WO2022077904A1

WO2022077904A1 - Top cover structure and lithium battery with same

Info

Publication number: WO2022077904A1
Application number: PCT/CN2021/094806
Authority: WO
Inventors: 马亚强; 徐卫东
Original assignee: 厦门海辰新能源科技有限公司
Priority date: 2020-10-13
Filing date: 2021-05-20
Publication date: 2022-04-21
Also published as: CN212967854U

Abstract

A top cover structure (100) and a lithium battery with same. The top cover structure (100) of a lithium battery comprises a cover plate component (110), poles (120), and upper plastic parts (130). By providing bosses (111) on the cover plate component, the bosses (111) can be embedded in the upper plastic parts (130), and the upper plastic parts (130) can be wrapped around both the bosses (111) and protruding ends of the poles (120), such that the connections between the poles (120) and the upper plastic parts (130) can be tighter and firmer, and the connection stability of the bosses (111) and the upper plastic parts (130) is enhanced. In addition, the bosses (111) are arranged to protrude from the upper surface of the cover plate component (110), such that the penetration of an electrolyte can be effectively blocked, and the safety of a lithium battery is improved.

Description

Top cover structure and lithium battery having the same

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the priority of the Chinese Patent Application No. "202022268083.6", which was filed by Xiamen Haichen New Energy Technology Co., Ltd. on October 13, 2020 and titled "A Lithium Battery Top Cover Structure".

technical field

The present disclosure relates to the technical field of lithium batteries, and in particular, to a top cover structure and a lithium battery having the same.

Background technique

Lithium battery is a battery with metal lithium as the negative electrode, also known as lithium metal battery. Lithium batteries are classified into primary batteries and secondary batteries according to different battery configurations. The most common lithium battery structure uses metallic lithium as the negative electrode, manganese dioxide as the positive electrode, and lithium salt dissolved in an organic solvent as the electrolyte.

In the related art, the top cover of the lithium battery mostly adopts a concave structure at the pole connecting hole. However, the recessed structure is equivalent to reducing the thickness of the cover plate, thereby weakening the strength of the top cover. Since the battery electrolyte is extremely corrosive, the recessed structure can easily cause the external electrolyte to soak in and erode the internal sealing ring, resulting in leakage. The poles and plastic parts in the top cover have insufficient torsional resistance and poor stability. And when the finished secondary battery is assembled, the busbar will be welded on the pole for electrical connection. This process will generate a high temperature at the joint of the pole and the plastic part, causing the pole of the top cover to sink as a whole, and the sealing ring The amount of compression becomes smaller, resulting in the risk of poor cell sealing.

Application content

The present disclosure aims to solve at least one of the technical problems existing in the prior art. To this end, the present disclosure proposes a top cover structure of a lithium battery, and the top cover structure of the lithium battery has the advantage of enhancing the stability of the top cover.

The present disclosure also proposes a lithium battery having the above-mentioned top cover structure.

The top cover structure of the lithium battery according to the embodiment of the present disclosure includes: a cover plate assembly, the cover plate assembly has a through hole, the cover plate assembly is provided with a boss; through the hole, and one end of the pole is a protruding end, the protruding end protrudes out of the cover plate assembly, and the protruding end and the boss are located on the same side of the cover plate assembly ; an upper plastic part, the upper plastic part is sleeved on the protruding end, and at least part of the boss is embedded with the upper plastic part.

According to the top cover structure of the lithium battery according to the embodiment of the present disclosure, by arranging the boss on the cover plate assembly, the boss can be embedded in the upper plastic part, and the upper plastic part can encapsulate the boss and the protruding end of the pole together In this way, the connection between the pole and the upper plastic part can be made more tightly and firmly, and the stability of the connection between the boss and the upper plastic part can be strengthened; In this way, the immersion of the electrolyte can be effectively blocked, and the safety of the lithium battery can be improved.

In some examples of the present disclosure, from the free end of the boss to the fixed end of the boss, the boss gradually decreases in thickness in the axial direction of the through hole.

In some examples of the present disclosure, there are a plurality of the bosses, the plurality of bosses are distributed at intervals along the circumferential direction of the through hole, and at least a part of each boss is the same as the upper plastic part. Chimeric.

In some examples of the present disclosure, there is one boss, the boss is annular, and the boss surrounds the outer circumference of the pole.

In some examples of the present disclosure, the inner peripheral wall of the boss is provided with a first tooth-like structure, the upper plastic part has a second tooth-like structure, the first tooth-like structure and the second tooth-like structure Structural mosaicism.

In some examples of the present disclosure, the outer peripheral wall of the boss is provided with a third tooth-like structure, the upper plastic part has a fourth tooth-like structure, the third tooth-like structure and the fourth tooth-like structure Structural mosaicism.

In some examples of the present disclosure, the edge of the through hole is bent toward the upper plastic part to form the boss.

In some examples of the present disclosure, the upper plastic part has an embedded part, and the pole includes: a column body, the column body includes an upper end fitting section, a lower end fitting section, and the upper end fitting section and the lower end fitting section The matching groove between the sections extends along the circumferential direction of the cylinder, the upper matching section is configured with the protruding end for matching with the upper plastic part, and the lower matching section is connected to the upper plastic part. The cover plate assembly is matched, and the embedded portion is embedded in the matching groove; a base, the base is connected with the lower end matching section, and the base is located on the cover plate assembly away from the protrusion On one side of the platform, the peripheral edge of the base protrudes from the peripheral edge of the cylinder, and the part of the base protruding from the cylinder is embedded in the cover plate assembly.

In some examples of the present disclosure, a matching space is formed at a position where the base is connected to the column, and the cover plate assembly includes: a base plate, the base plate is provided with the boss and the first hole, The edge of the first hole forms a first matching part; a lower plastic part, the base plate and the lower plastic part are stacked and arranged, the lower plastic part has a second hole, the second hole and the first The holes are opposite and communicated to form the through hole, the edge of the second hole forms a second matching portion, and the first matching portion and the second matching portion are embedded in the matching space.

In some examples of the present disclosure, the cover plate assembly further includes a sealing ring, the sealing ring is sleeved on the pole, the first matching part, the second matching part and the pole connect the The sealing ring is clamped in the matching space.

In some examples of the present disclosure, a side of the cover plate assembly away from the boss is provided with a groove, and the through hole is located in the groove.

In some examples of the present disclosure, the groove is a square groove or a rectangular groove, and the side length of the groove is greater than or equal to the outer diameter of the sealing ring.

In some examples of the present disclosure, the outer diameter of the sealing ring is greater than or equal to the radial dimension of the through hole.

In some examples of the present disclosure, lines are provided on the peripheral wall surface of the upper end fitting section.

In some examples of the present disclosure, the upper plastic part is an injection molded part, and a surface of the upper plastic part facing away from the cover plate assembly has a step.

In some examples of the present disclosure, the protruding end protrudes from the surface of the upper plastic part facing away from the substrate, and the protruding height is 0.1 mm-1 mm.

The lithium battery according to the embodiment of the present disclosure includes the top cover structure as described above.

According to the lithium battery of the embodiment of the present disclosure, by disposing the boss on the cover plate assembly, the boss can be embedded in the upper plastic part, and the upper plastic part can wrap the boss and the protruding end of the pole together, thereby , which can make the connection between the pole and the upper plastic part more tightly and firmly, strengthen the stability of the connection between the boss and the upper plastic part, and then make the top cover structure of the lithium battery more stable and reliable.

Additional aspects and advantages of the present disclosure will be set forth, in part, from the following description, and in part will become apparent from the following description, or may be learned by practice of the present disclosure.

Description of drawings

The above and/or additional aspects and advantages of the present disclosure will be apparent and readily understood from the following description of embodiments in conjunction with the accompanying drawings, wherein:

1 is an exploded view of a top cover structure of a lithium battery according to an embodiment of the present disclosure;

2 is an exploded view of a top cover structure of a lithium battery according to an embodiment of the present disclosure;

3 is a schematic structural diagram of a boss of a top cover structure of a lithium battery according to an embodiment of the present disclosure;

4 is a schematic structural diagram of an upper plastic part of a top cover structure of a lithium battery according to an embodiment of the present disclosure;

5 is a partial cross-sectional structural schematic diagram of a top cover structure of a lithium battery according to an embodiment of the present disclosure;

6 is a schematic cross-sectional structural diagram of a pole column of a cap structure of a lithium battery according to an embodiment of the present disclosure;

7 is a partial cross-sectional structural schematic diagram of a substrate of a top-cap structure of a lithium battery according to an embodiment of the present disclosure;

8 is a partial cross-sectional structural schematic diagram of a lower plastic part of a top cover structure of a lithium battery according to an embodiment of the present disclosure.

Reference number:

Top cover structure 100, cover plate assembly 110, base plate 112, first hole 1121, first matching part 11211, lower plastic part 113, second hole 1131, second matching part 1132, sealing ring 114, groove 115, through hole 140,

Pole 120, cylinder 121, upper matching section 1211, lower matching section 1212, matching groove 1213, base 123,

The boss 111, the first tooth structure 1111,

The upper plastic part 130 , the second tooth structure 131 , the embedded part 132 , and the step 133 .

Detailed ways

The embodiments of the present disclosure will be described in detail below. The embodiments described with reference to the accompanying drawings are exemplary, and the embodiments of the present disclosure will be described in detail below.

The top cover structure 100 of a lithium battery according to an embodiment of the present disclosure will be described below with reference to FIGS. 1 to 8 .

Referring to FIG. 1 and FIG. 2 , the top cover structure 100 of the lithium battery may include: a cover plate assembly 110 , a pole 120 and an upper plastic part 130 . The cover plate assembly 110 has a through hole 140 , the cover plate assembly 110 may be provided with a boss 111 , and the boss 111 may be disposed around the periphery of the through hole 140 . The pole 120 can pass through the through hole 140 , and one end of the pole 120 is a protruding end, the protruding end can protrude from the cover plate assembly 110 , and the protruding end and the boss 111 can be located on the cover plate assembly 110 . ipsilateral. The upper plastic part 130 can be sleeved on the protruding end, and at least part of the boss 111 can be fitted with the upper plastic part 130 .

Therefore, the pole 120 and the upper plastic part 130 can be connected together, and because the boss 111 is provided, the upper plastic part 130 can wrap the boss 111 and the protruding ends of the pole 120 together, and the boss 111 can be fitted In the upper plastic part 130 , the connection between the pole 120 and the upper plastic part 130 can be more tightly and firmly connected, and the stability of the connection between the boss 111 and the upper plastic part 130 is enhanced. Since the boss 111 is disposed on the cover plate assembly 110, the cover plate assembly 110, the pole post 120 and the upper plastic part 130 can be connected together, and the cover plate assembly 110 can be arranged between the pole pole 120 and the upper plastic part 130. In turn, the top cover structure 100 of the lithium battery can be more stable and reliable.

In addition, the provision of the bosses 111 can ensure that the thickness of the cover plate assembly 110 can be reduced under the premise of requiring the same strength, which can not only effectively reduce the production cost of the cover plate assembly 110, but also increase the internal space of the cell , increasing the energy density. Moreover, the boss 111 protrudes from the upper surface of the cover plate assembly 110 , which can effectively block the intrusion of the electrolyte and improve the safety of the lithium battery.

According to the top cover structure 100 of the lithium battery according to the embodiment of the present disclosure, by arranging the bosses 111 on the cover plate assembly 110 , the bosses 111 can be fitted in the upper plastic part 130 , and the upper plastic parts 130 can connect the bosses 111 and the poles The protruding ends of the poles 120 are wrapped together, so that the connection between the poles 120 and the upper plastic part 130 can be more tightly and firmly connected, and the stability of the connection between the boss 111 and the upper plastic part 130 is strengthened; The 111 is arranged to protrude from the upper surface of the cover plate assembly 110, thereby effectively blocking the intrusion of the electrolyte and improving the safety of the lithium battery.

According to an embodiment of the present disclosure, referring to FIGS. 3 and 7 , in the direction from the free end of the boss 111 to the fixed end of the boss 111 , the thickness of the boss 111 in the axial direction of the through hole 140 gradually decreases . Further, as shown in FIG. 3 and FIG. 7 , the diameter of the free end of the boss 111 may be larger than the diameter of the fixed end of the boss 111 . Therefore, the longitudinal section of the boss 111 may be an inverted trapezoid, which not only saves the cost of the boss 111 . The manufacturing cost is low, and the tightness and firmness of the fitting between the boss 111 and the upper plastic part 130 can be improved.

According to an embodiment of the present disclosure, referring to FIGS. 3 and 7 , there may be a plurality of bosses 111 , the plurality of bosses 111 may be spaced apart along the circumferential direction of the through hole 140 , and at least a part of each boss 111 Both can be fitted with the upper plastic part 130 . The plurality of bosses 111 can strengthen the connection between the bosses 111 and the upper plastic part 130 , so that the bosses 111 can be stably and tightly embedded in the upper plastic part 130 , preventing the bosses 111 and the upper plastic part 130 from falling off, thereby enhancing the Strength of the cap structure 100 . In the description of the present disclosure, "plurality" means two or more.

In the first embodiment of the present disclosure, as shown in FIGS. 1-3 , there may be one boss 111 , and the boss 111 may be annular, and the boss 111 may surround the outer circumference of the pole 120 . When the protruding end of the pole 120 protrudes from the cover plate assembly 110 , the boss 111 can be wrapped around the outer circumference of the pole 120 , and the boss 111 can be embedded in the upper plastic part 130 , so that the The protruding end is attached and connected to the upper plastic part 130 , so that the cover plate assembly 110 , the pole 120 and the upper plastic part 130 can be connected together.

In the first embodiment of the present disclosure, as shown in FIGS. 3 and 4 , the inner peripheral wall of the boss 111 may be provided with a first tooth-like structure 1111 , and the upper plastic part 130 has a second tooth-like structure 131 . The tooth-like structure 1111 can be fitted with the second tooth-like structure 131, so that the boss 111 can be connected with the upper plastic part 130, and the first tooth-like structure 1111 and the second tooth-like structure 131 can be connected to improve the upper plastic part. The torsional force between the member 130 and the boss 111 can be improved, thereby improving the stability of the top cover structure 100 .

In the first embodiment of the present disclosure, as shown in FIGS. 3 and 4 , the outer peripheral wall of the boss 111 may be provided with a third tooth-like structure, the upper plastic part 130 has a fourth tooth-like structure, and the third tooth-like structure The structure can be fitted with the fourth tooth-like structure, so that the boss 111 and the upper plastic part 130 can be connected, and the third tooth-like structure and the fourth tooth-like structure can be connected to improve the connection between the upper plastic part 130 and the boss 111 the torsional force, thereby improving the stability of the top cover structure 100 .

It should be noted that, whether the toothed structure is provided on the inner peripheral wall of the boss 111 or the toothed structure is provided on the outer peripheral wall of the boss 111 , the flexibility of the boss 111 and the upper plastic part 130 in connection and cooperation can be increased. In addition, the torsional force between the upper plastic part 130 and the boss 111 can be improved, so that the connection between the upper plastic part 130 and the boss 111 can be more tightly and firmly, so that the stability of the top cover structure 100 can be improved.

According to an embodiment of the present disclosure, as shown in FIGS. 1-3 , the edge of the through hole 140 can be bent toward the upper plastic part 130 to form the boss 111 , so the boss 111 can be integrally formed with the through hole 140 , and There is no need to separately set the boss 111 as a component structure, which can not only reduce the manufacturing cost, but also reduce the production difficulty of the process. Besides, the boss

111 and the through hole 140 are integrally formed on the cover plate assembly 110 , which not only enhances the stability of the cover plate assembly 110 , but also enables the cover plate assembly 110 , the upper plastic part 130 and the pole post 120 to be assembled and connected through the boss 111 . The structure is more compact and firm.

According to an embodiment of the present disclosure, referring to FIGS. 4-6 , the pole 120 may include a column 121 and a base 123 . The column body 121 may include an upper end fitting section 1211 , a lower end fitting section 1212 , and a fitting groove 1213 between the upper end fitting section 1211 and the lower end fitting section 1212 , and the fitting groove 1213 may extend along the circumferential direction of the column body 121 . The upper plastic part 130 has an embedded part 132 , and the embedded part 132 can be embedded in the matching groove 1213 . Therefore, the pole 120 can be connected with the upper plastic part 130, the protruding end can be inserted into the upper plastic part 130, and the embedded part 132 can be inserted into the matching groove 1213, so that the pole 120 can be connected to the upper plastic part 130. The connection of the parts 130 is more tight and firm, so as to prevent the pole 120 from being separated from the upper plastic part 130 , and can also improve the compressive and tensile strength of the pole 120 .

Further, as shown in FIGS. 4-6 , the lower end fitting section 1212 can be fitted with the cover plate assembly 110 , the base 123 can be connected with the lower end fitting section 1212 , and the base plate 123 can be located on the cover plate assembly 110 away from the boss 111 On one side of the base 123 , the peripheral edge of the base 123 may protrude from the peripheral edge of the cylinder 121 , and the part of the base 123 protruding from the cylinder 121 may be embedded in the cover plate assembly 110 . Therefore, the pole 120 can be connected with the cover plate assembly 110 , and since the periphery of the base 123 protrudes from the periphery of the column body 121 , the base 123 and the cover plate assembly 110 can be clamped and connected to avoid the pole 120 . It is separated from the cover plate assembly 110 ; since the part of the base 123 protruding from the column body 121 is embedded in the cover plate assembly 110 , the connection between the pole 120 and the cover plate assembly 110 can be more tightly and firmly.

According to an embodiment of the present disclosure, as shown in FIG. 5 and FIG. 6 , lines may be provided on the peripheral wall surface of the upper end fitting section 1211 . The lines can increase the friction between the upper end fitting section 1211 and the upper plastic part 130, so that the pole 120 and the upper plastic part 130 can be connected by a rotating and screwing connection, and the connected structure is more stable and firm, which can improve the Torsion between the pole 120 and the upper plastic part 130 .

In an embodiment of the present disclosure, as shown in FIG. 1 , FIG. 2 , FIG. 5 and FIG. 8 , a matching space can be formed at the position where the base 123 and the column body 121 are connected, and the matching space can be matched with the cover plate assembly 110 connect. The cover plate assembly 110 may include a base plate 112 and a lower plastic part 113 . The base plate 112 may be provided with a boss 111 and a first hole 1121, and the edge of the first hole 1121 may form a first matching portion 11211; the base plate 112 may be stacked with the lower plastic part 113, and the lower plastic part 113 may have a second hole 1131, the second hole 1131 and the first hole 1121 can be opposite and communicated to form a through hole 140, and the through hole 140 can provide an escape space for the pole 120, so that the cylinder 121 of the pole 120 can pass through the cover plate assembly 110 .

Further, as shown in FIG. 1 , FIG. 2 , FIG. 5 and FIG. 8 , the edge of the second hole 1131 can form a second matching portion 1132 , and the first matching portion 11211 and the second matching portion 1132 can be embedded in the matching space Therefore, the pole 120 can be connected together with the lower plastic part 113 and the substrate 112, and the connected structure is more stable and firm.

In an embodiment of the present disclosure, as shown in FIG. 1 , FIG. 2 and FIG. 5 , the cover plate assembly 110 may further include a sealing ring 114 , and the sealing ring 114 may be sleeved on the pole 120 . The two matching parts 1132 and the pole 120 can clamp the sealing ring 114 in the matching space. The sealing ring 114 can limit the position of the pole 120 , and the sealing ring 114 is sleeved on the outer circumference of the pole 120 , which can make the connection between the pole 120 and the cover plate assembly 110 more tightly.

Further, as shown in FIG. 5 , the inner diameter of the sealing ring 114 may be the same as the outer diameter of the matching space, the outer diameter of the sealing ring 114 may be greater than or equal to the radial dimension of the through hole 140 , and the material of the sealing ring 114 may be compressible of rubber material. Therefore, the sealing ring 114 is clamped in the matching space by the first matching part 11211 , the second matching part 1132 and the pole 120 , which can effectively solve the compression of the sealing ring 114 during the long-term use of the top cover structure 100 of the lithium battery. The problem of poor sealing caused by the rebound.

In one embodiment of the present disclosure, as shown in FIG. 1 , FIG. 2 , FIG. 5 and FIG. 7 , a side of the cover plate assembly 110 away from the boss 111 may be provided with a groove 115 , and the through hole 140 may be located in the groove 115 , and the diameter of the through hole 140 may be the same as the inner diameter of the groove 115 . Further, as shown in FIG. 1 , FIG. 2 and FIG. 5 , the groove 115 can be a square groove or a rectangular groove, and the side length of the groove 115 can be greater than or equal to the outer diameter of the sealing ring 114 . The sealing ring 114 and the second matching portion 1132 are accommodated in the groove 115 together, so that the lower plastic part 113 , the base plate 112 and the sealing ring 114 can be connected together.

According to an embodiment of the present disclosure, as shown in FIGS. 1 and 4 , the upper plastic part 130 may be an injection molded part, and the surface of the upper plastic part 130 facing away from the cover plate assembly 110 has a step 133 to ensure the upper surface of the upper plastic part 130 is flat flatness. In order to improve the stability of the upper plastic part 130 in the later stage, the injection molding process is particularly critical. Therefore, the upper plastic part 130 can be made of PPS injection molding, and the drying temperature of the upper plastic part 130 can be set at 100° C.-120° C. The melting temperature of the piece 130 can be set at 300-340°C, and the mold temperature of the upper plastic piece 130 can be set at 120-180°C.

According to an embodiment of the present disclosure, as shown in FIG. 5 , the protruding end may protrude from the surface of the upper plastic part 130 facing away from the substrate 112 , and the protruding height is 0.1 mm-1 mm. In this way, the high temperature generated by the bus bar during welding can be effectively avoided, so that the joint part of the pole 120 and the upper plastic part 130 will be softened, so that the pole 120 can be prevented from sinking to the inside of the cell, thereby avoiding the sealing ring. 114 The amount of compression becomes smaller.

Further, as shown in FIG. 5 , the protruding height of the protruding end protruding from the surface of the upper plastic part 130 facing away from the substrate 112 is in the range of 0.2mm-0.5mm, which can effectively ensure that the sinking amount of the pole 120 is within the range of 0.2 mm to 0.5 mm. Within the control range, the sealing performance of the pole 120 can be guaranteed.

As shown in FIGS. 1-8 , a lithium battery according to an embodiment of the present disclosure may include the top cover structure 100 of any one of the above-mentioned lithium batteries.

According to the lithium battery according to the embodiment of the present disclosure, by disposing the boss 111 on the cover plate assembly 110 , the boss 111 can be embedded in the upper plastic part 130 , and the upper plastic part 130 can protrude the boss 111 and the pole 120 Therefore, the connection between the pole 120 and the upper plastic part 130 can be made more tightly and firmly, and the stability of the connection between the boss 111 and the upper plastic part 130 is strengthened; in addition, the boss 111 is set to protrude on the upper surface of the cover plate assembly 110 , thereby effectively blocking the intrusion of the electrolyte and improving the safety of the lithium battery.

In the description of the present disclosure, it is to be understood that the terms "thickness", "upper", "lower", "front", "rear", "top", "inner", "outer", "axial", The orientations or positional relationships indicated by "radial direction", "circumferential direction", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present disclosure and simplifying the description, rather than indicating or implying the indicated devices or elements It must have, be constructed, and operate in a particular orientation, and therefore should not be construed as a limitation of the present disclosure.

In the description of this specification, reference to the description of the terms "one embodiment," "some embodiments," "example," etc. means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in the present disclosure. in at least one embodiment or example. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example.

Although embodiments of the present disclosure have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions, and alterations can be made in these embodiments without departing from the principles and spirit of the present disclosure, The scope of the present disclosure is defined by the claims and their equivalents.

Claims

A top cover structure for a lithium battery, comprising:

a cover plate assembly, the cover plate assembly has a through hole, and the cover plate assembly is provided with a boss;

a pole, the pole is penetrated in the through hole, and one end of the pole is a protruding end, the protruding end protrudes from the cover plate assembly, and the protruding end is connected to the The boss is located on the same side of the cover plate assembly;

The upper plastic part is sleeved on the protruding end, and at least part of the boss is fitted with the upper plastic part.
The top cover structure of the lithium battery according to claim 1, wherein, in the direction from the free end of the boss to the fixed end of the boss, the boss is in the axial direction of the through hole The upper thickness gradually decreases.
The top cover structure of the lithium battery according to claim 1, characterized in that, there are a plurality of the bosses, the plurality of bosses are distributed at intervals along the circumferential direction of the through hole, and each boss At least part of it is fitted with the upper plastic part.
The top cover structure of the lithium battery according to claim 1, wherein there is one boss, the boss is annular, and the boss surrounds the outer circumference of the pole.
The top cover structure of the lithium battery according to claim 4, wherein the inner peripheral wall of the boss is provided with a first tooth-like structure,

The upper plastic part has a second tooth-like structure, and the first tooth-like structure is fitted with the second tooth-like structure.
The top cover structure of the lithium battery according to claim 4, wherein the outer peripheral wall of the boss is provided with a third tooth-like structure,

The upper plastic part has a fourth tooth-like structure, and the third tooth-like structure is fitted with the fourth tooth-like structure.
The top cover structure of the lithium battery according to claim 1, wherein the edge of the through hole is bent toward the upper plastic part to form the boss.
The top cover structure of the lithium battery according to any one of claims 1-7, wherein the upper plastic part has an embedded part,

The pole includes:

A cylinder, the cylinder includes an upper-end matching section, a lower-end matching section, and a matching groove located between the upper-end matching section and the lower-end matching section, the matching groove extending along the circumferential direction of the cylinder, so The upper end fitting section forms the protruding end for fitting with the upper plastic part, the lower end fitting section is fitted with the cover plate assembly, and the embedded portion is embedded in the fitting groove;

A base, the base is connected with the lower end matching section, and the base is located on the side of the cover plate assembly that is away from the boss, and the periphery of the base protrudes out of the cylinder. the peripheral edge, and the part of the base protruding from the cylinder is embedded in the cover plate assembly.
The top cover structure of the lithium battery according to claim 8, wherein a matching space is formed at the position where the base is connected to the cylinder,

The cover plate assembly includes:

a base plate, the base plate is provided with the boss and a first hole, and the edge of the first hole forms a first matching part;

A lower plastic part, the base plate and the lower plastic part are stacked and arranged, the lower plastic part has a second hole, the second hole is opposite to and communicated with the first hole, so as to form the through hole, so The edge of the second hole forms a second matching portion, and the first matching portion and the second matching portion are embedded in the matching space.
The top cover structure of the lithium battery according to claim 9, wherein the cover plate assembly further comprises a sealing ring, the sealing ring is sleeved on the pole, the first matching part, the second The matching portion and the pole pin clamp the sealing ring in the matching space.
The top cover structure of the lithium battery according to claim 10, wherein a side of the cover plate assembly facing away from the boss is provided with a groove, and the through hole is located in the groove.
The top cover structure of the lithium battery according to claim 11, wherein the groove is a square groove or a rectangular groove, and the side length of the groove is greater than or equal to the outer diameter of the sealing ring.
The top cover structure of the lithium battery according to claim 10, wherein the outer diameter of the sealing ring is greater than or equal to the radial dimension of the through hole.
The top cover structure of the lithium battery according to claim 8, wherein the peripheral wall surface of the upper end fitting section is provided with lines.
The top cover structure of the lithium battery according to claim 1, wherein the upper plastic part is an injection molded part, and a surface of the upper plastic part facing away from the cover plate assembly has a step.
The top cover structure of the lithium battery according to claim 1, wherein the protruding end protrudes from the surface of the upper plastic part facing away from the substrate, and the protruding height is 0.1mm-1mm.
A lithium battery, characterized by comprising the top cover structure of the lithium battery according to any one of claims 1-16.