CN216311861U

CN216311861U - Steel shell for packaging winding core and secondary battery

Info

Publication number: CN216311861U
Application number: CN202122036717.XU
Authority: CN
Inventors: 陈杰
Original assignee: Huizhou Liwinon Energy Technology Co Ltd
Current assignee: Huizhou Liwinon Energy Technology Co Ltd
Priority date: 2021-08-27
Filing date: 2021-08-27
Publication date: 2022-04-15
Anticipated expiration: 2031-08-27

Abstract

The utility model discloses a steel shell for packaging a winding core and a secondary battery, wherein the steel shell comprises: the first shell is used for accommodating the winding core and comprises a first plate and side walls fixedly arranged on four sides of the first plate, and a first through hole and a second through hole penetrate through the side walls; the second shell is welded with the first shell and used for covering the opening of the first shell, the second shell comprises a second plate and a positioning piece arranged on the second plate, and the positioning piece is matched with the side wall. When a soft package is used for a roll core, the occupied space of the head sealing area and the side edge folding edge is large, so that the energy density of the battery is influenced, the roll core can be accommodated into the shell by the steel shell, the head is not required to be sealed, the side edge folding edge is not required to be folded, the energy density of the battery is increased, and meanwhile, the steel shell has the characteristics of high strength and difficulty in deformation relative to an aluminum-plastic film; the locating piece that the second casing set up can prevent that first casing and second casing from taking place to shift when the welding.

Description

Steel shell for packaging winding core and secondary battery

Technical Field

The utility model belongs to the technical field of lithium ion battery manufacturing, and particularly relates to a steel shell for packaging a winding core and a secondary battery.

Background

Batteries have been widely used by people since the practical utility model, especially along with more and more electronic products in modern life, the application range of batteries is also bigger and bigger, and the application market of batteries is also continuously expanding.

As shown in fig. 1, most of the existing lithium ion batteries use a soft package packaging process, and a soft package roll core has a large occupied space due to a head sealing area and a side edge folding edge, so that the energy density of the battery is influenced. In addition, the soft package battery is easy to deform due to the lower strength of the aluminum plastic film, so that the problems of the appearance and the performance of the battery are caused.

SUMMERY OF THE UTILITY MODEL

Based on the problems in the background art, the utility model aims to provide a steel shell for packaging a winding core and a secondary battery, wherein the steel shell can accommodate the winding core into the shell, so that the space occupied by a head sealing area and a side edge folding edge when the winding core uses a soft package is reduced, and the energy density of the battery is improved.

In order to realize the purpose of the utility model, the utility model adopts the following technical scheme:

the utility model provides a steel shell for packaging a winding core, which comprises:

the first shell is used for accommodating the winding core and comprises a first plate and side walls fixedly arranged on four sides of the first plate, and a first through hole and a second through hole penetrate through the side walls;

the second shell is welded with the first shell and used for packaging, and the second shell comprises a second plate and a positioning piece arranged on the second plate, and the positioning piece is matched with the side wall.

The size of the first through hole is larger than that of the second through hole, the first through hole and the second through hole are circular through holes, the first through hole is located in the central area of the side wall, and the second through hole is located on one side of the first through hole. The shape of setting element with the opening shape phase-match of first casing, above-mentioned scheme because first board with the lateral wall is the integrated into one piece structure, and with the second casing is mutually supported, possess fine leakproofness, can prevent the weeping.

Specifically, the outer diameter of the positioning piece is smaller than the inner diameter of the side wall. According to the scheme, the positioning piece can be embedded into the first shell, the position between the first shell and the second shell can be fixed during welding, and the first shell and the second shell are prevented from displacing during welding.

Specifically, the positioning element and the second plate are integrally formed or welded on any surface of the second plate. The second shell can be formed by injection molding and stamping through a die, or the positioning piece is welded on any surface of the second shell. According to the scheme, the second shell which is integrally formed by injection molding and die stamping has better sealing performance, and meanwhile, the welding process is reduced; the positioning piece is welded on the second shell, so that a new die is not needed, and the position and the size of the positioning piece can be adjusted at any time. In addition, the thickness of setting element is little to with the lateral wall laminating, can not collide with the core basically. The roll core has a round angle in the length direction (the side edges at two sides of the roll core), so that the positioning piece can not touch the roll core in the length direction. Roll up core width direction (head and afterbody) and have the diaphragm, roll up the core with can have the clearance between the lateral wall, consequently the setting element can not touch at head and afterbody and roll up the core yet, and occupation space can not basically not collide with roll core, consequently need not increase the height and the internal diameter of lateral wall.

Specifically, the setting element for protrusion in the convex part on second board surface, the convex part is cyclic annular, the shape size of cyclic annular convex part with the opening phase-match of first casing, the leakproofness of improvement battery that can be fine, simultaneously can be better prevent when the welding first casing with the skew takes place for the second casing.

Specifically, the first through hole is provided with a pole, and the second through hole is provided with a sealing plug. Because of the limited internal space of the battery, the first shell also has some folded tab spaces on one side of the pole, and almost no gaps are left on the other side walls. If the second through hole is arranged on other side walls, the liquid is not easy to be injected during liquid injection, and even overflows, so that the first through hole and the second through hole are arranged on the same side of the side walls. And the second through hole is sealed by the sealing plug after liquid injection, the sealing plug is removed after formation, air is exhausted, and a circular stainless steel sheet is welded on the second through hole by adopting laser welding to seal the second through hole.

Specifically, the utmost point post includes: the first metal sheet and the first insulating sheet are arranged outside the first shell, the second metal sheet and the second insulating sheet are arranged inside the first shell, the first insulating sheet is arranged between the first metal sheet and the side wall, and the second insulating sheet is arranged between the second metal sheet and the side wall. According to the scheme, the first insulating sheet and the second insulating sheet are arranged, so that the first metal sheet, the second metal sheet and the side wall can be prevented from being in contact with each other to generate short circuit. Simultaneously the sheetmetal all is sheet structure with the insulating piece, for prior art uses columnar structure utmost point post, sheet structure's thickness is very little, and width size is big simultaneously, consequently can reduce under the prerequisite that does not influence the conductivity the thickness of utmost point post, and then the better thickness that reduces the battery head, the energy density of increase battery.

Specifically, the outer side of the side wall on the same surface with the pole is also provided with a negative metal sheet. According to the scheme, the negative metal sheet is used as a negative leading-out end and is welded on the shell by laser, so that the negative metal sheet is convenient to electrically connect with a lead of an external circuit in a soldering mode, and comprises a nickel sheet, a copper sheet and a copper-nickel alloy sheet.

The present invention also provides a secondary battery including: any one in above-mentioned scheme the steel-shelled and hold in the core is rolled up to the inside of steel-shelled, roll up the core with the steel-shelled welding. Will roll up the core hold with inside the steel-clad can be right for using the plastic-aluminum membrane roll up the core and encapsulate, can better protect roll core not impaled when receiving the striking, the steel-clad can not increase the volume of battery at the encapsulation of head different from the encapsulation of soft package simultaneously to the energy density of increase chargeable call.

Specifically, roll up core including rolling up core main part, anodal ear and negative pole ear, anodal ear with first sheetmetal welding, the negative pole ear with first casing welding.

Specifically, an insulating spacer is arranged between the positive and negative electrode lugs and the winding core main body. According to the scheme, the insulating spacer can prevent the anode tab and the cathode tab from being in contact with the side wall of the winding core main body to cause short circuit.

The utility model at least comprises the following beneficial effects: (1) the steel shell can contain the roll core into the shell, so that the energy density of a battery is influenced because the head sealing area and the side edge folding edge occupy larger space when the roll core uses a soft package, and the steel shell has the characteristics of high strength and difficulty in deformation relative to an aluminum-plastic film; (2) the locating piece that the second casing set up can prevent that first casing and second casing from taking place to shift when the welding.

Drawings

Fig. 1 is a pouch battery mentioned in the background art;

fig. 2 is a schematic structural view of a secondary battery according to the present invention;

FIG. 3 is a perspective view of the steel can of the present invention;

FIG. 4 is a perspective view of a first housing of the present invention;

FIG. 5 is a side view of a second housing of the present invention;

FIG. 6 is a bottom view of the second housing of the present invention;

FIG. 7 is a welded structure of the present invention;

FIG. 8 is another weld configuration of the present invention;

the labels in the figure are: 1-a first housing; 11-a first plate; 12-a side wall; 121 — a first via; 122-a second via; 2-a second housing; 21-a second plate; 22-a positioning element; 3-pole column; 31-a first metal sheet; 32-a first insulating sheet; 33-a second metal sheet; 34-a second insulating sheet; 4-a winding core; 41-core body; 42-pole ear; 5-nickel sheet; 6-sealing plug; 7-an insulating spacer; h-welding position; a1-core; a2-multiple tabs; a3-external tab; b-an aluminum plastic film; c-sticking glue to the pole ear.

Detailed Description

The present invention will be further described below with reference to the accompanying drawings for easier understanding, but the present invention can be implemented in various forms, and is not limited to the embodiments described herein and does not constitute any limitation to the present invention.

As shown in fig. 2, the present invention provides a secondary battery including: the steel shell and the winding core 4 which is accommodated in the steel shell and welded with the steel shell.

As shown in fig. 3, the steel shell includes a first shell 1 and a second shell 2.

As shown in fig. 4, the first casing 1, configured to accommodate the winding core 4, includes a first plate 11 and a sidewall 12 fixedly disposed on four sides of the first plate 11, and a first through hole 121 and a second through hole 122 are disposed on the same side of the sidewall 12.

The first plate 11 and the side wall 12 are of an integrally formed structure, the first housing 1 can be obtained by injection molding and die stamping, and the side wall 12 can also be welded to four sides of the first plate 11 by welding.

The size of the first through hole 121 is larger than that of the second through hole 122, the first through hole 121 and the second through hole 122 are both circular through holes, the first through hole 121 is located in the central area of the sidewall 12, and the second through hole 122 is located at one side of the first through hole 121.

As shown in fig. 5 to 6, the second housing 2, welded to the first housing 1, is used for packaging, and includes a second plate 21 and a positioning member 22 disposed on the second plate 21, and the positioning member 22 is engaged with the sidewall 12.

Further, the outer diameter of the positioning member 22 is smaller than the inner diameter of the sidewall 12. According to the scheme, the positioning piece 22 can be embedded into the first shell 1, and the position between the first shell 1 and the second shell 2 can be fixed during welding, so that the first shell 1 and the second shell 2 are prevented from displacing during welding.

Further, the positioning member 22 is integrally formed with the second plate 21, or welded to any one surface of the second plate 21. The second housing 2 may be formed by injection molding, die stamping, or welding the positioning member 22 to any surface of the second housing 2. According to the scheme, the second shell 2 integrally formed by injection molding and die stamping has better sealing performance, and meanwhile, the welding process is reduced; by welding the positioning member 22 to the second housing 2, the position and size of the positioning member 22 can be adjusted at any time without using a new mold. In addition, the positioning member 22 has a small thickness and is attached to the side wall 12 so as not to substantially collide with the winding core 4. The winding core 4 has rounded corners in the longitudinal direction (both side edges of the winding core 4), so that the positioning member 22 does not contact the winding core 4 in the longitudinal direction. The diaphragm is arranged in the width direction (head and tail) of the roll core 4, a gap exists between the roll core 4 and the side wall 12, so that the roll core 4 cannot be touched by the positioning piece 22 at the head and the tail, the space cannot be occupied basically, the roll core 4 cannot be touched, and the height and the inner diameter of the side wall 12 do not need to be increased.

Furthermore, the positioning element 22 is a convex part protruding from the surface of the second plate 21, the convex part is annular, and the shape and size of the annular convex part are matched with the opening of the first casing 1, so that the sealing performance of the battery can be well improved, and the first casing 1 and the second casing 2 can be better prevented from deviating during welding.

Further, as shown in fig. 7, the laser is welded at the joint gap between the first casing 1 and the second casing 2, and the welding position H is located at the joint gap between the side wall 12 and the second casing 2, as shown in fig. 8, the laser may also be welded at the part of the side wall 12 where the first casing 1 and the positioning member 22 overlap, and the welding position H is located at the side wall 12. The scheme improves the operability of laser welding.

Further, the first through hole 121 is provided with the post 3, and the second through hole 122 is provided with the sealing plug 6. Because the internal space of the battery is limited, the first shell 1 on one side of the pole 3 has some folded pole lug spaces, and the other side wall 12 has almost no gap. If the second through hole 122 is disposed on the other side wall 12, the liquid is not easy to be injected, and even overflows, so the first through hole 121 and the second through hole 122 are disposed on the same side of the side wall 12. The second through hole 122 is sealed by a sealing plug 6 after liquid injection, the sealing plug 6 is removed after formation, air is exhausted, and a circular stainless steel sheet is welded on the second through hole 122 by laser welding to seal the second through hole 122.

Further, the pole 3 includes: a first metal sheet 31 and a first insulating sheet 32 disposed outside the first casing 1, and a second metal sheet 33 and a second insulating sheet 34 disposed inside the first casing 1, the first insulating sheet 32 being disposed between the first metal sheet 31 and the side wall 12, the second insulating sheet 34 being disposed between the second metal sheet 33 and the side wall 12. In the above-described embodiment, the first insulating sheet 32 and the second insulating sheet 34 are provided, so that the first metal piece 31 and the second metal piece 33 can be prevented from being in contact with the side wall 12 and causing a short circuit. Simultaneously the sheetmetal all is sheet structure with the insulating piece, uses column structure's utmost point post 3 for prior art, and sheet structure's thickness is very little, and width size is big simultaneously, consequently can be under the prerequisite that does not influence the conductivity, reduces utmost point post 3's thickness, and then the better thickness that reduces the battery head, the energy density of increase battery.

The insulating material of the insulating sheet includes, but is not limited to, polypropylene glue, fluororubber, chloroprene rubber, bromobutyl, polyethylene, polyester compound, anti-electrolyte oxidation glue, ethylene propylene, butyl, curing glue, FPA, and ceramic.

The first metal sheet 31 is provided with a convex portion, and the first insulating sheet 32, the second metal sheet 33 and the second insulating sheet 34 are provided with through holes at positions corresponding to the convex portion, and the convex portion penetrates through the through holes to be welded with the positive tab 42. The compounding methods between the metal sheet and the insulating sheet and between the insulating sheet and the side wall 12 include, but are not limited to, riveting, glue bonding, hot-press compounding, ultrasonic welding, plastic spraying curing, high-temperature curing agent, sintering and other compounding combination methods.

Furthermore, a nickel sheet 5 is arranged on the outer side of the side wall 12 on the same surface with the pole 3. According to the scheme, the nickel sheet 5 is arranged to serve as a negative electrode leading-out end and is welded on the side wall 12 by laser, so that the electric connection of tin soldering with a lead of an external circuit is facilitated.

Further, the winding core 4 includes a core main body 41 and a tab 42.

The roll core main body 41 is obtained by stirring positive and negative active slurry, coating the positive and negative current collectors, rolling, slitting and die cutting, and winding the positive and negative plates and the diaphragm. The tabs 42 are divided into positive tabs and negative tabs, which are respectively led out from the positive plate and the negative plate in the winding core main body 41. The positive tab and the first metal sheet 31 are welded, the negative tab and the first case 1 are welded, the insulating spacer 7 is provided between the tab 42 and the winding core main body 41, and the tab 42 and the side wall 12 can be prevented from touching the winding core main body 41 to cause a short circuit by the insulating spacer 7. The winding core main body 41 is placed into the first shell 1 in a turning mode, the opening of the first shell 1 is sealed by the second shell 2, the positioning piece 22 of the second shell 2 is matched with the side wall 12 of the first shell 1, then the positioning piece 22 and the side wall 12 are welded into a whole through laser welding on the outer side of the first shell 1, packaging of the battery is achieved, and the semi-finished battery is manufactured. The semi-finished battery is subjected to the working procedures of baking, liquid injection, formation, sealing, capacity grading and the like to prepare a secondary battery;

furthermore, in order to prevent the secondary battery from surface scratch and electric leakage in the subsequent transportation and assembly processes, a protective plate is welded and protective glue is pasted on the surface of the battery, and the waterproof and dustproof effects can be achieved, so that the battery is better protected.

The foregoing is a more detailed description of the present application in connection with specific embodiments thereof, and it is not intended that the present application be limited to the specific embodiments thereof. For those skilled in the art to which the present application pertains, a number of simple deductions or substitutions can be made without departing from the inventive concept of the present application.

Claims

1. A steel shell for packaging a winding core is characterized by comprising:

the second shell is welded with the first shell and used for covering the opening of the first shell, the second shell comprises a second plate and a positioning piece arranged on the second plate, and the positioning piece is matched with the side wall.

2. The steel shell according to claim 1, wherein the positioning member has an outer diameter smaller than an inner diameter of the side wall.

3. The steel shell according to claim 1, wherein the positioning member is integrally formed with the first plate or welded to any one side of the second plate.

4. The steel shell according to claim 1, wherein the positioning element is a protrusion protruding from the surface of the second plate, and the protrusion is annular.

5. The steel casing according to claim 1, wherein the first through hole is provided with a pole and the second through hole is provided with a sealing plug.

6. The steel shell according to claim 5, wherein the pole comprises: the first metal sheet and the first insulating sheet are arranged outside the first shell, the second metal sheet and the second insulating sheet are arranged inside the first shell, the first insulating sheet is arranged between the first metal sheet and the side wall, and the second insulating sheet is arranged between the second metal sheet and the side wall.

7. The steel shell according to claim 6, wherein a negative metal sheet is further arranged on the outer side of the side wall on the same surface as the pole.

8. A secondary battery, characterized by comprising: the steel shell according to any one of claims 1 to 7, and a winding core accommodated in the steel shell, wherein the winding core is welded to the steel shell.

9. The secondary battery of claim 8, wherein the jelly roll comprises a jelly roll body, a positive tab and a negative tab.

10. The secondary battery according to claim 9, wherein insulating spacers are provided between the positive electrode tab and the negative electrode tab and the winding core main body, respectively.