozzle is separated after the liquid injection is completed, effectively solving the problem of low yield of battery products caused by the defects of the battery liquid injection hole structure and liquid injection method in the prior art.

[0029] Optionally, there are two circumferential side through-holes 133, and the two circumferential side through-holes 133 are symmetrically arranged with respect to the through-hole section 132. Exemplarily, in the embodiment of the present invention, circumferential side through-holes 133 are added by extending outward on both sides of the through-hole section 132. In the form of symmetrical arrangement, the gas in the inner shell during liquid injection can be evenly discharged outward from the circumferential side through-holes 133 on both sides, further improving the balance stability of the internal and external air pressures during liquid injection.

[0030] Optionally, the top diameter of the blind hole section 131 is larger than the bottom diameter. Exemplarily, in the embodiment of the present invention, the blind hole section 131 near the top of the cover body 1 is a conical structure with a top diameter larger than the bottom diameter. Correspondingly, the embodiment of the present invention is also configured with a corresponding sealing aluminum sheet 3. The middle part of the sealing aluminum sheet 3 is a frustum of a cone structure matching the blind hole section 131, and convex ears 31 matching the two circumferential side through-holes 133 are protruded on both sides. During the sealing assembly, the side wall of the frustum of the cone of the sealing aluminum sheet 3 cooperates with the conical side wall of the blind hole section 131, with a smooth transition and a larger contact area compared to ordinary blind holes, which can further improve the sealing performance.

[0031] Optionally, the length of the circumferential side through-hole 133 at the top of the cover body 1 is greater than the length at the bottom of the cover body 1. Exemplarily, corresponding to the side wall of the blind hole section 131, the end side wall of the circumferential side through-hole 133 in the length direction can also be set to a corresponding inclined structure. When cooperating with the convex ear 31 of the sealing aluminum sheet 3, the sealing cooperation area is correspondingly increased. During the assembly process of the sealing aluminum sheet 3, the inclined side wall structure can also play a role of assembly guidance, enabling the sealing aluminum sheet 3 to accurately sink into the liquid injection hole 13 to ensure the assembly accuracy and facilitating welding and sealing.

[0032] Optionally, it further includes a bottom plastic part 2. The bottom plastic part 2 is arranged at the bottom of the cover body 1, and a liquid injection opening 21 corresponding to the liquid injection hole 13, a pole post opening 22 corresponding to the pole post hole 11, and a ventilation hole 23 corresponding to the explosion-proof valve hole 12 are arranged on the bottom plastic part 2. Exemplarily, in the embodiment of the present invention, a bottom plastic part 2 is further arranged at the bottom of the cover body 1, which is used for insulating isolation and limit fixation of the battery internal cell after being covered on the battery lower shell.

[0033] Further, a positioning protrusion 14 communicating with the through-hole section 132 is provided at the bottom of the cover body 1, and a positioning portion 24 matching the positioning protrusion 14 is provided on the bottom plastic part 2. The positioning portion 24 includes a positioning groove 241 on one side of the bottom plastic part 2 and a liquid injection protrusion 242 protruding from the other side of the bottom plastic part 2. The liquid injection opening 21 communicates with the bottom of the positioning groove 241 and the liquid injection protrusion 242. When combining the bottom plastic part 2 and the cover body 1, the combination and assembly can be carried out through the positioning protrusion 14 and the positioning portion 24. The positioning protrusion 14 is nested in the positioning groove 241 to achieve rapid and accurate combination, ensuring that the liquid injection hole 13, the pole column hole 11, and the explosion-proof valve hole 12 can be accurately aligned with the corresponding holes on the bottom plastic part 2, facilitating subsequent welding and fixing.

[0034] Further, a plurality of liquid distribution holes 243 communicating with the bottom of the positioning groove 241 and the liquid injection protrusion 242 are provided on the positioning portion 24. The plurality of liquid distribution holes 243 are arranged at equal angular intervals around the liquid injection opening 21. When injecting liquid, the electrolyte can be evenly injected into the battery housing through the plurality of liquid distribution holes 243, improving the even infiltration of the electrolyte into the internal battery cells during the liquid injection process.

[0035] Optionally, the bottom plastic part 2 is provided in multiple sections. Exemplarily, in the embodiment of the present invention, the bottom plastic part 2 is a prefabricated two-piece split structure, where the liquid injection opening 21, the ventilation hole 23, and one of the pole column openings 22 are located on one section, and the other pole column opening 22 is located on the other section. When combining and assembling with the cover body 1, welding and fixing can be carried out separately in sequence, further improving the combination convenience.

[0036] The liquid injection opening 21 corresponding to the liquid injection hole 13, the pole column opening 22 corresponding to the pole column hole 11, and the ventilation hole 23 corresponding to the explosion-proof valve hole 12

[0037] The embodiment of the present invention also provides a battery, including the Figures 1 to 6 shown battery top cover. It should be noted that Figures 1 to 6 the form of the cover body 1 in is mainly applicable to the conventional square shell battery form. In other possible implementation manners of the present invention, the cover body 1 with the liquid injection hole 13 structure can also be specially shaped for use in cylindrical batteries.

[0038] Unless otherwise defined, technical or scientific terms used herein shall have the ordinary meanings as understood by those of ordinary skill in the field to which this utility model pertains. The terms "first", "second" and similar terms used in the description and claims of this utility model patent application do not denote any order, quantity or importance, but are merely used to distinguish different components. Similarly, terms such as "a" or "an" do not denote a quantity limitation, but rather indicate the presence of at least one. The terms "comprising" or "including" and similar terms mean that the elements or items appearing before "comprising" or "including" cover the elements or items listed after "comprising" or "including" and their equivalents, and do not exclude other elements or items. The terms "connected" or "coupled" and similar terms are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The terms "upper", "lower", "left", "right" etc. are only used to indicate relative positional relationships, and when the absolute position of the object being described changes, the relative positional relationships may also change accordingly.

[0039] The above are only optional embodiments of this utility model, and are not intended to limit this utility model. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of this utility model shall be included within the protection scope of this utility model.

Claims

1. A battery top cover, characterized in that: The invention comprises a cover body (1), wherein the cover body (1) is provided with a pole hole (11), an explosion-proof valve hole (12) and a liquid injection hole (13); the liquid injection hole (13) is a countersunk hole, comprising a blind hole section (131) connected to the top of the cover body (1) and a through hole section (132) connected to the bottom of the cover body (1); a peripheral through hole (133) communicating with both sides of the cover body (1) is provided at the bottom of the blind hole section (131); the peripheral through hole (133) is in a strip shape and is arranged along the radial direction of the through hole section (132).

2. A battery top cover according to claim 1, characterized in that: The width of the peripheral through hole (133) is smaller than the diameter of the through hole section (132).

3. A battery top cover according to claim 1, characterized in that: Two circumferential through holes (133) are provided, and the two circumferential through holes (133) are symmetrically arranged relative to the through hole section (132).

4. A battery top cover according to claim 1, characterized in that: The top diameter of the blind hole section (131) is larger than the bottom diameter.

5. A battery top cover according to claim 1, characterized in that: The length of the peripheral through hole (133) at the top of the cover body (1) is greater than the length at the bottom of the cover body (1).

6. A battery top cover according to any one of claims 1 to 5, characterized in that: The invention also comprises a bottom plastic part (2), wherein the bottom plastic part (2) is arranged at the bottom of the cover body (1), and the bottom plastic part (2) is provided with a liquid injection opening (21) corresponding to the liquid injection hole (13), a pole opening (22) corresponding to the pole hole (11), and a vent hole (23) corresponding to the explosion-proof valve hole (12).

7. A battery top cover according to claim 6, characterized in that: The bottom of the cover body (1) is provided with a positioning protrusion (14) connected to the through hole section (132); the bottom plastic part (2) is provided with a positioning portion (24) matching the positioning protrusion (14); the positioning portion (24) comprises a positioning groove (241) located on one side of the bottom plastic part (2) and a liquid injection protrusion (242) protruding from the other side of the bottom plastic part (2); the liquid injection opening (21) is connected to the bottom of the positioning groove (241) and the liquid injection protrusion (242).

8. A battery top cover according to claim 7, characterized in that: The positioning portion (24) is provided with a plurality of liquid separation holes (243) communicating with the bottom of the positioning groove (241) and the liquid injection protrusion (242); the plurality of liquid separation holes (243) are arranged at equal angles around the liquid injection opening (21).

9. A battery top cover according to claim 6, characterized in that: The bottom plastic part (2) is provided with multiple sections.

10. A battery, characterized in that: Comprising the battery top cover according to any one of claims 1 to 5.

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