CN216213745U

CN216213745U - Square secondary battery's top cap and secondary battery

Info

Publication number: CN216213745U
Application number: CN202122503981.XU
Authority: CN
Inventors: 丁坤; ***
Original assignee: Phylion Battery Co Ltd
Current assignee: Phylion Battery Co Ltd
Priority date: 2021-10-18
Filing date: 2021-10-18
Publication date: 2022-04-05
Anticipated expiration: 2031-10-18

Abstract

The utility model relates to a top cover of a square secondary battery and the secondary battery, which comprises a cover plate, a cell support and a pole, wherein two ends of one side of the cover plate are connected with a conductive block at intervals through a conductive insulating frame, the cell support is arranged at the other side of the cover plate, the pole penetrates through the conductive block, the cover plate and the cell support to be connected with a connecting sheet, the connecting sheet is a double-layer conducting sheet which is arranged in a stacked mode, one end of the double-layer conducting sheet is pressed on the lower surface of the cell support by the pole, and the other end of the double-layer conducting sheet is bent below the pole and clamps a pole lug. The utility model has the advantages of few parts, stable performance, low cost and simple process.

Description

Square secondary battery's top cap and secondary battery

Technical Field

The utility model relates to the technical field of secondary batteries, in particular to a top cover of a square secondary battery and the secondary battery.

Background

Unlike the conventional battery, the secondary battery can be repeatedly charged. Recently, a high power secondary battery using a non-aqueous electrolyte and having a high energy density has been developed. When the battery cell is made into a battery pack, a low-capacity battery is formed as a power source for various portable small electronic devices such as a portable phone, a laptop computer, and a camcorder. When several to several tens of secondary battery cells are connected in series or in parallel, a large-sized battery is formed, which can be used for a power source such as a driving motor in an electric vehicle.

The existing secondary battery generally comprises a shell, a positive pole piece, a negative pole piece, a diaphragm and electrolyte, wherein the positive pole piece, the negative pole piece, the diaphragm and the electrolyte are contained in the shell, a pole lug is arranged on the pole piece, one end of the shell is open, the shell cover shields the opening, a sealing structure is formed between the shell cover and the shell through welding, two electrode leading-out holes are formed in the shell cover and are respectively connected with a positive electrode sealing structure and a negative electrode sealing structure, the electrode sealing structure is that a concave pad and a convex pad are respectively arranged on the upper surface and the lower surface of the shell cover at the position of a motor leading-out hole, the lower surface of the convex pad is provided with the pole lug, the upper surface of the concave pad is provided with a connecting sheet, and the connecting sheet is fixedly connected onto the shell cover through a rivet so as to lead the pole lug out of the battery through a metal rivet, and simultaneously, the concave pad and the convex pad are matched with the shell cover to separate the pole lug from the shell cover and realize sealing.

However, in practical use, the square lithium ion battery is generally provided with a mode of directly welding the tab and the pole to lead out, so that the height of the pole group is difficult to control, poor connection is easy to occur by adopting the mode to connect, normal use of the secondary battery is influenced, and the operation is complex on the other hand, so that the structural assembly of the battery shell cover is excessive and the cost is high.

SUMMERY OF THE UTILITY MODEL

Therefore, the technical problem to be solved by the utility model is to overcome the defects of complex structure and inconvenient installation of the battery shell cover in the prior art, and provide the top cover of the square secondary battery and the secondary battery, which have the advantages of few parts, stable performance, low cost and simple process.

In order to solve the technical problem, the utility model provides a top cover of a square secondary battery, which comprises a cover plate, a cell support and a pole, wherein two ends of one side of the cover plate are connected with conductive blocks at intervals through a conductive insulating frame, the cell support is arranged on the other side of the cover plate, the pole penetrates through the conductive blocks, the cover plate and the cell support and is connected with a connecting sheet, the connecting sheet is a double-layer conductive sheet which is arranged in a stacked mode, one end of the double-layer conductive sheet is pressed on the lower surface of the cell support by the pole, and the other end of the double-layer conductive sheet is bent below the pole and clamps a pole lug.

In an embodiment of the utility model, a safety valve is arranged in the middle of the cover plate, a protective cap covering the safety valve is mounted on the cover plate, exhaust holes are arranged at two ends of the cover plate, and the cell support is provided with an opening corresponding to the positions of the safety valve and the exhaust holes.

In one embodiment of the utility model, the safety valve is circular and comprises a welding part at the periphery and a middle blasting part, the blasting part is connected with the welding part through a first thinned scribing part, and the blasting part is uniformly divided into a plurality of pieces through a second scribing part.

In one embodiment of the present invention, the blast portion between the second score portions bulges outward, and the height of the intersection of the second score portions is lower than the height of the first score portion.

In an embodiment of the utility model, the middle part and two ends of the battery cell support extend towards the battery cell direction to form supporting parts, and the periphery of the cover plate is provided with welding steps protruding downwards.

In an embodiment of the utility model, a sealing gasket is arranged between the pole and the battery cell support and between the pole and the cover plate, the cross section of the sealing gasket is concave, and the cover plate is clamped in the concave.

In one embodiment of the utility model, the pole and the connecting piece are connected by double ultrasonic welding.

The utility model provides a square secondary battery, which comprises the top cover, a pole group and a square shell for accommodating the pole group, wherein the top of the pole group is provided with a pole lug, the pole lug is clamped by a connecting sheet, and the opening of the shell is sealed by a cover plate.

Compared with the prior art, the technical scheme of the utility model has the following advantages:

the top cover is simple in structure, stable in function and convenient to assemble;

the secondary battery has the advantages of simple structure, stable connection, low cost and simple and convenient installation.

Drawings

In order that the present disclosure may be more readily and clearly understood, reference is now made to the following detailed description of the embodiments of the present disclosure taken in conjunction with the accompanying drawings, in which

FIG. 1 is a schematic view of a top cover of the present invention;

FIG. 2 is an exploded view of the top cover of the present invention;

FIG. 3 is a partial cross-sectional view of the overcap of the present invention;

fig. 4 is a schematic view of a cover plate and a cell holder according to the present invention;

FIG. 5 is a cross-sectional view of the safety valve of the present invention;

fig. 6 is an exploded view of a secondary battery of the present invention;

fig. 7 is a sectional view of a secondary battery of the present invention.

The specification reference numbers indicate: 10. a top cover; 11. a cover plate; 111. welding a step; 112. a gasket; 12. a battery cell bracket; 121. an opening part; 122. reinforcing ribs; 123. a support portion; 13. a pole column; 14. a conductive insulating frame; 15. a conductive block; 16. connecting sheets; 161. a conductive sheet; 17. a safety valve; 171. welding the part; 172. a blasting section; 173. a first scribing part; 174. a second scribing part; 18. a protective cap; 19. an exhaust hole;

20. a pole group; 21. a tab;

30. a housing.

Detailed Description

The present invention is further described below in conjunction with the following figures and specific examples so that those skilled in the art may better understand the present invention and practice it, but the examples are not intended to limit the present invention.

Referring to fig. 1 to 3, there is shown a top cap 10 of a prismatic secondary battery according to the present invention. The top cover 10 of the utility model comprises a cover plate 11, a cell support 12 and a pole 13, wherein the cover plate 11 is a substantially rectangular plate-shaped structure made of a metal material, and the metal material can be a material such as aluminum alloy. Two ends of the cover plate 11 in the length direction are provided with two conductive ports, specifically, two ends of one side of the cover plate 11 are connected with conductive blocks 15 at intervals through conductive insulating frames 14, the conductive insulating frames 14 separate the conductive blocks 15 from the cover plate 11 made of a metal material, so that current leakage to the cover plate 11 is prevented, and meanwhile, the battery cell support 12 is arranged on the other side of the cover plate 11 and separates the cover plate 11 from the pole group 20 to prevent the pole group 20 from directly contacting the cover plate 11. In this embodiment, the cell holder 12 is made of an insulating material, for example, an insulating resin material such as polybutylene terephthalate, polyphenylene sulfide, or perfluoroalkoxy fluororesin. In order to lead out the current of the pole group 20, the pole 13 passes through the conductive block 15, the cover plate 11 and the cell support 12 and is connected with a connecting sheet 16, the connecting sheet 16 is a double-layer conductive sheet 161 which is stacked, one end of the double-layer conductive sheet 161 is pressed on the lower surface of the cell support 12 by the pole 13, and the other end of the double-layer conductive sheet is bent under the pole 13 and clamps the tab 21. Since the connecting piece 16 has two layers, the tab 21 can be sandwiched from both sides of the tab 21, and electrical connection with the tab 21 can be secured. The current generated by the electrode group 20 is led out by the tab 21 and then conducted to the conductive block 15 through the electrode post 13, so as to be conductively connected with external electric equipment, thereby realizing power supply to the electric equipment. Because the connection of the pole 13 and the tab 21 is through the clamping of the connecting sheet 16 to the tab 21, and the tab 21 is pressed below the pole 13, the pole 13 also has pressure to the tab 21, so that the stability of the electric connection between the pole 13 and the tab 21 is ensured, the assembly is simple, and the cost is low. In order to further reduce the contact resistance of the pole 13 and the tab 21, the pole 13 and the connecting piece 16 are connected by double ultrasonic welding. In this embodiment, the conductive sheet 161 corresponding to the positive electrode is an aluminum foil, and the conductive sheet 161 corresponding to the negative electrode is a copper foil.

Further, referring to fig. 4, a safety valve 17 for reducing the internal pressure of the secondary battery is provided at the center of the cap plate 11. When the internal pressure of the secondary battery rises to exceed a predetermined value, the safety valve 17 is ruptured to release the gas inside, preventing the secondary battery from exploding. The protective cap 18 covering the safety valve 17 is mounted on the cover plate 11, the safety valve 17 is sealed in the secondary battery, the safety valve 17 cannot be contacted with the outside, namely the safety valve 17 cannot be damaged due to the acting force of the outside, the protection effect of the safety valve 17 is ensured, and meanwhile, the protective cap 18 can prevent the broken safety valve 17 from splashing when the safety valve 17 is cracked, so that the safety is safer. In this embodiment, the cover plate 11 is further provided with exhaust holes 19 at two ends. Through the cooperation setting of exhaust hole 19 and relief valve 17, can realize secondary battery's the formation of sealing to need not to set up alone again and annotate the liquid mouth, simplified secondary battery's structure. In order to ensure the communication between the safety valve 17 and the exhaust hole 19 and the interior of the secondary battery, the cell holder 12 has an opening 121 at a position corresponding to the safety valve 17 and the exhaust hole 19, and the opening 121 is provided with a reinforcing rib 122 for reinforcing the opening.

Referring to fig. 5, a cross-sectional view of the safety valve 17 is shown, the safety valve 17 has a circular shape, and includes a welded portion 171 at the periphery and a middle burst portion 172, the burst portion 172 is connected to the welded portion 171 by a first score portion 173 having a thin wall thickness, and the burst portion 172 is uniformly divided into a plurality of pieces by a second score portion 174. Therefore, when the internal pressure of the secondary battery rises to exceed a preset value, the safety valve 17 is simultaneously cracked from the middle to the periphery, and the opening of the safety valve 17 is completely opened at the fastest speed, so that the rapid pressure reduction is realized, and the safety of the secondary battery is improved. Specifically, the blasting portions 172 between the second scribing portions 174 are bulged outward, and the height of the intersection of the second scribing portions 174 is lower than the height of the first scribing portion 173. The first and

second scribing portions

173 and 174 are not provided on the same plane, and the safety valve 17 can be opened at a higher speed and with high opening accuracy according to the principle of the inclined lever.

Referring to fig. 3 and 4, the middle part and both ends of the cell support 12 both extend toward the cell direction to form support parts 123, so that on one hand, there is enough space between the cell support 12 and the electrode assembly 20 to accommodate the connection pieces 16 holding the tabs 21, and on the other hand, when sealing and welding, the melted metal material can be blocked, and short circuit can be prevented. In order to further prevent molten metal from entering the secondary battery when the cover plate 11 is welded to the case 30, a welding step 111 protruding downward is formed around the cover plate 11. On the one hand, the opening of the housing 30 can be sealed, and on the other hand, the cover plate 11 and the housing 30 are welded from the outside during welding, and the protruding welding step 111 blocks the weld and forms a first barrier to the melted material.

Further, referring to fig. 3, in order to electrically isolate the terminal 13 from the cell support 12, the cover plate 11 and the conductive insulating frame 14, a sealing gasket 112 is disposed between the terminal 13 and the cell support 12 and the cover plate 11, a cross section of the sealing gasket 112 is in a shape of Chinese character 'ao', and the cover plate 11 is clamped in the shape of Chinese character 'ao'. The conductive insulating frame 14 and the battery cell support 12 are arranged corresponding to the protruding portions of the sealing gasket 112, so that tight connection of various structures is ensured, and the installation of the pole 13 is facilitated.

Referring to fig. 6 and 7, a schematic view of a prismatic secondary battery according to the present invention is shown. The secondary battery comprises the top cover 10, a pole group 20 and a square shell 30 for accommodating the pole group 20, wherein the top of the pole group 20 is provided with a pole lug 21, the connecting piece 16 clamps the pole lug 21, and the cover plate 11 seals an opening of the shell 30. Since the tab 21 is held by the bent connection piece 16, the distance between the lower surface of the cap plate 11 and the upper surface of the electrode assembly 20 is reduced, and the volume of the secondary battery is further reduced.

In the present invention, to assemble the secondary battery, first, the safety valve 17 and the protective cap 18 are welded and fixed to the cap plate 11, respectively.

Then, the pole 13 sequentially penetrates through the conductive block 15, the conductive insulating frame 14, the sealing gasket 112, the cover plate 11 and the cell support 12; the top diameter of utmost point post 13 is great to can restrict in conducting block 15, according to the order that each structure arranged around utmost point post 13, continue the lower extreme and pass conducting block 15, electrically conductive insulating frame 14 in proper order, sealed pad 112 card is on apron 11, can make utmost point post 13 pass sealed pad 112 earlier, with sealed pad 112 apron 11, also can make utmost point post 13 pass sealed pad 112 earlier sealed pad 11 again with sealed pad 112 card income apron 11 earlier, then utmost point post 13 wears out electric core support 12.

Secondly, the pole 13 is fixed with the connecting piece 16 to form the top cover 10; that is, the top cover 10 can be separately assembled and then connected to the pole group 20. In this embodiment, the terminal 13 is fixed to the connecting sheet 16 by double ultrasonic welding, after welding, a welding spot is formed at the end of the terminal 13, the welding spot is matched with the large-diameter end of the terminal 13 to limit the conducting sheet 161, the conductive insulating member, the cover plate 11 and the cell support 12, and the top cover 10 forms an integrated structure.

Again, the pole set 20 is loaded into the housing 30; the connecting sheet 16 clamps and fixes the tab 21 of the pole group 20, and bends the connecting sheet 16; the other end of the tab 16 and the tab 21 are compressed between the lower end of the pole 13 and the top of the pole set 20.

Finally, the top cover 10 and the case 30 are fixed by welding. The installation of the secondary battery is completed.

It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications therefrom are within the scope of the utility model.

Claims

1. A top cap of a square secondary battery, characterized in that: including apron, electric core support and utmost point post, the both ends of apron one side have the conducting block through electrically conductive insulation frame interval connection, electric core support set up in the apron opposite side, utmost point post passes conducting block, apron and electric core leg joint have the connection piece, the double-deck conducting strip of connection piece for range upon range of setting, double-deck conducting strip one end quilt utmost point post pressfitting is in electric core support lower surface, the other end buckle in utmost point post below and centre gripping utmost point ear.

2. A top cap of a prismatic secondary battery according to claim 1, characterized in that: the safety valve is arranged in the middle of the cover plate, the cover plate is provided with a protective cap covering the safety valve, exhaust holes are formed in two ends of the cover plate, and the battery cell support is provided with opening portions corresponding to the safety valve and the exhaust holes.

3. A top cap of a prismatic secondary battery according to claim 2, characterized in that: the safety valve is circular and comprises a welding part on the periphery and a middle blasting part, the blasting part is connected with the welding part through a first thinned scribing part, and the blasting part is uniformly divided into a plurality of pieces through a second scribing part.

4. A top cap of a prismatic secondary battery according to claim 3, characterized in that: and blasting parts among the second scribing parts bulge outwards, and the height of the intersection point of the second scribing parts is lower than that of the first scribing parts.

5. A top cap of a prismatic secondary battery according to claim 1, characterized in that: the battery cell support middle part and both ends all extend to the battery cell direction and have the supporting part, apron is provided with the welding step of outstanding downwards all around.

6. A top cap of a prismatic secondary battery according to claim 1, characterized in that: the terminal post and a sealing gasket is arranged between the battery cell support and the cover plate, the cross section of the sealing gasket is in a concave shape, and the cover plate is clamped in the concave opening in the shape of the concave shape.

7. A top cap of a prismatic secondary battery according to claim 1, characterized in that: the pole is connected with the connecting sheet through double ultrasonic welding.

8. A square secondary battery characterized in that: the top cover comprises a pole group and a square shell for accommodating the pole group, wherein the top of the pole group is provided with a pole lug, the pole lug is clamped by the connecting sheet, and the cover plate seals an opening of the shell.