CN114512745A - An explosion-proof rechargeable battery and its casing - Google Patents

Abstract

The invention discloses an explosion-proof rechargeable battery and a shell thereof, wherein the shell of the explosion-proof rechargeable battery comprises a bottom shell and an upper cover component, the edges of the bottom shell and the upper cover component are welded to form a sealed accommodating cavity, and the explosion-proof rechargeable battery is characterized in that: the explosion-proof device is arranged on the inner bottom surface of the shell and/or the inner top surface of the upper cover assembly and comprises a metal elastic sheet with conductive performance. The explosion-proof rechargeable battery and the shell have the advantages of high reliability, high safety, low cost and wide application range.

Description

An explosion-proof rechargeable battery and its casing

technical field

The invention relates to the technical field of rechargeable batteries, in particular to a rechargeable battery and a battery casing capable of explosion-proof and anti-heating.

Background technique

Current rechargeable batteries, when overcharged or overdischarged, generate gas inside, and the battery will heat up. When the internal air pressure reaches a certain value, the battery shell will burst open, and the internal substances will be ejected, affecting the safe use of the battery.

In Chinese patent CN109309264A, an explosion-proof rechargeable battery is disclosed, and the following content is specifically disclosed: "An explosion-proof rechargeable battery includes positive and negative electrodes, memory metal, storage medium, and casing. It is well known that memory metal is an alloy. It can be used in It is randomly made into a shape at a lower temperature, and then it can be changed back to the original shape after heating, and has memory, so it is called "memory metal". The memory metal in the explosion-proof rechargeable battery of the present invention is in the shape of a long strip. , one end is fixed on the positive or negative electrode of the battery, the other end is not fixed free, the temperature of the storage medium can be directly transmitted to the memory metal strip through the electrode. The memory metal strip is processed at a temperature lower than the critical point temperature of the storage medium deformation and ignition In a straight state, the memory metal strip is bent at normal temperature, and the degree of bending is controlled so that when the explosion-proof rechargeable battery is working or charging, the curved and protruding part of the memory metal strip can normally contact the corresponding electrode of the electrical appliance or charging device; this technical solution is adopted. After that, when the explosion-proof rechargeable battery is charging and working, once overloaded, the internal storage medium heats up to the critical point temperature of deformation and combustion, the high temperature is transmitted to the memory metal strip through the electrode, and the curved part of the memory metal strip immediately returns to a straight shape. The straight memory metal strip is separated from the contact with the corresponding electrode of the electrical appliance or charging device, and is disconnected from the corresponding electrode in contact. After the circuit breaker, the explosion-proof rechargeable battery stops charging and discharging with the electrical appliance or charging device, and the temperature of the storage medium begins to drop. When After the temperature dropped to normal temperature, the memory metal strip returned to its curved shape."

The above-mentioned patent can make the memory metal detach from the charging device in a high temperature state through the characteristics of the "memory metal" that changes shape with temperature change, thereby breaking the circuit. Avoid battery explosion caused by overheating.

However, the above patent still exists: the structure is unreliable, and it is easy to lose power when charging occurs at normal temperature. The memory metal is on the outside and has extremely low reliability. And the problem of battery explosion caused by changes in the internal pressure of the battery cannot be solved.

SUMMARY OF THE INVENTION

In view of this, the first objective of the present invention is to provide an explosion-proof rechargeable battery with high reliability and a casing thereof.

The purpose of the present invention is achieved through the following technical solutions: an explosion-proof rechargeable battery case, comprising a bottom case and an upper cover assembly, the bottom case and the edge of the upper cover assembly are welded to form a sealed accommodating cavity, which It is characterized in that: the inner bottom surface of the casing and/or the inner top surface of the upper cover assembly is provided with an explosion-proof device, and the explosion-proof device includes a metal shrapnel with electrical conductivity

Preferably, the upper cover assembly includes an annular metal outer ring, an annular insulating inner ring and a metal cap, the middle of the metal cap has a cap head protruding upward, and the edge of the metal outer ring is connected to the bottom shell Welding and sealing, the metal cap is located inside the metal outer ring and the cap head protrudes upward from the middle hole of the metal outer ring, the insulating inner ring is located between the metal outer ring and the metal cap, The lower part of the cap head is sealed and connected with a downwardly convex pressure elastic piece, the pressure elastic piece is raised above a set pressure value, and a ventilation hole is arranged on the cap head.

Preferably, the pressure elastic sheet is welded with the metal cap.

Preferably, the upper cover assembly includes an annular metal outer ring, an annular insulating inner ring and a metal cap, the middle of the metal cap has a cap head protruding upward, and the edge of the metal outer ring is connected to the bottom shell Welding and sealing, the metal cap is located inside the metal outer ring and the cap head protrudes upward from the middle hole of the metal outer ring, the insulating inner ring is located between the metal outer ring and the metal cap, The lower part of the cap head is provided with an elastic sheet assembly, and the elastic sheet assembly includes an upper convex temperature elastic sheet and a lower convex pressure elastic sheet welded together, and the elastic sheet assembly is insulated and sealed with the edge of the head head of the metal cap, so The cap head is provided with a ventilation hole; the top of the temperature elastic sheet is in contact with the inner top surface of the cap head; the temperature elastic sheet will protrude down away from the inner top surface of the cap head when the temperature exceeds the set temperature value, and the pressure The shrapnel will bulge if it exceeds the set pressure value

Preferably, the metal shrapnel is made of pure metal or a non-metal inner container with a metal outer skin.

The second object of the present invention is to provide an explosion-proof rechargeable battery with high reliability.

An explosion-proof rechargeable battery includes the above-mentioned casing, and also includes a battery winding core, the battery winding core is located in a sealed accommodating cavity formed by the bottom case and the upper cover assembly, and the bottom of the battery winding core is A negative electrode lug is provided, the negative electrode lug is welded with the bottom surface of the bottom case, a positive electrode lug is provided on the top of the battery core, and the positive electrode lug is in contact with the downwardly convex pressure elastic sheet.

Beneficial effects:

1) The explosion-proof device of the present invention forms a part of the battery casing, which saves the size and space of the battery.

2) The shrapnel of the present invention can be made of metal materials or non-metallic materials inlaid with metal, and the cost is low.

3) The explosion-proof device of the present invention is inside the battery core and cannot be disassembled, making the battery safer and more reliable.

4) The explosion-proof casing of the present invention can be applied to all rechargeable batteries, including square, round, button, special-shaped and so on.

Description of drawings

The accompanying drawings of the present invention are described below.

1 is a front view of an explosion-proof rechargeable battery in Example 1;

Fig. 2 is the A-A sectional view of Fig. 1;

Figure 3 is a isometric view of the battery winding core 1;

Figure 4 is a second axonometric view of the battery winding core;

5 is an exploded view 1 of the explosion-proof rechargeable battery in the normal working state in Example 1;

6 is an exploded diagram 2 of the explosion-proof rechargeable battery in the normal working state in Example 1;

FIG. 7 is an exploded view of the explosion-proof rechargeable battery in the explosion-proof state in Example 1. FIG.

Detailed ways

The following describes in detail the embodiments of the present application, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals refer to the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, but should not be construed as a limitation on the present application. On the contrary, the embodiments of the present application include all changes, modifications and equivalents falling within the spirit and scope of the appended claims.

Embodiment 1: As shown in Figures 1-7, this embodiment provides a casing of an explosion-proof rechargeable battery, including a bottom casing 1 and an upper cover assembly 2, the bottom casing is open at the top, and the casing is made of metal conductive material , the cross section of the bottom shell can be circular, polygonal, special-shaped, etc. The edge of the upper cover assembly is connected with the edge of the top opening of the bottom case by welding, and the bottom case and the inside of the upper cover assembly form a closed and sealed accommodating cavity for installing the battery core.

In this embodiment, the upper cover assembly includes an annular metal outer ring 21 , an annular insulating inner ring 22 and a metal cap 23 . The shape of the outer edge of the metal outer ring is consistent with the cross-sectional shape of the bottom case, and the outer edge of the metal outer ring is welded with the edge of the top opening of the bottom case. The middle part of the metal outer ring has a hole. The middle part of the metal cap has a cap head 231 protruding upward, and an annular metal disk 232 is around the cap head. The metal cap is located inside the metal outer ring, and the cap head of the metal cap protrudes outward from the hole in the middle of the metal outer ring. The insulating inner ring is arranged between the metal outer ring and the metal cap, and a via hole for the cap head is arranged in the middle of the insulating inner ring. The top surface of the insulating inner ring is bonded to the bottom surface of the metal outer ring, and the bottom surface of the insulating inner ring is bonded to the top surface of the metal plate of the metal cap, that is, the connection between the metal outer ring and the metal cap is realized. And avoid the mutual conduction between the two.

In this embodiment, the lower part of the cap head of the metal cap, that is, the bottom surface of the metal plate, is sealed and connected with a downwardly protruding pressure elastic piece 3, and the pressure elastic piece will protrude when the pressure exceeds the set pressure value. A vent hole 234 is provided on the cap head. In this embodiment, the edge of the pressure elastic piece is set to be circular, and its edge is completely welded with the metal disk. The pressure elastic piece is selected from a metal material with electrical conductivity, or a non-metallic material with a conductive metal material on the outside. .

This embodiment also provides an explosion-proof rechargeable battery with high reliability.

An explosion-proof rechargeable battery includes the casing described in this embodiment, and also includes a battery winding core 4 , and the battery winding core is located in a sealed accommodating cavity formed by the bottom case and the upper cover assembly. A negative electrode lug 41 is disposed at the bottom of the battery core, and the negative electrode lug is welded to the bottom surface of the bottom case. The top of the battery core is provided with a positive electrode lug 42, the upper and lower sides of the positive electrode lug are provided with an insulating film 43, the middle part of the insulating film is opened, and the positive contact end of the positive electrode lug is formed by the opening. exposed at the place and in contact with the downwardly convex pressure elastic sheet. As another implementation manner in this embodiment, the middle bottom of the pressure elastic sheet is provided with a convex point, which is convenient for contact with the positive electrode ear.

In this embodiment, when the pressure in the accommodating cavity does not reach the set value, the pressure elastic sheet is in a normal state of downward protrusion, the pressure elastic sheet is in contact with the positive electrode tab, and the head of the metal cap is The positive terminal and the bottom case are the negative terminal, and the rechargeable battery can be charged by connecting the positive and negative terminals. During the charging or discharging process, if the pressure in the accommodating cavity exceeds the set value, the pressure elastic piece will deform, that is, the pressure elastic piece will change from a downward convex state to an upward convex state, and the pressure elastic piece will be connected with the battery. The positive tab of the winding core is disconnected to disconnect the outside world from the internal polarity of the battery, preventing charging or discharging. To achieve the purpose of explosion-proof.

In this embodiment, the pressure setting value is 0.2 MPa. Of course, the value can be different according to the specific situation, and different types, specifications, or materials of shrapnel can be selected to achieve different pressure setting values.

1) The explosion-proof device of this embodiment forms a part of the battery casing, which saves the size and space of the battery. 2) The shrapnel of this embodiment can be made of metal materials or non-metallic materials inlaid with metal, and the cost is low. 3) The explosion-proof device of this embodiment is inside the battery core and cannot be disassembled, which makes the battery safer and more reliable. 4) The explosion-proof casing of this embodiment can be applied to all rechargeable batteries, including square, round, button, special-shaped and so on.

Embodiment 2: This embodiment provides a casing of an explosion-proof rechargeable battery, including a bottom casing 1 and an upper cover assembly 2, the bottom casing is open at the top, the casing is made of a metal conductive material, and the cross-section of the bottom casing can be For circles, polygons, special-shaped and so on. The edge of the upper cover assembly is connected with the edge of the top opening of the bottom case by welding, and the bottom case and the inside of the upper cover assembly form a closed and sealed accommodating cavity for installing the battery core.

In this embodiment, the upper cover assembly includes an annular metal outer ring 21 , an annular insulating inner ring 22 and a metal cap 23 . The shape of the outer edge of the metal outer ring is consistent with the cross-sectional shape of the bottom case, and the outer edge of the metal outer ring is welded with the edge of the top opening of the bottom case. The middle part of the metal outer ring has a hole. The middle part of the metal cap has a cap head 231 protruding upward, and an annular metal disk 232 is around the cap head. The metal cap is located inside the metal outer ring, and the cap head of the metal cap protrudes outward from the hole in the middle of the metal outer ring. The insulating inner ring 22 is arranged between the metal outer ring and the metal cap, and a via hole for the cap head is arranged in the middle of the insulating inner ring. The top surface of the insulating inner ring is bonded to the bottom surface of the metal outer ring, and the bottom surface of the insulating inner ring is bonded to the top surface of the metal plate of the metal cap, that is, the connection between the metal outer ring and the metal cap is realized. And avoid the mutual conduction between the two.

In this embodiment, the lower part of the cap head of the metal cap, that is, the bottom surface of the metal plate, is connected with an elastic sheet component. The shrapnel component is selected from a metal material with electrical conductivity. The elastic sheet assembly includes an upper convex temperature elastic sheet and a lower convex pressure elastic sheet welded together. The elastic sheet assembly is insulated and sealed with the inner end face of the metal plate of the metal cap, and a vent hole 234 is provided on the cap head. , the top of the temperature elastic sheet protrudes into the inner cavity of the cap head and contacts with the inner top surface of the cap head; the temperature elastic sheet will protrude downwards away from the inner top surface of the cap head when the temperature exceeds the set temperature value, and the The pressure shrapnel will bulge if it exceeds the set pressure value. It also includes an annular insulating sheet, which is respectively bonded to the inner end surface of the metal plate of the metal cap and the upper top surface of the elastic sheet assembly.

This embodiment also provides an explosion-proof rechargeable battery with high reliability.

An explosion-proof rechargeable battery includes the casing described in this embodiment, and also includes a battery winding core 4 , and the battery winding core is located in a sealed accommodating cavity formed by the bottom case and the upper cover assembly. The bottom of the battery core is provided with a negative electrode lug 41, and the negative electrode lug is welded with the bottom surface of the bottom case to realize the conduction of the negative electrode of the bottom case. The top of the battery core is provided with a positive electrode lug 42, the upper and lower sides of the positive electrode lug are provided with an insulating film 43, the middle part of the insulating film is opened, and the positive contact end of the positive electrode lug is formed by the opening. The temperature elastic sheet is exposed at the bottom and is in contact with the downwardly convex pressure elastic sheet, and the temperature elastic sheet is in contact with the inner top surface of the cap head of the metal cap, thereby realizing the positive conduction of the cap. As another implementation manner in this embodiment, the middle bottom of the pressure elastic sheet is provided with a convex point, which is convenient for contact with the positive electrode ear.

In this embodiment, when the pressure in the accommodating cavity does not reach the set value, the pressure elastic sheet is in a normal state of downward protrusion, and the pressure elastic sheet is in contact with the positive electrode tab; and the temperature of the temperature elastic sheet does not exceed the set value. When the value is fixed, the temperature elastic sheet is in a normal state of upward convexity, and the temperature elastic sheet is in contact with the cap head. At this time, the positive terminal of the cap head of the metal cap is connected to the positive terminal, and the bottom case is the negative terminal, and the connection of the positive and negative electrodes can realize the charging of the rechargeable battery.

During the charging or discharging process, if the pressure in the accommodating cavity exceeds the set value, the pressure elastic piece will deform, that is, the pressure elastic piece will change from a downward convex state to an upward convex state, and the pressure elastic piece will be connected with the battery. The positive tab of the winding core is disconnected, the cap head no longer conducts the positive electrode, disconnects the connection between the outside world and the internal polarity of the battery, prevents charging or discharging, and achieves the purpose of explosion-proof. During the charging or discharging process, if the temperature in the accommodating chamber is too high, causing the temperature of the temperature shrapnel to exceed the set value, the temperature shrapnel will change from a normal upward convex state to a downward convex state. The inner top surface of the cap head is disconnected, the cap head no longer conducts the positive electrode, disconnects the polar connection between the outside world and the inside of the battery, prevents charging or discharging, and can also achieve the purpose of explosion-proof.

In this embodiment, the pressure setting value is 0.2 MPa. Of course, the value can be different according to the specific situation, and different types, specifications, or materials of shrapnel can be selected to achieve different pressure setting values. The temperature setting value may be 80-100° C., and the temperature elastic sheet may be made of memory metal materials on the market. It can also be made by superimposing two metal materials with different temperature coefficients. This is the prior art and will not be repeated here.

Using the explosion-proof rechargeable battery and the casing in this embodiment, 1) the explosion-proof device in this embodiment forms a part of the battery casing, which saves the size and space of the battery. 2) The shrapnel of this embodiment can be made of metal material or non-metallic material inlaid with metal, and the cost is low. 3) The explosion-proof device of this embodiment is inside the battery core and cannot be disassembled, which makes the battery safer and more reliable. 4) The explosion-proof casing of this embodiment can be applied to all rechargeable batteries, including square, round, button, special and so on.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should Various changes can be made without departing from the scope of the invention as defined by the claims.

Claims (8)

1. A casing of an explosion-proof rechargeable battery, comprising a bottom casing and an upper cover assembly, the bottom casing and the edge of the upper cover assembly are welded to form a sealed accommodating cavity, characterized in that: the inner bottom surface of the casing and/or An explosion-proof device is provided on the inner top surface of the upper cover assembly, and the explosion-proof device includes a metal dome with electrical conductivity. 2 . The explosion-proof rechargeable battery case according to claim 1 , wherein the upper cover assembly comprises an annular metal outer ring, an annular insulating inner ring and a metal cap, and a middle portion of the metal cap has an upward protrusion. 3 . The cap head, the edge of the metal outer ring is welded and sealed with the bottom shell, the metal cap is located inside the metal outer ring, and the cap head protrudes upward from the middle hole of the metal outer ring, so The insulating inner ring is located between the metal outer ring and the metal cap, the lower part of the cap head is sealed and connected with a downwardly convex pressure elastic piece, the pressure elastic piece will bulge when the pressure value exceeds the set value, and the cap head is Provided with ventilation holes. 3 . The casing of the explosion-proof rechargeable battery according to claim 1 , wherein the pressure elastic sheet is welded with the metal cap. 4 . 4 . The casing of the explosion-proof rechargeable battery according to claim 1 , wherein the upper cover assembly comprises an annular metal outer ring, an annular insulating inner ring and a metal cap, and the middle part of the metal cap has an upwardly convex shape. 5 . The edge of the metal outer ring is welded and sealed with the bottom shell, the metal cap is located in the metal outer ring, and the cap head protrudes upward from the middle hole of the metal outer ring, The insulating inner ring is located between the metal outer ring and the metal cap, and the lower part of the cap head is provided with an elastic sheet assembly, and the elastic sheet assembly includes an upwardly convex temperature elastic sheet and a downwardly convex pressure elastic sheet welded together. The elastic sheet assembly is connected in an insulating and sealing manner with the edge of the cap head of the metal cap, and the cap head is provided with a ventilation hole; the top of the temperature elastic sheet is in contact with the inner top surface of the cap head; the temperature elastic sheet exceeds the set temperature The value will bulge downward away from the inner top surface of the cap head, and the pressure spring will bulge when the pressure value exceeds the set value. 5 . The explosion-proof rechargeable battery case according to claim 4 , characterized in that it comprises an annular insulating sheet, and the insulating sheet is respectively bonded to the inner bottom surface of the metal cap and the upper top surface of the elastic sheet assembly. 6 . 6. The explosion-proof rechargeable battery case according to claim 1, 2, 3, 4 or 5, characterized in that: the metal shrapnel is made of pure metal or a non-metal inner tank with a metal outer skin. 7. An explosion-proof rechargeable battery comprising the casing of any preceding claim. 8 . The explosion-proof rechargeable battery according to claim 5 , characterized in that it comprises a battery roll core, the battery roll core is located in a sealed accommodation cavity formed by the bottom case and the upper cover assembly, and the battery roll The bottom of the core is provided with a negative electrode lug, the negative electrode lug is welded with the bottom surface of the bottom case, and the top of the battery core is provided with a positive electrode lug, and the positive electrode lug is in contact with the downwardly protruding pressure elastic piece.

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