Lower plastic part, battery top cover assembly and lithium battery

Abstract

The utility model provides a lower plastic part, a battery top cover assembly and a lithium battery, and relates to the technical field of batteries, bosses are fixedly arranged on the bottom surfaces of the two ends of a lower plastic part body in the length direction respectively, and concave cavities are formed in the top surface, corresponding to the bosses, of the lower plastic part body; one of the concave cavities is opposite to and communicated with the liquid injection hole in the cover plate of the battery top cover assembly, and the liquid discharge hole staggered with the liquid injection hole is formed in the concave cavity, so that the concave cavity not only plays a role in reducing weight, but also serves as a buffer cavity for electrolyte injection, and the electrolyte is discharged through the liquid discharge hole after entering the concave cavity, so that the service life of the battery is prolonged. The direct impact of the electrolyte on the battery cell is avoided, and the risk of damage to the battery cell is reduced. As the liquid injection hole is positioned at one end of the length direction of the cover plate and is far away from the explosion-proof valve, the electrolyte is prevented from polluting the explosion-proof valve, and the safety performance is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to a lower plastic part, a battery top cover assembly and a lithium battery. Background Art

[0002] The structure of a lithium-ion battery mainly includes a battery cell, a shell, and a top cover assembly. The top cover assembly includes a cover plate, a lower plastic part, and a protective element. Existing technology opens a through hole on the lower plastic part body opposite to the injection hole on the cover plate for battery injection, but it has the following disadvantages: 1. During injection, the electrolyte will directly impact the battery cell pack after passing through the injection hole of the lower plastic part. The impact of the electrolyte can easily damage the battery cell; 2. Because the injection hole is close to the explosion-proof valve on the cover plate, the electrolyte can easily be brought out during injection and contaminate the explosion-proof valve, reducing the safety performance of the explosion-proof valve. Utility Model Content

[0003] In view of this, the present invention proposes a lower plastic part, a battery top cover assembly and a lithium battery to solve the problems that the battery core will be damaged during liquid filling and the electrolyte brought out during liquid filling will contaminate the explosion-proof valve.

[0004] The technical solution of the present utility model is achieved as follows:

[0005] In the first aspect, the utility model provides a lower plastic part, including a plastic part body, wherein bosses are fixedly provided on the bottom surfaces of both ends of the plastic part body in the length direction, and a concave cavity is provided on the top surface of the plastic body corresponding to the bosses, one of the concave cavities is opposite to and connected to the injection hole on the cover plate of the battery top cover assembly, and a drainage hole is provided on the concave cavity, which is staggered with the position of the injection hole.

[0006] On the basis of the above technical solution, preferably, two partitions are fixedly arranged vertically at intervals in the middle of the concave cavity along the width direction of the plastic part body, and the two partitions divide the concave cavity into an injection cavity and two liquid separation cavities that are interconnected. The injection cavity and the injection hole on the cover plate of the battery top cover assembly are opposite and connected, and the drainage hole is located in the liquid separation cavity.

[0007] On the basis of the above technical solution, preferably, the drainage hole includes a plurality of first through holes, and the plurality of first through holes are arranged at intervals on the bottom surface of the liquid separation cavity along the length direction of the liquid separation cavity.

[0008] On the basis of the above technical solution, preferably, the drainage hole further includes a plurality of second through holes, and the plurality of second through holes are arranged at intervals on the inner side wall of the liquid separation cavity along the length direction of the liquid separation cavity.

[0009] On the basis of the above technical solution, preferably, a through hole connecting the injection chamber and the liquid separation chamber is provided on the bottom surface of the partition, and an annular flange is provided inside the liquid separation chamber. The annular flange divides the liquid separation chamber into a diversion chamber and a drainage chamber, and a plurality of first through holes are located in the drainage chamber. The annular flange surface is provided with a plurality of liquid inlet holes connecting the diversion chamber and the drainage chamber.

[0010] On the basis of the above technical solution, preferably, the first through hole and the second through hole are round holes or long holes.

[0011] In the second aspect, the utility model also provides a battery top cover assembly, including a cover plate and the lower plastic part described in the first aspect, the lower plastic part is fixedly arranged on the bottom surface of the cover plate, an explosion-proof valve is provided at the middle of the cover plate, and an injection hole is provided at one end of the cover plate in the longitudinal direction, and the concave cavity on the lower plastic part is opposite to and connected to the injection hole.

[0012] In a third aspect, the present invention further provides a lithium battery, which adopts the battery top cover assembly described in the second aspect.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] (1) By fixing bosses on the bottom surfaces of both ends of the plastic body in the longitudinal direction, a concave cavity is provided on the top surface of the plastic body corresponding to the boss, and one of the concave cavities is made to be opposite to and connected to the injection hole on the cover plate of the battery top cover assembly, and a drainage hole is provided on the concave cavity that is staggered from the injection hole. Thus, the concave cavity not only plays a role in reducing weight, but also serves as a buffer chamber for electrolyte injection. After the electrolyte enters the concave cavity, it is discharged through the drainage hole, avoiding direct impact of the electrolyte on the battery cell and reducing the risk of damage to the battery cell. Since the injection hole is located at one end of the cover plate in the longitudinal direction, it is far away from the explosion-proof valve and keeps a long distance from the explosion-proof valve to prevent the electrolyte from contaminating the explosion-proof valve, thereby improving safety performance.

[0015] (2) The concave cavity is divided into an injection cavity and a separation cavity by a partition. The electrolyte first enters the injection cavity and is buffered and stored there. The electrolyte does not flow directly out of the concave cavity. Instead, it flows through the injection cavity into the separation cavity and is discharged through the drainage hole in the separation cavity, ensuring the uniform distribution of the electrolyte inside the battery. The provision of the partition also enhances the structural strength of the lower plastic part, improving the overall stability and impact resistance.

[0016] (3) By providing an annular flange inside the liquid separation cavity, it is divided into a diversion cavity and a drainage cavity. The electrolyte flows in the diversion cavity and is evenly distributed to the drainage cavity through multiple liquid inlet holes, ensuring that the amount of electrolyte discharged from each first through hole is relatively balanced, thereby improving the uniformity of the overall drainage. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1 This is a schematic diagram of the three-dimensional structure of the lower plastic part disclosed in the utility model from a first perspective;

[0019] Figure 2 This is a schematic diagram of the three-dimensional structure of the lower plastic part disclosed in the present utility model from a second viewing angle;

[0020] Figure 3 for Figure 1 A partial enlarged view of the middle A;

[0021] Figure 4 This is a schematic diagram of the three-dimensional structure of the battery top cover assembly disclosed in the present utility model;

[0022] Reference numerals:

[0023] 1. Lower plastic part; 11. Plastic part body; 12. Boss; 13. Cavity; 14. Drain hole; 15. Partition; 131. Injection cavity; 132. Liquid separation cavity; 141. First through hole; 142. Second through hole; 151. Through hole; 16. Annular flange; 1321. Diversion cavity; 1322. Drain cavity; 161. Liquid inlet hole; 2. Cover plate; 21. Injection hole; 22. Explosion-proof valve. DETAILED DESCRIPTION

[0024] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0025] Example 1

[0026] like Figure 1 As shown, combined Figure 2 and 3The present invention discloses a lower plastic component 1 comprising a plastic body 11. The plastic body 11 is a plate-like structure made of plastic material and is used to establish electrical isolation between the battery cell and the cover plate 2. Bosses 12 are fixedly provided on the bottom surfaces of both ends of the plastic body 11 in the longitudinal direction. The bosses 12 serve to limit the end faces of the battery cell and ensure that the battery cell is fixed in the axial direction of the housing.

[0027] In this embodiment, a cavity 13 is provided on the top surface of the lower plastic body corresponding to the boss 12. The provision of the cavity 13 reduces the weight of the lower plastic part 1 and improves the lightweight structure. One of the cavities 13 is opposite and connected to the injection hole 21 on the cover plate 2 of the battery top cover assembly. The cavity 13 is provided with a drainage hole 14 that is staggered from the injection hole 21. The provision of the cavity 13 not only reduces weight but also serves as a buffer chamber for electrolyte injection. After the electrolyte enters the cavity 13, it is discharged through the drainage hole 14, avoiding direct impact of the electrolyte on the battery cell and reducing the risk of damage to the battery cell. Since the injection hole 21 is located at one end of the cover plate 2 in the longitudinal direction, it is far away from the explosion-proof valve 22. Maintaining a long distance from the explosion-proof valve 22 prevents electrolyte from contaminating the explosion-proof valve 22, thereby improving safety performance.

[0028] As some preferred embodiments, two partitions 15 are fixedly arranged vertically at intervals in the middle of the concave cavity 13 along the width direction of the plastic body 11. The two partitions 15 divide the concave cavity 13 into an injection cavity 131 and two liquid separation cavities 132 that are interconnected. The injection cavity 131 and the injection hole 21 on the cover plate 2 of the battery top cover assembly are opposite and connected, and the drainage hole 14 is located in the liquid separation cavity 132.

[0029] The concave cavity 13 is divided into an injection cavity 131 and a separation cavity 132 by a partition 15. The electrolyte first enters the injection cavity 131 and is buffered and stored there. The electrolyte does not flow directly out of the concave cavity 13. Instead, it flows through the injection cavity 131 into the separation cavity 132 and is discharged through the drainage holes 14 in the separation cavity 132, ensuring uniform distribution of the electrolyte within the battery. The provision of the partition 15 also enhances the structural strength of the lower plastic component 1, improving its overall stability and impact resistance.

[0030] In some embodiments, the drainage hole 14 includes a plurality of first through holes 141, which are spaced apart along the length of the liquid separation chamber 132 and arranged on the inner bottom surface of the liquid separation chamber 132. The provision of multiple first through holes 141, distributed along the inner bottom surface of the liquid separation chamber 132, facilitates rapid electrolyte drainage and reduces filling time. Furthermore, the electrolyte can be discharged simultaneously from multiple points, avoiding the problem of localized uneven drainage that may occur with a single drainage hole 14.

[0031] Based on the above solution, the drainage hole 14 further includes a plurality of second through holes 142, which are spaced apart along the length of the liquid separation chamber 132 and arranged at the bottom of the inner side wall of the liquid separation chamber 132. By adding the second through holes 142 at the bottom of the inner side wall of the liquid separation chamber 132, the electrolyte has multiple drainage directions, thereby accelerating the drainage speed.

[0032] Since the first through holes 141 are arranged at intervals on the bottom surface of the liquid separation chamber 132 along the length direction of the liquid separation chamber 132, after the electrolyte enters the diversion chamber from the injection chamber 131, it will flow along the length direction of the liquid separation chamber 132. The first through holes 141 close to the partition 15 will bear more electrolyte discharge, while the first through holes 141 away from the partition 15 will discharge less electrolyte, which is not conducive to uniform drainage and will result in reduced electrolyte infiltration efficiency.

[0033] To this end, the present embodiment provides the following technical solution: a through hole 151 is provided on the bottom surface of the partition 15 to connect the injection chamber 131 and the liquid separation chamber 132; an annular flange 16 is provided inside the liquid separation chamber 132; the annular flange 16 separates the liquid separation chamber 132 into a guide chamber 1321 and a drainage chamber 1322; a plurality of first through holes 141 are located in the drainage chamber 1322; a plurality of liquid inlet holes 161 are provided on the side of the annular flange 16 to connect the guide chamber 1321 and the drainage chamber 1322.

[0034] An annular flange 16 is provided within the liquid separation chamber 132, dividing it into a diversion chamber 1321 and a drainage chamber 1322. The electrolyte first enters the diversion chamber 1321, where it flows longitudinally, helping to balance the flow rate of the electrolyte. The electrolyte then passes through the liquid inlet holes 161 on the bottom surface of the sidewall of the annular flange 16 and is evenly distributed into the drainage chamber 1322. This arrangement ensures a more uniform distribution of the electrolyte within the drainage chamber 1322. After being evenly distributed within the diversion chamber 1321, the electrolyte enters the drainage chamber 1322 through the liquid inlet holes 161 and is then discharged from the first through hole 141 at the bottom. This multi-stage diversion and uniform distribution design enhances drainage uniformity.

[0035] The electrolyte flows in the flow guiding cavity 1321 and is evenly distributed to the drainage cavity 1322 through the multiple liquid inlet holes 161, ensuring that the amount of electrolyte discharged from each first through hole 141 is relatively balanced, thereby improving the overall drainage uniformity.

[0036] Preferably, the first through hole 141 and the second through hole 142 are round holes or long holes.

[0037] Example 2

[0038] This embodiment also discloses a battery top cover assembly, see the attached Figure 4As shown, it includes a cover plate 2 and the lower plastic part 1 described in Example 1. The lower plastic part 1 is fixedly arranged on the bottom surface of the cover plate 2. An explosion-proof valve 22 is provided in the middle of the cover plate 2. A liquid injection hole 21 is provided at one end of the cover plate 2 in the longitudinal direction. The concave cavity 13 on the lower plastic part 1 is opposite to and connected to the liquid injection hole 21.

[0039] The battery top cover assembly disclosed in this embodiment utilizes the lower plastic component 1 of the first embodiment. Electrolyte is injected through the injection hole 21 at one longitudinal end of the cover plate 2. After entering the recessed cavity 13, the electrolyte is buffered and stored before being discharged through the drainage hole 14. This prevents the electrolyte from directly impacting the battery cells, reducing the risk of damage to the cells. Because the injection hole 21 is located at one longitudinal end of the cover plate 2, it is relatively far from the explosion-proof valve 22. Maintaining a relatively long distance from the explosion-proof valve 22 prevents electrolyte contamination of the explosion-proof valve 22, thereby improving safety.

[0040] Example 3

[0041] This embodiment also discloses a lithium battery that utilizes the battery top cover assembly disclosed in Example 2. In addition to the technical benefits of the battery top cover assembly, the lithium battery disclosed in this embodiment has a corresponding liquid injection hole 21 and a concave cavity 13. After the sealing pin and the sealing aluminum block complete the sealing at the liquid injection hole 21, if the sealing pin falls off during use of the lithium battery, it can fall into the concave cavity 13 and avoid falling directly into the housing, thereby improving the safety of the lithium battery.

[0042] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A lower plastic part, characterized in that: The invention comprises a plastic body (11), wherein bosses (12) are fixedly provided on the bottom surfaces of both ends of the plastic body (11) in the longitudinal direction, and a concave cavity (13) is provided on the top surface of the plastic body (11) corresponding to the bosses (12), wherein one of the concave cavities (13) is opposite to and communicates with a liquid injection hole (21) on a cover plate (2) of a battery top cover assembly, and a liquid discharge hole (14) is provided on the concave cavity (13) and is staggered with the liquid injection hole (21).

2. The lower plastic part according to claim 1, wherein: Two partitions (15) are fixedly arranged vertically at intervals in the middle of the concave cavity (13) along the width direction of the plastic body (11). The two partitions (15) divide the concave cavity (13) into a liquid injection cavity (131) and two liquid separation cavities (132) that are interconnected. The liquid injection cavity (131) and the liquid injection hole (21) on the cover plate (2) of the battery top cover assembly are opposite to and connected to each other, and the drainage hole (14) is located in the liquid separation cavity (132).

3. The lower plastic part according to claim 2, wherein: The drainage hole (14) comprises a plurality of first through holes (141), and the plurality of first through holes (141) are arranged at intervals on the inner bottom surface of the liquid separation cavity (132) along the length direction of the liquid separation cavity (132).

4. The lower plastic part according to claim 3, wherein: The drainage hole (14) further comprises a plurality of second through holes (142), and the plurality of second through holes (142) are arranged at intervals along the length direction of the liquid separation cavity (132) at the bottom of the inner side wall of the liquid separation cavity (132).

5. The lower plastic part according to claim 4, wherein: The bottom surface of the partition (15) is provided with a through hole (151) connecting the liquid injection cavity (131) and the liquid separation cavity (132); an annular flange (16) is provided inside the liquid separation cavity (132); the annular flange (16) separates the liquid separation cavity (132) into a diversion cavity (1321) and a liquid discharge cavity (1322); a plurality of first through holes (141) are located in the liquid discharge cavity (1322); a plurality of liquid inlet holes (161) connecting the diversion cavity (1321) and the liquid discharge cavity (1322) are provided on the side surface of the annular flange (16).

6. The lower plastic part according to claim 3, wherein: The first through hole (141) and the second through hole (142) are circular holes or elongated holes.

7. A battery top cover assembly, characterized in that: The invention comprises a cover plate (2) and a lower plastic part (1) as claimed in any one of claims 1 to 6, wherein the lower plastic part (1) is fixedly arranged on the bottom surface of the cover plate (2), an explosion-proof valve (22) is provided at the middle of the cover plate (2), a liquid injection hole (21) is provided at one end in the longitudinal direction of the cover plate (2), and a concave cavity (13) on the lower plastic part (1) is opposite to and connected to the liquid injection hole (21).

8. A lithium battery, characterized in that: The lithium battery adopts the battery top cover assembly described in claim 7.

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