CN210837928U

CN210837928U - Square lithium battery

Info

Publication number: CN210837928U
Application number: CN201921584346.5U
Authority: CN
Inventors: 胡忠汉
Original assignee: Hunan Hongyi Technology Co ltd
Current assignee: Hunan Hongyi Technology Co ltd
Priority date: 2019-09-23
Filing date: 2019-09-23
Publication date: 2020-06-23
Anticipated expiration: 2029-09-23

Abstract

The utility model relates to a square lithium cell. The square lithium battery comprises a battery body, wherein the battery body is provided with a liquid injection hole and a liquid injection port communicated with the liquid injection hole; the sealing plug is in sealing fit with the liquid injection hole; a repair welding piece is welded and sealed with the liquid injection port; the air bag contains the gas to be detected, and is arranged between the sealing plug and the repair welding sheet; when the repair welding piece is welded and sealed on the liquid injection port, heat for fusing the air bag is provided, so that the air bag releases the detected gas to a position between the sealing plug and the repair welding piece. The utility model provides a direction lithium cell through placing the air pocket between sealing plug and repair welding piece, utilizes the heat when repair welding piece welds the air pocket to the release is examined between gaseous to sealing plug and the repair welding piece, and whether detectable repair welding piece has accomplished the sealed to annotating the liquid mouth, thereby improves square lithium cell's use reliability and security.

Description

Square lithium battery

Technical Field

The utility model relates to a battery leakproofness detects technical field, especially relates to a square lithium cell.

Background

Lithium batteries are receiving attention due to their advantages of high energy density, high output power, long charge/discharge life, fast charge, green and pollution-free properties, wide operating temperature range, and low self-discharge.

The chemical system in the lithium battery is active in property, and the lithium battery is very easy to generate side reaction with external moisture and air to cause the performance degradation or the failure of the battery, so that the packaging airtightness is very important for the reliability and the safety of the lithium battery. How to effectively detect the air tightness of the lithium battery and ensure that packaging defective products cannot flow into the consumer market has very important significance.

At present, part square lithium cell can use the plug to annotate liquid mouth and seal after annotating the liquid to ensure that battery inside keeps certain vacuum, then annotate liquid mouth top laser welding aluminum sealing sheet and implement sealedly. Because the leakproofness of plug leads to the inside measuring gas of injecting into battery in advance can't get into the space between plug and the aluminum sealing sheet to the welding gas tightness of aluminum sealing sheet can't be detected.

SUMMERY OF THE UTILITY MODEL

Therefore, the square lithium battery with good sealing performance is needed to be provided aiming at the problem that the welding air tightness of the sealing aluminum sheet cannot be detected by the existing square lithium battery.

A square lithium battery comprises a battery body, wherein the battery body is provided with a liquid injection hole and a liquid injection port communicated with the liquid injection hole; the sealing plug is in sealing fit with the liquid injection hole; the repair welding piece is welded and sealed with the liquid injection port; an air bag containing a gas to be detected therein, the air bag being disposed between the sealing plug and the repair-welding piece; when the repair welding piece is welded and sealed on the liquid injection port, heat for fusing the air bag is provided, so that the air bag releases the detected gas to a position between the sealing plug and the repair welding piece.

According to the lithium battery with the direction, after electrolyte is injected into the liquid injection port, the sealing plug is plugged into the liquid injection hole, the air bag is placed on the sealing plug before the repair welding piece is welded to the liquid injection port, then the repair welding piece is welded and sealed corresponding to the liquid injection port, at the moment, a large amount of heat is generated by welding, the air bag is heated, and then the detected gas is released to the position between the sealing plug and the repair welding piece in a melting mode. Carry out airtight detection to square lithium cell through airtight check out test set, detect whether have the gas leakage that is examined, then can judge whether repair welding piece department is sealed well.

In one embodiment, the top of the sealing plug is provided with a recess in which the air bag is placed.

In one embodiment, the top of the sealing plug is provided with a cross-shaped groove or a straight-line-shaped groove for the sealing plug to be screwed into the liquid injection hole; the groove is at least partially arranged in the cross-shaped groove or the straight-line-shaped groove.

In one embodiment, the groove may be disposed at a central position of the cross-shaped groove or the in-line groove.

In one embodiment, the air pocket is at least partially protruding from the sealing plug.

In one embodiment, the sealing plug is an elastic sealing plug or the air bag is an elastic air bag; the air bag is at least partially arranged on the liquid injection port in a protruding mode.

In one embodiment, the sealing plug includes a cylindrical body and a conical head, and the conical head is disposed at one end of the cylindrical body.

In one embodiment, the detected gas is one of nitrogen, hydrogen or inert gas; the inert gas is helium, neon, argon, krypton, xenon or radon.

In one embodiment, the air pocket is spherical, elliptical or square in shape.

In one embodiment, the material of the air bag is one of PP, PE, PET or PVC.

Drawings

Fig. 1 is a schematic structural diagram of a square lithium battery according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of another view angle of the lithium square battery shown in fig. 1;

fig. 3 is a schematic diagram of a part a of the enlarged structure of the lithium square battery shown in fig. 2;

fig. 4 is a schematic structural diagram of a sealing plug of a square lithium battery in an embodiment of the present invention.

Detailed Description

In order to facilitate understanding of the present invention, the present invention will be described more fully hereinafter with reference to the accompanying drawings. Preferred embodiments of the present invention are shown in the drawings. The invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

When an element is referred to as being "on" another element, it can be directly on the other element or intervening elements may also be present, unless otherwise specified. It will also be understood that when an element is referred to as being "between" two elements, it can be the only one between the two elements, or one or more intervening elements may also be present.

Where the terms "comprising," "having," and "including" are used herein, another element may be added unless an explicit limitation is used, such as "only," "consisting of … …," etc. Unless mentioned to the contrary, terms in the singular may include the plural and are not to be construed as being one in number.

Furthermore, the drawings are not 1: 1, and the relative dimensions of the various elements in the figures are drawn for illustration only and not necessarily to true scale.

In order to facilitate understanding of the technical solution of the present invention, before the detailed description, the airtight detection of the existing square lithium battery is described first.

The existing airtight detection mode of the square lithium battery is to inject helium gas after the battery liquid injection is finished, plug a rubber plug at a liquid injection port and then put airtight detection equipment for airtight detection.

Usually, the plug is filling in annotates the liquid hole after, because the plug is elastic, so there is stress release, and at this moment, the plug can be filled very tightly, and it is extremely little to let out leakage quantity, so when annotating liquid mouth department and carrying out secondary aluminum sheet welded seal, the helium can't be followed plug department and escaped to the space between welding aluminum sheet and the plug, so can't detect the aluminum sheet and whether accomplished sealed to annotating the liquid mouth.

In addition, in the use of follow-up square lithium cell, also can have because of the sealed condition of inefficacy of plug, for example because of electrolyte is after release lithium ion and pole piece emergence chemical reaction, can produce complicated gas, the increase of battery internal pressure, make the plug outwards expand relaxedly and lead to the unable normal seal of plug, perhaps the plug is by the corrosive effect of electrolyte and ageing and lead to the unable normal seal of plug etc. if the aluminum sheet has sealed bad condition during this time, and cause the battery to reveal, not only can influence the normal use of battery, also there is combustion explosion's hidden danger simultaneously.

Therefore, it is required to provide a square lithium battery and a method for detecting air tightness thereof, which can detect air tightness of an aluminum sheet and ensure reliable air tightness of the battery.

As shown in fig. 1 and 2, a square lithium battery 100 according to an embodiment of the present invention includes a battery body 10, a sealing plug 20 (see fig. 3), a repair welding piece 30, and an air bag 40 (see fig. 3).

The battery body 10 is provided with a liquid injection hole 11 and a liquid injection port 12 communicated with the liquid injection hole, the sealing plug 20 is in sealing fit with the liquid injection hole 11, the repair welding sheet 30 is in welding seal with the liquid injection port 12, the gas bag 40 contains the detected gas, the gas bag 40 is arranged between the sealing plug 20 and the repair welding sheet 30, and when the repair welding sheet 30 is in welding seal with the liquid injection port 12, heat for melting the gas bag 40 is provided, so that the gas bag 40 releases the detected gas to a position between the sealing plug 20 and the repair welding sheet 30.

Thus, after the electrolyte is injected into the injection hole 12, the sealing plug is plugged into the injection hole 11, the air bag 40 is placed on the sealing plug 20 before the soldering patch 30 is welded to the injection hole 12, and then the soldering patch 30 is welded and sealed corresponding to the injection hole 12, at this time, a large amount of heat is generated by welding, so that the air bag 40 is heated, and the detected gas is further released to be between the sealing plug 20 and the soldering patch 30 by melting. The lithium battery pack 100 is subjected to airtightness detection by an airtightness detection device, and whether the detected gas leaks or not is detected, so that whether the sealing at the repair welding piece 30 is good or not can be judged.

The utility model discloses a square lithium cell 100, whether detectable repair welding piece 30 accomplished sealed to annotating liquid mouth 12 to detection mode and easy operation, the event can guarantee square lithium cell 100's use reliability and security. In addition, the air bag 40 occupies a small space, so that the structure of the square lithium battery is not changed, and the cost is saved.

Specifically, in one embodiment, the battery body 10 includes a case 13 and a cover plate 14 covering one side of the case 13, the case 13 has a lamination or winding of separators therein, and the cover plate 14 is provided with a positive electrode 141, a negative electrode 142 and a safety member 143. As shown in FIG. 3, in the embodiment of the present invention, the pouring hole 11 penetrates the lid plate 14, and the pouring outlet 12 is located on the outer surface of the lid plate 14.

In some embodiments, the pour hole 11 is a counterbore and the seal plug 20 is at least partially seated at a step of the counterbore.

In some embodiments, as shown in fig. 3 and 4, the top of the sealing plug 20 is provided with a recess in which the air bag 40 is placed. Since the gap between the top of the sealing plug 20 and the repair-welding piece 30 is small, the provision of the recess provides a certain space for accommodating the airbag 40, thereby increasing the capacity of the airbag 40 for storing the gas to be tested, and further, the airbag 40 melts and releases a large amount of the gas to be tested between the sealing plug 20 and the repair-welding piece 30, thereby improving the accuracy of the gas-tight test. Specifically, the shape of the groove may be a hemisphere or other shape matching the shape of the air bag 40, and is not limited herein.

In some embodiments, the top of the sealing plug 20 is provided with a cross-shaped groove or a straight groove for screwing the sealing plug 20 into the injection hole 11, and the groove is at least partially arranged in the cross-shaped groove or the straight groove. The cross-shaped groove or the straight-line-shaped groove is arranged at the top of the sealing plug 20, so that the sealing plug 20 can be conveniently operated in a limited space to be in sealing fit with the liquid injection hole 11, and at least part of the groove is arranged in the cross-shaped groove or the straight-line-shaped groove, so that the space is saved while the sealing plug 20 is not hindered from being screwed in. It will be appreciated that the plug 20 may be screwed into sealing engagement with the pour hole 11 using a driver to engage a cruciform recess or a straight recess in the top of the plug 20.

Further, the groove may be disposed at a central position of the cross-shaped groove or the in-line groove.

Referring again to fig. 4, in some embodiments, the sealing plug 20 includes a cylindrical body 22 and a conical head 23, and the conical head 23 is disposed at one end of the cylindrical body 22. The conical head 23 is utilized to facilitate the sealing plug 20 to enter the liquid injection hole 11 to complete sealing matching, the cylindrical body 22 has a simple shape, and more space can be provided for placing the air bag 40, for example, when the liquid injection hole 11 is a counter bore, the sealing plug 20 can completely enter the through hole part of the counter bore without being arranged at the counter bore. In other embodiments, the sealing plug 20 may also be in the shape of a nail, which is not limited herein.

Referring again to fig. 3, in some embodiments, the air bag 40 at least partially protrudes from the sealing plug 20. In this way, the volume of the bag 40 is increased, the capacity for storing the test gas in the bag 40 is increased, and the bag 40 is broken by a large amount of the test gas released between the sealing plug 20 and the repair-welding piece 30, thereby improving the accuracy of the airtightness detection.

In other embodiments, the sealing plug 20 is an elastic sealing plug or the air bag 40 is an elastic air bag, and the air bag 40 is at least partially protruded from the injection port 12. Before the repair welding piece 30 is welded to the liquid injection port 12, the repair welding piece 30 is fixed at a welding position corresponding to the liquid injection port 12, if the air bag 40 is at least partially protruded from the liquid injection port 12, the sealing plug 20 is arranged to be an elastic sealing plug or the air bag 40 is an elastic air bag, when the air bag 40 is compressed by times, the air bag 40 is elastically deformed or the air bag 40 causes the elastic sealing plug 20 to be elastically deformed, so that the fixation of the repair welding piece 20 at the welding position corresponding to the liquid injection port 12 is not influenced, therefore, the volume of the air bag 40 can be further increased, the capacity of storing the detected gas in the air bag 40 is increased, and the accuracy of airtight detection is improved.

In some embodiments, the shape of the air pocket 40 is spherical, elliptical, or square, and preferably, the shape of the air pocket 40 is elliptical.

In some embodiments, the material of the air bag 40 is one of PP (polypropylene), PE (polyethylene), PET (polyethylene terephthalate), or PVC (polyvinyl chloride). Preferably, the material of the air bag 40 is PP. It should be understood that the material of the gas bag 40 should not react with any substance in the battery body 10, for example, the electrolyte.

In some embodiments, the detected gas is one of nitrogen, hydrogen, or an inert gas, and the inert gas is helium, neon, argon, krypton, xenon, or radon. Preferably, the test gas is helium.

Based on the above square lithium battery 100, the utility model also provides an airtight detection method of square lithium battery, including the step:

s110: providing a battery body 10, wherein the battery body 10 is provided with a liquid injection hole 11 and a liquid injection port 12 communicated with the liquid injection hole 11;

the liquid inlet 11 can penetrate through the cover plate 14 of the battery body 10, and the liquid inlet 12 is positioned on the outer surface of the cover plate 14.

S120: sealing and matching the sealing plug 20 with the liquid injection hole 11;

the sealing plug 20 may be an elastic sealing plug, the top of the sealing plug 20 is provided with a cross-shaped groove or a straight-line-shaped groove for the sealing plug 20 to be screwed into the injection hole 11, and the sealing plug 20 can be screwed into the injection hole 11 to be in sealing fit by using a screwdriver to be matched with the cross-shaped groove or the straight-line-shaped groove at the top of the sealing plug 20.

In some embodiments, the sealing plug 20 includes a cylindrical body 22 and a conical head 23, and the conical head 23 is disposed at one end of the cylindrical body 22. The conical head 23 is used for facilitating the sealing plug 20 to enter the liquid filling hole 11 to complete sealing fit. In other embodiments, the sealing plug 20 may also be in the shape of a nail, which is not limited herein.

S130: placing an airbag 40 on the sealing plug 20, wherein the airbag 40 contains the gas to be detected;

the shape of the air bag 40 is spherical, elliptical or square, and preferably, the shape of the air bag 40 is elliptical.

The material of the air bag 40 is one or a combination of more of PP (polypropylene), PE (polyethylene), PET (polyethylene terephthalate) or PVC (polyvinyl chloride). Preferably, the material of the air bag 40 is PP.

The detected gas is one or a combination of a plurality of nitrogen, hydrogen or inert gas, and the inert gas is helium, neon, argon, krypton, xenon or radon. Preferably, the test gas is helium.

In some embodiments, the top of the sealing plug 20 is provided with a recess in which the air bag 40 is placed. Further, the groove is at least partially arranged in the cross-shaped groove or the in-line groove.

S140: welding the repair welding sheet 30 to the liquid injection port 12 to be in sealing fit with the liquid injection port 12, wherein when the repair welding sheet 30 is welded and sealed to the liquid injection port 12, heat for enabling the air bag 40 to be melted is provided, so that the air bag 40 releases the detected gas to a position between the repair welding sheet 30 and the sealing plug 20;

the air bag 40 is at least partially protruded from the sealing plug 20, and further, the sealing plug 20 is an elastic sealing plug or the air bag 40 is an elastic air bag, and the air bag 40 is at least partially protruded from the injection port 12.

S150: and detecting whether the detected gas escapes from the square lithium battery 100.

Wherein, whether the square lithium battery 100 has the detected gas to escape can be detected by the gas detection device. In particular, the gas detection apparatus may be a vacuum box leak detector apparatus, including a vacuum box having a vacuum chamber, a vacuum pump apparatus, and a leak detector. The square lithium battery 100 after the step S140 is placed in the vacuum chamber of the vacuum box, and the vacuum chamber is vacuumized by using a vacuuming device, and at this time, whether the leak detector leaks the detected gas or not is checked.

The utility model discloses an airtight detection method of square lithium cell 100 and square lithium cell compares prior art and has following advantage:

(1) the air bag 40 is arranged between the sealing plug 20 and the repair welding sheet 30, and the air bag 40 is broken by using the heat of the repair welding sheet 30, so that the detected gas is released to the position between the sealing plug 20 and the repair welding sheet 30, whether the repair welding sheet 30 completes the sealing of the liquid injection port 12 can be detected, and the use reliability and the safety of the square lithium battery 100 are improved;

(2) the groove is formed in the top of the sealing plug 20, and the air bag 40 is placed in the groove, so that the small size of a gap between the top of the sealing plug 20 and the repair welding sheet 30 can be compensated, a certain space for accommodating the air bag 40 is provided, the capacity of storing the detected gas in the air bag 40 is increased, and the accuracy of air tightness detection is improved;

(3) the cross-shaped groove or the straight-line-shaped groove for the sealing plug 20 to be screwed into the liquid injection hole 11 is formed in the top of the sealing plug 20, and at least part of the groove is formed in the cross-shaped groove or the straight-line-shaped groove, so that the space is saved while the sealing plug 20 is not prevented from being screwed in;

(4) by arranging the sealing plug 20 to comprise the cylindrical body 22 and the conical head 23, when the liquid injection hole 11 is a counter bore, the sealing plug 20 can completely enter the through hole part of the counter bore and is not arranged at the counter bore, so that more space can be provided for placing the air bag 40;

(5) by arranging the sealing plug 20 as an elastic sealing plug or the air bag 40 as an elastic air bag, and arranging at least part of the air bag 40 to protrude from the liquid injection port 12, the fixing of the repair welding sheet 20 at the welding position corresponding to the liquid injection port 12 is not affected, the volume of the air bag 40 can be further increased, and the accuracy of air tightness detection is improved.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only represent some embodiments of the present invention, and the description thereof is specific and detailed, but not to be construed as limiting the scope of the present invention. It should be noted that, for those skilled in the art, without departing from the spirit of the present invention, several variations and modifications can be made, which are within the scope of the present invention. Therefore, the protection scope of the present invention should be subject to the appended claims.

Claims

1. A square lithium battery, comprising:

the battery comprises a battery body, a battery cover and a battery cover, wherein the battery body is provided with a liquid injection hole and a liquid injection port communicated with the liquid injection hole;

the sealing plug is in sealing fit with the liquid injection hole;

the repair welding piece is welded and sealed with the liquid injection port;

an air bag containing a gas to be detected therein, the air bag being disposed between the sealing plug and the repair-welding piece;

when the repair welding piece is welded and sealed on the liquid injection port, heat for fusing the air bag is provided, so that the air bag releases the detected gas to a position between the sealing plug and the repair welding piece.

2. The lithium prismatic battery of claim 1, wherein said sealing plug has a recess in the top thereof, said air pocket being disposed in said recess.

3. The square lithium battery as claimed in claim 2, wherein the top of the sealing plug is provided with a cross-shaped groove or a straight-line-shaped groove for the sealing plug to be screwed into the liquid injection hole;

the groove is at least partially arranged in the cross-shaped groove or the straight-line-shaped groove.

4. A lithium prismatic battery according to claim 3, wherein said groove is provided at the center of said cross-shaped groove or said in-line groove.

5. A lithium prismatic battery according to claim 1, wherein said air pocket is at least partially raised from said sealing plug.

6. The lithium prismatic battery of claim 1, wherein said sealing plug is an elastic sealing plug or said air bag is an elastic air bag;

the air bag is at least partially arranged on the liquid injection port in a protruding mode.

7. The lithium square battery of claim 1, wherein the sealing plug comprises a cylindrical body and a conical head, and the conical head is disposed at one end of the cylindrical body.

8. The square lithium battery according to any one of claims 1 to 7, wherein the gas to be detected is one of nitrogen, hydrogen, or an inert gas;

the inert gas is helium, neon, argon, krypton, xenon or radon.

9. The square lithium battery as claimed in any one of claims 1 to 7, wherein the shape of the air pocket is spherical, elliptical or square.

10. The lithium square battery according to any of claims 1 to 7, wherein the material of the air bag is one of PP, PE, PET or PVC.