CN214957234U

CN214957234U - Miniature lithium ion battery with explosion-proof trace

Info

Publication number: CN214957234U
Application number: CN202120537492.3U
Authority: CN
Inventors: 王昉; 李臻; 孙法炯
Original assignee: Guangdong Zhili Technology Co ltd
Current assignee: Guangdong Zhili Technology Co ltd
Priority date: 2021-03-15
Filing date: 2021-03-15
Publication date: 2021-11-30
Anticipated expiration: 2031-03-15

Abstract

The utility model discloses and provides a compact structure, the inside effective space of battery is big, explosion-proof effectual miniature lithium ion battery with explosion-proof trace. The utility model comprises a shell, an electric core and a sealing assembly, wherein the upper end of the shell is provided with an opening, the sealing assembly comprises a cover plate, an annular fixing assembly, a central cover and a sealing rubber ring, the cover plate is provided with a through hole, the annular fixing assembly is fixedly arranged on the cover plate, the inner side of the annular fixing assembly is provided with an annular concave part, the outer edge of the central cover is connected with the sealing rubber ring in a clamping way and then is connected in the annular concave part, the depth of the outer edge of the central cover entering the annular concave part is unequal, and the central cover seals the through hole through the sealing fixing assembly; the opening is lived to the apron seal, and electric core encapsulation is in the shell simultaneously, and the positive pole and the center of electric core are covered the electricity and are connected, and the negative pole and the shell electricity of electric core are connected, and the inboard of apron, the inboard of center lid and the inboard of shell all are provided with insulating sticky tape in addition. The utility model discloses be applied to miniature lithium ion battery's technical field.

Description

Miniature lithium ion battery with explosion-proof trace

Technical Field

The utility model relates to a lithium ion battery, in particular to miniature lithium ion battery with explosion-proof trace.

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.

Chinese patent application No. CN202011296439 discloses a cover plate assembly for a lithium ion battery. The edge of the cover body is composed of a first continuous edge and a second continuous edge, and a first distance from a point on the first continuous edge to the center of the cover body is smaller than a second distance from a point on the second continuous edge to the center of the cover body. The distance between the closing-in position and the center after the edge is buckled is asymmetric, so that the explosion-proof problem of the battery can be solved, but the rolling hook and the closing-in position occupy partial space of the outer ring of the battery, and the effective space inside the battery is reduced.

Therefore, a miniature lithium ion battery which is compact in structure and large in effective space inside the battery is developed, the explosion-proof structure of the miniature lithium ion battery is designed on the sealing cover plate, and once the explosion-proof structure on the cover plate fails, the explosion-proof effect of the whole battery is lost. Therefore, at present, there is an urgent need to develop a micro lithium ion battery with multiple explosion-proof functions, so as to further improve the safety performance of the micro lithium ion battery.

SUMMERY OF THE UTILITY MODEL

The utility model aims to solve the technical problem that overcome prior art not enough, provide a compact structure, the inside effective space of battery is big, explosion-proof effectual miniature lithium ion battery who has explosion-proof trace.

The utility model adopts the technical proposal that: the utility model comprises a shell 10, an electric core 11 and a sealing component, wherein the upper end of the shell 10 is provided with an opening 12, the seal assembly includes an outer conductive metal body and an inner conductive metal body, the inner conductive metal body being a central cover 3, a central hole is arranged on the outer conductive metal body, the central cover 3 is positioned in the central hole, an insulator 4 is arranged between the central cover 3 and the outer conductive metal body, the outer conductive metal body seals the opening 12, while the battery cell 11 is encapsulated in the shell 10, the positive electrode of the battery cell 11 is electrically connected with the central cover 3, the negative pole of the battery cell 11 is electrically connected with the shell 10, the inner sides of the outer conductive metal body, the center cover 3 and the shell 10 are all provided with insulating tapes 13, and a V-shaped explosion-proof mark 15 is arranged on the shell 10 and/or the outer conductive metal body.

Preferably, the outer conductive metal body comprises a cover plate 1, a ring-shaped fixing member 2 and an outer cover 8, the ring-shaped fixing member 2 and the outer cover 8 are respectively provided with a first opening 5 and a second opening 9 which are communicated with each other, an interlayer space 6 is arranged between the inner side of the ring-shaped fixing member 2 and the inner side of the outer cover 8, a first radius D4 of the first opening 5 and a second radius D5 of the second opening 9 are both smaller than a cover radius D3 of the center cover 3, the insulator 4 is sleeved on the outer edge of the center cover 3 and is arranged in the interlayer space 6, and the ring-shaped fixing member 2 and the outer cover 8 jointly clamp the outer edge of the center cover 3 through the insulator 4; the cover plate 1 seals the opening 12, and the cover plate 1 and the housing 10 are connected and sealed by laser welding.

Preferably, the depth of the V-shaped explosion-proof mark 15 is 50% -95% of the thickness of the cover plate 1 or the shell 10; the shape of the V-shaped explosion-proof mark 15 is cross-shaped, L-shaped, U-shaped or rectangular.

Preferably, the processing method of the V-shaped explosion-proof mark 15 is laser, or molding, or etching, or engraving.

Preferably, the first radius D4 and/or the second radius D5 are asymmetrical over the entire circumference, as are the width of the clamping portion of the central cover 3 by the intermediate space 6; the width of the sandwich space 6 on one side of the clamping portion of the center cover 3 is the difference between the first radius D4 and the second radius D5, and the width of the sandwich space 6 on the other side of the clamping portion of the center cover 3 is the difference between the second radius D5 and the cover radius D3.

Furthermore, at least one of the connection among the cover plate 1, the annular fixing piece 2 and the outer cover 8 adopts welding, and the welding is laser welding or resistance welding; the thickness of the cover plate 1, the annular fixing piece 2 and the annular outer cover 8 is 0.02mm-0.3mm, and the materials are as follows: aluminum, copper, iron, nickel, stainless steel, or nickel-plated stainless steel.

Further, the center cover 3 is a flat annular metal, the center of the center cover 3 protrudes at least to one side, and the center cover 3 is made of a single metal or formed by compounding a plurality of layers of different metals; the material of the metal of the center cover 3 can be: aluminum, copper, iron, nickel, stainless steel, or nickel-plated stainless steel.

Preferably, the outer cover 8 is disposed in the central hole, the outer cover 8 and the cover plate 1 are designed integrally, the annular fixing member 2 is a supporting wall 7 disposed around the opening of the second opening 9, the lower end of the supporting wall 7 is vertically disposed on the upper surface of the cover plate 1, the upper end of the supporting wall 7 is closed to the center of the second opening 9, and the interlayer space 6 is disposed between the bending portion of the upper closed end of the supporting wall 7 and the upper surface of the cover plate 1; the supporting wall 7 is composed of a first continuous supporting wall and a second continuous supporting wall, the second height H2 of the second continuous supporting wall being higher than the first height H1 of the first continuous supporting wall; the upper end of the support wall 7 is closed by the insulator 4 against the rim of the central cover 3 to form a seal.

Further, the height difference between the second height H2 and the first height H1 is 0.05-0.5 mm.

Further, the asymmetric means that the edge of at least one of the ring binder 2 and the outer cap 8 is composed of a first continuous edge and a second continuous edge, and a first distance D1 from a point on the first continuous edge to the center of the lid plate 1 is smaller than a second distance D2 from a point on the second continuous edge to the center of the lid plate 1; the difference between the second distance D2 and the first distance D1 is 0.05-0.5 mm.

Further, the insulator 4 is made of a polymer plastic that is not soluble in lithium ion electrolyte, and may be PP, PE, PI, PET, PEEK, or silicone rubber.

Further, electrolyte is injected into a sealed space formed by the sealing assembly and the shell 10; the battery cell 11 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 14 is provided at the winding center of the cell 11.

Further, the sealing assembly and the housing 10 are connected and sealed by laser welding.

The utility model has the advantages that: because the utility model adopts the design of compact double explosion-proof and non-channeling sealing, the utility model comprises a shell 10, an electric core 11 and a sealing component, the upper end of the shell 10 is provided with an opening 12, the sealing component comprises an outer conductive metal body and an inner conductive metal body, the inner conductive metal body is a central cover 3, the outer conductive metal body is provided with a central hole, the central cover 3 is positioned in the central hole, an insulator 4 is arranged between the central cover 3 and the outer conductive metal body, and the shell 10 and/or the outer conductive metal body is provided with a V-shaped explosion-proof trace 15; wherein the outer conductive metal body has a double-layer structure, and the center cover 3 is clamped by the insulator 4. Therefore, when the structure of the present invention is applied to a micro lithium ion battery, when the internal pressure of the battery rises, the bottom of the housing 10 is protruded outward due to the V-shaped explosion-proof mark 15, and the cover plate 1 starts to deform, and since the pressing force is asymmetric, the center cover 3 is tilted first, and the gas is released from the gap formed between the insulator 4 and the center cover 3. This compact structure, explosion-proof effectual can also increase the inside effective space of battery. Meanwhile, when the explosion-proof structure of the cover plate 1 fails, the bottom of the shell 10 is provided with the V-shaped explosion-proof trace 15, so that the shell 10 still has an explosion-proof effect, and the safety performance of the miniature lithium ion battery is further improved through a double explosion-proof design.

Drawings

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

FIG. 2 is a top view of the housing with the V-shaped vent trace in a cross-shape;

FIG. 3 is a top view of the housing with the V-shaped vent trace being L-shaped;

FIG. 4 is a top view of the housing with the V-shaped vent trace being U-shaped;

FIG. 5 is a top view of the housing with the V-shaped vent trace being rectangular;

FIG. 6 is a cross-sectional view of an explosion-proof cover plate assembly of an embodiment;

FIG. 7 is an exploded view of an unheated vent panel assembly according to one embodiment;

FIG. 8 is a top view of the embodiment with an annular outer cover and the cover plate attached;

FIG. 9 is a sectional view of the embodiment after an annular outer cap and the cover plate are coupled;

FIG. 10 is a cross-sectional view of an example two explosion proof cover plate assembly;

FIG. 11 is an exploded view of an unheated vent panel assembly according to the second embodiment;

FIG. 12 is a top plan view of an example second vent panel assembly;

FIG. 13 is a cross-sectional view of an embodiment explosion-proof cover plate assembly;

FIG. 14 is an exploded view of an embodiment explosion proof cover plate assembly;

fig. 15 is a cross-sectional view of a micro lithium ion battery of the present invention.

Fig. 16 is a cross-sectional view of a miniature lithium-ion cell of the present invention.

Detailed Description

In the present embodiment, as shown in fig. 15, the present invention includes a housing 10, a battery cell 11 and a sealing assembly, the upper end of the housing 10 is provided with an opening 12, the sealing assembly comprises an outer conductive metal body and an inner conductive metal body, the inner conductive metal body is a central cover 3, the outer conductive metal body is provided with a central hole, the central cover 3 is positioned in the central hole, an insulator 4 is arranged between the central cover 3 and the outer conductive metal body, which seals the opening 12, while the battery cell 11 is encapsulated in the shell 10, the positive electrode of the battery cell 11 is electrically connected with the central cover 3, the negative pole of the battery cell 11 is electrically connected with the shell 10, the inner sides of the outer conductive metal body, the center cover 3 and the shell 10 are all provided with insulating tapes 13, and a V-shaped explosion-proof mark 15 is arranged on the shell 10 and/or the outer conductive metal body. In this embodiment, the outer conductive metal body includes a cover plate 1, a ring fixture 2 and an outer cover 8, the ring fixture 2 and the outer cover 8 are respectively provided with a first opening 5 and a second opening 9 which are communicated with each other, an interlayer space 6 is provided between the inner side of the ring fixture 2 and the inner side of the outer cover 8, a first radius D4 of the first opening 5 and a second radius D5 of the second opening 9 are both smaller than a cover radius D3 of the center cover 3, the insulator 4 is sleeved on the outer edge of the center cover 3 and is disposed in the interlayer space 6, and the ring fixture 2 and the outer cover 8 clamp the outer edge of the center cover 3 together through the insulator 4; the cover plate 1 seals the opening 12, and the cover plate 1 and the housing 10 are connected and sealed by laser welding.

In the present embodiment, as shown in fig. 1 to 5, in the present embodiment, the depth of the V-shaped explosion proof trace 15 is 50% to 95% of the thickness of the cover plate 1 or the housing 10; the shape of the V-shaped explosion-proof mark 15 is cross-shaped, L-shaped, U-shaped or rectangular.

In the embodiment, the processing method of the V-shaped explosion-proof mark 15 is laser, or molding, or etching, or engraving.

In the present embodiment, as shown in fig. 16, the battery cell 11 is formed by winding a positive plate, a negative plate, and a separator, an outermost ring is covered by an insulating tape 13, a positive tab is formed by bending an aluminum foil connected to the positive plate, and a part of the positive tab is covered by a tab insulating tape; the negative electrode tab is formed by bending a copper foil connected to a negative electrode sheet, and part of the negative electrode tab is covered by a tab insulating adhesive tape; in order to fully utilize the effective space in the shell 10, the widths of the positive plate and the negative plate are variable, and the diaphragm is arranged between the positive plate and the negative plate; a plug 14 is arranged at the winding center of the battery cell 11; electrolyte is injected into the sealing assembly and the sealing space formed by the sealing assembly; after the sealing assembly welded with the positive tab is covered, the sealing assembly is connected and sealed with the housing 10 by a laser welding method. The volume of the inner space of the shell 10 after sealing is less than or equal to 1 cubic centimeter.

The structure of the sealing assembly has the following three groups of embodiments:

example one

In the present embodiment, as shown in fig. 6 to 9, the cover plate 1 is machined from stainless steel and has a through hole in the center, in which there is a section of annular projection perpendicular to the plane, the thickness of which is optimally between 0.05 and 0.3 mm. The outer cover 8 is also machined from stainless steel and has a through hole in the center, the thickness of which is optimally between 0.05 and 0.3 mm. The outer diameter of the outer cap 8 is just the same as the inner diameter of the recess of the cap plate 1, and the outer cap 8 is put in and then welded together, most commonly by laser welding. The welded outer cover 8 and the cover plate 1 are combined into a cover body, wherein the diameter of the hole of the outer cover 8 is smaller than that of the through hole of the cover plate 1. The inner hole edge of the outer cap 8 is formed by a first continuous edge and a second continuous edge, a first distance D1 from a point on the first continuous edge to the center of the cap body is less than a second distance D2 from a point on the second continuous edge to the center of the cap body.

Then, an insulator 4 and a central cover 3 are sequentially placed in the cover body, wherein the insulator 4 is a sealing ring and is made of a high polymer material which is not dissolved in lithium ion liquid, such as PP, PE, PI, PET or silicon rubber, and PP is selected here. The central cover 3 is made of sheet metal and is convex at the center. The material used may be a single metal such as aluminum, or a composite material such as an inner layer, most preferably aluminum, combined with an outer layer, preferably stainless steel, nickel-plated stainless steel, or the like, preferably nickel-plated stainless steel.

And (3) putting the combined parts into a special die, and stamping the annular bulge to form a U-shaped ring. The U-shaped annular outer layer metal compresses the edge of the central cover 3 of the inner layer through an insulator to form sealing. The edge-to-center radius D3 of the central cover 3 is greater than the maximum radius D5 of the outer cover 8 from the inner edge to the center and is also greater than the radius D4 of the U-shaped ring-shaped closing-in back edge to the center. The U-shaped ring is sealed inside the cell after the cell is made.

Example two

As shown in fig. 10 to 12, in the present embodiment, the cover plate 1 is made of stainless steel, and the center is a straight-walled through hole, wherein the height H2 of one side is higher than the other half H1, the height difference is preferably between 0.1 mm and 0.2mm, and the thickness of the material of the cover plate 1 is preferably between 0.05 mm and 0.3 mm. The outer cover 8 is also machined from stainless steel and has a through hole in the center, the thickness of which is optimally between 0.05 and 0.3 mm. The outer lid 8 is welded to the lid 1, most commonly by laser welding. The welded outer cover 8 and the cover plate 1 are combined into a cover body, wherein the diameter of the hole of the outer cover 8 is smaller than that of the through hole of the cover plate 1.

Then, an insulator 4 and a central cover 3 are sequentially placed in the cover body, wherein the insulator 4 is made of a high polymer material which is not dissolved in lithium ion liquid, such as PP, PE, PI, PET or silicon rubber, and PP is selected. The central cover 3 is made of sheet metal and is convex at the center. The material used may be a single metal such as aluminum, or a composite material such as an inner layer, most preferably aluminum, combined with an outer layer, preferably stainless steel, nickel-plated stainless steel, or the like, preferably nickel-plated stainless steel.

And (3) putting the combined parts into a special die, and stamping the annular bulge to form a U-shaped ring. The bent back edge of the cover plate 1 is composed of a first continuous edge and a second continuous edge, and a first distance D1 from a point on the first continuous edge to the center of the cover body is smaller than a second distance D2 from a point on the second continuous edge to the center of the cover body.

The U-shaped annular outer layer metal compresses the edge of the central cover 3 of the inner layer through the rubber ring to form sealing. The edge-to-center radius D3 of the central cover 3 is greater than the maximum radius D5 of the outer cover 8 from the inner edge to the center and is also greater than the radius D4 of the U-shaped ring-shaped closing-in back edge to the center. After the battery is manufactured, the U-shaped ring is arranged outside the battery.

EXAMPLE III

In the present embodiment, as shown in fig. 13, 14 and 8, the cover plate 1 is made of stainless steel and has a through hole in the center, wherein there is a section of annular protrusion perpendicular to the plane, and the thickness is preferably between 0.05-0.3 mm. The outer cover 8 is also machined from stainless steel and has a through hole in the center, the thickness of which is optimally between 0.05 and 0.3 mm. The outer diameter of the outer cap 8 is just the same as the inner diameter of the recess of the cap plate 1, and the outer cap 8 is put in and then welded together, most commonly by laser welding. The welded outer cover 8 and the cover plate 1 are combined into a cover body, wherein the diameter of the hole of the outer cover 8 is smaller than that of the through hole of the cover plate 1. The inner hole edge of the outer cap 8 is formed by a first continuous edge and a second continuous edge, a first distance D1 from a point on the first continuous edge to the center of the cap body is less than a second distance D2 from a point on the second continuous edge to the center of the cap body.

Then, an insulator 4 and a central cover 3 are sequentially placed in the cover body, wherein the insulator 4 is made of a high polymer material which is not dissolved in lithium ion liquid, such as PP, PE, PI, PET or silicon rubber, and PP is selected. The central cover 3 is made of preformed metal, and two bulges are arranged on two sides of a piece of round metal. The material used may be a single metal such as aluminum, or a composite material such as an inner layer, most preferably aluminum, combined with an outer layer, preferably stainless steel, nickel-plated stainless steel, or the like, preferably nickel-plated stainless steel.

And (3) putting the combined parts into a special die, and stamping the annular bulge to form a U-shaped ring. The U-shaped annular outer layer metal compresses the edge of the central cover 3 of the inner layer through the rubber ring to form sealing. The edge-to-center radius D3 of the central cover 3 is greater than the maximum radius D5 of the outer cover 8 from the inner edge to the center and is also greater than the radius D4 of the U-shaped ring-shaped closing-in back edge to the center. The U-shaped ring is sealed inside the cell after the cell is made.

The structure in the above embodiment was tested: when the internal pressure of the miniature lithium ion battery is higher than 3MPA, the shell protrudes outwards, the central cover begins to deform, then the rubber ring moves, gas is released from a gap formed between the rubber ring and the central cover, and the rubber ring and the central cover are not separated from the cover body.

While the embodiments of the present invention have been described in terms of practical embodiments, they are not intended to limit the scope of the 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 with explosion proof trace, includes shell (10), electric core (11) and seal assembly, the upper end of shell (10) is equipped with opening (12), its characterized in that: the sealing component comprises an outer conductive metal body and an inner conductive metal body, the inner conductive metal body is a central cover (3), the outer conductive metal body is provided with a central hole, the central cover (3) is positioned in the central hole, an insulator (4) is arranged between the central cover (3) and the outer conductive metal body, the outer conductive metal body seals the opening (12), meanwhile, the battery cell (11) is encapsulated in the shell (10), the positive electrode of the battery cell (11) is electrically connected with the central cover (3), the negative electrode of the battery cell (11) is electrically connected with the shell (10), the inner side of the outer conductive metal body, the inner side of the central cover (3) and the inner side of the shell (10) are all provided with insulating adhesive tapes (13), and a V-shaped explosion-proof mark (15) is arranged on the shell (10) and/or the outer conductive metal body.

2. The lithium ion micro battery with explosion vent according to claim 1, wherein: the outer conductive metal body comprises a cover plate (1), an annular fixing piece (2) and an outer cover (8), the annular fixing piece (2) and the outer cover (8) are respectively provided with a first open hole (5) and a second open hole (9) which are communicated with each other, an interlayer space (6) is arranged between the inner side of the annular fixing piece (2) and the inner side of the outer cover (8), the first radius (D4) of the first open hole (5) and the second radius (D5) of the second open hole (9) are both smaller than the cover radius (D3) of the center cover (3), the insulator (4) is sleeved on the outer edge of the center cover (3) and arranged in the interlayer space (6), and the annular fixing piece (2) and the outer cover (8) clamp the outer edge of the center cover (3) together through the insulator (4); the cover plate (1) seals the opening (12), and the cover plate (1) and the shell (10) are connected and sealed through laser welding.

3. The lithium ion micro battery with explosion vents as claimed in claim 2, wherein: the depth of the V-shaped explosion-proof mark (15) is 50% -95% of the thickness of the cover plate (1) or the shell (10); the V-shaped anti-explosion mark (15) is in a cross shape, an L shape, a U shape or a rectangle shape.

4. The lithium ion micro-battery with explosion vent according to any one of claims 1 to 3, wherein: the processing method of the V-shaped anti-explosion mark (15) is laser, mould pressing, etching or engraving.

5. The lithium ion micro battery with explosion vents as claimed in claim 2, wherein: the first radius (D4) and/or the second radius (D5) are asymmetrical over the entire circumference, the intermediate space (6) also being asymmetrical with respect to the width of the clamping portion of the central cover (3); the width of one surface of the interlayer space (6) facing the clamping portion of the central cover (3) is the difference between the first radius (D4) and the second radius (D5), and the width of the other surface of the interlayer space (6) facing the clamping portion of the central cover (3) is the difference between the second radius (D5) and the cover radius (D3).

6. The lithium ion micro battery with explosion vents as claimed in claim 2, wherein: at least one of the connection among the cover plate (1), the annular fixing piece (2) and the outer cover (8) adopts welding, and the welding is laser welding or resistance welding; the thickness of the cover plate (1), the annular fixing piece (2) and the outer cover (8) is 0.02mm-0.3mm, and the material of the cover plate (1), the annular fixing piece (2) and the outer cover (8) is one of the following materials: aluminum, copper, iron, nickel, stainless steel, nickel-plated stainless steel.

7. The lithium ion micro battery with explosion vents as claimed in claim 2, wherein: the center cover (3) is made of flat annular metal, the center of the center cover (3) protrudes at least to one side, and the center cover (3) is made of single metal or formed by compounding a plurality of layers of different metals; the material of the metal of the center cover (3) can be one of the following materials: aluminum, copper, iron, nickel, stainless steel, or nickel-plated stainless steel.

8. The lithium ion micro battery with explosion vents as claimed in claim 2, wherein: the outer cover (8) is arranged in the central hole, the outer cover (8) and the cover plate (1) are designed into a whole, the annular fixing piece (2) is a supporting wall (7) arranged at the opening of the second open hole (9) in a surrounding mode, the lower end of the supporting wall (7) is vertically arranged on the upper surface of the cover plate (1), the upper end of the supporting wall (7) is closed to the center of the second open hole (9), and the interlayer space (6) is formed between the bent part of the closed upper end of the supporting wall (7) and the upper surface of the cover plate (1); the supporting wall (7) is composed of a first continuous supporting wall and a second continuous supporting wall, the second height (H2) of the second continuous supporting wall being higher than the first height (H1) of the first continuous supporting wall; the closing part of the upper end of the supporting wall (7) presses the edge of the center cover (3) through the insulator (4) to form a seal; the difference in height between the second height (H2) and the first height (H1) is 0.05-0.5 mm.

9. The lithium ion micro battery with the explosion vent as claimed in claim 5, wherein: the asymmetric mean that the edge of at least one of the annular fixing piece (2) and the outer cover (8) is composed of a first continuous edge and a second continuous edge, and a first distance (D1) from a point on the first continuous edge to the center of the cover plate (1) is smaller than a second distance (D2) from a point on the second continuous edge to the center of the cover plate (1); the difference between the second distance (D2) and the first distance (D1) is 0.05-0.5 mm.

10. The lithium ion micro battery with explosion vent according to claim 1, wherein: the insulator (4) is made of high polymer plastic which can not be dissolved in lithium ion liquid and can be PP, PE, PI, PET, PEEK or silicon rubber; electrolyte is also injected into a sealed space formed by the sealing assembly and the shell (10); the battery cell (11) is formed by winding a positive plate, a negative plate and a diaphragm, an insulating adhesive tape (13) is arranged outside the battery cell (11), and the diaphragm is arranged between the positive plate and the negative plate; a plug (14) is arranged in the winding center of the battery cell (11).