CN210349998U

CN210349998U - Square lithium battery

Info

Publication number: CN210349998U
Application number: CN201921607011.0U
Authority: CN
Inventors: 廖霞霞
Original assignee: E-Power Tech Co ltd
Current assignee: E-Power Tech Co ltd
Priority date: 2019-09-25
Filing date: 2019-09-25
Publication date: 2020-04-17
Anticipated expiration: 2029-09-25

Abstract

The embodiment of the application provides a square lithium battery, which comprises a lithium battery core, a shell and an insulating connection structure; the lithium battery cell is formed by superposing at least two single battery cells; the lithium battery cell is arranged in the accommodating cavity of the shell; insulating connection structure includes insulating piece and end support piece, and the insulating piece wraps up in the outside of lithium cell, and the end support piece is connected with the bottom of insulating piece, and the end support piece is formed with first seepage hole along single cell length extending direction's at least one end, and first seepage hole corresponds the interval space department that sets up formation between the side reason of adjacent two single cells, and the bottom of insulating piece is formed with first infiltration hole, first seepage hole and first infiltration hole intercommunication. According to the square lithium battery provided by the embodiment of the application, the spacing space can gather and contain more gas in the insulating sheet, and in the standing and exhausting stage of the battery, the gas in the spacing space can be rapidly and unobscured and discharged from the bottom of the lithium battery cell through the first leakage hole and the first penetration hole, so that the discharge speed and efficiency of bubbles of the lithium battery cell are greatly promoted.

Description

Square lithium battery

Technical Field

The utility model relates to a lithium cell production field especially indicates a square lithium cell.

Background

In the design of square battery structure, in order to prevent the core pole piece of electric core and the contact of aluminium system shell bottom and take place the short circuit, can increase end support piece and insulating piece structure between shell bottom and core to play bearing and insulating effect. The bottom supporting sheet and the insulating sheet are provided with a plurality of through holes correspondingly, so that electrolyte can be absorbed into the battery core from the bottom of the battery shell. However, in the related art, gas inside the battery cell is not smoothly discharged from the bottom, and in the high-temperature standing treatment stage of the battery, the gas inside the battery cell can only be slowly discharged from the upper part of the battery, so that more gas inside the battery cell remains, a large amount of strip-shaped bubbles are easily formed, and large-area lithium precipitation of the battery in the subsequent manufacturing process is possibly caused. The large-area lithium separation phenomenon can bring short circuit risk to the battery in the subsequent use process, and potential safety hazard is caused.

SUMMERY OF THE UTILITY MODEL

In view of this, it is desirable to provide a square lithium battery that can facilitate the discharge of gas inside a cell.

In order to achieve the above object, an embodiment of the present application provides a square lithium battery, including a lithium battery cell, a housing, and an insulating connection structure, where the lithium battery cell is formed by stacking at least two single battery cells; the shell forms a containing cavity, and the lithium battery cell is arranged in the containing cavity; insulating connection structure includes insulating piece and base blade, wherein, the insulating piece wrap up in the outside of lithium cell, the base blade with the bottom of insulating piece is connected in order to support the lithium cell, the base blade is followed single electric core length extending direction's at least one end is formed with first seepage hole, first seepage hole correspondence sets up in adjacent two the interval space department that forms between the side reason of single electric core, the bottom of insulating piece is formed with first infiltration hole, first seepage hole with first infiltration hole intercommunication.

Further, the bottom of the insulation sheet is formed into a rectangular structure corresponding to the size of the bottom of the lithium battery cell.

Further, the first leakage hole penetrates through the edge of the bottom support sheet; and/or the first leakage hole is a U-shaped opening.

Further, the shell including set up in hold the spacing portion of chamber bottom, the end piece connect in the outside of insulating piece, the end piece supports in spacing portion, the end piece with hold mutual interval between the basal surface in chamber.

Furthermore, the base support sheet is formed with a second seepage hole along a plurality of at least one side edge of the superposition arrangement direction of the single electric core, a plurality of second seepage holes are further formed at the bottom of the insulating sheet, and the second seepage holes correspond to the second seepage holes.

Furthermore, the size of the second leakage hole is larger than that of the second penetration hole, and at least one second penetration hole is correspondingly arranged on one second leakage hole.

Further, the bottom supporting sheet is connected with the bottom of the insulating sheet in a hot melting mode.

Further, the bottom supporting sheet is of a rectangular structure which is adaptive to the bottom size of the insulating sheet; and/or, four corners of the bottom support sheet are arc chamfers.

Further, the insulating sheet is of a Mylar film structure; and/or the thickness of the insulating sheet is 0.08-0.12 mm.

Further, the bottom supporting sheet is made of a PP insulating material; and/or the thickness of the bottom supporting sheet is 0.6-1.0 mm.

The square lithium cell that the embodiment of the application provided, the interval space can gather in the insulating sheet, accept more gas, set up first leak orifice and first infiltration hole respectively with above-mentioned interval space relevant position on base support piece and insulating sheet, the abundant infiltration of electrolyte in battery manufacture process can be ensured in first leak orifice and the cooperation of first infiltration hole, and in the battery exhaust stage of stewing, gather in the above-mentioned interval space, the gas of acceping can be fast, discharge from the bottom of lithium cell through first leak orifice and first infiltration hole via sheltering from, greatly promote the exhaust speed and the efficiency of the bubble of lithium cell.

Drawings

Fig. 1 is a sectional view of a partial structure of a lithium square battery according to an embodiment of the present application;

fig. 2 is a cross-sectional view of a square lithium battery according to an embodiment of the present application, taken along the direction a-a in fig. 1;

FIG. 3 is a schematic view of an embodiment of the present disclosure;

FIG. 4 is a schematic structural diagram of a base sheet according to an embodiment of the present application;

fig. 5 is a schematic structural diagram of a bottom portion of an insulation sheet according to an embodiment of the present application.

Description of the reference numerals

A lithium battery cell 10; a first single cell 101; a second single cell 102; a spacing space 103; a housing 20; a stopper portion 201; an insulating sheet 30; the first penetration hole 301; a second penetration hole 302; a base plate 40; a first leakage orifice 401; second leakage orifice 402

Detailed Description

The following description of the embodiments of the present application will be made in conjunction with the accompanying drawings of the present application, and it is obvious that the described embodiments are only a part of the embodiments, and other embodiments obtained by those skilled in the art without any inventive work based on the embodiments of the present application are within the scope of the present application.

It should be noted that, without conflict, terms used in this application, such as "upper," "lower," and the like, to indicate relative spatial positions, are used for ease of description to describe one element or feature's relationship to another element or feature as illustrated in the figures. For example, one of ordinary skill in the art will readily understand that the "top" of a lithium battery is the end of the battery where the electrode leads are located, and the "bottom" is the end of the battery away from the electrode leads.

The embodiment of the application provides a square lithium battery capable of easily discharging gas in a battery cell, please refer to fig. 1, fig. 2 and fig. 3, and the square lithium battery comprises a lithium battery cell 10, a shell 20 and an insulating connection structure, wherein the lithium battery cell 10 is formed by overlapping and arranging at least two single battery cells; the housing 20 forms a containing cavity, and the lithium battery cell 10 is arranged in the containing cavity; insulating connection structure includes insulating piece 30 and base support piece 40, wherein, insulating piece 30 wraps up in the outside of lithium cell 10, base support piece 40 is connected in order to support lithium cell 10 with the bottom of insulating piece 30, base support piece 40 is formed with first leakage hole 401 along single cell length extending direction's at least one end, first leakage hole 401 corresponds the interval space 103 department that sets up formation between the side reason of adjacent two single cells, the bottom of insulating piece 30 is formed with first infiltration hole 301, first leakage hole 401 and first infiltration hole 301 intercommunication.

The bottom of the insulating sheet 30 refers to an area of the insulating sheet 30 corresponding to the bottom of the lithium battery cell 10; referring to fig. 1, the housing 20 further includes a limiting portion 201 disposed at the bottom of the accommodating cavity, and the bottom supporting sheet 40 is supported on the limiting portion 201, that is, in this embodiment, the bottom supporting sheet 40 is located outside the insulating sheet, so that the bottom supporting sheet 40 and the bottom surface of the accommodating cavity are spaced from each other, and thus a certain space for flowing gas and electrolyte can be formed at the lower portion and the side edge of the bottom supporting sheet 40.

Referring to fig. 2, a lithium battery cell 10 formed by overlapping two single battery cells is taken as an example, specifically, for convenience of description, one of the single battery cells is named as a first single battery cell 101, and another single battery cell is named as a second single battery cell 102, a certain gap space 103 is formed at a side edge of the lithium battery cell 10 formed by overlapping and arranging the first single battery cell 101 and the second single battery cell 102, and the gap space 103 can collect and contain more gas in an insulating sheet; referring to fig. 2 and 3, a first leakage hole 401 and a first penetration hole 301 are respectively formed in the bottom support sheet 40 and the insulation sheet 30 at positions corresponding to the spacing space 103, the first leakage hole 401 and the first penetration hole 301 are matched to ensure sufficient penetration of electrolyte in the battery manufacturing process, and in the battery standing and exhausting stage, gas collected and contained in the spacing space 103 can be rapidly and unobscured and discharged from the bottom of the lithium battery cell 10 through the first leakage hole 401 and the first penetration hole 301, so that the discharging speed and efficiency of bubbles in the lithium battery cell 10 are greatly improved.

It should be noted that, the square lithium battery in the embodiment of the present application is directed to a round lithium battery, and the approximate shape of the square lithium battery may be a square, a rectangle, and the like, which is not limited herein.

In one embodiment, referring to fig. 5, the bottom of the insulation sheet 30 is formed into a rectangular structure corresponding to the bottom size of the lithium battery cell 10, and further, referring to fig. 4, the outline of the bottom support sheet 40 is roughly shaped into a rectangular structure corresponding to the bottom size of the insulation sheet 30. Referring to fig. 3 and 5, it can be understood that the insulation sheet 30 actually wraps the bottom and the side of the lithium battery cell 10 to insulate the lithium battery cell 10 from the aluminum cell casing 20.

It should be noted that the bottom supporting sheet may be disposed inside the insulating sheet 30, that is, the bottom supporting sheet 40 is disposed between the insulating sheet 30 and the lithium battery cell 10; it may be disposed outside the insulation sheet 30, that is, the bottom bracket sheet 40 is disposed between the insulation sheet 30 and the bottom surface of the housing 20.

In one embodiment, referring to fig. 4, the first leakage holes 401 penetrate the edge of the bottom supporting sheet 40, so as to facilitate the manufacturing process and reduce the production cost. In some embodiments, the first leakage hole 401 is a U-shaped opening, which can greatly improve the efficiency of gas passing through under the condition of ensuring that the supporting function of the base plate 40 meets the requirement.

In the square lithium battery provided in this embodiment, four corners of the bottom support sheet 40 are arc chamfers, please refer to fig. 3, after the bottom support sheet 40 is covered by the housing 20, the arc chamfers of the rectangular bottom support sheet 40 do not adhere to the inner wall of the housing 20, that is, a gap is formed between the chamfers and the inner wall of the housing 20, and a certain exhaust space is still formed at the chamfers, which is a means for promoting gas exhaust.

It is understood that the shape of the first penetration hole 301 may be a rectangle, a circle, an ellipse, or other shapes that do not affect the exhaust function.

Referring to fig. 4, in an embodiment, a second leakage hole 402 is formed at least one side edge of the bottom supporting sheet 40 along the overlapping arrangement direction of the plurality of single cells, referring to fig. 5, a plurality of second leakage holes 302 are further formed at the bottom of the insulating sheet 30, and the second leakage holes 402 are disposed corresponding to the second leakage holes 302. The cooperation of the second leakage hole 402 and the second penetration hole 302 can further increase the air exhaust passage and the air exhaust rate of the lithium battery cell.

The size of the second leakage hole 402 is larger than the second penetration hole 302, and one second leakage hole 402 is correspondingly provided with at least one second penetration hole 302, so that the structural strength, the insulation effect and the processing difficulty of the bottom supporting plate 40 of the insulation sheet 30 can be considered.

Specifically, referring to fig. 3, in order to ensure that the gas inside the lithium battery cell 10 is exhausted as much as possible, the insulating sheet 30 is provided with as many second penetration holes 302 for the gas to pass through, and considering that the second penetration holes 302 on the insulating sheet 30 need to be matched with the second leakage holes 402 on the bottom bracket sheet 40, the size of the second leakage holes 402 is larger than that of the second penetration holes 302 to ensure a better gas exhaust effect and also ensure an insulation effect of the insulating sheet 30; a second leakage hole 402 corresponds to at least one second infiltration hole 302 and sets up, under the prerequisite of guaranteeing that the bearing function of base support piece 40 satisfies the requirement, can realize better exhaust efficiency, has also reduced the material of base support piece 40 and has used, has reduced the quality of base support piece 40, has practiced thrift the manufacturing cost of battery.

In the square lithium battery provided by this embodiment, the bottom supporting sheet 40 is connected to the bottom of the insulating sheet 30 by thermal melting. Specifically, the bottom support sheet 40 and the insulating sheet 30 after hot melting connection are bonded and fixed, and the situation that the pore fit between the bottom support sheet 40 and the insulating sheet 30 does not deviate in the subsequent manufacturing, transportation and use processes of the battery is ensured.

In the square lithium battery provided in this embodiment, the insulating sheet 30 adopts a Mylar film structure. The Mylar film structure has a flat surface, good flexibility and reliable insulation performance, and it is understood that the material of the insulation sheet 30 is not limited to the Mylar film structure, but may be other polymers with similar electrical insulation and heat resistance properties, such as polyimide, polyethylene, polyvinylidene fluoride, etc.

In the embodiment of the present application, the thickness of the insulation sheet 30 is 0.08-0.12 mm, for example, 0.08mm, 0.1mm or 0.12mm, and thus, the insulation sheet 30 does not affect the design thickness or quality of the lithium battery. It is understood that the material and thickness of the insulating sheet 30 should be determined according to the design requirements of the square lithium battery.

In the square lithium battery provided by the embodiment, the bottom support sheet 40 is made of a PP (polypropylene) insulating material, so that the electric insulating effect of the bottom support sheet 40 can be better ensured. Of course, the material used for the bottom support sheet 40 is not limited to PP insulating material, but may be other polymers with similar electrical insulation and heat resistance, such as polyimide, polyethylene, polyvinylidene fluoride, etc.

In the embodiment of the present application, the thickness of the bottom support sheet 40 is 0.6-1.0 mm, for example, 0.6mm, 0.8mm or 1.0mm, etc., so that the supporting function of the bottom support sheet 40 can be better realized. It is understood that the material and thickness of the bottom support sheet 40 should be determined according to the design requirements of the lithium square battery.

The above description is only a preferred embodiment of the present application and is not intended to limit the present application, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A square lithium battery, comprising:

the lithium battery cell (10), the lithium battery cell (10) is formed by overlapping and arranging at least two single battery cells;

a housing (20), wherein a containing cavity is formed in the housing (20), and the lithium battery cell (10) is arranged in the containing cavity;

insulating connection structure, insulating connection structure includes insulating piece (30) and base support piece (40), wherein, insulating piece (30) wrap up in the outside of lithium cell (10), base support piece (40) with the bottom of insulating piece (30) is connected in order to support lithium cell (10), base support piece (40) are followed single electric core length extending direction's at least one end is formed with first seepage hole (401), first seepage hole (401) correspond and set up in adjacent two interval space (103) department that forms between the side reason of single electric core, the bottom of insulating piece (30) is formed with first infiltration hole (301), first seepage hole (401) with first infiltration hole (301) intercommunication.

2. The square lithium battery according to claim 1, wherein the bottom of the insulation sheet (30) is formed in a rectangular structure corresponding to the bottom size of the lithium battery cell (10).

3. The lithium square battery according to claim 1, wherein the first leakage hole (401) penetrates through an edge of the base sheet (40); and/or the first leakage hole (401) is a U-shaped opening.

4. The lithium prismatic battery according to claim 1, wherein said housing (20) comprises a stopper portion (201) disposed at the bottom of said receiving cavity, said base sheet (40) is connected to the outside of said insulating sheet (30), said base sheet (40) is supported on said stopper portion (201), and said base sheet (40) and the bottom surface of said receiving cavity are spaced from each other.

5. The square lithium battery according to claim 1, wherein a second leakage hole (402) is formed in at least one side edge of the bottom support sheet (40) along the stacking direction of the plurality of single cells, a plurality of second leakage holes (302) are further formed in the bottom of the insulation sheet (30), and the second leakage hole (402) is disposed corresponding to the second leakage holes (302).

6. The lithium square battery according to claim 5, wherein the second leakage hole (402) is larger than the second penetration holes (302), and at least one second penetration hole (302) is correspondingly arranged on one second leakage hole (402).

7. The lithium square battery according to claim 1, wherein the bottom support sheet (40) is thermally fused to the bottom of the insulation sheet (30).

8. A lithium prismatic battery according to claim 1, characterized in that said bottom support sheet (40) has a rectangular configuration adapted to the bottom dimensions of said insulating sheet (30); and/or the four corners of the bottom support sheet (40) are arc chamfers.

9. A lithium prismatic battery according to claim 1, characterized in that said insulating sheet (30) is of Mylar film structure; and/or the thickness of the insulation sheet (30) is 0.08-0.12 mm.

10. The lithium square battery of claim 1, wherein said bottom support sheet (40) is a PP insulating material; and/or the thickness of the bottom support sheet (40) is 0.6-1.0 mm.