阅读说明：本技术 Ctp高集成锂离子电池及其制作方法 (CTP high-integration lithium ion battery and manufacturing method thereof ) 是由 邓湘平 张宝 王兆栋 雷田雨 陆娟 于 2021-09-22 设计创作，主要内容包括：本发明公开一种CTP高集成锂离子电池及其制作方法,该电池包括：一端开口的壳体,设置在所述壳体的开口端的盖板,设置于所述壳体内的卷芯组、以及包裹所述卷芯组的底托与绝缘膜；所述卷芯组由多个第一卷芯单元与第二卷芯单元通过正负极极耳与正极连接片、负极连接片、正负极极耳连接片、正极保护片、负极保护片串并联焊接构成；所述第一卷芯单元包括至少两个串联的卷芯,所述第二卷芯单元至少包括两个串联的卷芯；所述盖板包括：基板、正极柱、负极柱、置于所述基板上的注液口；所述正极柱与所述正极连接片相连,所述负极柱与所述负极连接片相连。本发明能提升电池包的空间利用率与系统能量密度,可大幅降低电池的制造成本。(The invention discloses a CTP highly integrated lithium ion battery and a manufacturing method thereof, wherein the battery comprises: the winding device comprises a shell with an opening at one end, a cover plate arranged at the opening end of the shell, a winding core group arranged in the shell, a bottom support wrapping the winding core group and an insulating film; the winding core group is formed by welding a plurality of first winding core units and second winding core units in series-parallel connection through positive and negative electrode lugs and positive electrode connecting sheets, negative electrode connecting sheets, positive and negative electrode lug connecting sheets, positive electrode protection sheets and negative electrode protection sheets; the first winding core unit comprises at least two winding cores which are connected in series, and the second winding core unit comprises at least two winding cores which are connected in series; the cover plate includes: the liquid injection device comprises a substrate, a positive pole column, a negative pole column and a liquid injection port arranged on the substrate; the positive pole column is connected with the positive connecting piece, and the negative pole column is connected with the negative connecting piece. The invention can improve the space utilization rate and the system energy density of the battery pack and greatly reduce the manufacturing cost of the battery.)

1. A CTP high-integration lithium ion battery, comprising: the winding device comprises a shell with an opening at one end, a cover plate arranged at the opening end of the shell, a winding core group arranged in the shell, a bottom support wrapping the winding core group and an insulating film;

the winding core group is formed by welding a plurality of first winding core units and second winding core units in series-parallel connection through positive and negative electrode lugs and positive electrode connecting sheets, negative electrode connecting sheets, positive and negative electrode lug connecting sheets, positive electrode protection sheets and negative electrode protection sheets; the first winding core unit comprises at least two winding cores which are connected in series, and the second winding core unit comprises at least two winding cores which are connected in series;

the cover plate includes: the liquid injection device comprises a substrate, a positive pole column, a negative pole column and a liquid injection port arranged on the substrate; the positive pole column is connected with the positive connecting piece, and the negative pole column is connected with the negative connecting piece.

2. The CTP high integrated lithium ion battery of claim 1, wherein the winding core group comprises a plurality of first winding core units and second winding core units symmetrically connected in parallel, and the plurality of first winding core units and second winding core units symmetrically connected in parallel are arranged in series in a length direction.

3. The CTP high-integration lithium ion battery of claim 2, wherein the positive tab and the negative tab of the first winding core unit and the second winding core unit are disposed on the same side, and the positive tab is opposite to the positive tab, and the negative tab is opposite to the negative tab, and the positive tab and the negative tab disposed at two ends of the winding core set are respectively sandwiched between the positive connection sheet and the positive protection sheet, and the negative connection sheet and the negative protection sheet, and the positive tab and the negative tab disposed in the middle are sandwiched between the positive tab connection sheet and the positive protection sheet, and the positive tab connection sheet and the negative protection sheet, and are fixed by ultrasonic welding.

4. The CTP high integration lithium ion battery of claim 1, wherein the positive tab is laser welded to the positive post and the negative tab is laser welded to the negative post.

5. The CTP highly integrated lithium ion battery of claim 1, wherein the positive electrode connecting sheet and the positive electrode protecting sheet are made of aluminum; the negative electrode connecting sheet and the negative electrode protecting sheet are made of copper materials; the positive and negative electrode lug connecting sheets are made of nickel materials with surface treatment.

6. The CTP high-integration lithium ion battery of claim 1, wherein the cover plate is further provided with an insulating brake frame, and the positive and negative electrode tab connecting sheets are fixed on the insulating brake frame of the cover plate by means of a snap groove or a buckle.

7. The CTP high-integration lithium ion battery of claim 6, wherein the bottom support and the insulating film are of a unitary structure, and the upper edge of the insulating film is connected with the insulating stop frame of the cover plate by hot stamping.

8. The CTP high integrated lithium ion battery of claim 1, wherein the shoe is provided with a plurality of positioning holes and an array of electrolyte holes.

9. The CTP high integrated lithium ion battery of claim 1, wherein an explosion-proof valve is further disposed on said cover plate.

10. The CTP high integrated lithium ion battery of claim 9,

in the length direction, when the number of the first winding core unit or the second winding core unit is more than 2, a plurality of explosion-proof valves can be arranged on the cover plate.

11. The manufacturing method of the CTP high-integration lithium ion battery is characterized in that the CTP high-integration lithium ion battery comprises a first winding core unit and a second winding core unit, wherein the first winding core unit comprises a first winding core and a third winding core which are connected in series; the second roll core unit comprises a second roll core and a fourth roll core which are connected in series, and the manufacturing method comprises the following steps:

the first winding core and the third winding core are respectively arranged in parallel with the second winding core and the fourth winding core symmetrically, wherein a first positive lug of the first winding core is opposite to a second positive lug of the second winding core and is arranged on a positive connecting sheet; the first negative lug of the first winding core is opposite to the second negative lug of the second winding core, the third positive lug of the third winding core is opposite to the fourth positive lug of the fourth winding core and is jointly arranged on the positive and negative lug connecting sheets, and the third negative lug of the third winding core is opposite to the fourth negative lug of the fourth winding core and is arranged on the negative connecting sheets; covering the positive electrode protection sheet and the negative electrode protection sheet on all the opposite positive electrode tabs and negative electrode tabs respectively, and connecting the positive electrode tabs and the negative electrode tabs through ultrasonic welding to form a positive electrode tab welding mark and a negative electrode tab welding mark;

after forming the tab welding seal, placing the winding core group on the cover plate which is placed upside down, fixing the positive and negative tab connecting sheets on the insulation stop frame in a clamping groove or a buckling mode, respectively connecting the positive connecting sheet and the positive pole column, and connecting the negative connecting sheet and the negative pole column by laser welding, and forming a positive cover plate welding seal and a negative cover plate welding seal;

after the cover plate welding print is formed and the winding core group is connected with the cover plate in a welding mode, the first winding core unit and the second winding core unit are folded towards the middle and combined, and are encapsulated and fixed;

and then wrapping the base support and the insulating film in an integrated structure on the wrapped and fixed roll core group, and finishing the entering of the shell after the upper edge of the insulating film is connected with the insulating stop frame of the cover plate through hot ironing.

Technical Field

The invention relates to the technical field of lithium ion batteries, in particular to a CTP high-integration lithium ion battery and a manufacturing method thereof.

Background

At present, battery packs of battery enterprises and vehicle enterprises at home and abroad still basically adopt a grouping mode of assembling the battery packs from a single battery to a module and then assembling the battery packs by the module, hundreds of batteries are connected in series and parallel by using a large number of parts to reach the set capacity and voltage, the space utilization rate and the energy density of the battery packs are sacrificed, and meanwhile, the processing cost cannot be effectively controlled.

On the other hand, with the further improvement of the technical threshold requirement of the new subsidy policy of the new energy automobile, the battery enterprises are also actively exploring a new technical direction of the lithium battery, wherein the large battery core and the module size or the direct abandonment of the module are accepted in the industry. For example, a brand-new CTP high-integration power battery development platform (Cell To Pack) is introduced in the penningde era, namely, a battery core is directly integrated into a battery Pack. Compared with the traditional three-level assembly mode of the battery core, the module and the battery pack, the technology can reduce the number of the battery cores or the modules in the battery pack and the use of parts, thereby achieving the purposes of optimizing the space utilization rate, reducing the total weight of the battery pack, achieving the effect of improving the energy density of the battery, and being beneficial to effectively reducing the manufacturing cost of vehicle enterprises and battery enterprises.

At present, in the direction of new lithium battery technology, there is a need to provide a new CTP high-integration lithium ion battery.

Disclosure of Invention

In order to overcome the above defects in the prior art, embodiments of the present invention provide a CTP high-integration lithium ion battery and a manufacturing method thereof, which can achieve a common increase in energy density and voltage of a single battery cell, achieve a completely non-modular assembly from the battery cell to a battery pack, further increase a space utilization rate and a system energy density of the battery pack, and greatly reduce a manufacturing cost of the battery.

In order to achieve the purpose, the invention adopts the following technical scheme:

a CTP high integrated lithium ion battery comprising: the winding device comprises a shell with an opening at one end, a cover plate arranged at the opening end of the shell, a winding core group arranged in the shell, a bottom support wrapping the winding core group and an insulating film;

the winding core group is formed by welding a plurality of first winding core units and second winding core units in series-parallel connection through positive and negative electrode lugs and positive electrode connecting sheets, negative electrode connecting sheets, positive and negative electrode lug connecting sheets, positive electrode protection sheets and negative electrode protection sheets; the first winding core unit comprises at least two winding cores which are connected in series, and the second winding core unit comprises at least two winding cores which are connected in series;

the cover plate includes: the liquid injection device comprises a substrate, a positive pole column, a negative pole column and a liquid injection port arranged on the substrate; the positive pole column is connected with the positive connecting piece, and the negative pole column is connected with the negative connecting piece.

In a preferred embodiment, the winding core group comprises a plurality of symmetrical parallel first winding core units and second winding core units, and the symmetrical parallel first winding core units and the symmetrical parallel second winding core units are arranged in series in the length direction.

In a preferred embodiment, the positive tab and the negative tab of the first winding core unit and the second winding core unit are arranged on the same side, and the positive tab is opposite to the positive tab, and the negative tab is opposite to the negative tab, and arranged on the positive tab and the negative tab at the two ends of the winding core set are respectively clamped between the positive connecting sheet and the positive protective sheet, between the negative connecting sheet and the negative protective sheet, and between the positive tab and the negative tab arranged in the middle and the positive tab connecting sheet and the positive protective sheet, between the positive tab connecting sheet and the negative tab connecting sheet and between the negative tab and the negative protective sheet, and are fixed by ultrasonic welding.

In a preferred embodiment, the positive connecting piece and the positive pole are connected by laser welding, and the negative connecting piece and the negative pole are connected by laser welding.

In a preferred embodiment, the positive electrode connecting sheet and the positive electrode protective sheet are made of aluminum; the negative electrode connecting sheet and the negative electrode protecting sheet are made of copper materials; the positive and negative electrode lug connecting sheets are made of nickel materials with surface treatment.

In a preferred embodiment, the cover plate is further provided with an insulating brake frame, and the positive and negative electrode tab connecting sheets are fixed on the insulating brake frame of the cover plate in a clamping groove or a buckling mode.

In a preferred embodiment, the base support and the insulating film are of a unitary structure, and the upper edge of the insulating film is connected with the insulating stop frame of the cover plate by hot stamping.

In a preferred embodiment, the base support is provided with a plurality of positioning holes and an array of electrolyte holes.

In a preferred embodiment, the cover plate is further provided with an explosion-proof valve.

In a preferred embodiment, when the number of the first core unit or the second core unit is greater than 2 in the longitudinal direction, a plurality of explosion-proof valves may be provided on the cover plate.

A manufacturing method of a CTP high-integration lithium ion battery comprises a first winding core unit and a second winding core unit, wherein the first winding core unit comprises a first winding core and a third winding core which are connected in series; the second roll core unit comprises a second roll core and a fourth roll core which are connected in series, and the manufacturing method comprises the following steps:

the first winding core and the third winding core are respectively arranged in parallel with the second winding core and the fourth winding core symmetrically, wherein a first positive lug of the first winding core is opposite to a second positive lug of the second winding core and is arranged on a positive connecting sheet; the first negative lug of the first winding core is opposite to the second negative lug of the second winding core, the third positive lug of the third winding core is opposite to the fourth positive lug of the fourth winding core and is jointly arranged on the positive and negative lug connecting sheets, and the third negative lug of the third winding core is opposite to the fourth negative lug of the fourth winding core and is arranged on the negative connecting sheets; covering the positive electrode protection sheet and the negative electrode protection sheet on all the opposite positive electrode tabs and negative electrode tabs respectively, and connecting the positive electrode tabs and the negative electrode tabs through ultrasonic welding to form a positive electrode tab welding mark and a negative electrode tab welding mark;

after forming the tab welding seal, placing the winding core group on the cover plate which is placed upside down, fixing the positive and negative tab connecting sheets on the insulation stop frame in a clamping groove or a buckling mode, respectively connecting the positive connecting sheet and the positive pole column, and connecting the negative connecting sheet and the negative pole column by laser welding, and forming a positive cover plate welding seal and a negative cover plate welding seal;

after the cover plate welding print is formed and the winding core group is connected with the cover plate in a welding mode, the first winding core unit and the second winding core unit are folded towards the middle and combined, and are encapsulated and fixed;

and then wrapping the base support and the insulating film in an integrated structure on the wrapped and fixed roll core group, and finishing the entering of the shell after the upper edge of the insulating film is connected with the insulating stop frame of the cover plate through hot ironing.

The technical scheme of the invention has the following remarkable beneficial effects:

the novel CTP highly-integrated lithium ion battery provided by the invention has the beneficial effects that:

the novel CTP high-integration lithium ion battery directly comprises a plurality of internal winding cores connected in series and in parallel, and a battery external structural part is shared, so that a monomer battery core with higher energy density and higher voltage can be prepared, the CTP high-integration or completely module-free technology is realized, the assembly link of a battery module is omitted, the production efficiency, the space utilization rate and the system energy density from the battery to a battery pack are obviously improved, and the manufacturing cost of the battery is greatly reduced.

Specific embodiments of the present invention are disclosed in detail with reference to the following description and drawings, indicating the manner in which the principles of the invention may be employed. It should be understood that the embodiments of the invention are not so limited in scope. The embodiments of the invention include many variations, modifications and equivalents within the spirit and scope of the appended claims. Features that are described and/or illustrated with respect to one embodiment may be used in the same way or in a similar way in one or more other embodiments, in combination with or instead of the features of the other embodiments.

Drawings

The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way. In addition, the shapes, the proportional sizes, and the like of the respective members in the drawings are merely schematic for facilitating the understanding of the present invention, and do not specifically limit the shapes, the proportional sizes, and the like of the respective members of the present invention. Those skilled in the art, having the benefit of the teachings of this invention, may choose from the various possible shapes and proportional sizes to implement the invention as a matter of case.

Fig. 1 is a schematic structural diagram of a novel CTP high-integration lithium ion battery provided in a first embodiment of the present application;

fig. 2 is a schematic structural view of a winding core set according to a first embodiment of the present application;

FIG. 3 is a schematic structural view of the cover plate shown in FIG. 1;

FIG. 4 is a three-dimensional view illustrating the welding of the winding core assembly and the cover plate according to the first embodiment of the present application;

fig. 5 is a schematic structural diagram of a novel CTP high-integration lithium ion battery provided in a second embodiment of the present application;

fig. 6 is a flowchart illustrating steps of a manufacturing method of a CTP high-integration lithium ion battery provided in the present application.

Reference numerals of the above figures:

1. a winding core group; 2. a cover plate; 3. a positive electrode connecting sheet; 4. a negative electrode connecting sheet; 5. connecting sheets for positive and negative electrode tabs; 6. a positive electrode protective sheet; 7. a negative electrode protection sheet; 8. a bottom support; 9. an insulating film; 10. a housing; 11. a first reel unit; 12. a second core unit; 31. welding and printing the positive cover plate; 41. welding and printing the negative cover plate; 61. welding and printing the positive electrode tab; 71. welding and printing a negative electrode tab; 101. a first winding core; 102. a second winding core; 103. a third winding core; 104. a fourth winding core; 201. a substrate; 202. a positive post; 203. a negative pole post; 204. a liquid injection port; 205. an explosion-proof valve; 206. an insulating stopper frame; 1011. a first positive tab; 1012. a first negative electrode tab; 1021. a second positive tab; 1022. a second negative tab; 1031. a third positive tab; 1032. a third negative tab; 1041. a fourth positive tab; 1042. and a fourth negative tab.

Detailed Description

The technical solutions of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments, it should be understood that these embodiments are merely illustrative of the present invention and are not intended to limit the scope of the present invention, and various equivalent modifications of the present invention by those skilled in the art after reading the present invention fall within the scope of the appended claims.

It will be understood that when an element is referred to as being "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and the like as used herein are for illustrative purposes only and do not denote a unique embodiment.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the description of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

In terms of power cell development, the trend is to make a large cell with higher capacity or directly modularize the cell, which poses more serious challenges to the fabrication and safety reliability of the single cell. From electric core structural design, electric core develops to length direction, and electric core has bigger specific surface area, does not influence under the condition of the infiltration effect of electrolyte, can effectively dispel the heat simultaneously, and the security is higher, and more is fit for the battery package and assembles.

Referring to fig. 1, fig. 2 and fig. 3 in combination, the CTP high integrated lithium ion battery provided in the present application may include: the utility model provides a roll up core group, including casing, one end open-ended casing, the setting is in the apron of the open end of casing, set up in roll up core group in the casing and parcel the collet and the insulating film of roll up core group.

The winding core group 1 is formed by welding a plurality of first winding core units 11 and second winding core units 12 in series-parallel connection through a positive electrode lug, a negative electrode connecting sheet 3, a negative electrode connecting sheet 4, a positive electrode lug connecting sheet 5, a positive electrode protecting sheet 6 and a negative electrode protecting sheet 7. The cover plate 2 can comprise a substrate 201, a positive pole 202, a negative pole 203, and a liquid injection port 204 arranged on the substrate 201; the positive pole column 202 is connected with the positive connecting piece 3, and the negative pole column 203 is connected with the negative connecting piece 4. In addition, the core pack 1 may be provided with an explosion-proof valve 205 and an insulating stopper frame 206.

The novel CTP high-integration lithium ion battery directly comprises a plurality of internal winding cores connected in series and in parallel, and a battery external structural part is shared, so that a monomer battery core with higher energy density and higher voltage can be prepared, the CTP high-integration or completely module-free technology is realized, the assembly link of a battery module is omitted, the production efficiency, the space utilization rate and the system energy density from the battery to a battery pack are obviously improved, and the manufacturing cost of the battery is greatly reduced.

In the present embodiment, the first core unit 11 includes at least two cores connected in series, and the second core unit 12 includes at least two cores connected in series.

In the first embodiment, the first core unit 11 is mainly exemplified by including two cores connected in series, and the second core unit 12 is exemplified by including two cores connected in series.

Referring to fig. 2, the winding core group 1 is formed by connecting two first winding core units 11 (first winding core 101 and third winding core 103) connected in series and two second winding core units 12 (second winding core 102 and fourth winding core 104) connected in series in parallel in a two-in-two series "butterfly welding" manner.

Specifically, first core 101 and third core 103 are symmetrically juxtaposed to second core 102 and fourth core 104, respectively. Wherein, the first positive tab 1011 of the first winding core 101 is opposite to the second positive tab 1021 of the second winding core 102 and is arranged on the positive connecting sheet 3; the first negative tab 1012 of the first winding core 101 is opposite to the second negative tab 1022 of the second winding core 102, and the third positive tab 1031 of the third winding core 103 is opposite to the fourth positive tab 1041 of the fourth winding core 104, and are jointly placed on the positive and negative tab connecting sheets 5; the third negative electrode tab 1032 of the third winding core 103 is opposite to the fourth negative electrode tab 1042 of the fourth winding core 104 and is arranged on the negative electrode connecting sheet 4; and all the opposite positive electrode tabs and negative electrode tabs are respectively covered with the positive electrode protection sheet 6 and the negative electrode protection sheet 7 and are connected by ultrasonic welding to form a positive electrode tab welding print 61 and a negative electrode tab welding print 71.

In a further embodiment, as shown in fig. 4, after the tab welding, the winding core assembly 1 is placed on the cover plate 2 which is placed upside down, the positive and negative tab connecting pieces 5 are fixed on the insulation stop frame 206 by a clamping groove or a buckling manner, and the positive connecting piece 3 and the positive post 202, and the negative connecting piece 4 and the negative post 203 are respectively connected by laser welding, and the positive cover plate welding mark 31 and the negative cover plate welding mark 41 are formed.

In this embodiment, the positive and negative tab connecting pieces 5 are fixed on the insulating stop frame 206 of the cover plate 2 by means of a slot or a buckle, so as to prevent the tab tearing caused by the internal shaking of the positive and negative tab connecting pieces 5, or the core is extruded by the positive and negative tab connecting pieces 5 to cause a short circuit, thereby increasing the safety of the battery cell.

In a further embodiment, after the winding core assembly 1 is welded with the cover plate 2, the first winding core unit 11 and the second winding core unit 12 are folded towards the middle and are encapsulated and fixed; and then, the winding core group 1 is wrapped by the base support 8 and the insulating film 9 which are of an integrated structure, and the upper edge of the insulating film 9 is connected with the insulating stop frame 206 of the cover plate 2 through hot ironing, so that the shell entering is completed, as shown in figure 1.

In this embodiment, through collet 8 and the insulating film 9 to roll up core group 1 parcel integrated configuration to carry out the heat with the insulation stop frame 206 of apron 2 and scald continuously, play internal insulation, prevent that roll core from rocking, increase the security, make things convenient for follow-up income shell.

In one embodiment, the positive electrode connecting sheet 3 and the positive electrode protective sheet 6 are made of aluminum, the negative electrode connecting sheet 4 and the negative electrode protective sheet 7 are made of copper, and the positive and negative electrode tab connecting sheets 5 are made of nickel with surface treatment.

In this embodiment, when the positive and negative electrode tab connecting sheets 5 are made of nickel material with surface treated, they can be better welded with the positive electrode aluminum tab and the negative electrode copper tab by ultrasonic welding.

In a further embodiment, the base support 8 is provided with a plurality of positioning holes and an array of electrolyte holes.

Fig. 5 is a schematic structural diagram of a novel CTP highly integrated lithium ion battery formed by two parallel strings and three strings according to a second embodiment of the present application.

Furthermore, the plurality of first winding core units 11 and the plurality of second winding core units 12 are connected by welding the plurality of positive and negative electrode tab connecting sheets 5, and are matched with the corresponding cover plate 2, the shell 10 and the like, so that two-parallel multi-string high-voltage large battery cell monomers can be manufactured.

In this embodiment, for the safety in utilization of guarantee this application electricity core, in length direction, when first core unit 11 or second core unit 12's quantity is greater than 2, can set up a plurality of explosion-proof valves 205 on the apron 2 to can effectively ensure the security of electricity core under extreme condition.

Referring to fig. 6, in the present description, a method for manufacturing a CTP high-integration lithium ion battery is further provided, where the CTP high-integration lithium ion battery includes a first winding core unit and a second winding core unit, and the first winding core unit includes a first winding core and a third winding core connected in series; the second roll core unit comprises a second roll core and a fourth roll core which are connected in series, and the manufacturing method comprises the following steps:

step S10: the first winding core and the third winding core are respectively arranged in parallel with the second winding core and the fourth winding core symmetrically, wherein a first positive lug of the first winding core is opposite to a second positive lug of the second winding core and is arranged on a positive connecting sheet; the first negative lug of the first winding core is opposite to the second negative lug of the second winding core, the third positive lug of the third winding core is opposite to the fourth positive lug of the fourth winding core and is jointly arranged on the positive and negative lug connecting sheets, and the third negative lug of the third winding core is opposite to the fourth negative lug of the fourth winding core and is arranged on the negative connecting sheets; covering the positive electrode protection sheet and the negative electrode protection sheet on all the opposite positive electrode tabs and negative electrode tabs respectively, and connecting the positive electrode tabs and the negative electrode tabs through ultrasonic welding to form a positive electrode tab welding mark and a negative electrode tab welding mark;

step S12: after forming the tab welding seal, placing the winding core group on the cover plate which is placed upside down, fixing the positive and negative tab connecting sheets on the insulation stop frame in a clamping groove or a buckling mode, respectively connecting the positive connecting sheet and the positive pole column, and connecting the negative connecting sheet and the negative pole column by laser welding, and forming a positive cover plate welding seal and a negative cover plate welding seal;

step S14: after the cover plate welding print is formed and the winding core group is connected with the cover plate in a welding mode, the first winding core unit and the second winding core unit are folded towards the middle and combined, and are encapsulated and fixed;

step S16: and then wrapping the base support and the insulating film in an integrated structure on the wrapped and fixed roll core group, and finishing the entering of the shell after the upper edge of the insulating film is connected with the insulating stop frame of the cover plate through hot ironing.

For the development of power cells, the trend is to manufacture large cells with higher capacity or directly modularize the cells, which poses more serious challenges to the manufacture and safety and reliability of single cells.

In the cell structure in the prior art, the positive and negative electrode tabs are welded and attached in series and parallel, so that short circuit risk is easily caused, the welding combination is complex, and the manufacturability is low; in addition, the existing battery cell develops towards the thickness direction, so that the problem of uneven soaking of electrolyte and the problem of heat dissipation safety of the battery cell can be caused.

The application provides a brand-new electric core and a manufacturing process, and the electric core structure is simplified, and has higher manufacturability, safety and electrical property. Specifically, this application makes the innovative design from electric core structural design and technology, and electric core develops to length direction, has bigger surface area to dispel the heat, and more is fit for the battery package and assembles. In addition, roll up the core series connection inside electric core through positive negative pole utmost point ear connection piece 5, simple structure can acquire higher electric core voltage, realizes the direct moduleization of electric core.

It should be noted that, in the description of the present application, the terms "first", "second", and the like are used for descriptive purposes only and for distinguishing similar objects, and no precedence between the two is intended or should be construed to indicate or imply relative importance. In addition, in the description of the present application, "a plurality" means two or more unless otherwise specified.

The above embodiments in the present specification are all described in a progressive manner, and the same and similar parts among the embodiments may be referred to each other, and each embodiment is described with emphasis on being different from other embodiments.

The above embodiments are only a few embodiments of the present invention, and the embodiments of the present invention are described above, but the present invention is only used for the understanding of the present invention, and is not limited to the embodiments. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.