CN214043809U

CN214043809U - Sealing ring and lithium battery

Info

Publication number: CN214043809U
Application number: CN202023351621.4U
Authority: CN
Inventors: 郭镖; 薛建军; 薛江丽; 杨光; 陈玮; 康丽; 张颂; 李娉婷
Original assignee: Guangzhou Great Power Energy & Technology Co ltd
Current assignee: Zhuhai Guanli Battery Co ltd
Priority date: 2020-12-31
Filing date: 2020-12-31
Publication date: 2021-08-24
Anticipated expiration: 2030-12-31

Abstract

The utility model provides a sealing ring and a lithium battery, relating to the technical field of lithium battery manufacture, the sealing ring comprises an upper sealing ring main body, wherein the lower end of the upper sealing ring main body is connected with a lower sealing ring main body; the outer diameter of the upper sealing ring main body is larger than that of the lower sealing ring main body. The step is formed between the upper sealing ring main body and the lower sealing ring main body of the sealing ring, and the girdling is positioned at the step, so that the contact between the girdling and the bent and stacked lugs can be avoided, the bent and stacked lugs are accidentally broken, the lugs cannot be contacted with the girdling, and the potential safety hazard of short circuit caused by the contact between the lugs and the girdling is eliminated; and because the lower sealing ring main body is used for isolating the folded tab, the requirement on the accuracy of the tab length is reduced, the tab length can have larger error, the spot welding position accuracy can have larger error, and the difficulty of battery assembly production is reduced.

Description

Sealing ring and lithium battery

Technical Field

The utility model belongs to the technical field of the technique that the lithium cell was made and specifically relates to a sealing washer and lithium cell are related to.

Background

The positive lug in the lithium battery is generally in a bending and stacking state, the shell of the lithium battery is generally provided with a beam waist, and the beam waist protrudes towards the inner side of the shell, so that the distance between the shell and the positive lug is further shortened; if the positive lug that buckles the stack contacts with the beam waist, lead to the short circuit easily, have the potential safety hazard, need adjust the length of utmost point ear and carry out strict restriction to avoid the positive lug of bending to contact with the beam waist.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a sealing washer and lithium cell to alleviate the technical problem who has the potential safety hazard of short circuit between positive ear and the beam waist.

The utility model provides a sealing ring, which comprises an upper sealing ring main body, wherein the lower end of the upper sealing ring main body is connected with a lower sealing ring main body;

the outer diameter of the upper sealing ring main body is larger than that of the lower sealing ring main body, so that a step is formed at the joint of the upper sealing ring main body and the lower sealing ring main body.

Furthermore, an upper accommodating cavity is formed in the upper sealing ring main body, and a limiting protrusion is arranged on the side wall of the upper accommodating cavity.

Further, the sealing ring is made of PBT materials.

The utility model also provides a lithium battery, which comprises a cap component, wherein the cap component comprises a bottom cap component, a PTC sheet, an upper cap and the sealing ring; a bottom cover component, a PTC sheet and an upper cover are sequentially arranged in the upper accommodating cavity of the upper sealing ring main body from bottom to top; the restricting protrusion in the upper receiving chamber serves to restrict the upper cover, the PTC sheet, and the upper cover in the upper receiving chamber.

Further, the bottom cover assembly comprises a lower cover with a through hole, an explosion-proof membrane and a fixing piece for fixing the explosion-proof membrane on the lower cover; and the rupture membrane is positioned between the lower cover and the PTC sheet.

Further, the lithium battery also comprises an outer shell and a lithium battery core; one end of the outer shell is provided with an opening, and the lithium battery core is positioned in the outer shell; the sealing washer inlays in the open end of shell body.

Further, the outer shell has a girdling part, and a part of the girdling part protruding towards the inner side of the outer shell is inserted into the step of the sealing ring.

Further, the inner curled edge of the opening end of the outer shell is buckled with the sealing ring.

Further, the sealing ring is provided with a sealing layer on the inner side and/or the outer side.

Furthermore, the lithium battery core is provided with a positive plate and a negative plate, and a tab of an extraction electrode on the positive plate or the negative plate is connected with the cap assembly.

The step is formed between the upper sealing ring main body and the lower sealing ring main body of the sealing ring, and the girdling is positioned at the step, so that the contact between the girdling and the bent and stacked lugs can be avoided, the bent and stacked lugs are accidentally broken, the lugs cannot be contacted with the girdling, and the potential safety hazard of short circuit caused by the contact between the lugs and the girdling is eliminated; and because the lower sealing ring main body is used for isolating the folded tab, the requirement on the accuracy of the tab length is reduced, the spot welding position accuracy can have larger error, and the difficulty of battery assembly production is reduced.

Drawings

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

Fig. 1 is a schematic structural diagram of a seal ring according to an embodiment of the present invention;

FIG. 2 is a schematic view of another angle of the seal ring shown in FIG. 1;

FIG. 3 is a schematic cross-sectional view A-A of the seal ring of FIG. 2;

fig. 4 is a schematic structural diagram of a lithium battery provided by an embodiment of the present invention.

Icon: 100-an upper seal ring body; 200-lower seal ring main body; 300-step; 400-a restraining projection; 500-upper cover; 600-PTC sheet; 800-a bottom cover assembly; 900-beam waist; 110-an outer shell; 120-lithium battery core; 130-pole ear.

Detailed Description

The technical solution of the present invention will be described clearly and completely with reference to the following embodiments, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

As shown in fig. 1-3, the present invention provides a seal ring, which includes an upper seal ring main body 100, wherein a lower seal ring main body 200 is connected to a lower end of the upper seal ring main body 100;

the outer diameter of the upper seal ring main body 100 is greater than the outer diameter of the lower seal ring main body 200, so that a step 300 is formed at the joint of the upper seal ring main body 100 and the lower seal ring main body 200.

In some embodiments, the lower end of the upper seal ring body 100 of the seal ring is provided with a lower seal ring body 200, and the outer diameter of the lower seal ring body 200 is smaller than that of the upper seal ring body 100, so that a step 300 is formed at the junction between the upper seal ring and the lower seal ring; when the sealing ring is applied to a lithium battery, the beam waist 900 on the outer shell 110 of the lithium battery is located at the step 300, so that the beam waist 900 is isolated from the tab 130, and the tab 130 is prevented from contacting the beam waist 900 of the outer shell 110 to cause short circuit when the tab 130 is bent and stacked; the lower seal ring main body 200 isolates the beam waist 900 from the tab 130, so that the spot welding position precision can have larger error, and the difficulty of battery assembly production is reduced.

In order to facilitate the installation of the seal ring with other cap assemblies, an upper receiving cavity is further formed in the upper seal ring main body 100, and a limiting protrusion 400 is formed on a sidewall of the upper receiving cavity.

The bottom cover assembly 800, the PTC sheet 600 and the upper cover 500 of the cap assembly need to be placed into the sealing ring, then the sealing ring is embedded into the outer shell 110, the limiting protrusion on the side wall of the upper accommodating cavity can well limit the bottom cover assembly 800, the PTC sheet 600, the upper cover 500 and the like which are arranged in the upper accommodating cavity in the sealing ring, and the bottom cover assembly 800, the PTC sheet 600, the upper cover 500 and the like in the sealing ring are prevented from being separated from the sealing ring when the cap assembly is connected with the outer shell 110.

Based on the above embodiment, further, the sealing ring is made of PBT material.

At present, the sealing ring is mainly PP (polypropylene is thermoplastic resin prepared by polymerizing propylene, is white waxy material, is transparent and light in appearance, has the density of 0.89-0.91 g/cm3, is inflammable, has the melting point of 165 ℃, is softened at about 155 ℃, and has the use temperature range of-30-140 ℃) and is the main material of the existing semi-sealed battery due to various reasons of easy processing, high yield, low price and the like.

And the PP as a sealing material can be aged, corroded and pulverized for a long time to cause the reduction of the sealing performance of the battery, thereby causing the reduction of the performance of the battery.

The sealing ring is made of PBT material (PBT), which belongs to polyester series, and is formed by condensing 1.4-butanediol (1.4-Butylene glycol) and terephthalic acid (PTA) or terephthalate (DMT), and is made into milky semitransparent to opaque crystalline thermoplastic polyester resin through a mixing procedure.

The sealing ring made of the PBT material has a remarkable effect in the semi-sealed battery, and the problem that the battery shell seeps and rusts due to the aging of the PP sealing element in the storage process of the semi-sealed battery, particularly in severe environments such as high temperature and high humidity and the like is solved.

The utility model provides a ladder 300 is formed between the upper seal ring main body 100 and the lower seal ring main body 200 of the seal ring, the beam waist 900 is positioned at the ladder 300, thereby avoiding the contact between the beam waist 900 and the tab 130 which is folded and stacked, so that the tab 130 which is folded and stacked is accidentally broken, the tab 130 can not contact with the beam waist 900, and the potential safety hazard of short circuit caused by the contact between the tab 130 and the beam waist 900 is eliminated; and because the lower sealing ring main body 200 is used for isolating the beam waist 900 from the bent and stacked lug 130, the requirement on the precision of the length of the lug 130 is reduced, so that the spot welding position precision can have larger error, and the difficulty of battery assembly production is reduced.

As shown in fig. 4, the present invention further provides a lithium battery, which comprises a cap assembly, wherein the cap assembly comprises a bottom cap assembly 800, a PTC sheet 600, an upper cap 500 and the sealing ring.

Further, a bottom cover assembly 800, a PTC sheet 600 and an upper cover 500 are sequentially disposed in the upper receiving chamber of the upper sealing ring main body 100 from bottom to top; the restriction protrusion 400 in the upper receiving cavity serves to restrict the upper cover 500, the PTC sheet 600 and the upper cover 500 in the upper receiving cavity.

Further, the bottom cover assembly 800 includes a lower cover having a through hole, an explosion-proof membrane, and a fixing piece for fixing the explosion-proof membrane on the lower cover; and the rupture membrane is located between the lower cover and the PTC sheet 600, and the rupture membrane is completely sealed, isolating the inside of the lithium battery cell from the outside atmosphere.

When the internal pressure of the lithium battery is overlarge, the explosion-proof membrane is broken, and the pressure is released from the broken part of the explosion-proof membrane; the rupture pressure of the rupture membrane is far less than the pressure of the pressure relief of other places of the lithium battery, and the explosion caused by the overlarge internal pressure of the lithium battery is effectively avoided.

Further, the battery pack further comprises an outer shell 110 and a lithium battery cell 120; an opening is formed at one end of the outer shell 110, and the lithium battery cell 120 is positioned in the outer shell 110; the sealing ring is embedded in the opening end of the outer shell 110.

Further, the outer shell 110 has a beam waist 900, and a portion of the beam waist 900 protruding into the outer shell 110 is inserted into the step 300 of the sealing ring.

Further, the inner curled edge of the open end of the outer housing 110 is fastened to the sealing ring.

In some embodiments, the sealing ring and the PTC sheet 600, the upper cap 500 and the lower cap assembly 800 constitute a cap assembly that can be fitted into the open end of the outer case 110, and the upper end of the sealing ring is fastened to the upper cap 500 by an inner bead of the open end of the outer case 110.

The outer housing 110 is generally formed integrally and is generally made of stainless steel or aluminum, and the outer housing 110 may also be a nickel-plated steel shell.

In order to further ensure the sealing performance of the lithium battery, the sealing glue is covered or sprayed on the outer side and the inner side of the sealing ring to form a sealing layer, so that the sealing between the sealing ring and the outer shell 110, the sealing ring and the bottom cover assembly 800, the sealing ring and the PTC sheet 600, and the sealing ring and the upper cover 500 are better sealed, and the weight loss of the battery is reduced. The sealing compound may be coated only on the outside or inside of the sealing ring.

There are other measures to increase the sealing performance, such as covering the whole upper cover 500 with epoxy resin to perform the secondary sealing function; and the vent hole of the upper cover 500 is not generally provided in the middle of the upper cover 500.

Further, the lithium battery cell 120 has a positive plate and a negative plate, and a tab 130 of an extraction electrode on the positive plate or the negative plate is connected to the cap assembly.

Further, a tab 130 of the electrode led out from the positive plate is connected with the cap assembly, and the tab 130 is bent and stacked.

The lithium battery is provided with a positive plate and a negative plate, the bottom cover assembly 800 of the cap assembly can be welded with the tab 130 of the positive plate or the negative plate, and when the cap assembly is embedded on the shell body 110, the tab 130 is bent and stacked; because the upper sealing ring main body 100 is positioned between the beam waist 900 and the tab 130 which is folded and stacked, the tab 130 which is folded and stacked is prevented from contacting the beam waist 900, and the problem of short circuit caused by folding the tab 130 which is folded and stacked and the beam waist 900 is avoided; and the spot welding position precision of the tab 130 and the cap assembly can have larger error, and the difficulty of battery assembly production is reduced.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present invention.

Claims

1. The sealing ring is characterized by comprising an upper sealing ring main body (100), wherein the lower end of the upper sealing ring main body (100) is connected with a lower sealing ring main body (200);

the outer diameter of the upper sealing ring main body (100) is larger than that of the lower sealing ring main body (200), so that a step (300) is formed at the joint of the upper sealing ring main body (100) and the lower sealing ring main body (200).

2. A seal ring according to claim 1, characterized in that an upper receiving chamber is provided in the upper seal ring body (100), and a limiting protrusion (400) is provided on a side wall of the upper receiving chamber.

3. The seal ring according to claim 1, characterized in that the seal ring is made of PBT material.

4. A lithium battery comprising a cap assembly including a bottom cap assembly (800), a PTC sheet (600), an upper cap (500), and the sealing ring according to any one of claims 1 to 3;

a bottom cover component (800), a PTC sheet (600) and an upper cover (500) are sequentially arranged in an upper accommodating cavity of the upper sealing ring main body (100) from bottom to top; the restriction protrusion (400) in the upper receiving cavity serves to restrict the upper cover (500), the PTC sheet (600) and the upper cover (500) in the upper receiving cavity.

5. The lithium battery as claimed in claim 4, wherein the bottom cover assembly (800) comprises a lower cover having a through hole, an explosion-proof membrane, and a fixing piece for fixing the explosion-proof membrane on the lower cover; and the rupture membrane is positioned between the lower cover and the PTC sheet (600).

6. The lithium battery of claim 4, further comprising an outer casing (110) and a lithium battery cell (120); the outer shell (110) is provided with an opening at one end, and the lithium battery cell (120) is positioned in the outer shell (110); the sealing ring is embedded in the opening end of the outer shell (110).

7. The lithium battery according to claim 6, wherein the outer case (110) has a girdling (900), and a portion of the girdling (900) protruding into the outer case (110) is inserted into a step (300) of the sealing ring.

8. The lithium battery of claim 6, wherein an internal bead of the open end of the outer casing (110) snaps over the sealing ring.

9. A lithium battery as claimed in claim 8, characterized in that the sealing ring is provided with a sealing layer on the inside and/or outside.

10. The lithium battery of claim 6, wherein the lithium battery cell (120) has a positive plate and a negative plate, and a tab (130) of the positive plate or the negative plate from which an electrode is drawn is connected to the cap assembly.