A top cover assembly of a secondary battery

Abstract

The present invention discloses a top cover assembly of a secondary battery, which relates to the field of secondary batteries. Aiming at the problems that the existing top cover structure is relatively complex, the sealing performance of the top cover assembly is weak and it is easy to be separated from the pole post. At the same time, the base body is located inside the housing, affecting the space utilization rate inside the housing and further affecting the energy density of the power battery, the following scheme is now proposed. It includes a top cover plate, and symmetrically distributed terminal lead-out holes are formed on the surface of the top cover plate, and the terminal lead-out holes penetrate through the top cover plate. A first explosion-proof ventilation hole is formed on the surface of the top cover plate, and the first explosion-proof ventilation hole is arranged in the middle of the two terminal lead-out holes. An annular groove is arranged on the outer surface of the top cover plate. The structure of the present invention is novel, and the device can not only prevent the pole post from being separated from the top cover plate and improve the sealing performance of the device; at the same time, it improves the use safety of the battery and is beneficial to improving the energy density inside the battery.

Description

Technical Field

[0001] The present invention relates to the field of secondary batteries, and particularly to a top cover assembly of a secondary battery. Background Art

[0002] New energy vehicles are widely promoted in China and even the world. However, there are still many areas that need improvement to completely replace fuel vehicles. For example, the driving range of vehicles is short, the cost of battery packs is high, and the reliability of battery packs and other issues need to be further solved. Based on the above problems, higher requirements are put forward for the power battery, the core component of electric vehicles. For example, the power battery needs to achieve higher energy density, lower cost, etc.

[0003] Currently, the power battery generally adopts a square hard shell structure. The power battery housing includes a housing and a top cover assembly. The power battery housing provides a sealed space to accommodate the electrode assembly and the electrolyte. The electrical energy of the electrode assembly is led out of the sealed space through the pole column of the top cover assembly. In the existing top cover assembly, the top cover plate is a metal plate and is provided with through holes. The pole column is divided into a base portion and an extension portion, and the cross-sectional area of the base portion is larger than the aperture of the through hole. During assembly, the base portion is located below the top cover plate (i.e., inside the housing). After the extension portion passes through the through hole, the extension portion is fixed by using a snap ring or a riveting method. In this way, the pole column is fixed to the top cover plate. Since the base portion is located inside the housing, the space utilization rate inside the housing will be reduced, thereby reducing the energy density of the power battery.

[0004] Due to the complex structure of the pole column itself and the assembly process, it will not only affect the assembly efficiency of the secondary battery, but also often cause the pole column to be disconnected from the top cover plate due to insufficient fixing force; at the same time, the sealing performance of the top cover assembly is reduced, and further the use reliability of the secondary battery is reduced. Therefore, in order to solve such problems, we propose a top cover assembly of a secondary battery. Summary of the Invention

[0005] A top cover assembly of a secondary battery proposed by the present invention solves the problems that the existing top cover structure is relatively complex, the sealing performance of the top cover assembly is weak and it is easy to be disconnected from the pole column, and at the same time, the base is located inside the housing, affecting the space utilization rate inside the housing, and further affecting the energy density of the power battery.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A top cover assembly for a secondary battery, comprising a top cover plate. Symmetrically distributed terminal lead-out holes are formed on the surface of the top cover plate, and the terminal lead-out holes penetrate through the top cover plate. A first explosion-proof ventilation hole is formed on the surface of the top cover plate, and the first explosion-proof ventilation hole is arranged in the middle of the two terminal lead-out holes. An annular groove is arranged on the outer surface of the top cover plate. A first fixing member and a second fixing member are respectively fixedly installed in the two terminal lead-out holes, and a third fixing member is fixedly installed inside the first explosion-proof ventilation hole. A lower insulating bracket is arranged on the inner surface of the top cover plate. Two symmetrically distributed terminal through-holes are formed on the surface of the lower insulating bracket close to the top cover plate, and the terminal through-holes correspond to the terminal lead-out holes respectively. The inner wall of the terminal through-hole is provided with uniformly distributed special-shaped grooves. A second explosion-proof ventilation hole is formed in the middle position of the lower insulating bracket. An explosion-proof valve is arranged inside the second explosion-proof ventilation hole, and a blasting area is arranged inside the explosion-proof valve. An annular notch is formed at the connection between the blasting area and the explosion-proof valve. A first sunk groove is formed on the surface of the explosion-proof valve. The explosion-proof valve is fixedly connected with the third fixing member. Electrode terminals are arranged inside the terminal through-holes respectively, and the electrode terminals are respectively matched with the first fixing member and the second fixing member. A welding part is arranged on the lower surface of the electrode terminal, and a metal part is welded at the welding part of the electrode terminal. A protective cover is arranged inside the second explosion-proof ventilation hole. Uniformly distributed square bosses are arranged on the upper surface of the protective cover. The square bosses are arranged close to the outer side of the protective cover. Uniformly distributed protective through-holes are formed on the surface of the protective cover, and the protective through-holes penetrate through the protective cover.

[0008] Preferably, uniformly distributed circular through-holes are formed on the surface of the explosion-proof valve and the inner wall of the annular groove.

[0009] Preferably, a protective film is fixedly installed on one side of the third fixing member away from the lower insulating bracket.

[0010] Preferably, uniformly distributed special-shaped flanges are arranged on the surface of the lower insulating bracket close to the top cover plate, and the special-shaped flanges are respectively arranged around the terminal through-holes. A matching groove corresponding to the special-shaped flange is arranged on the inner surface of the top cover plate.

[0011] Preferably, symmetrically distributed notches are formed on the surface of the lower insulating bracket, and the notches are respectively arranged on both sides of the second explosion-proof ventilation hole.

[0012] Preferably, uniformly distributed elastic buckles are fixedly connected to one side of the protective cover close to the top cover plate, and the elastic buckles respectively correspond to the positions of the notches and are respectively matched with the notches.

[0013] Preferably, liquid injection holes corresponding to each other are formed on the surfaces of the top cover plate and the lower insulating bracket.

[0014] Preferably, positioning holes are provided on the surfaces of the electrode terminals, and the positioning holes penetrate through the electrode terminals.

[0015] The beneficial effects of the present invention are as follows:

[0016] 1. The metal part is made of copper, which is convenient for ultrasonic welding to connect the electrode terminals more firmly. Using ultrasonic welding can make the connection between the metal part and the electrode terminals more stable and improve the sealing effect; at the same time, the first fixing part, the second fixing part and the third fixing part are integrally formed with the top cover plate by injection molding, which can prevent the pole column from detaching from the top cover plate; by pouring colloid inside the circular perforation, the sealing of the installation part of the explosion-proof valve can be realized, and the sealing performance of the device can be improved.

[0017] 2. An annular indentation is provided in the bursting area of the explosion-proof valve; due to the annular indentation, the existence of the annular indentation can enable the rapid release of the air pressure inside the battery. When the pressure inside the battery is too high, it is very easy for the main body to burst from the annular indentation, thereby improving the safety of battery use; the entire device is installed on the top cover plate, and the internal occupied space is small, which is beneficial to improving the energy density inside the battery.

[0018] In summary, the device can not only make the connection between the metal part and the electrode terminals more stable, prevent the pole column from detaching from the top cover plate, and improve the sealing performance of the device; at the same time, it improves the safety of battery use, and the internal occupied space is small, which is beneficial to improving the energy density inside the battery, and has strong practicability. Brief Description of the Drawings

[0019] Figure 1 It is an exploded view of the present invention.

[0020] Figure 2 It is a sectional view after assembly of the second negative pole column terminal and the top cover plate of the present invention.

[0021] Figure 3 It is a sectional view after assembly of the explosion-proof valve and the third fixing part and the top cover plate of the present invention.

[0022] Figure 4 It is a reverse view of the top cover plate of the present invention.

[0023] Figure 5 It is a schematic view before welding the electrode terminal and the metal part of the present invention.

[0024] Figure 6 It is an assembly schematic view of the electrode terminal and the lower insulating bracket of the present invention.

[0025] Figure 7 It is a reverse view of the lower insulating bracket of the present invention.

[0026] Figure 8 This is a schematic diagram for the installation of the top cover plate, lower insulating bracket, and electrode terminal of the present invention.

[0027] Reference numerals in the figure: 1. First fixing member; 2. Second fixing member; 3. Top cover plate; 4. Terminal lead-out hole; 5. First explosion-proof ventilation hole; 6. Annular groove; 7. Circular perforation; 8. Third fixing member; 9. Protective film; 10. Lower insulating bracket; 11. Terminal through-hole; 12. Special-shaped groove; 13. Special-shaped flange; 14. Second explosion-proof ventilation hole; 15. Notch; 16. Explosion-proof valve; 17. Blasting area; 18. Annular indentation; 19. First sinking groove; 20. Electrode terminal; 21. Positioning hole; 22. Protective cover; 23. Square boss; 24. Elastic buckle; 25. Protective perforation; 26. Metal part; 27. Welding part; 28. Liquid injection hole. Detailed implementation manners

[0028] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments.

[0029] Refer to Figure 1-8, A top cover assembly of a secondary battery, including a top cover plate 3. Symmetrically distributed terminal lead-out holes 4 are provided on the surface of the top cover plate 3, and the terminal lead-out holes 4 penetrate through the top cover plate 3. A first explosion-proof vent hole 5 is provided on the surface of the top cover plate 3, and the first explosion-proof vent hole 5 is arranged in the middle of the two terminal lead-out holes 4. An annular groove 6 is provided on the outer surface of the top cover plate 3. A first fixing member 1 and a second fixing member 2 are respectively fixedly installed in the two terminal lead-out holes 4, and a third fixing member 8 is fixedly installed inside the first explosion-proof vent hole 5. A lower insulating bracket 10 is provided on the inner surface of the top cover plate 3. Two symmetrically distributed terminal through-holes 11 are provided on the surface of the lower insulating bracket 10 close to the top cover plate 3, and the terminal through-holes 11 correspond to the terminal lead-out holes 4 respectively. Irregularly shaped grooves 12 are evenly distributed on the inner wall of the terminal through-holes 11. A second explosion-proof vent hole 14 is provided at the middle position of the lower insulating bracket 10. An explosion-proof valve 16 is provided inside the second explosion-proof vent hole 14, and a blasting area 17 is provided inside the explosion-proof valve 16. An annular notch 18 is provided at the connection between the blasting area 17 and the explosion-proof valve 16. A first sink 19 is provided on the surface of the explosion-proof valve 16. The explosion-proof valve 16 is fixedly connected to the third fixing member 8. Electrode terminals 20 are respectively provided inside the terminal through-holes 11, and the electrode terminals 20 are respectively matched with the first fixing member 1 and the second fixing member 2. A welding portion 27 is provided on the lower surface of the electrode terminal 20, and a metal member 26 is welded to the electrode terminal 20 at the welding portion 27. A protective cover 22 is provided inside the second explosion-proof vent hole 14. Square bosses 23 are evenly distributed on the upper surface of the protective cover 22, and the square bosses 23 are arranged close to the outside of the protective cover 22. Protective through-holes 25 are evenly distributed on the surface of the protective cover 22, and the protective through-holes 25 penetrate through the protective cover 22. Circular through-holes 7 are evenly distributed on the surfaces of the explosion-proof valve 16 and the inner wall of the annular groove 6. A protective film 9 is fixedly installed on the side of the third fixing member 8 away from the lower insulating bracket 10. Irregularly shaped flanges 13 are evenly distributed on the surface of the lower insulating bracket 10 close to the top cover plate 3, and the irregularly shaped flanges 13 are respectively distributed around the terminal through-holes 11. A mating groove corresponding to the irregularly shaped flanges 13 is provided on the inner surface of the top cover plate 3. Notches 15 are symmetrically distributed on the surface of the lower insulating bracket 10, and the notches 15 are respectively arranged on both sides of the second explosion-proof vent hole 14. Elastic buckles 24 are evenly connected to the side of the protective cover 22 close to the top cover plate 3, and the elastic buckles 24 correspond to the positions of the notches 15 and are respectively matched with the notches 15. Liquid injection holes 28 corresponding to each other are provided on the surfaces of the top cover plate 3 and the lower insulating bracket 10. Positioning holes 21 are provided on the surfaces of the electrode terminals 20, and the positioning holes 21 penetrate through the electrode terminals 20.

[0030] In a specific embodiment, the top cover assembly of the secondary battery provided by the present invention is used for the encapsulation of the secondary battery, which can not only make the connection between the metal part 26 and the electrode terminal 20 more stable, prevent the pole column from detaching from the top cover plate 3, and improve the sealing performance of the device; at the same time, it improves the use safety of the battery, and has a low internal occupied space, which is beneficial to improving the energy density inside the battery and has strong practicability.

[0031] When the device of the present invention is in use, the head and bottom of the electrode terminal 20 are made of aluminum, and a welding part 27 is provided on one side of the motor terminal. The metal part 26 is welded to the welding part 27 of the motor terminal by ultrasonic welding; the material of this metal part 26 is copper, which is convenient for using ultrasonic welding to connect the electrode terminal 20 more firmly. Using ultrasonic welding can make the connection between the metal part 26 and the electrode terminal 20 more stable and improve the sealing effect; a lower insulating bracket 10 is provided between the motor terminal and the top cover plate 3, and the top cover plate 3 and the electrode terminal 20 are separated by the lower insulating bracket 10 to avoid electric leakage; at the same time, the explosion-proof valve 16 is assembled to the first explosion-proof ventilation hole 5 provided on the top cover plate 3 in sequence, and the explosion-proof valve 16 is flush with the reverse side of the first explosion-proof ventilation hole 5. At the same time, the first fixing part 1, the second fixing part 2 and the third fixing part 8 are fixedly connected to the top cover plate 3 by injection molding, and then form an integral sealing structure with the top cover plate 3, thereby improving the sealing structure of the top cover assembly and avoiding detachment from the pole column at the same time; a part of the third fixing part 8 wraps the explosion-proof valve 16 and a part wraps the lower insulating bracket 10; at the same time, to prevent liquid leakage from the top cover plate 3; at the same time, corresponding circular through holes 7 are provided inside the annular groove 6 and on the surface of the explosion-proof valve 16, and the explosion-proof valve 16 is sealed at the installation position by pouring colloid into the circular through holes 7;

[0032] When the device is in use, an annular notch 18 is provided in the bursting area 17 of the explosion-proof valve 16; through the annular notch 18, the presence of the annular notch 18 can quickly release the air pressure inside the battery. When the pressure inside the battery is too high, the body is very easy to burst from the annular notch 18, thereby improving the use safety of the battery; the entire device is installed on the top cover plate 3, and the internal occupied space is low, which is beneficial to improving the energy density inside the battery.

[0033] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and should be covered by the protection scope of the present invention.

Claims

1. A top cover assembly for a secondary battery, comprising a top cover plate (3), characterized in that, symmetrically distributed terminal lead-out holes (4) are formed on the surface of the top cover plate (3), and the terminal lead-out holes (4) penetrate through the top cover plate (3). A first explosion-proof ventilation hole (5) is formed on the surface of the top cover plate (3), and the first explosion-proof ventilation hole (5) is arranged in the middle of the two terminal lead-out holes (4). An annular groove (6) is arranged on the outer surface of the top cover plate (3). A first fixing member (1) and a second fixing member (2) are respectively fixedly installed in the two terminal lead-out holes (4), and a third fixing member (8) is fixedly installed inside the first explosion-proof ventilation hole (5). A lower insulating bracket (10) is arranged on the inner surface of the top cover plate (3). Two symmetrically distributed terminal through holes (11) are formed on the surface of the lower insulating bracket (10) close to the top cover plate (3), and the terminal through holes (11) correspond to the terminal lead-out holes (4) respectively. The inner wall of the terminal through hole (11) is provided with uniformly distributed special-shaped grooves (12). A second explosion-proof ventilation hole (14) is formed in the middle position of the lower insulating bracket (10), and an explosion-proof valve (16) is arranged inside the second explosion-proof ventilation hole (14). A blasting area (17) is arranged inside the explosion-proof valve (16). An annular notch (18) is formed at the connection between the blasting area (17) and the explosion-proof valve (16). A first sunk groove (19) is formed on the surface of the explosion-proof valve (16). The explosion-proof valve (16) is fixedly connected with the third fixing member (8). Electrode terminals (20) are arranged inside the terminal through holes (11), and the electrode terminals (20) are respectively matched with the first fixing member (1) and the second fixing member (2). A welding part (27) is arranged on the lower surface of the electrode terminal (20), and a metal part (26) is welded at the welding part (27) of the electrode terminal (20). A protective cover (22) is arranged inside the second explosion-proof ventilation hole (14), and uniformly distributed square bosses (23) are arranged on the upper surface of the protective cover (22). The square bosses (23) are arranged close to the outside of the protective cover (22). Uniformly distributed protective through holes (25) are formed on the surface of the protective cover (22), and the protective through holes (25) penetrate through the protective cover (22); uniformly distributed circular through holes (7) are formed on the surface of the explosion-proof valve (16) and the inner wall of the annular groove (6). A protective film (9) is fixedly installed on the side of the third fixing member (8) away from the lower insulating bracket (10).

2. The top cover assembly for a secondary battery according to claim 1, characterized in that, uniformly distributed special-shaped flanges (13) are arranged on the surface of the lower insulating bracket (10) close to the top cover plate (3), and the special-shaped flanges (13) are respectively distributed around the terminal through holes (11). A mating groove corresponding to the special-shaped flange (13) is arranged on the inner surface of the top cover plate (3).

3. The top cover assembly of a secondary battery according to claim 1, characterized in that, symmetrically distributed notches (15) are provided on the surface of the lower insulating bracket (10), and the notches (15) are respectively arranged on both sides of the second explosion-proof vent hole (14).

4. The top cover assembly of a secondary battery according to claim 3, characterized in that, a uniformly distributed elastic buckle (24) is fixedly connected to one side of the protective cover (22) close to the top cover plate (3), and the elastic buckles (24) correspond to the positions of the notches (15) and are respectively matched with the notches (15).

5. The top cover assembly of a secondary battery according to claim 1, characterized in that, liquid injection holes (28) corresponding to each other are formed on the surfaces of the top cover plate (3) and the lower insulating bracket (10).

6. The top cover assembly of a secondary battery according to claim 1, characterized in that, positioning holes (21) are formed on the surfaces of the electrode terminals (20), and the positioning holes (21) penetrate through the electrode terminals (20).

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