CN213716960U

CN213716960U - Miniature lithium ion battery

Info

Publication number: CN213716960U
Application number: CN202022804884.XU
Authority: CN
Inventors: 孙法炯; 王昉
Original assignee: Zhuhai Zhi Li Battery Co ltd
Current assignee: Zhuhai Zhi Li Battery Co ltd
Priority date: 2020-11-29
Filing date: 2020-11-29
Publication date: 2021-07-16
Anticipated expiration: 2030-11-29

Abstract

The invention discloses and provides a miniature lithium ion battery with simple structure and good explosion-proof effect. The anti-explosion cover plate assembly comprises a shell, an anti-explosion cover plate assembly and a battery cell, wherein an inlet is formed in the shell, the anti-explosion cover plate assembly comprises a cover body, the cover body seals the inlet, and battery cell insulating glue is arranged on the inner side of the cover body and the inner side of the shell; the cover body is provided with an opening which is communicated with the upper surface and the lower surface of the cover body, a downward extending edge is arranged at the edge below the opening, the opening is provided with a rubber ring, the upper end of the edge is connected with the edge below the opening, the lower end of the edge forms a closing-in, and the conductive column is inserted on the rubber ring; the upper surface of the cover body is provided with an annular rubber ring pressing plate, the annular rubber ring pressing plate is positioned above the opening, the small circular diameter of the annular rubber ring pressing plate is smaller than the diameter of the outer ring of the rubber ring, the upper edge of the rubber ring is positioned below the annular rubber ring pressing plate, and a gap is reserved between the upper edge of the rubber ring and the annular rubber ring pressing plate. The invention is applied to the technical field of miniature lithium ion batteries.

Description

Miniature lithium ion battery

Technical Field

The invention relates to a lithium ion battery, in particular to a miniature lithium ion battery.

Background

The miniature lithium ion rechargeable battery is widely applied at present, and particularly along with the promotion of a wireless Bluetooth headset, the miniature lithium ion rechargeable battery is required to be small in size, high in specific energy and good in safety.

Chinese patents CN102804473B and CN104332647B each disclose a structure for a micro lithium ion battery to meet the market demand, but the outer side wall has three layers, and the multiple layers of side walls are not good for improving the specific energy of the battery, and how to prevent explosion is not described.

Chinese patent application publication No. CN109980155A, which discloses a cover plate assembly for a lithium ion battery. This apron subassembly includes: the cover plate comprises a cover plate body, wherein a through hole is formed in the middle of the cover plate body, the through hole extends to form a cylinder body, and the cylinder body protrudes out of at least one surface of the cover plate body; the anti-explosion cover plate comprises a cover plate body, a pressure relief portion and a cover plate body, wherein the cover plate body is provided with a plurality of through holes, the pressure relief portion is arranged in the cover plate body and is connected with the cover plate body in a sealing mode, the pressure relief portion is made of inorganic glass, and when the cover plate body deforms, cracks are generated on the glass body and then the cover plate body falls off, so that the anti-explosion purpose is achieved. When the cover plate assembly is used for a micro battery, the effective area of the cover plate assembly is small, and the inside of the cover plate assembly needs higher pressure to enable the pressure relief part to generate cracks, so that the pressure relief part and the central conductor fly out of the cover plate body together, and the explosion-proof effect is lost. In addition, the glass body needs to be calcined and formed at high temperature, and cannot be made to be too small and too thin, so that the internal effective space of the battery is occupied, and particularly the volume of the miniature lithium ion battery is less than 1 cubic centimeter.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides the miniature lithium ion battery with simple structure and good explosion-proof effect.

The technical scheme adopted by the invention is as follows: the anti-explosion cover plate assembly comprises a shell, an anti-explosion cover plate assembly and a battery cell, wherein the shell is provided with an inlet, the anti-explosion cover plate assembly comprises a cover body, the cover body seals the inlet, the battery cell is positioned in a sealed space formed by the cover body and the shell, the positive electrode of the battery cell is electrically connected with the cover body, the negative electrode of the battery cell is electrically connected with the shell, and the inner side of the cover body and the inner side of the shell are both provided with battery cell insulating glue; the cover body is provided with an opening, the opening is communicated with the upper surface and the lower surface of the cover body, a downward extending edge is arranged at the edge below the opening, a rubber ring is arranged on the opening, the upper end of the edge is connected with the edge below the opening, a closing-in is formed at the lower end of the edge, the closing-in of the edge embraces the lower edge of the rubber ring, and the outer ring of the rubber ring is hermetically connected with the opening and the edge; the explosion-proof cover plate assembly further comprises a conductive column, the conductive column is inserted into the rubber ring, and the conductive column is hermetically connected with the inner ring of the rubber ring; an annular rubber ring pressing plate is arranged on the cover body and located above the opening, the small circular diameter of the annular rubber ring pressing plate is smaller than the diameter of the outer ring of the rubber ring, the upper edge of the rubber ring is located below the annular rubber ring pressing plate, and a gap is reserved between the upper edge of the rubber ring and the annular rubber ring pressing plate.

Further, after the lower end of the edge is closed, the edge is inclined inwards.

Further, the edge of rubber ring is equipped with annular step, annular step is located the below of annular rubber ring clamp plate.

Further, the lower end of the conductive column penetrates through the rubber ring, a soldering lug is arranged at the upper end of the conductive column, and the soldering lug is larger than the inner ring of the rubber ring.

Further, the conductive column is made of aluminum, copper, nickel, titanium or stainless steel; the soldering lug is a nickel lug, a copper lug, a titanium lug or a stainless steel lug; the soldering lug is welded at the upper end of the conductive column.

Further, the cover body is a stainless steel sheet, an aluminum sheet, a copper sheet, a nickel sheet or a titanium alloy sheet, the rubber ring pressing plate is a stainless steel pressing plate, a nickel pressing plate or a titanium alloy pressing plate, and the rubber ring pressing plate is welded on the cover body.

The rubber ring is made of polypropylene, polyethylene, polyamide, polyimide or poly terephthalic acid high polymer plastic.

Further, the cover body is inboard the through-hole is equipped with on the electric core insulating glue, the anodal ear of electric core passes through the welding behind the through-hole is in lead electrical pillar lower extreme, afterwards the through-hole covers one deck again electric core insulating glue.

Furthermore, the volume of the inner space of the sealed shell is less than or equal to 1 cubic centimeter.

Furthermore, electrolyte is injected into a sealed space formed by the cover body and the shell; the battery cell is formed by winding a positive plate, a negative plate and a diaphragm, wherein the diaphragm is arranged between the positive plate and the negative plate; and a plug is arranged at the winding center of the battery cell.

The invention has the beneficial effects that: because the utility model comprises a shell, an explosion-proof cover plate component and an electric core, the shell is provided with an inlet, the explosion-proof cover plate component comprises a cover body, the cover body seals the inlet, the electric core is positioned in a sealing space formed by the cover body and the shell, the anode of the electric core is electrically connected with the cover body, the cathode of the electric core is electrically connected with the shell, and the inner side of the cover body and the inner side of the shell are both provided with electric core insulating glue; the cover body is provided with an opening, the opening is communicated with the upper surface and the lower surface of the cover body, a downward extending edge is arranged at the edge below the opening, a rubber ring is arranged on the opening, the upper end of the edge is connected with the edge below the opening, a closing-in is formed at the lower end of the edge, the closing-in of the edge embraces the lower edge of the rubber ring, and the outer ring of the rubber ring is hermetically connected with the opening and the edge; the explosion-proof cover plate assembly further comprises a conductive column, the conductive column is inserted into the rubber ring, and the conductive column is hermetically connected with the inner ring of the rubber ring; the cover is characterized in that an annular rubber ring pressing plate is arranged on the cover body and located above the opening, the small circular diameter of the annular rubber ring pressing plate is smaller than the diameter of the outer ring of the rubber ring, the upper edge of the rubber ring is located below the annular rubber ring pressing plate, and a gap is reserved between the upper edge of the rubber ring and the annular rubber ring pressing plate, so that when the internal pressure of a battery becomes large, the cover body deforms, the opening becomes large, the rubber ring is pushed outwards from the inner side, the outer ring of the rubber ring is further enabled to be spaced from the opening and the edge, pressure relief is achieved, the annular rubber ring pressing plate can buckle the upper edge of the rubber ring, the phenomenon that the rubber ring falls off and flies out is effectively prevented, the structure is simple, and the anti-explosion effect is good.

Drawings

FIG. 1 is a cross-sectional view of the present invention;

FIG. 2 is an exploded view of the explosion proof cover plate assembly;

fig. 3 is a cross-sectional view of the vent panel assembly.

Detailed Description

As shown in fig. 1 to 3, in the present embodiment, a wound battery cell 12 is placed at the inlet end of the casing 10, and the cover body 1 is welded and sealed at the inlet end of the casing 10. The positive electrode of the battery cell 12 is electrically connected with the cover body 1, the negative electrode of the battery cell 12 is electrically connected with the shell 10, and the battery cell insulating glue 14 is arranged on the inner side of the cover body 1 and the inner side of the shell 10.

In this embodiment, an electrolyte is further injected into a sealed space formed by the cap body 1 and the case 10; the battery cell 12 is formed by winding a positive plate, a negative plate and a diaphragm, wherein the diaphragm is arranged between the positive plate and the negative plate; a plug 16 is provided at the winding center of the cell 12. The battery cell insulating glue 14 on the inner side of the cover body 1 is provided with a through hole 15, a positive lug of the battery cell 12 passes through the through hole 15 and then is welded at the lower end of the conductive column 5, and then the through hole 15 is covered with a layer of the battery cell insulating glue 14.

In this embodiment, the material of the cover body 1 may be stainless steel, aluminum, copper, nickel, titanium or alloy sheets thereof, and here, 304 stainless steel sheet is selected; the thickness of the sheet may be 0.01 to 0.5 mm, preferably 0.1 to 0.2 mm; an opening 2 is formed through punch forming, the opening 2 is communicated with the upper surface and the lower surface of the cover body 1, and a side 3 extending downwards is arranged at the edge below the opening 2; the opening 2 is provided with a rubber ring 4, the material of the rubber ring can be high polymer plastics such as polypropylene, polyethylene, polyamide, polyimide or polyterephthalic acid, and the like, wherein injection molding polypropylene is selected; the upper end of the edge 3 is connected with the edge below the opening 2, the lower end of the edge 3 forms a closing-in after mechanical die pressing, the closing-in embraces the lower edge of the rubber ring 4 and inclines inwards, and thus the outer ring of the rubber ring 4, the opening 2 and the edge 3 form good sealing; the rubber ring also comprises a conductive column 5 inside, wherein the conductive column 5 can be formed by punching a metal, such as aluminum or copper, but two different metals are adopted for welding in consideration of corrosion and the requirement of leading out a battery current collector; the conductive column 5 is made of aluminum, copper, nickel, titanium or stainless steel, the soldering lug 9 is made of nickel, copper, titanium or stainless steel sheet, and the like, when the conductive column 5 is used for leading out the anode of the battery, the conductive column 5 is formed by ultrasonic welding of the aluminum and the nickel sheet 9, and when the conductive column 5 is used for leading out the cathode of the battery, the conductive column 5 is formed by laser welding of the copper and the nickel sheet 9; the outer diameter of the conductive column 5 is at least 0.01 mm, preferably 0.05-0.1 mm larger than the inner diameter of the rubber ring 4, the conductive column 5 is inserted into the rubber ring 4, and the lower end of the conductive column penetrates through the rubber ring 4 and forms tight seal with the inner ring of the rubber ring 4; an annular rubber ring pressing plate 6 is arranged on the cover body 1, the material of the annular rubber ring pressing plate can be stainless steel, nickel or titanium alloy and the like, the stainless steel is adopted here, the thickness is 0.01-0.2 mm, the best thickness is 0.05-0.1 mm, the annular rubber ring pressing plate 6 is welded above the opening 2 by adopting an energy storage spot welding method, the small circular diameter of the annular rubber ring pressing plate 6 is smaller than the diameter of the outer ring of the rubber ring 4, the upper edge of the rubber ring 4 is positioned below the annular rubber ring pressing plate 6, and a gap 7 is formed between the upper edge of the rubber ring 4 and the annular rubber ring pressing plate 6.

And (3) testing: the cover plate assembly is sealed in an independent space, when the internal pressure is higher than 3MPA, the cover plate begins to deform, the rubber ring moves, gas is released from a gap formed between the rubber ring and the cover plate, and the rubber ring and the conductive column are not separated from the cover body.

The explosion-proof principle of the invention is as follows: when the lithium ion battery explosion-proof cover plate assembly is welded on the shell 10 of the battery, when the internal pressure of the battery is increased, the cover body 1 deforms, so that the opening 2 is enlarged, the rubber ring 4 is pushed outwards by internal pressure, and gaps are generated between the outer ring of the rubber ring 4 and the opening 2 and between the outer ring and the edge 3, so that pressure relief is realized, the annular rubber ring pressing plate 6 can buckle the upper edge of the rubber ring 4, the phenomenon that the rubber ring 4 falls off and flies out is effectively prevented, the structure is simple, and the explosion-proof effect is good.

While the embodiments of the present invention have been described in terms of practical embodiments, they are not to be construed as limiting the meaning of the present invention, and modifications of the embodiments and combinations with other embodiments will be apparent to those skilled in the art in light of the present description.

Claims

1. A miniature lithium ion battery comprises a shell (10), an explosion-proof cover plate assembly (11) and a battery cell (12), wherein an inlet (13) is formed in the shell (10), the explosion-proof cover plate assembly (11) comprises a cover body (1), the cover body (1) seals the inlet (13), the battery cell (12) is positioned in a sealed space formed by the cover body (1) and the shell (10), the positive electrode of the battery cell (12) is electrically connected with the cover body (1), the negative electrode of the battery cell (12) is electrically connected with the shell (10), and battery cell insulating glue (14) is arranged on the inner side of the cover body (1) and the inner side of the shell (10); the method is characterized in that: the cover comprises a cover body (1), and is characterized in that an opening (2) is formed in the cover body (1), the opening (2) is communicated with the upper surface and the lower surface of the cover body (1), a side (3) extending downwards is arranged at the edge below the opening (2), a rubber ring (4) is arranged on the opening (2), the upper end of the side (3) is connected with the edge below the opening (2), a closing-in is formed at the lower end of the side (3), the closing-in of the side (3) embraces the lower edge of the rubber ring (4), and the outer ring of the rubber ring (4) is hermetically connected with the opening (2) and the side (3); the anti-explosion cover plate assembly further comprises a conductive column (5), the conductive column (5) is inserted into the rubber ring (4), and the conductive column (5) is connected with the inner ring of the rubber ring (4) in a sealing mode; the improved rubber ring cover is characterized in that an annular rubber ring pressing plate (6) is arranged on the cover body (1), the annular rubber ring pressing plate (6) is located above the opening (2), the small circular diameter of the annular rubber ring pressing plate (6) is smaller than the diameter of the outer ring of the rubber ring (4), the upper edge of the rubber ring (4) is located below the annular rubber ring pressing plate (6), and a gap (7) is reserved between the upper edge of the rubber ring (4) and the annular rubber ring pressing plate (6).

2. The lithium ion micro-battery of claim 1, wherein: after the lower end of the edge (3) is closed, the edge (3) is inclined inwards.

3. The lithium ion micro-battery of claim 1, wherein: the edge of the rubber ring (4) is provided with an annular step (8), and the annular step (8) is positioned below the annular rubber ring pressing plate (6).

4. The lithium ion micro-battery of claim 1, wherein: the lower end of the conductive column (5) penetrates through the rubber ring (4), a soldering lug (9) is arranged at the upper end of the conductive column (5), and the soldering lug (9) is larger than the inner ring of the rubber ring (4).

5. The lithium ion micro-battery of claim 4, wherein: the conductive column (5) is made of aluminum, copper, nickel, titanium or stainless steel; the soldering lug (9) is a nickel lug, or a copper lug, or a titanium lug, or a stainless steel lug; the soldering lug (9) is welded at the upper end of the conductive column (5).

6. The lithium ion micro-battery of claim 1, wherein: the cover is characterized in that the cover body (1) is a stainless steel sheet, an aluminum sheet, a copper sheet, a nickel sheet or a titanium alloy sheet, the rubber ring pressing plate (6) is a stainless steel pressing plate, a nickel pressing plate or a titanium alloy pressing plate, and the rubber ring pressing plate (6) is welded on the cover body (1).

7. The lithium ion micro-battery of claim 1, wherein: the rubber ring (4) is made of polypropylene, polyethylene, polyamide, polyimide or polyethylene terephthalate high polymer plastic.

8. The lithium ion micro-battery of claim 1, wherein: the battery cell insulation rubber (14) on the inner side of the cover body (1) is provided with a through hole (15), a positive lug of the battery cell (12) passes through the through hole (15) and then is welded at the lower end of the conductive column (5), and then the through hole (15) is covered with a layer of battery cell insulation rubber (14).

9. The lithium ion micro-battery of claim 1, wherein: the volume of the inner space of the shell (10) after sealing is less than or equal to 1 cubic centimeter.

10. The lithium ion micro-battery of claim 1, wherein: electrolyte is also injected into a sealed space formed by the cover body (1) and the shell (10); the battery cell (12) is formed by winding a positive plate, a negative plate and a diaphragm, and the diaphragm is arranged between the positive plate and the negative plate; a plug (16) is arranged in the winding center of the battery cell (12).