CN114597602B

CN114597602B - Film-coated tab for soft-packaged battery and preparation method thereof

Info

Publication number: CN114597602B
Application number: CN202011416248.8A
Authority: CN
Inventors: 郭永明; 张中林; 郎晓强; 陈思岚; 王安平
Original assignee: BYD Co Ltd
Current assignee: BYD Co Ltd
Priority date: 2020-12-04
Filing date: 2020-12-04
Publication date: 2023-05-05
Anticipated expiration: 2040-12-04
Also published as: CN114597602A

Abstract

The application provides a tectorial membrane utmost point ear for soft packet of battery, including utmost point ear and locating relatively first tectorial membrane and the second tectorial membrane of the relative both sides of utmost point ear, the utmost point ear includes the sheetmetal and pastes locates the utmost point ear glue of the relative both sides of sheetmetal. The first film and the second film respectively comprise a first area, the first area of the first film is opposite to the first area of the second film and covers the tab adhesive of the tab, and the first area of the first film and the first area of the second film are respectively attached to the tab adhesive in a hot pressing mode. According to the laminated tab, the first laminated film and the second laminated film are bonded in a hot pressing mode and cover the tab glue of the tab, dust, impurity particles and the like can be prevented from being adsorbed on the surface of the tab glue, and the influence on the subsequent heat sealing process of the tab is reduced. The application also provides a preparation method of the film-covered tab for the soft-package battery.

Description

Film-coated tab for soft-packaged battery and preparation method thereof

Technical Field

The application relates to the technical field of tabs, in particular to a film-covered tab for a soft-package battery and a preparation method thereof.

Background

With the improvement of the requirements on the heat sealing strength of the aluminum plastic film and the tab, the control of the tab adhesive surface particles of the tab product is more and more strict. However, in the subsequent welding process of the tab, turnover and other processes, dust and impurity particles are inevitably adsorbed on the surface of the tab adhesive, so that the peeling strength of the heat sealing surface is reduced, and the risk of electrolyte permeation is increased. Therefore, a new scheme is needed to design the tab to avoid dust, impurity particles and the like from being adsorbed on the surface of the tab adhesive, so as to reduce the influence on heat sealing.

Disclosure of Invention

The present application aims to solve at least one of the technical problems existing in the prior art. Therefore, the application provides the laminated tab for the soft-packaged battery and the preparation method thereof, and the tab glue for laminating the laminated tab in a hot-pressing way and covering the tab can avoid dust, impurity particles and the like from being adsorbed on the surface of the tab glue, so that the influence on the subsequent heat sealing process of the tab is reduced.

In order to achieve the above-mentioned purpose, this application provides a tectorial membrane utmost point ear for soft packet of battery on the one hand, including utmost point ear and locate relatively the first tectorial membrane and the second tectorial membrane of the relative both sides of utmost point ear, the utmost point ear includes the sheetmetal and pastes locates the utmost point ear glue of the relative both sides of sheetmetal. The first film and the second film respectively comprise a first area, the first area of the first film is opposite to the first area of the second film and covers the tab adhesive of the tab, and the first area of the first film and the first area of the second film are respectively attached to the tab adhesive in a hot pressing mode.

In another aspect, the present application further provides a method for preparing a laminated tab for a soft-pack battery, including the following steps: providing a tab, wherein the tab comprises a metal sheet and tab adhesives attached to two opposite sides of the metal sheet; providing a first coating and a second coating; aligning the first coating film and the second coating film, so that the first coating film and the second coating film are respectively positioned on two opposite sides of the tab, wherein the first coating film and the second coating film respectively comprise a first area, and the first area of the first coating film is opposite to the first area of the second coating film and covers the tab adhesive of the tab; and aligning the first region of the first coating and the first region of the second coating by using a first pressure head, and respectively carrying out hot press lamination on the first region of the first coating and the first region of the second coating with the tab adhesive by outputting heat through the first pressure head.

Compared with the prior art, the beneficial effect that this application had is: the first coating film and the second coating film are bonded through hot pressing and cover the tab glue of the tab, so that dust, impurity particles and the like can be prevented from being adsorbed on the surface of the tab glue, and the influence on the subsequent heat sealing process of the tab is reduced.

Additional aspects and advantages of the application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the application.

Drawings

Fig. 1 is a schematic view of a covered tab for a pouch cell in some embodiments of the present application.

Fig. 2 is a sectional view of the film-coated tab shown in fig. 1 along the II-II direction.

Fig. 3 is a schematic view of a covered tab for a pouch cell in accordance with further embodiments of the present application.

Fig. 4 is a schematic view of a covered tab for a pouch cell in accordance with yet other embodiments of the present application.

Fig. 5 is a flowchart of a method for manufacturing a laminated tab for a soft pack battery according to an embodiment of the present application.

Description of the main reference signs

Film-covered tab 1

Tab 10

First coating film 11

Second coating film 12

Sheet metal 101

First surface 1011

Second surface 1012

First end 1013

Second end 1014

Welded region 1015

Tab adhesive 102

First tab adhesive 1021

Second ear glue 1022

First region 131

Second region 132

Third region 133

Chamfer 134

First indentation area 1321

Second indentation area 1331

First direction A

Second direction B

The following detailed description will further illustrate the application in conjunction with the above-described figures.

Detailed Description

Embodiments of the present application are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals refer to the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary only for the purpose of explaining the present application and are not to be construed as limiting the present application.

Referring to fig. 1 and 2, the present application provides a laminated tab 1 for a soft package battery, which includes a tab 10, and a first laminated film 11 and a second laminated film 12 disposed on opposite sides of the tab 10. The tab 10 includes a metal sheet 101 and tab adhesives 102 attached to two opposite sides of the metal sheet 101.

Specifically, as shown in fig. 2, the metal sheet 101 includes a first surface 1011 and a second surface 1012 disposed opposite to each other, and the tab adhesive 102 includes a first tab adhesive 1021 and a second tab adhesive 1022. The first tab adhesive 1021 and the second tab adhesive 1022 are symmetrically disposed on opposite sides of the metal sheet 101, and the first tab adhesive 1021 and the second tab adhesive 1022 respectively cover a portion of the metal sheet 101 and are attached to the first surface 1011 and the second surface 1012 of the metal sheet 101 by means of hot melting. As shown in fig. 1, the length direction of the first tab adhesive 1021 and the second tab adhesive 1022 is defined as a first direction a, opposite ends of the first tab adhesive 1021 and the second tab adhesive 1022 in the first direction a extend from opposite ends of the metal sheet 101 in the first direction a to the outside of the metal sheet 101 by a certain length, and the ends of the corresponding ends of the first tab adhesive 1021 and the second tab adhesive 1022 in the first direction a are flush and welded together. The first tab adhesive 1021 and the second tab adhesive 1022 may be formed by folding the same tab adhesive 102 in half, or may be two tab adhesives 102, which is not specifically limited in this application.

As shown in fig. 1 and 2, in the embodiment of the present application, the first film 11 and the second film 12 respectively include a first region 131, the first region 131 of the first film 11 and the first region 131 of the second film 12 face each other and cover the tab adhesive 102 of the tab 10, and the first region 131 of the first film 11 and the first region 131 of the second film 12 are respectively bonded with the tab adhesive 102 of the tab 10 by hot pressing. Specifically, as shown in fig. 2, in some embodiments of the present application, the first region 131 of the first film 11 is bonded by hot pressing and covers the first tab adhesive 1021, and correspondingly, the first region 131 of the second film 12 is bonded by hot pressing and covers the second tab adhesive 1022. According to the method, the tab glue 102 on the two opposite sides of the tab 10 is respectively bonded and covered by the first coating film 11 and the second coating film 12 in a hot pressing mode, so that particles can be prevented from being adsorbed on the surface of the tab glue 102, and the influence on the subsequent heat sealing process of the tab 10 is reduced. Before heat-sealing the tab 10, the first and

second films

11 and 12 on the surface of the tab adhesive 102 need to be peeled off to expose the tab adhesive 102 for heat-sealing with a packaging film (e.g., an aluminum plastic film). The first film 11 and the second film 12 may be formed by folding the same film in two, or may be two films, which is not particularly limited in this application.

In the embodiment of the application, the tab adhesive 102 is a multi-layer structure, which includes a lamination layer (not shown in the figure) far away from the metal sheet 101 and located at the outermost side, in order to enable the first and

second films

11 and 12 to be thermally pressed and laminated with the tab adhesive 102 without affecting the function of the tab adhesive 102 for heat sealing, the melting points of the first and

second films

11 and 12 are respectively lower than the melting points of the lamination layers of the tab adhesive 102 covered by the first and second films. Preferably, in the embodiment of the present application, the lamination layer of the tab adhesive 102, the first film 11 and the second film 12 are made of the same material and have different melting points by a modification method, and under the condition of heating and pressurizing, the same material of the three materials is helpful for the hot-press adhesion of the lamination layer of the tab adhesive 102 and the first film 11 and the second film 12, so as to improve the lamination strength of the first film 11 and the second film 12 and the tab adhesive 102. Specifically, in some embodiments of the present application, the lamination layer of the tab adhesive 102 may be a modified PET material with a melting point of 138 ℃ to 142 ℃, and the first and

second films

11 and 12 are both modified PET materials with a melting point of 133 ℃ to 137 ℃. It should be noted that, for a certain material, modification means that one or more properties of the material are changed to meet the use requirement by changing at least one of the components of the raw materials required for preparing the material, the selected stabilizer, the type and amount of the catalyst, the production process and other factors. The modification of the material includes blending modification, copolymerization modification, surface coating modification and other common methods, and will not be described here.

Alternatively, in other embodiments, the lamination layer of the tab adhesive 102, the first cover film 11 and the second cover film 12 may also use other kinds of modified materials, such as modified PP materials, which meet the requirements. Alternatively, in other embodiments, different materials may be used for the lamination layer of the tab adhesive 102, the first lamination film 11 and the second lamination film 12, for example, a modified PET material is used for the lamination layer of the tab adhesive 102, and a modified PP material is used for the first lamination film 11 and the second lamination film 12, so long as the melting point of the first lamination film 11 and the second lamination film 12 is lower than that of the lamination layer of the tab adhesive 102, so that the first lamination film 11 and the second lamination film 12 can be laminated with the tab adhesive 102 in a hot press manner without affecting the function of the tab adhesive 102 for subsequent heat sealing, which will not be described herein.

It can be understood that the peel strength of the first region 131 of the first film 11 and the first region 131 of the second film 12 after the first region 131 of the second film 12 and the corresponding tab adhesive 102 are thermally pressed and bonded should be controlled within a reasonable range, so that the first region 131 of the first film 11 and the first region 131 of the second film 12 and the tab adhesive 102 are not easily separated to protect the surface of the tab adhesive 102 after the first region 131 of the first film 11 and the first region 131 of the second film 12 are thermally pressed and bonded, and the surface of the tab adhesive 102 is not easily torn off from the surface of the tab adhesive 102 so as to facilitate the subsequent heat sealing of the tab 10. In some embodiments of the present application, the peel strength of the first region 131 of the first film 11 and the first region 131 of the second film 12 after the hot press lamination of the corresponding tab adhesive 102 is controlled to be in a range of 0.01N/mm to 0.05N/mm.

Wherein at least one corner of at least one of the first cover film 11 and the second cover film 12 is provided with a chamfer 134 to facilitate tearing off the at least one cover film. Preferably, in some embodiments of the present application, the first film 11 and the second film 12 are respectively provided with at least one chamfer 134, and the chamfer 134 on the first film 11 is staggered with the chamfer 134 on the second film 12, so that the first film 11 and the second film 12 can be conveniently torn off from the tab adhesive 102.

In the embodiment of the present application, the thickness of each of the first and

second films

11 and 12 ranges from 0.1mm to 0.15mm. The thickness of the first coating 11 and the second coating 12 is controlled within the range of 0.1mm to 0.15mm, so that the thickness of the first coating 11 and the second coating 12 is thinner, the first coating 11 and the second coating 12 can be quickly bonded to the tab adhesive 102 in a hot-pressing way, the time consumption is less, and the lamination material is saved and the cost is reduced.

Referring to fig. 1 and fig. 2 again, in some embodiments of the present application, the first film 11 and the second film 12 further include a second area 132, and the second area 132 of the first film 11 is opposite to the second area 132 of the second film 12 and covers at least a portion of the surface of the metal sheet 101 exposed outside the tab adhesive 102, and the second area 132 of the first film 11 and the second area 132 of the second film 12 are respectively attached to the metal sheet 101 by thermal fusion. Specifically, as shown in fig. 2, the second region 132 of the first film 11 is heat-fused to cover at least a portion of the metal sheet 101 exposed outside the first tab adhesive 1021, and the second region 132 of the second film 12 is heat-fused to cover at least a portion of the metal sheet 101 exposed outside the second tab adhesive 1022. Therefore, the bonding area of the first and

second films

11 and 12 and the tab 10 is increased, so that the bonding of the first and

second films

11 and 12 and the tab 10 is more reliable, the first and

second films

11 and 12 are not easy to separate from the tab 10, and the first areas 131 of the first and

second films

11 and 12 are ensured to cover the tab adhesives 102 on two opposite sides of the tab 10, so as to avoid the surface of the tab adhesive 102 from adsorbing impurity particles.

Further, as shown in fig. 1 and 2, in some embodiments of the present application, the first film 11 and the second film 12 further include a third area 133, and the third area 133 of the first film 11 is opposite to the third area 133 of the second film 12 and is attached by hot melting. The third region 133 of the first film 11 and the third region 133 of the second film 12 refer to portions of the opposite ends of the first film 11 and the second film 12 in the first direction a, which exceed the opposite ends of the metal sheet 101 in the first direction a and are not covered by the tab adhesive 102. By bonding the third region 133 of the first film 11 and the third region 133 of the second film 12 by hot melt, both ends of the first film 11 and the second film 12 are bonded, respectively, the tab 10 between the first film 11 and the second film 12 can be clamped, and further the bonding between the first film 11 and the second film 12 and the tab 10 can be enhanced, so that the first film 11 and the second film 12 are not easily separated from the tab 10.

It can be appreciated that in some embodiments of the present application, the hot-press bonding of the first region 131 of the first film 11 and the first region 131 of the second film 12 with the tab adhesive 102, the hot-melt bonding of the second region 132 of the first film 11 and the second region 132 of the second film 12 with the metal sheet 101, and the hot-melt bonding of the third region 133 of the first film 11 and the third region 133 of the second film 12 are performed by bonding the film with the tab adhesive 102, the film with the metal sheet 101, and the film with the film, respectively, in consideration of the difference in materials and bonding areas of the three bonding main bodies, it is difficult to achieve the same pressure head and add certain pressure and heat, therefore, in some embodiments of the present application, the first pressure head is used to achieve the thermal compression bonding of the first region 131 of the first film 11 and the first region 131 of the second film 12 with the tab adhesive 102, the second pressure head is used to achieve the thermal fusion bonding of the second region 132 of the first film 11 and the second region 132 of the second film 12 with the metal sheet 101, and the third pressure head is used to achieve the thermal fusion bonding of the third region 133 of the first film 11 and the third region 133 of the second film 12. The pressure and heat required to be added by the first pressure head, the second pressure head and the third pressure head are respectively related to the material to be pressed and the pressing area, and are required to be determined according to specific conditions, and the method is not limited herein.

It should be noted that, in some embodiments of the present application, the second region 132 of the first film 11 and the second region 132 of the second film 12 include two portions adjacent to two opposite ends of the tab adhesive 102 in the second direction B, so the hot-melt bonding of the second region 132 of the first film 11 and the second region 132 of the second film 12 with the metal sheet 101 may be performed by two second pressure heads, or may be performed by two times by the same second pressure head. Wherein the second direction B is perpendicular to the first direction a.

Similarly, in some embodiments of the present application, the third region 133 of the first film 11 and the third region 133 of the second film 12 include two portions adjacent to opposite ends of the tab adhesive 102 in the first direction a, and therefore, the hot-melt bonding between the third region 133 of the first film 11 and the third region 133 of the second film 12 may be performed by two third pressure heads, or may be performed by the same third pressure head in two times.

Preferably, as shown in fig. 1, in some embodiments of the present application, the second pressing head is provided with a first pressing structure, after the second pressing head is used to thermally melt and attach the second area 132 of the first film 11 and the second area 132 of the second film 12 to the metal sheet 101, the second area 132 of the first film 11 and the second area 132 of the second film 12 are respectively formed with a first pressing area 1321, and the first pressing area 1321 of the first film 11 is opposite to the first pressing area 1321 of the second film 12. Specifically, as shown in fig. 1, in some embodiments of the present application, the second pressing head is provided with two first pressing structures extending along the first direction a and spaced along the first direction a, and the second area 132 of the first film 11 and the second area 132 of the second film 12 are respectively formed with two first pressing areas 1321 extending along the first direction a and spaced along the first direction a under the action of the heat output by the second pressing head and the first pressing structures. Of course, in other embodiments of the present application, the number of the first imprint structures may be one, three or other reasonable number.

It can be appreciated that by adding the first embossing structure to the second pressing head, the first embossing area 1321 is formed correspondingly after the second area 132 of the first film 11 and the second area 132 of the second film 12 are bonded with the metal sheet 101 by hot melting, so that the bonding area between the second area 132 of the first film 11 and the second area 132 of the second film 12 and the metal sheet 101 can be increased, which is beneficial to enhancing the bonding strength between the second area 132 of the first film 11 and the second area 132 of the second film 12 and the metal sheet 101. Specifically, in some embodiments of the present application, by the hot-melt bonding action of the second pressing head provided with the first pressing structure, the peel strength of the second area 132 of the first film 11 and the second area 132 of the second film 12 after the hot-melt bonding with the metal sheet 101 is 0.1N/mm to 0.3N/mm, which is higher than the peel strength of the first area 131 of the first film 11 and the first area 131 of the second film 12 after the hot-press bonding with the tab adhesive 102, the second area 132 of the first film 11 and the second area 132 of the second film 12 are not easily separated from the metal sheet 101, so as to further improve the reliability of the first area 131 of the first film 11 and the first area 131 of the second film 12 in the bonding covering the tab adhesive 102, and avoid the dust particles from being adsorbed on the surface of the tab adhesive 102.

Further preferably, as shown in fig. 1, in some embodiments of the present application, the second pressing head is provided with the first pressing structure, and the third pressing head is provided with the second pressing structure, after the third pressing head is used to thermally fuse and attach the third region 133 of the first film 11 and the third region 133 of the second film 12, the third region 133 of the first film 11 and the third region 133 of the second film 12 are respectively formed with the second pressing region 1331, and the second pressing region 1331 of the first film 11 is opposite to the second pressing region 1331 of the second film 12. Specifically, as shown in fig. 1, in some embodiments of the present application, the third pressing head is provided with a second pressing structure extending along the second direction B, and the third area 133 of the first film 11 and the third area 133 of the second film 12 are respectively formed with two second pressing mark areas 1331 extending along the second direction B under the effect of the heat output by the third pressing head and the second pressing structure, and the two second pressing mark areas 1331 are respectively adjacent to two opposite ends of the tab adhesive 102 in the first direction a. Of course, in other embodiments of the present application, the number of the second embossed structures may be at least two, so as to form at least two second embossed regions 1331 in each portion of the third region 133 of the first cover film 11 and the third region 133 of the second cover film 12 in the first direction a.

Similarly, by adding the second embossing structure on the third pressing head, the second indentation area 1331 is correspondingly formed after the third area 133 of the first coating film 11 and the third area 133 of the second coating film 12 are bonded by hot melting, so that the bonding area of the third area 133 of the first coating film 11 and the third area 133 of the second coating film 12 can be increased, and the bonding strength of the third area 133 of the first coating film 11 and the third area 133 of the second coating film 12 can be enhanced. Specifically, in some embodiments of the present application, by the hot-melt lamination of the third pressing head provided with the second pressing structure, the peel strength of the third region 133 of the first film 11 and the third region 133 of the second film 12 after hot-melt lamination is greater than 0.1N/mm, and the third region 133 of the first film 11 and the third region 133 of the second film 12 may not be easily separated, so that the reliability of laminating the first region 131 of the first film 11 and the first region 131 of the second film 12 to cover the tab adhesive 102 may be improved, and dust particles and the like may be avoided from being adsorbed on the surface of the tab adhesive 102.

The first embossing structure on the second embossing structure and the second embossing structure on the third embossing structure may be cross-meshed, serpentine or linear bar-shaped, and the first embossing structure and the second embossing structure may be identical or different in grain and/or number, which is not particularly limited.

Of course, in other embodiments of the present application, only one of the second ram and the third ram may be provided with an embossing structure. Specifically, as shown in fig. 3, in other embodiments of the present application, only the second pressing head of the second pressing head and the third pressing head is provided with the first pressing structure, so that after the second area 132 of the first film 11 and the second area 132 of the second film 12 are bonded with the metal sheet 101 by hot melting, first pressing mark areas 1321 are formed respectively, and the first pressing mark areas 1321 of the first film 11 are opposite to the first pressing mark areas 1321 of the second film 12, thereby improving the reliability of bonding the first area 131 of the first film 11 and the first area 131 of the second film 12 to cover the tab adhesive 102. As shown in fig. 4, in still other embodiments of the present application, only the third pressing head of the second pressing head and the third pressing head is provided with the second pressing structure, so that after the third region 133 of the first film 11 and the third region 133 of the second film 12 are bonded by hot melting, the second pressing regions 1331 are formed respectively, and the second pressing regions 1331 of the first film 11 are opposite to the second pressing regions 1331 of the second film 12, so that the reliability of bonding the first region 131 of the first film 11 and the first region 131 of the second film 12 to cover the tab adhesive 102 is also improved.

Referring again to fig. 1 and 2, the metal sheet 101 includes a first end 1013 and a second end 1014 at opposite ends thereof in the second direction B, the first end 1013 being for making electrical connection between the pouch cells, the second end 1014 being for welding a cell foil (copper foil or aluminum foil) of the pouch cells. Specifically, as shown in fig. 1, the first end 1013 has a welding region 1015, and the welding region 1015 is used for welding with the first end 1013 of the metal sheet 101 of the other tab 10, and the second ends 1014 of the two metal sheets 101 welded to each other are respectively welded to the cell foil of the pouch cell, so as to achieve electrical connection between the two pouch cells.

Preferably, as shown in fig. 1 and 2, in some embodiments of the present application, the second region 132 of the first coating 11 and the second region 132 of the second coating 12 cover the welding region 1015 of the first end 1013 of the metal sheet 101, so that the welding region 1015 can be protected, and particle impurities are prevented from being adsorbed to the welding region 1015 before the first end 1013 is welded, which is beneficial to improving the welding effect. In some embodiments of the present application, as shown in fig. 1, when the second region 132 of the first film 11 and the second region 132 of the second film 12 are formed with the first indentation region 1321, and the second region 132 of the first film 11 and the second region 132 of the second film 12 cover the welding region 1015 of the first end 1013, the first indentation region 1321 and the welding region 1015 do not overlap, so that the subsequent welding effect can be prevented from being affected by the indentations in the welding region 1015. Before welding the first end 1013 of the metal sheet 101, the second region 132 of the first film 11 and the second region 132 of the second film 12 need to be peeled off to expose the welding region 1015 of the first end 1013, thereby avoiding the influence of the welding effect due to the high-temperature melting of the film caused by welding.

In addition, in the prior art, the second end 1014 of the metal sheet 101 is typically bent before being welded to the die foil of the pouch cell, so the second region 132 of the first film 11 and the second region 132 of the second film 12 do not need to cover the entire second end 1014. As shown in fig. 1 and 2, in some embodiments of the present application, the second region 132 of the first cover film 11 and the second region 132 of the second cover film 12 cover the surface of the second end 1014 adjacent to the tab adhesive 102.

Referring to fig. 5, the present application further provides a method for preparing the laminated tab 1 for a soft package battery, which specifically includes the following steps.

In step S1, a tab 10 is provided, and the tab 10 includes a metal sheet 101 and tab adhesives 102 adhered to two opposite sides of the metal sheet 101.

Step S2, providing a first coating film 11 and a second coating film 12.

In step S3, the first film 11 and the second film 12 are aligned, so that the first film 11 and the second film 12 are respectively located at two opposite sides of the tab 10, where the first film 11 and the second film 12 respectively include a first area 131, and the first area 131 of the first film 11 is opposite to the first area 131 of the second film 12 and covers the tab adhesive 102 of the tab 10.

Step S4, the first pressing head is used to align the first area 131 of the first film 11 and the first area 131 of the second film 12, and the heat is output by the first pressing head to thermally press and bond the first area 131 of the first film 11 and the first area 131 of the second film 12 with the tab adhesive 102.

When the first region 131 and the first region 131 of the second film 12 are respectively bonded with the tab adhesive 102 by hot pressing, the heat can be transferred to the tab adhesive 102 and the film by heating the metal sheet 101, or the heat can be transferred to the tab adhesive 102 and the film by the first pressure head. Preferably, in the embodiment of the present application, the first area 131 of the first film 11 and the first area 131 of the second film 12 are respectively bonded with the tab adhesive 102 by hot pressing through the output heat of the first pressure head, and compared with the metal sheet 101, the heat dissipation area of the first pressure head is small, the heat loss is less, and the efficiency of heat transfer is improved.

The first film 11 and the second film 12 may be formed by folding the same film in two, or may be two films, which is not particularly limited in this application.

In the preparation method provided by the application, the first coating film 11 and the second coating film 12 are respectively bonded by hot pressing and cover the tab glue 102 on two opposite sides of the tab 10, so that the particulate matter can be prevented from being adsorbed on the surface of the tab glue 102, and the influence on the subsequent heat sealing process of the tab 10 is reduced. Before the tab 10 is heat sealed, the first cover film 11 and the second cover film 12 on the surface of the tab adhesive 102 need to be torn off, so that the tab adhesive 102 is exposed to be heat sealed with a packaging film (for example, an aluminum plastic film).

In the embodiment of the present application, the tab adhesive 102 is a multi-layer structure, which includes a bonding layer far away from the metal sheet 101 and located at the outermost side. It can be understood that, in order to enable the first and

second films

11 and 12 to be thermally pressed and bonded to the tab adhesive 102 without affecting the function of the tab adhesive 102 for heat sealing, the melting points of the first and

second films

11 and 12 are lower than the melting point of the bonding layer of the tab adhesive 102 covered by the first and second films. Preferably, in the embodiment of the present application, the lamination layer of the tab adhesive 102, the first film 11 and the second film 12 are made of the same material and have different melting points by a modification method, and under the condition of heating and pressurizing, the same material of the three materials is helpful for the hot-press adhesion of the lamination layer of the tab adhesive 102 and the first film 11 and the second film 12, so as to improve the lamination strength of the first film 11 and the second film 12 and the tab adhesive 102. Specifically, in some embodiments of the present application, the lamination layer of the tab adhesive 102 is made of a modified PET material having a melting point of 138 ℃ to 142 ℃, the first film 11 and the second film 12 are made of a modified PET material having a melting point of 133 ℃ to 137 ℃, and correspondingly, when the first region 131 of the first film 11 and the first region 131 of the second film 12 are bonded with the tab adhesive 102 by hot pressing, the hot pressing temperature is 133 ℃ to 137 ℃, and the hot pressing time is 0.5s. The hot pressing temperature is controlled to be the same as or close to the same as the melting points of the first coating film 11 and the second coating film 12, and the hot pressing time is controlled to be a short time, so that the requirements of hot pressing and bonding of the first coating film 11 and the second coating film 12 with the tab adhesive 102 can be met, and damage to the first coating film 11 and the second coating film 12 caused by overhigh hot pressing temperature and overlong hot pressing time can be avoided.

Of course, in other embodiments, other kinds of modified materials, such as modified PP materials, that meet the requirements, may be used for the lamination layer of the tab adhesive 102, the first cover film 11, and the second cover film 12. In other embodiments, different materials may be used for the lamination layer of the tab adhesive 102, the first lamination film 11 and the second lamination film 12, for example, a modified PET material is used for the lamination layer of the tab adhesive 102, and a modified PP material is used for the first lamination film 11 and the second lamination film 12, so long as the melting point of the first lamination film 11 and the second lamination film 12 is lower than that of the lamination layer of the tab adhesive 102, so that the first lamination film 11 and the second lamination film 12 can be thermally pressed and laminated with the tab adhesive 102 without affecting the subsequent function of the tab adhesive 102 for heat sealing. It can be understood that when the lamination layer of the tab adhesive 102, the first film 11 and the second film 12 are made of other materials, the hot pressing temperature and the hot pressing time thereof are required to be determined according to practical situations, which is not limited herein.

Further, in some embodiments of the present application, the preparation method further includes step S5: the second pressure head is utilized to align the second area 132 of the first coating film 11 and the second area 132 of the second coating film 12, and the second area 132 of the first coating film 11 and the second area 132 of the second coating film 12 are respectively in hot melting bonding with the metal sheet 101 through the output of heat of the second pressure head. Therefore, in some embodiments of the present application, the first region 131 of the first film 11 and the first region 131 of the second film 12 are attached to the tab adhesive 102 on two opposite sides of the tab 10, and meanwhile, the second region 132 of the first film 11 and the second region 132 of the second film 12 are attached to the metal sheet 101 of the tab 10, so that the attaching area of the first film 11 and the second film 12 to the tab 10 is increased, the attaching of the first film 11 and the second film 12 to the tab 10 is more reliable, and the first film 11 and the second film 12 are not easy to separate from the tab 10, thereby ensuring that the first region 131 of the first film 11 and the first region 131 of the second film 12 cover the corresponding tab adhesive 102 to avoid the surface of the tab adhesive 102 from adsorbing particulate impurities.

Still further, in some embodiments of the present application, the preparation method further includes step S6: the third region 133 of the first coating film 11 and the third region 133 of the second coating film 12 are aligned by a third pressure head, and heat is output by the third pressure head to thermally fuse and attach the third region 133 of the first coating film 11 and the third region 133 of the second coating film 12. By bonding the third region 133 of the first film 11 and the third region 133 of the second film 12 by hot melt, both ends of the first film 11 and the second film 12 are bonded, respectively, the tab 10 between the first film 11 and the second film 12 can be clamped, and further the bonding between the first film 11 and the second film 12 and the tab 10 can be enhanced, so that the first film 11 and the second film 12 are not easily separated from the tab 10.

It can be appreciated that in some embodiments of the present application, the hot press bonding of the first region 131 of the first film 11 and the first region 131 of the second film 12 with the tab adhesive 102, the hot melt bonding of the second region 132 of the first film 11 and the second region 132 of the second film 12 with the metal sheet 101, and the hot melt bonding of the third region 133 of the first film 11 and the third region 133 of the second film 12 are respectively the film and the tab adhesive 102, the film and the metal sheet 101, and the film, and it is difficult to implement the above-mentioned first pressure head, the second pressure head, and the third pressure head with a certain pressure and heat being added, considering that the materials of the three groups of bonding bodies are different, and the bonding areas are different. The first pressure head, the second pressure head and the third pressure head are independent, that is, the working sequence of the first pressure head, the second pressure head and the third pressure head is not unique, that is, the step sequence of the preparation method is not limited to the sequence of the aforementioned S4-S5-S6, and can be other sequences such as S4-S6-S5 or S5-S4-S6. The pressure and heat needed to be added when the first pressure head, the second pressure head and the third pressure head work are respectively related to the material to be pressed and the pressing area, and the pressure and heat are needed to be determined according to specific conditions, and are not limited herein.

Optionally, in an embodiment of the present application, at least one of the second ram and the third ram is provided with an embossing structure. Preferably, in some embodiments of the present application, the second pressing head is provided with a first embossing structure, the second area 132 of the first film 11 and the second area 132 of the second film 12 are respectively formed with a first embossing area 1321 under the action of the heat output by the second pressing head and the first embossing structure, and the first embossing area 1321 on the first film 11 is opposite to the first embossing area 1321 on the second film 12 (see fig. 1). By adding the first embossing structure on the second pressing head, the first embossing area 1321 is correspondingly formed after the second area 132 of the first coating film 11 and the second area 132 of the second coating film 12 are bonded with the metal sheet 101 in a hot melting manner, so that the bonding area of the second area 132 of the first coating film 11 and the second area 132 of the second coating film 12 with the metal sheet 101 can be increased, the bonding strength of the second area 132 of the first coating film 11 and the second area 132 of the second coating film 12 with the metal sheet 101 can be enhanced, the reliability of bonding the first area 131 of the first coating film 11 and the first area 131 of the second coating film 12 with the tab adhesive 102 can be improved, and dust particles are prevented from being adsorbed on the surface of the tab adhesive 102.

Further preferably, in some embodiments of the present application, the third pressing head is provided with a second embossing structure, the third area 133 of the first film 11 and the third area 133 of the second film 12 are respectively formed with a second embossing area 1331 under the action of the heat output by the third pressing head and the second embossing structure, and the second embossing area 1331 on the first film 11 is opposite to the second embossing area 1331 on the second film 12 (see fig. 1). By adding the second embossing structure on the third pressing head, the second indentation area 1331 is correspondingly formed after the third area 133 of the first coating film 11 and the third area 133 of the second coating film 12 are in hot melting lamination, so that the lamination area of the third area 133 of the first coating film 11 and the third area 133 of the second coating film 12 can be increased, the bonding strength between the third area 133 of the first coating film 11 and the third area 133 of the second coating film 12 can be enhanced, the reliability of lamination of the first area 131 of the first coating film 11 and the first area 131 of the second coating film 12 to the lug adhesive 102 can be improved, and dust particles are prevented from being adsorbed on the surface of the lug adhesive 102.

As described above, before the tab 10 is heat sealed, the first cover film 11 and the second cover film 12 on the surface of the tab adhesive 102 need to be peeled off, so that the tab adhesive 102 is exposed, thereby facilitating the heat sealing with the packaging film (for example, an aluminum plastic film). Preferably, in some embodiments of the present application, after step S2, the preparation method further includes the steps of: at least one corner of at least one of the first and

second films

11 and 12 is provided with a chamfer 134 (see fig. 1). By providing the chamfer 134 on the first cover film 11 and/or the second cover film 12, the first cover film 11 and the second cover film 12 can be easily torn off from the tab adhesive 102. When the first film 11 and the second film 12 are provided with the chamfer 134, the chamfer 134 on the first film 11 is offset from the chamfer 134 on the second film 12.

It should be noted that, the laminated tab 1 prepared by the above preparation method also has other functions and features similar to those of the laminated tab 1 for a soft-pack battery, and the detailed description will be omitted herein for reference to the relevant content of the laminated tab 1 for a soft-pack battery.

In the description of the present specification, the reference to the terms "first", "second", and "third", etc. are used for name discrimination only, and do not have a specific designated meaning; the description of the terms "embodiment," "particular embodiment," "example," and the like, means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present application. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

While embodiments of the present application have been shown and described, it will be understood by those of ordinary skill in the art that: many changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the application, the scope of which is defined by the claims and their equivalents.

Claims

1. A film-coated tab for a pouch cell, comprising:

the tab comprises a metal sheet and tab adhesives adhered to two opposite sides of the metal sheet; and

the first coating film and the second coating film are oppositely arranged on two opposite sides of the tab;

the first covering film and the second covering film respectively comprise a first area, and the first area of the first covering film is opposite to the first area of the second covering film and covers the tab adhesive of the tab; the first region of the first coating film and the first region of the second coating film are respectively attached to the tab adhesive in a hot pressing mode;

the first coating film and the second coating film also respectively comprise a second area, the second area of the first coating film is opposite to the second area of the second coating film and covers at least part of the surface of the metal sheet exposed outside the tab adhesive, and the second area of the first coating film and the second area of the second coating film are respectively attached to the metal sheet in a hot melting mode;

The first coating film and the second coating film are used for being torn off before the tab and the packaging film of the soft package battery are subjected to heat sealing, so that the tab adhesive is exposed.

2. The laminated tab for a pouch cell of claim 1, wherein the first and second films further comprise a third region, respectively, the third region of the first film being directly opposite to the third region of the second film and being bonded by heat fusion.

3. The laminated tab for a pouch cell as claimed in claim 2, wherein a first indentation region is formed in each of the second region of the first laminated film and the second region of the second laminated film, and the first indentation region of the first laminated film is opposite to the first indentation region of the second laminated film; and/or

And a second indentation area is formed in the third area of the first coating and the third area of the second coating respectively, and the second indentation area of the first coating is opposite to the second indentation area of the second coating.

4. The covered tab for a pouch cell as defined in claim 3, wherein the metal sheet comprises a first end portion for making electrical connection between the pouch cells, the first end portion having a welding area;

When the first indentation area is formed in the second area of the first coating and the second area of the second coating, and the welding area of the first end is covered by the second area of the first coating and the second area of the second coating, the first indentation area and the welding area are not overlapped.

5. The covered tab for a pouch cell as defined in claim 4, wherein the metal sheet further comprises a second end opposite the first end, the second region of the first cover and the second region of the second cover covering a surface of the second end adjacent the tab adhesive.

6. The laminated tab for a pouch cell of claim 1, wherein the tab adhesive comprises an outermost lamination layer remote from the metal sheet, the first lamination having a melting point lower than that of the lamination layer of the tab adhesive covered thereby, and the second lamination having a melting point lower than that of the lamination layer of the tab adhesive covered thereby.

7. The laminated tab for a pouch cell of claim 6, wherein the lamination layer of the tab adhesive has a melting point of 138 ℃ to 142 ℃, and the first and second lamination films have melting points of 133 ℃ to 137 ℃.

8. The laminated tab for a pouch cell as defined in claim 1, wherein at least one corner of at least one of the first and second laminated films is provided with a chamfer.

9. The coated tab for a pouch cell as defined in claim 1, wherein the thickness of the first and second coating films ranges from 0.1mm to 0.15mm.

10. The laminated tab for a pouch battery according to claim 2, wherein the peel strength of the first region of the first laminated film and the first region of the second laminated film after hot press lamination with the tab adhesive ranges from 0.01N/mm to 0.05N/mm; and/or

The peel strength of the second area of the first coating film and the second area of the second coating film after the metal sheet is subjected to hot melt lamination ranges from 0.1N/mm to 0.3N/mm; and/or

And the peel strength of the third region of the first coating and the third region of the second coating after hot melt lamination is greater than 0.1N/mm.

11. The preparation method of the film-covered tab for the soft-package battery is characterized by comprising the following steps of:

providing a tab, wherein the tab comprises a metal sheet and tab adhesives attached to two opposite sides of the metal sheet;

Providing a first coating and a second coating;

aligning the first coating film and the second coating film, so that the first coating film and the second coating film are respectively positioned on two opposite sides of the tab, wherein the first coating film and the second coating film respectively comprise a first area, the first area of the first coating film is opposite to the first area of the second coating film and covers the tab adhesive of the tab, the first coating film and the second coating film respectively further comprise a second area, and the second area of the first coating film is opposite to the second area of the second coating film and covers at least part of the surface of the metal sheet exposed outside the tab adhesive;

aligning a first region of the first coating film and a first region of the second coating film by using a first pressure head, and outputting heat through the first pressure head to respectively thermally press and attach the first region of the first coating film and the first region of the second coating film to the tab adhesive, wherein the first coating film and the second coating film are used for being torn off before the tab and the packaging film of the soft package battery are thermally sealed, so that the tab adhesive is exposed; and

and aligning the second area of the first coating and the second area of the second coating by using a second pressure head, and outputting heat through the second pressure head to attach the second area of the first coating and the second area of the second coating to the metal sheet in a hot melting way.

12. The method of claim 11, wherein when the first region of the first coating and the first region of the second coating are bonded to the tab adhesive by hot pressing, the hot pressing temperature is 133 ℃ to 137 ℃ and the hot pressing time is 0.5s.

13. The method for manufacturing a laminated tab for a pouch cell as claimed in claim 11, wherein the first and second laminated films further comprise third regions, respectively, the third regions of the first laminated film being opposite to the third regions of the second laminated film; the preparation method further comprises the steps of:

and aligning a third region of the first coating and a third region of the second coating by using a third pressure head, and outputting heat through the third pressure head to thermally melt and attach the third region of the first coating and the third region of the second coating.

14. The method for manufacturing a laminated tab for a soft pack battery according to claim 13, wherein the second press head is provided with a first embossing structure, a first embossing region is formed in the second region of the first laminated film and the second region of the second laminated film under the action of heat output by the second press head and the first embossing structure, and the first embossing region on the first laminated film is opposite to the first embossing region on the second laminated film; and/or

The third pressing head is provided with a second pressing structure, a second pressing mark area is formed in the third area of the first film and the third area of the second film under the action of heat output by the third pressing head and the second pressing structure, and the second pressing mark area on the first film is opposite to the second pressing mark area on the second film.

15. The method for manufacturing a laminated tab for a pouch cell as claimed in claim 11, wherein after the first and second laminated films are provided, the method further comprises the steps of:

and forming a chamfer at least one corner of at least one of the first coating film and the second coating film.