CN213959095U

CN213959095U - Miniature lithium ion battery

Info

Publication number: CN213959095U
Application number: CN202022733637.5U
Authority: CN
Inventors: 王昉; 孙法炯
Original assignee: Guangdong Zhili Technology Co ltd
Current assignee: Guangdong Zhili Technology Co ltd
Priority date: 2020-11-23
Filing date: 2020-11-23
Publication date: 2021-08-13
Anticipated expiration: 2030-11-23

Abstract

The invention discloses a miniature lithium ion battery, and aims to provide a miniature lithium ion battery with a simple structure and a good explosion-proof effect. The battery comprises a shell, a rubber ring, a cover body and a battery cell, wherein the upper end of the shell is provided with an opening, the cover body seals the opening through the rubber ring, the battery cell is packaged in the shell, the anode of the battery cell is electrically connected with the cover body, the cathode of the battery cell is electrically connected with the shell, in addition, the inner side of the cover body and the inner side of the shell are both provided with insulating glue, after the shell is sealed, an inward-bent inward-folded pressing part is arranged at the opening, the rubber ring is sleeved on the outer edge of the cover body, and the upper end of the inward-folded pressing part is pressed on the outer side of the rubber ring and is buckled on the outer edge of the cover body through the rubber ring; the inner folding and pressing part is asymmetric on the circumference of the full seal, and the coating length of the shell at one end is longer than that at the other end. 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 pressure relief part is positioned in the cylinder and is in sealed connection with the cylinder, the pressure relief part is annular, and the pressure relief part is configured to generate cracks or fall off from the cover plate body in response to the deformation of the cover plate body; and a center conductor disposed in an inner ring of the pressure relief portion and penetrating the pressure relief portion in an axial direction. 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.

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 battery comprises a shell, a rubber ring, a cover body and a battery cell, wherein the upper end of the shell is provided with an opening, the cover body seals the opening through the rubber ring, the battery cell is packaged in the shell, the anode of the battery cell is electrically connected with the cover body, the cathode of the battery cell is electrically connected with the shell, in addition, the inner side of the cover body and the inner side of the shell are both provided with insulating glue, after the shell is sealed, an inward-bent inward-folded pressing part is arranged at the opening, the rubber ring is sleeved on the outer edge of the cover body, and the upper end of the inward-folded pressing part is pressed on the outer side of the rubber ring and is buckled on the outer edge of the cover body through the rubber ring; the inner folding and pressing part is asymmetric on the circumference of the full seal, and the coating length of the shell at one end is longer than that at the other end.

Further, the minimum inward-folding width and the maximum inward-folding width of the sealed shell are both larger than the shell wall thickness of the shell, wherein the width of the maximum inward-folding width is larger than the minimum inward-folding width.

Further, the minimum fold-in width and the maximum fold-in width are at least 0.01 mm greater than the housing wall thickness.

Further, the width of the maximum fold-in width is at least 0.1mm greater than the minimum fold-in width.

Further, the maximum height and the minimum height of the inward-folded pressing part when the inward-folded pressing part is unfolded and vertical are different by more than 0.1 mm.

Further, inwards extrude annular groove one on the shell, annular groove is close to the opening, thereby form the annular in the shell and seal the step, the outer edge setting of lid is in on the step is sealed to the annular, the annular seal the step with be provided with between the outer edge of lid the rubber ring.

Further, the cover body is formed by compounding an upper metal layer A, a middle metal layer B and a lower insulating glue, a through hole is formed in the insulating glue on the cover body, the positive lug of the battery cell is welded to the middle metal layer B after passing through the through hole, and then the through hole is covered with a layer of insulating glue.

Further, the material of the metal layer A is stainless steel, or nickel, or a nickel-plated steel belt; the metal layer B is made of aluminum, copper, stainless steel or nickel and a nickel-plated steel belt; the insulating glue is PET, PI, PP or PE.

Furthermore, the inner folding and pressing part and the shell are designed integrally; the volume of the inner space after the shell is sealed 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: the invention adopts a local compression design, and comprises a shell, a rubber ring, a cover body and an electric core, wherein the upper end of the shell is provided with an opening, the cover body seals the opening through the rubber ring, the electric core is packaged in 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, in addition, the inner side of the cover body and the inner side of the shell are both provided with insulating glue, after the shell is sealed, an inward-bent inward-folded compression part is arranged at the opening, the rubber ring is sleeved on the outer edge of the cover body, and the upper end of the inward-folded compression part is pressed on the outer side of the rubber ring and is buckled on the outer edge of the cover body through the rubber ring; the inner folding and pressing part is asymmetric on the circumference of the full seal, and the coating length of the shell at one end is larger than that at the other end, so the invention has simple structure, when the internal pressure of the shell is increased, one end of the cover body can be tilted to release pressure, and the other end of the cover body can be firmly buckled, thereby effectively preventing the cover body from falling off and flying out, and having good explosion-proof effect.

Drawings

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

fig. 2 is a sectional view of the case 1 and the cover 3 after being combined;

fig. 3 is an asymmetrical section of the housing 1 over the full closure circumference;

fig. 4 is an expanded view of the housing 1 and the inner fold compressed part 5;

fig. 5 is the top view of the asymmetry over the full closure perimeter.

Detailed Description

In the present embodiment as shown in fig. 1 to 5, a wound battery core 10 is put into the open end of the casing 1, an annular groove 6 is extruded inwards on a dedicated device, the annular groove 6 is close to the opening 4, so that an annular sealing step 7 is formed in the casing 1, the outer edge of the cover 3 is disposed on the annular sealing step 7, and the rubber ring 2 is disposed between the annular sealing step 7 and the outer edge of the cover 3. The cover body 3 seals the opening 4 through the rubber ring 2, meanwhile, the battery cell 10 is packaged in the shell 1, the positive electrode of the battery cell 10 is electrically connected with the cover body 3, the negative electrode of the battery cell 10 is electrically connected with the shell 1, and in addition, the inner side of the cover body 3 and the inner side of the shell 1 are both provided with insulating glue 11.

In this embodiment, an electrolyte is further injected into a sealed space formed by the lid 3 and the case 1; the battery cell 10 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 13 is disposed at the winding center of the battery cell 10, and the design of the plug 13 enables the overall structure of the battery to be more tightly combined.

In this embodiment, the whole thickness of the cover body 3 needs to be appropriate, the cover body is too thin and is easy to deform, the sealing difficulty is high, the cover body is too thick and occupies an effective internal space, and the cover body cannot deform to release gas when the internal pressure is increased, so that an explosion-proof effect cannot be achieved. The upper layer is made of 304 stainless steel and is optimally 0.1-0.2mm thick, the middle layer is made of aluminum sheets and is optimally 0.03-0.0.08 mm thick, the lower layer is made of PET adhesive tape and is optimally 0.02-0.0.04 mm thick, through holes are formed in the PET adhesive tape, and the aluminum sheets in the middle layer are communicated with the inner space wrapped by the shell through the through holes.

In this embodiment, after the enclosure is sealed, the upper end of the folded-in compressed part 5 is compressed outside the rubber ring 2 and is buckled on the outer edge of the cover 3 through the rubber ring 2, and the folded-in compressed part 5 is asymmetric in the whole sealing perimeter, as shown in fig. 3 and 5, wherein the folded-in width D2 is greater than the folded-in width D1, the difference between D2 and D1 is too small, the force acting on the cover 3 is uniform, and the explosion-proof effect cannot be achieved, so the difference is at least 0.1mm, and optimally 0.3-0.5 mm;

FIG. 4 is a configuration of the housing 1 before folding without the closure, wherein the highest point of the housing is 0.1mm higher than the lowest point of the housing, most preferably 0.3-0.5 mm higher;

in this embodiment, too thick wall thickness D of the case reduces the effective space inside the battery, and too thin wall thickness D is easy to deform, and the optimal thickness D is 0.1-0.2mm, as shown in fig. 3, after sealing, the folded-in width D1 and the folded-in width D2 are both greater than the wall thickness D of the case; wherein D1 is at least 0.01 mm, most preferably 0.05-0.1 mm greater than D; d2 is greater than D1 and greater than D, preferably 0.3-0.5 mm; ensuring effective sealing of the opening 4;

after the test, when the internal pressure is increased and exceeds 3MPa, the cover body at the D1 position is firstly deformed and tilted, the internal gas is released, the whole cover body does not fly out, and the explosion-proof effect is achieved.

The explosion-proof principle of the invention is as follows: work as during the internal pressure grow of 1 parcel of shell, not by in the lid 3 the one end that the tight portion 5 of infolding was buckled can the perk and carry out the pressure release, and the other end of lid 3 can by the tight portion 5 of infolding is firmly buckled, effectively prevents the phenomenon that the lid drops the departure, and is explosion-proof effectual.

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. The utility model provides a miniature lithium ion battery, includes shell (1), rubber ring (2), lid (3), electric core (10), the upper end of shell (1) is equipped with opening (4), lid (3) pass through rubber ring (2) seal up opening (4), simultaneously electric core (10) encapsulation in shell (1), the anodal of electric core (10) with lid (3) electricity is connected, the negative pole of electric core (10) with shell (1) electricity is connected, in addition the inboard of lid (3) with the inboard of shell (1) all is provided with insulating glue (11), its characterized in that: after the shell (1) is sealed, an inward-bent compression part (5) is arranged at the opening (4), the rubber ring (2) is sleeved on the outer edge of the cover body (3), and the upper end of the inward-bent compression part (5) is pressed on the outer side of the rubber ring (2) and buckled on the outer edge of the cover body (3) through the rubber ring (2); the inner folding and pressing part (5) is asymmetric on the circumference of the full seal, wherein the coating length of the shell at one end is longer than that at the other end; the cover body (3) is formed by compounding an upper metal layer A (8), a middle metal layer B (9) and a lower insulating glue (11), a through hole (12) is formed in the insulating glue (11) on the cover body (3), an anode tab of the battery cell (10) passes through the through hole (12) and then is welded on the middle metal layer B (9), and then the through hole (12) is covered with a layer of insulating glue (11).

2. The lithium ion micro-battery of claim 1, wherein: the minimum fold-in width (D1) and the maximum fold-in width (D2) of the sealed housing (1) are both greater than the housing wall thickness (D) of the housing (1), wherein the maximum fold-in width (D2) is greater than the minimum fold-in width (D1).

3. The lithium ion micro-battery of claim 2, wherein: the minimum fold-in width (D1), the maximum fold-in width (D2) being at least 0.01 mm greater than the housing wall thickness (D).

4. The lithium ion micro-battery of claim 2, wherein: the width of the maximum fold-in width (D2) is at least 0.1mm greater than the minimum fold-in width (D1).

5. The lithium ion micro-battery of claim 1, wherein: the difference between the maximum height and the minimum height of the inner folding pressing part (5) when the inner folding pressing part is not folded and is vertical is more than 0.1 mm.

6. The lithium ion micro-battery of claim 1, wherein: go up inward extrusion annular groove (6) one on shell (1), annular groove (6) are close to opening (4), thereby form annular in shell (1) and seal step (7), the outer edge of lid (3) sets up on annular seals step (7), the annular seal step (7) with be provided with between the outer edge of lid (3) rubber ring (2).

7. The lithium ion micro-battery of claim 1, wherein: the metal layer A is made of stainless steel, or nickel, or a nickel-plated steel belt; the metal layer B is made of aluminum, copper, stainless steel or nickel and a nickel-plated steel belt; the insulating glue (11) is PET, PI, PP or PE.

8. The lithium ion micro-battery of claim 1, wherein: the inner folding and pressing part (5) and the shell (1) are designed integrally; the volume of the inner space of the shell (1) after sealing is less than or equal to 1 cubic centimeter.

9. The lithium ion micro-battery of claim 1, wherein: electrolyte is also injected into a sealed space formed by the cover body (3) and the shell (1); the battery core (10) 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 (13) is arranged in the winding center of the battery cell (10).