CN217182372U

CN217182372U - Full utmost point ear lithium cell cover plate connection structure

Info

Publication number: CN217182372U
Application number: CN202220732367.2U
Authority: CN
Inventors: 岳治崇; 薛历兴; 梁永吉; 程乾龙; 张阔
Original assignee: Chuneng New Energy Co Ltd
Current assignee: Chuneng New Energy Co Ltd
Priority date: 2022-03-30
Filing date: 2022-03-30
Publication date: 2022-08-12
Anticipated expiration: 2032-03-30

Abstract

The utility model provides a full-lug lithium battery cover plate connecting structure, which can improve the electric connection between the full-lug structure and the cover plate and improve the over-current capability of the lithium battery by arranging conductive adhesive and bonding the full-lug end surface and a connecting sheet; the hot melt adhesive is adopted, and the coating is coated at normal temperature but has no viscosity, so that the welding is convenient; after welding is finished, viscosity can be generated by heating, automatic bonding is realized, and the manufacturing process is simple and convenient; the connecting sheet which is in a splayed and sunken design is adopted, so that the conductive adhesive is convenient to scrape to the bonding area and cannot be bonded to the laser welding area in the process; and an electrolyte filling hole is arranged, so that the electrolyte can be conveniently filled.

Description

Full utmost point ear lithium cell cover plate connection structure

Technical Field

The utility model relates to a lithium cell field especially relates to a full utmost point ear lithium cell cover plate connection structure.

Background

At present, the power lithium battery has the advantages of high capacity and high power, and is mainly applied to the fields of electric automobiles, energy storage power stations and the like. In order to solve the problem of high-power charging and discharging of the battery, the lithium battery adopts a full-lug structure to replace a traditional single-lug or multi-lug structure, so that the problems of large internal resistance and large local heating of the lithium battery are solved.

However, the existing connection mode between the full tab structure and the cover plate is laser welding, which can only realize local welding, cannot realize full-area connection of the lithium battery metal tab and the cover plate, can only realize contact of the laser welding position, and cannot realize complete welding at other parts, so that the over-current capability of the lithium battery is not comprehensively improved.

SUMMERY OF THE UTILITY MODEL

In view of this, the utility model provides a full utmost point ear lithium cell cover plate connection structure can improve the electric connection between full utmost point ear structure and the apron, improves the overcurrent ability of lithium cell.

The technical scheme of the utility model is realized like this: the utility model provides a full utmost point ear lithium cell cover plate connection structure, it includes anodal apron, two connection pieces, full utmost point ear roll core, negative pole apron and cylindrical shell, wherein, full utmost point ear roll core sets up in cylindrical shell, anodal apron and negative pole apron block off cylindrical shell both ends opening respectively, two connection pieces are fixed with anodal apron and negative pole apron welding through the strap respectively; the tab surface is divided into a laser welding area and an adhesive area, wherein,

two ends of the full-lug winding core are respectively provided with a leveled positive lug and a leveled negative lug;

the laser welding area is welded with the end surface of the leveled anode tab or cathode tab;

the bonding area is bonded and fixed with the end surface of the leveled anode tab or cathode tab through conductive glue.

On the basis of the technical scheme, preferably, the bonding area is provided with a plurality of electrolyte perfusion holes.

On the basis of the technical scheme, preferably, the two laser welding areas are arranged, and the surfaces of the connecting pieces are symmetrically arranged in a splayed shape; the area outside the two laser welding areas is a bonding area which is fully coated with conductive adhesive.

Preferably, the laser welding area sinks relative to the bonding area, and the sunk bottom surface is welded with the end surface of the leveled positive pole lug or negative pole lug.

Further preferably, the laser welding area has a sinking height of 0.05-1 mm relative to the bonding area.

It is further preferred that the height of the bonding area after the conductive paste is applied is flush with the laser welding area.

On the basis of the technical scheme, preferably, the conductive adhesive is hot melt adhesive.

Further preferably, the conductive adhesive is conductive silver adhesive.

The utility model discloses a full utmost point ear lithium cell cover connection structure has following beneficial effect for prior art:

(1) the conductive adhesive is arranged to bond the end face of the full tab and the connecting sheet, so that the electrical connection between the full tab structure and the cover plate can be improved, and the over-current capacity of the lithium battery can be improved;

(2) the hot melt adhesive is adopted, and the coating is coated at normal temperature but has no viscosity, so that the welding is convenient; after welding is finished, viscosity can be generated by heating, automatic bonding is realized, and the manufacturing process is simple and convenient;

(3) the connecting sheet which is in a splayed and sunken design is adopted, so that the conductive adhesive is convenient to scrape to the bonding area and cannot be bonded to the laser welding area in the process;

(4) and an electrolyte filling hole is arranged, so that the electrolyte can be conveniently filled.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

Fig. 1 is a perspective view of a full-tab lithium battery cover plate connection structure of the present invention;

fig. 2 is the front view of the positive cover plate and the connecting plate of the full-tab lithium battery cover plate connecting structure of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work all belong to the protection scope of the present invention.

As shown in fig. 1, the utility model discloses a full utmost point ear lithium battery cover connection structure, it includes that anodal apron 1, two connection pieces 2, full utmost point ear roll core 3, negative pole apron 4 and cylinder type casing 5.

The full-tab winding core 3 is generally formed by sequentially laminating a positive pole piece, an isolation film and a negative pole piece and then winding, the two ends of the full-tab winding core 3 are respectively a leveled positive pole tab 31 and a leveled negative pole tab 32, and the full-tab winding core 3 is arranged in the cylindrical shell 5. The above parts are prior art and are not described herein.

The positive electrode cover plate 1 and the negative electrode cover plate 4 respectively plug the openings at the two ends of the cylindrical shell 5, and specifically, can be fixed by welding.

And the connecting piece 2 is used for electrically connecting the positive electrode cover plate 1 and the negative electrode cover plate 4 with the leveled positive electrode lug 31 and the leveled negative electrode lug 32 respectively. Specifically, the two connecting pieces 2 are respectively welded and fixed with the anode cover plate 1 and the cathode cover plate 4 through metal strips. In the utility model, the surface of the connecting piece 2 is divided into a laser welding area 21 and a bonding area 22, wherein the laser welding area 21 is welded with the end surface of a leveled anode tab 31 or cathode tab 32; the bonding region 22 is bonded and fixed with the end face of the flattened positive electrode tab 31 or negative electrode tab 32 by conductive adhesive. Therefore, even if the laser welding area 21 is not firmly welded with the end face of the leveled anode tab 31 or cathode tab 32, the bonding area 22 can be bonded and fixed with the full tab through conductive adhesive, the conductive area of the battery is increased by the bonding area 22, the current is changed from small-area transmission to full-area transmission, the overcurrent capacity is greatly improved, the internal resistance and the heating of the battery are reduced by one order of magnitude, and the safety and the power performance of the battery are changed.

Specifically, the two laser welding areas 21 are arranged, and the surfaces of the connecting pieces 2 are symmetrically arranged in a splayed shape; the region outside the two laser welding regions 21 is a bonding region 22, and is fully coated with conductive adhesive. To ensure the effect of laser welding, the laser welding area 21 is not coated with conductive paste.

For the convenience of gluing, the laser welding area 21 sinks relative to the bonding area 22, and the sunk bottom surface is welded with the end surface of the flattened positive pole tab 31 or negative pole tab 32. By the sink design, it is possible to prevent the conductive paste from being applied to the laser land 21 during the paste application process.

Specifically, the height of the bonding area 22 after being filled with the conductive paste is flush with the laser welding area 21. Specifically, the sinking height of the laser welding area 21 relative to the bonding area 22 is 0.05-1 mm, and the thickness of the conductive adhesive coated on the bonding area 22 is 0.05-1 mm.

Specifically, the conductive adhesive is a hot melt adhesive, has a normal-temperature curing characteristic, is changed into a molten state when the temperature reaches the melting temperature, can bond metals, and has excellent conductivity. The conductive silver adhesive can be specifically used, adopts an ultrafine pure silver medium for conduction, is a single component, has high natural curing speed at room temperature, does not need refrigeration, and can be stored at room temperature.

In order to prevent the electrolyte from being injected into the bonding area 22 unsmoothly after the conductive adhesive is bonded to the full tab, a plurality of electrolyte injection holes 20 are formed in the bonding area 22, so that the electrolyte can enter conveniently.

The utility model discloses a full utmost point ear lithium cell, the preparation technology is as follows:

s1, the tabs at the two ends of the full-tab winding core 3 are made of metal foils at the edges of the pole pieces, and the metal foils at the edges of the pole pieces are kneaded to be flat through the tabs, and then the surfaces of the tabs are finished and leveled, so that the full-tab winding core 3 with the two ends respectively being a leveled positive electrode tab 31 and a leveled negative electrode tab 32 is obtained;

s2, coating the bonding region 22 with conductive adhesive with the thickness of 0.05-1 mm;

s3, welding the laser welding area 21 of the two connecting sheets 2 with the end surfaces of the flattened positive pole tab 31 and the flattened negative pole tab 32; wherein the welding mark cannot exceed the laser welding area 21 so as to avoid the condition of laser welding fire explosion

S4, after the connection part 2 and the full-lug winding core 3 are welded by laser, the connection piece 2 is heated again, the heating temperature is 50-120 ℃, the diaphragm of the battery cannot be damaged, the conductive adhesive coated on the connection piece 2 is changed into a molten state by the heating temperature, so that the bonding of the bonding region 22 and the anode tab 31 and the cathode tab 32 which are leveled at the two ends of the full-lug winding core 3 is realized, and further the electric conduction is realized.

And S5, respectively carrying out laser welding on the positive electrode cover plate 1 and the negative electrode cover plate 4 and the cylindrical shell 5 to finally manufacture the complete battery.

The above description is only a preferred embodiment of the present invention, and should not be taken as limiting the invention, and any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A full-lug lithium battery cover plate connecting structure comprises an anode cover plate (1), two connecting pieces (2), a full-lug winding core (3), a cathode cover plate (4) and a cylindrical shell (5), wherein the full-lug winding core (3) is arranged in the cylindrical shell (5), the anode cover plate (1) and the cathode cover plate (4) respectively plug openings at two ends of the cylindrical shell (5), and the two connecting pieces (2) are respectively welded and fixed with the anode cover plate (1) and the cathode cover plate (4) through metal bands; the method is characterized in that: the surface of the connecting piece (2) is divided into a laser welding area (21) and an adhesion area (22), wherein,

two ends of the full-lug winding core (3) are respectively provided with a leveled positive lug (31) and a leveled negative lug (32);

the laser welding area (21) is welded with the end face of the leveled anode tab (31) or cathode tab (32);

the bonding area (22) is bonded and fixed with the end surface of the flattened positive pole tab (31) or the flattened negative pole tab (32) through conductive glue.

2. The full-tab lithium battery cover plate connection structure of claim 1, wherein: the bonding area (22) is provided with a plurality of electrolyte perfusion holes (20).

3. The full-tab lithium battery cover plate connection structure of claim 1, wherein: the two laser welding areas (21) are symmetrically arranged on the surface of the connecting sheet (2) in a splayed shape; the area outside the two laser welding areas (21) is an adhesive area (22) which is fully coated with conductive adhesive.

4. The full-tab lithium battery cover plate connection structure of claim 3, wherein: the laser welding area (21) sinks relative to the bonding area (22), and the bottom surface after sinking is welded with the end surface of the flattened positive pole lug (31) or the flattened negative pole lug (32).

5. The full-tab lithium battery cover plate connection structure of claim 4, wherein: the laser welding area (21) sinks to a height of 0.05-1 mm relative to the bonding area (22).

6. The full-tab lithium battery cover plate connection structure of claim 4, wherein: the height of the bonding area (22) after being coated with the conductive adhesive is flush with that of the laser welding area (21).

7. The full-tab lithium battery cover plate connection structure of claim 1, wherein: the conductive adhesive is hot melt adhesive.

8. The full-tab lithium battery cover plate connection structure of claim 7, wherein: the conductive adhesive is conductive silver adhesive.