Base material trepanning device and composite current collector

Abstract

The invention discloses a base material perforating device and a composite current collector, and belongs to the technical field of current collectors, and the base material perforating device comprises a perforating assembly which is provided with a plurality of puncturing parts and is used for perforating a membrane material; the pressure bearing assembly is used for providing support for the membrane material during rolling and punching; the heating assembly is used for heating the puncture part so as to soften the film during puncture; the tensioning mechanism is used for providing tensioning force for the thin film; and the puncture part stays for a time t in the film after puncturing, so that secondary pore forming of the film at the inner end part of the punctured hole is promoted, and pores with larger sizes and crystallinity are formed. According to the device, the supporting layer with the special-shaped hole structure can be rapidly formed.

Description

Technical Field

[0001] The present invention relates to the technical field of thin film processing, and in particular to a substrate opening device and a composite current collector. Background Art

[0002] In secondary batteries, a current collector is needed, which is the part that converges current and is generally made of aluminum foil or copper foil. In the prior art, a composite current collector is proposed, which includes a polymer support layer and a metal layer arranged on both sides of the support layer. This can improve the safety of subsequent batteries. Compared with metal foil current collectors, this composite structure can also reduce the weight of the current collector and improve the energy density of lithium-ion batteries.

[0003] For composite current collectors, it is generally based on vapor deposition or water electroplating. The bonding force between the conductive layer and the support layer is relatively poor. At the same time, since the base film is relatively flat, the flatness of the conductive layer is also high, and the bonding force of the subsequent coating of the active material is also relatively poor. Generally, the support layer (base film) is treated by corona treatment to increase the roughness of its surface; or, the roughness of the conductive layer is increased by etching on the surface of the conductive layer, thereby improving the bonding force and active area with the active material. Summary of the invention

[0004] In the prior art, the method of opening holes in the base film is often directly based on the method of needle roller puncturing holes, which cannot meet the needs of special-shaped holes and has limited improvement in adhesion.

[0005] The present invention aims to solve one of the technical problems in the related art at least to a certain extent. To this end, one object of the present invention is to provide a hole-forming device for a current collector substrate, which can quickly form a support layer with a special-shaped hole structure.

[0006] The second objective of the present invention is to propose a composite current collector based on the above-mentioned pore structure.

[0007] The technical solution of the present invention is as follows:

[0008] A substrate opening device, comprising

[0009] The punching assembly is provided with a plurality of puncturing components for punching holes in the membrane material;

[0010] The pressure-bearing component is used to provide support for the membrane material during roller punching;

[0011] A heating component, used for heating the puncture component to soften the film during puncture;

[0012] and, a tensioning mechanism for providing tensioning force to the film;

[0013] The puncture component has a residence time t in the film after puncturing, so as to promote secondary pore formation in the film at the inner end of the punctured hole, thereby forming pores with larger size and crystallinity.

[0014] Based on the above technical solution, a special-shaped hole structure with a small outer diameter and a relatively larger inner diameter can be formed on the surface of the base film relatively quickly, which is beneficial to the subsequent increase in the anchoring effect of the current collector conductive layer.

[0015] Furthermore, the residence time t is set to 0.1-1.5 s, and more preferably 0.3-1.0 s.

[0016] Based on the above technical solution, a suitable pore size can be obtained.

[0017] Furthermore, the punching assembly is configured as a molded hole-punching structure that reciprocates up and down.

[0018] Furthermore, the piercing component is arranged on the reciprocating upper template.

[0019] Furthermore, the pressure-bearing component includes a lower template arranged corresponding to the upper template, and the base membrane to be processed is arranged on a platform on the surface of the lower template.

[0020] Furthermore, the punching assembly is configured as a roller-pressed hole-punching structure.

[0021] Furthermore, the puncture component is arranged on the roller body; and the pressure-bearing component is arranged as a pressure-bearing roller.

[0022] Furthermore, the puncture component is preheated before the puncture is completed, and no heating is performed during the puncture process.

[0023] Based on the above technical solution, based on non-continuous heating of the puncture component, the size of the secondary hole can be controlled and the impact on the size of the primary hole of the puncture can be reduced.

[0024] Furthermore, the temperature of the puncture component is within the glass transition temperature range of the base film.

[0025] Furthermore, the heating component is configured as a hot plate structure that contacts and transfers heat with the puncture component.

[0026] Furthermore, the heating component is configured as a hot plate structure that radiates heat to the puncture component.

[0027] Furthermore, it also includes a mat material assembly, which includes a first mat material assembly that is bonded to the surface of the base film to be processed and a second mat material assembly that is bonded to the surface of the pressure-bearing assembly. The mat material assembly is provided with a thin film mat material with a bonded film surface, which plays the role of isolation protection and precise control of puncture thickness.

[0028] Based on the above technical solution, the independently arranged movable cushion material can provide better protection for the punched components and facilitate maintenance and replacement.

[0029] Furthermore, the puncture component is divided into a tip portion as a high temperature zone and a root portion as a low temperature zone, and a heat insulation layer is provided at the root portion of the puncture component.

[0030] Based on the above technical solution, the impact on the outer part of the puncture hole during the puncture process can be reduced.

[0031] On the second aspect, the present application also discloses a composite current collector structure, including a base film, a first hole formed on the surface of the base film, and a second hole is arranged on the side of the first hole, which is axially intersecting and connected to the first hole. The second hole is formed on the basis of the first hole after heating and heat shrinkage, and has a greater crystallinity than the polymer material at the first hole. The second hole has a larger pore size than the first hole at the connecting point, and after the opening is further formed, a conductive layer is formed on the surface of the base film. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0033] Figure 1 It is a structural schematic diagram of a first punching device;

[0034] Figure 2 is a schematic structural diagram of a second punching device;

[0035] Figure 3 Schematic diagram of the cross-sectional structure of the prepared composite current collector.

[0036] The horizontal direction represents the lateral direction, and the vertical direction represents the thickness direction.

[0037] In the figure: 1-punching component; 11-piercing component; 12-insulating layer; 2-pressure bearing component; 3-heating component; 41-first cushion material component; 42-second cushion material component; 51-upper template; 52-lower template;

[0038] 01-base film; 011-first hole; 012-second hole; 02-conductive layer. DETAILED DESCRIPTION

[0039] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0040] Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0041] Reference Figure 1 and Figure 2 The present application discloses a substrate opening device, comprising:

[0042] The punching assembly 1 is provided with a plurality of puncturing components 11 for punching holes in the membrane material;

[0043] The pressure-bearing component 2 is used to provide support for the membrane material during roller punching;

[0044] A heating component 3, used for heating the puncture component 11 to soften the film during puncture;

[0045] and a tensioning component for providing tensioning force to the film;

[0046] The puncture component 11 has a residence time t in the film after puncturing to promote further local crystallization of the film to form larger pores. In some embodiments of the present application, the residence time t is set to 0.1-1.5s, and more preferably 0.3-1.0s.

[0047] Specifically,

[0048] like Figure 1 The puncture component 11 can be installed on an assembly such as a template or a roller body to perform continuous puncture processing on the base film; the puncture component 11 includes a puncture needle or a molded frustum-shaped (needle-shaped) die head.

[0049] During molding, the piercing component 11 is installed on the reciprocating upper template 51, and the corresponding pressure-bearing component 2 is set to a position-matched lower template 52, and the base film is set on the platform on the surface of the lower template 52. The base film smoothly transitions from the platform surface, and rollers are set on both sides of the lower template 52 to maintain the tension of the molding action part, and a winding and unwinding roller group can be further set. Of course, other structures in the component, such as the driving part is set to a cylinder, an electric push rod, etc., and are positioned and guided by related guide rods. At the same time, the upper template can be adjusted to an appropriate working stroke to meet the puncture depth requirements of puncturing different blind holes. Other detailed structures are commonly used components in molding processing and will not be repeated;

[0050] At this time, the heating component 3 can be set as a hot plate, and a number of heating rods (heating wires) are evenly laid inside the hot plate. The hot plate is set in close contact with the puncture component 11 to better transfer heat to the puncture component 1. The heating temperature of the heating component 3 should be within the glass transition temperature range, which is convenient for puncture and can ensure that the temperature of the puncture tip is above the crystallization temperature of the basement membrane after puncture (this temperature can be adaptively set based on the residence time t during puncture and the type of basement membrane), so as to promote further local crystallization and shrinkage to form larger holes ( Figure 3 in the second hole); in addition, the heating process of the heating component 3 is non-continuous, that is, the preheating process is completed before the puncture, and the puncture process is no longer heated.

[0051] After driving the mold closing and acupuncture, the mold closing dwell time t is controlled, and the drive motor of the winding and unwinding roller is stopped to keep the base film relatively still relative to the puncture component. After the mold is opened, the drive motor is controlled to run to the next opening area and the above-mentioned mold closing and opening operations are repeated.

[0052] like Figure 2 When rolling, the puncture component 11 is set as a needle roller, and the pressure-bearing component is set as a pressure-bearing roller that cooperates with the needle roller. A number of roller bodies, such as guide rollers, tension rollers, etc., are also arranged on both sides of the pressure-bearing roller for transmitting and tensioning the base film; and the stop during puncture is achieved by controlling the intermittent rotation of the needle roller.

[0053] At this time, the heating assembly 3 can be set up with a hot plate structure that fits the surface of the roller body. The heating wires can be evenly distributed in the hot plate and rotate with the roller body. The wiring can be axially led out through the electric slip ring. It can also be set up as follows Figure 2 The separate heating structure shown in the figure includes a plurality of heat pipes arranged around the outer edge of the needle roller. Each heat pipe can be arranged axially and fixed at intervals on the arc-shaped cover body to heat the puncture component (puncture needle) on the roller body.

[0054] When opening a hole, the outer side of the heated puncture component will contact the base membrane, softening it to form a hole structure similar to the shape of the puncture component; when staying, due to the downward pressure and the tension on both sides of the base membrane, the tip of the puncture component will still fit the base membrane, while the root of the puncture component assembly will have a certain gap with the base membrane; during the period when the puncture component is maintained in the base membrane, the heat of the tip can be transferred to the surrounding side of the bottom of the opening more quickly, thereby forming a locally enlarged hole structure in the hole; it is beneficial to further evaporate and form an anchoring structure for the conductive layer, thereby increasing the adhesion of the conductive layer to a certain extent.

[0055] In addition, the device also includes a transmission component for continuously conveying the base film to be processed; in some embodiments of the present application, the transmission component includes a guide roller; the tensioning mechanism is configured as a related tension roller group, etc., for collaboratively controlling the transmission direction and tension of the film material, and the position of the related roller body corresponds to the setting of the pressure roller, so that the film material is attached to the surface of the pressure roller at a certain wrap angle, which is beneficial to the tensioning and flattening of the base film and ensures the processing effect;

[0056] And, the mat material assembly includes a first mat material assembly 41 that is attached to the surface of the base film to be processed and a second mat material assembly 42 that is attached to the surface of the pressure-bearing assembly 2. The mat material assembly is provided with a thin film mat material with a film-attached surface to play the role of isolation protection and precise control of puncture thickness;

[0057] The mat assembly also includes a roller group for driving the mat to move, such as an unwinding roller and a winding roller for unwinding and rewinding the mat, and a guide roller group for adjusting the direction of the mat transmission. The film mat is preferably kept relatively still with the film material to reduce wear; the protective film material can be selected from commercially available conventional film materials, such as PET, PP, PS, PE, and other commercially available conventional film materials, and its thickness is set to 10-1000μm.

[0058] Independently set movable cushion materials can provide better protection for the punched components and facilitate maintenance and replacement.

[0059] Considering that the temperature at the root of the puncture component 11 is relatively high, during the retention period, it may affect the hole position near the surface layer of the formed hole, so that the hole diameter near the surface layer will further increase, and the preset hole structure cannot be formed.

[0060] Therefore, if Figure 1 In order to separate the puncture component 11 into a high temperature zone at the tip and a low temperature zone at the root, a heat insulation layer 12 is provided at the root of the puncture component 11, thereby reducing the impact on the outer part of the puncture hole during the puncture process; the heat insulation layer 12 can be provided as a heat insulation coating, such as a ceramic coating, including materials with low thermal conductivity such as aluminum oxide. The puncture tip of the puncture component 11 can also be provided as a material with good thermal conductivity, while the low temperature zone at the root is provided as a material with poor thermal conductivity.

[0061] In the second aspect, the present application also discloses a composite current collector structure, including a base film 01, a first hole 011 is formed on the surface of the base film, and a second hole 012 is provided on the side of the first hole 011, which intersects with the first hole 011 axially and is connected to the first hole 011. The second hole 012 is formed on the basis of the first hole 011 after heating and heat shrinkage, and has a greater crystallinity than the polymer material at the first hole 011, and the second hole 012 has a larger hole size at the connection point than the first hole 011;

[0062] After the openings are formed, a conductive layer 02 is formed.

[0063] When forming the conductive layer 02, it can be based on the existing evaporation device, and the wrap angle between the base film 01 and the evaporation roller can be adjusted to be not less than 30°, preferably not less than 45°, so that the first hole 011 and the second hole 012 are expanded in the longitudinal direction (length direction), which is conducive to forming a conductive layer in the hole. Since the size of the second hole 012 is relatively larger, although there may be a evaporation blind area on the top of the inner wall near the connection between the two holes, on the one hand, the metal vapor has fluidity, and on the other hand, due to the relatively large wrap angle of the support layer on the evaporation roller, the hole entrance space can be increased to a certain extent, the obstruction of the hole can be reduced, and the second hole can be directly exposed in the evaporation area to a certain extent. As the side wall and bottom of the second hole 012 can be deposited and attached to the conductive layer and gradually thicken.

[0064] While the second hole 012 has a greater degree of crystallinity, the local hardness and mechanical strength of the hole surface are also increased, which is also beneficial in the subsequent evaporation process, so that this part will not be torn due to the large wrap angle. In addition, the hole strength is improved, and when a conductive layer is formed on the hole surface later, the conductive layer is relatively difficult to break.

[0065] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the drawings or conventionally expressed in the prior art, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0066] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists, A and B exist at the same time, and B exists. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0067] The term "multiple" as used in this application refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple sheets" refers to more than two sheets (including two sheets).

[0068] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A substrate opening device, characterized in that: include: The punching assembly is provided with a plurality of puncturing components for punching holes in the membrane material; The pressure-bearing component is used to provide support for the membrane material during roller punching; A heating component, used for heating the puncture component to soften the film during puncture; and, a tensioning mechanism for providing tensioning force to the film; The puncture component has a residence time t in the film after puncturing, so as to promote secondary pore formation in the film at the inner end of the punctured hole, thereby forming pores with larger size and crystallinity.

2. The substrate punching device according to claim 1, characterized in that: The residence time t was set to 0.1-1.5 s.

3. The substrate punching device according to claim 2, characterized in that: The punching assembly is configured as a molded hole-opening structure that reciprocates up and down; the puncture component is mounted on the reciprocating upper template; the pressure-bearing assembly includes a lower template that is configured to correspond to the upper template, and the base film to be processed is configured on a platform on the surface of the lower template.

4. The substrate punching device according to claim 2, characterized in that: The punching component is configured as a roller-pressed hole-opening structure; the puncturing component is arranged on the roller body; and the pressure-bearing component is configured as a pressure-bearing roller.

5. The substrate punching device according to any one of claims 1 to 4, characterized in that: The puncture component is preheated before puncturing is completed, and is not heated during the puncturing process; the temperature of the puncture component is within the glass transition temperature range of the base film.

6. The substrate punching device according to claim 5, characterized in that: The heating component is configured as a hot plate structure that contacts and transfers heat to the puncture component.

7. The substrate punching device according to claim 5, characterized in that: The heating component is configured as a hot plate structure for radiating heat transfer with the piercing component.

8. The substrate punching device according to any one of claims 1 to 4, 6 and 7, characterized in that: It also includes a mat material assembly, which includes a first mat material assembly that is bonded to the surface of the base film to be processed and a second mat material assembly that is bonded to the surface of the pressure-bearing assembly. The mat material assembly is provided with a thin film mat material with a bonded film surface to play the role of isolation protection and precise control of puncture thickness.

9. The substrate punching device according to claim 8, characterized in that: The puncture component is divided into a tip portion as a high temperature zone and a root portion as a low temperature zone, and a heat insulation layer is arranged at the root portion of the puncture component.

10. A composite current collector structure, comprising a base film, characterized in that: Based on the punching device as described in claim 9, a first hole is formed on the surface of the base film, and a second hole is arranged on the side of the first hole to intersect with the first hole axially and is connected to the first hole. The second hole has a greater crystallinity than the polymer material at the first hole, and the second hole has a larger pore size than the first hole at the connecting point, and further after the opening is formed, a conductive layer is formed on the surface of the base film.

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