CN112086290A - Flexible extensible supercapacitor array based on mechanical buckling principle and preparation method thereof - Google Patents

Abstract

The invention provides a flexible extensible supercapacitor array based on a mechanical buckling principle and a preparation method thereof, wherein the flexible extensible supercapacitor array comprises the following steps: the device comprises a flexible substrate of a silicone film, a plurality of rigid substrates which are fixed on the flexible substrate of the silicone film and form a dispersion array, a laser-induced graphene foam electrode array of an interdigital structure which is fixed on the rigid substrate, and a silicone film packaging layer which covers the surface of the laser-induced graphene foam electrode array of the interdigital structure. The flexible extension of the energy storage device can be realized, and the regulation and control of the output voltage and current of the energy storage device can also be realized through the regulation and control (series connection or parallel connection) of the connection mode of the interdigital electrodes, so that the application range and the field of the super capacitor array are greatly expanded; in the same space structure, the transition metal phosphide ultrathin nanosheets and the graphene are used for energy storage in a synergistic manner, so that the purpose of effectively improving the energy density of the supercapacitor on the premise of not sacrificing the cycle life and the power density of the supercapacitor is achieved.

Description

Flexible and extensible supercapacitor array based on mechanical buckling principle and preparation method

technical field

The invention belongs to the technical field of electrochemical energy storage, and in particular relates to a flexible and extensible supercapacitor array and a preparation method based on the mechanical buckling principle.

Background technique

The rapid development of portable, wearable, and implantable electronic devices has greatly promoted the demand for flexible and stretchable electrochemical energy storage devices and their integrated microsystems in modern society. Due to its unique planar interdigitated electrode structure, planar micro-supercapacitors have no need for separators, and the electrode spacing can be infinitely close (usually tens to hundreds of microns), which is not easy to short-circuit under bending and twisting conditions, and is easy to integrate with other electronic devices on flexible substrates. It has become one of the research hotspots in the field of flexible energy storage devices.

However, planar micro-supercapacitors exhibit energy density due to limited electrode area, lower specific capacitance of conventional carbon-based electrode active materials, and smaller electrode thickness (bending strain proportional to material thickness) due to flexibility requirements. The low and limited ductility properties seriously hinder its practical application.

SUMMARY OF THE INVENTION

In view of the defects and deficiencies existing in the prior art, the purpose of the present invention is to propose a flexible and extensible supercapacitor array based on the principle of mechanical buckling and a preparation method, using the laser direct writing technology to prepare a graphene substrate with a specific shape, and a hydrothermal method to prepare the transition Metal phosphide ultrathin nanosheets are loaded on graphene substrates, solid electrolytes, buried wires and encapsulation are deposited to complete the assembly of all-solid-state flexible and malleable supercapacitor arrays. It can not only realize the flexibility and extensibility of the energy storage device, but also realize the regulation of its output voltage and current through the regulation of the interdigital electrode connection (series or parallel), thereby greatly expanding the application scope and field of supercapacitor arrays; In the same spatial structure, the present invention utilizes transition metal phosphide ultrathin nanosheets and graphene to synergize energy storage, thereby achieving the purpose of effectively improving the energy density of the supercapacitor without sacrificing cycle life and power density.

The present invention specifically adopts the following technical solutions:

A flexible and extensible supercapacitor array based on the principle of mechanical buckling, characterized in that it comprises: a flexible substrate of silicone resin film, a plurality of rigid substrates fixed on the flexible substrate of silicone resin film to form a dispersed array, An interdigitated structure laser-induced graphene foam electrode array on a rigid substrate, and a silicone resin film encapsulation layer covering the surface of the interdigitated structure laser-induced graphene foam electrode array.

Preferably, the material of the rigid substrate is SiO ₂ or Si.

Preferably, the laser-induced graphene foam electrode array of the interdigital structure includes an energy storage sheet unit fixed on a rigid substrate and a serpentine wire connecting the energy storage sheet unit; the electrode sheet unit is transitioned from bottom to top: The composite electrode is composed of metal phosphide thin nanosheets coupled with laser-induced graphene foam, and a solid-state electrolyte; the material of the serpentine wire is laser-induced graphene foam.

Preferably, the serpentine wire makes the energy storage chip units form series or parallel or mixed connection.

Preferably, the transition metal phosphide thin nanosheets are one or more of zinc, manganese, cobalt, nickel, iron, copper phosphide nanosheets; the solid electrolyte is PVA/KCl, PVA/KOH, One or more of PVA/H ₂ SO ₄ , PVA/H ₃ PO ₄ , PVA/LiCl, PVA/LiOH; the silicone resin film flexible substrate is made of polydimethylsiloxane and copolyester .

Preferably, the thickness of the silicone resin film flexible substrate is 100 μm; the thickness of the laser-induced graphene foam electrode array of the interdigital structure is 100 μm; the length of the transition metal phosphide thin nanosheet is 100 nm, The thickness is 4 nm; the thickness of the solid electrolyte is 10 μm; the size of the rigid substrate is 1 cm*1 cm*0.05 cm.

And, a preparation method of a flexible and extensible supercapacitor array based on the principle of mechanical buckling, characterized in that it includes the following steps:

Step S1: using spin coating technology to prepare a silicone resin film flexible substrate;

Step S2: using double-sided adhesive tape to fix multiple rigid substrates on the flexible silicone resin film in a dispersed array arrangement;

Step S3: sticking the polyimide film on the substrate, and reducing the polyimide film with a carbon dioxide laser to form a laser-induced graphene foam electrode array with an interdigital structure; the laser-induced graphene foam electrode with an interdigital structure The array includes an energy storage chip structure fixed on a rigid base and a serpentine wire connecting the energy storage chip units;

Step S4 : preparing ultrathin nanosheets of transition metal oxides by a hydrothermal method, and converting them into thin nanosheets of transition metal phosphides by high-temperature reduction, and then depositing thin nanosheets of transition metal phosphides by spraying and using a mask On the structure of the energy storage sheet, a composite electrode of the transition metal phosphide thin nanosheet coupled with the laser-induced graphene foam is formed;

Step S5: depositing a solid electrolyte on the composite electrode coupled with the transition metal phosphide thin nanosheet and the laser-induced graphene foam;

Step S6 : forming a silicone resin film encapsulation layer on the surface of the laser-induced graphene foam electrode array of the interdigital structure by spin coating technology.

Preferably, the material of the rigid substrate is SiO ₂ or Si; the transition metal phosphide nanosheets are one or more of zinc, manganese, cobalt, nickel, iron and copper phosphide nanosheets; the The solid electrolyte is one or more of PVA/KCl, PVA/KOH, PVA/H ₂ SO ₄ , PVA/H ₃ PO ₄ , PVA/LiCl, PVA/LiOH; the material of the silicone resin film flexible substrate For polydimethylsiloxane and copolyester.

Preferably, the serpentine wire makes the structure of the energy storage sheet form a series or a parallel or a mixed connection.

Compared with the prior art, the present invention and its preferred solution can not only realize the flexibility and extensibility of the energy storage device, but also realize the regulation of its output voltage and current by regulating the connection mode of the interdigital electrodes (series or parallel), thereby The application scope and field of supercapacitor arrays are greatly expanded; in the same spatial structure, the present invention utilizes transition metal phosphide ultrathin nanosheets and graphene to synergize energy storage, thereby realizing the supercapacitor cycle life and power density without sacrificing the energy storage. Under the premise of effectively improving its energy density. The flexible and extensible preparation method of inorganic micro-nanoelectronic devices using the principle of mechanical buckling has the advantages of strong versatility, easy integration, easy promotion, low production cost and simple operation. It can effectively solve the problem that the rigidity of traditional energy supply devices is not suitable for wearing. , poor battery life, frequent recycling and other problems have promoted the application and development of wearable electronic devices, which have a wide range of applications in the fields of electronic skin, wearable physiological monitoring and treatment devices, flexible conductive fabrics, thin film transistors and transparent thin film flexible gate circuits. prospect.

Description of drawings

The present invention will be described in further detail below in conjunction with the accompanying drawings and specific embodiments:

FIG. 1 is a schematic diagram of a flexible substrate structure after processing in step 1 of an embodiment of the present invention;

FIG. 2 is a schematic structural diagram of adding SiO ₂ /Si rigid substrate on the flexible substrate after processing in step 2 according to the embodiment of the present invention;

3 is a schematic structural diagram after processing in step 3 of the embodiment of the present invention;

4 is a schematic structural diagram after processing in step 4 of the embodiment of the present invention;

5 is a schematic structural diagram after processing in step 5 of the embodiment of the present invention;

6 is a schematic structural diagram after processing in step 6 of the embodiment of the present invention;

7 is a schematic diagram of a tensile test according to an embodiment of the present invention;

FIG. 8 is a schematic diagram of a performance test of an embodiment of the present invention.

Detailed ways

In order to make the features and advantages of this patent more obvious and easy to understand, the following specific examples are given and described in detail as follows:

In this example, the scheme is explained in detail through the preparation process of the flexible and extensible supercapacitor array based on the principle of mechanical buckling:

As shown in FIG. 1 , step S1 is first to prepare a flexible substrate of a silicone resin film. In this embodiment, a spin coating method is used to prepare a silicone resin film on a clean petri dish, and after heating and curing, a flexible, extensible and stretchable silicone resin film 1 is obtained as a flexible substrate. Silicone materials are available in polydimethylsiloxane (PDMS) and copolyester (Ecoflex) with a thickness of 100μm.

As shown in Figure 2, step S2 is to use a double-sided tape array to disperse and fix the SiO ₂ /Si rigid substrate 2 on the flexible substrate of the silicone resin film to isolate the strain and the interdigital electrode energy storage unit between the flexible stretchable substrate and the interdigital electrode energy storage unit. stress to achieve the purpose of protecting the interdigital electrodes. In this embodiment, the double-sided tape can be 3M VHB tape, and the size of the rigid substrate 2 is 1 cm*1 cm*0.05 cm.

As shown in Figure 3, step S3 is to paste a PI (polyimide film) film on the substrate, and use a carbon dioxide laser to reduce the PI film to prepare an interdigitated structure of laser-induced graphene foam electrode array 3 with a thickness of 100 μm, Its morphology is realized by computer-controlled laser direct writing technology; the interdigitated laser-induced graphene (LIG) foam electrode array includes an energy storage sheet structure 4 fixed on a rigid substrate and a serpentine wire connecting the energy storage sheet units. . Among them, the material of the serpentine wire is laser-induced graphene foam, and the serpentine wire and the flexible stretchable substrate are not in close contact, and the stretch deformation of the serpentine wire is used to obtain the flexibility and extensibility of the entire interdigital electrode array. The interdigitated electrode array can realize series and parallel or a combination of series and parallel by using serpentine wires, so as to control its output voltage and current.

The power of the carbon dioxide laser used in this embodiment is 3.4 W.

As shown in Figure 4, step S4 is to use a mask and spraying technology to combine the transition metal phosphide nanosheets (about 100 nm in length, about 4 nm in thickness) prepared by hydrothermal method combined with high temperature reduction method. The LIG coupling on 4 forms a composite electrode material and keeps the serpentine wires from interacting with the thin transition metal phosphide nanosheets. So as to achieve the purpose of increasing the energy storage density. The transition metal phosphide thin nanosheets are one or more of zinc, manganese, cobalt, nickel, iron and copper phosphide nanosheets.

As shown in FIG. 5 , step S5 is to deposit a solid electrolyte 5 on the energy storage sheet structure 4 . A certain amount of KCl, KOH, H ₂ SO ₄ , H ₃ PO ₄ , LiCl, or LiOH and deionized water, PVA powder were mixed and heated to 90 ^o C for 30 minutes, and then deposited on the energy storage sheet structure 4 , its thickness is 10 μm.

As shown in FIG. 6 , step S6 is the packaging of the supercapacitor array. Using spin coating technology, the supercapacitor array is encapsulated with silicone resin, so that a silicone resin film encapsulation layer 6 is formed on the surface of the interdigitated structure of the laser-induced graphene foam electrode array, and its thickness is also 100 μm.

As shown in FIG. 7 , it is an electronic photograph of the stretching process of the flexible and extensible supercapacitor array prepared by the scheme of this embodiment. The flexible stretchable supercapacitor arrays assembled in series (top half) and parallel (bottom half) have stretchability as high as 100%.

FIG. 8 is the output performance of the flexible and extensible supercapacitor array prepared by the solution of this embodiment under the condition of series and parallel. As shown in Figure 8, the output voltage of the flexible and stretchable supercapacitor array assembled in series is as high as 2.4V (4 times that of a single interdigitated electrode capacitor); the output current of the flexible and stretchable supercapacitor array assembled in parallel is a single interdigitated electrode. capacitors; and the capacitive performance of the flexible stretchable supercapacitor arrays, whether assembled in series or in parallel, remained almost unchanged during the stretching process. Secondly, through the solution of this embodiment, the efficient parallel assembly of 20 interdigital electrode capacitors is realized, and the capacitance of the system is almost proportional to the number of assembled capacitors. This highly tunable nature of output voltage and current can greatly improve the application range and field of supercapacitors.

This patent is not limited to the above-mentioned best embodiment, anyone can come up with other various forms of flexible and extensible supercapacitor arrays and preparation methods based on the principle of mechanical buckling under the inspiration of this patent. All equivalent changes and modifications made shall fall within the scope of this patent.

Claims (9)

1. A flexible and extensible supercapacitor array based on the principle of mechanical buckling, characterized in that, comprising: a flexible substrate of a silicone resin film, a plurality of rigid substrates constituting a dispersed array fixed on the flexible substrate of a silicone resin film, A laser-induced graphene foam electrode array with an interdigitated structure on the rigid substrate, and a silicone resin film encapsulation layer covering the surface of the interdigitated structure of the laser-induced graphene foam electrode array. 2 . The flexible and extensible supercapacitor array based on the principle of mechanical buckling according to claim 1 , wherein the rigid substrate is made of SiO ₂ or Si. 3 . 3. The flexible and extensible supercapacitor array based on the principle of mechanical buckling according to claim 1, wherein the laser-induced graphene foam electrode array of the interdigital structure comprises an energy storage sheet unit fixed on a rigid substrate and A serpentine wire connecting the energy storage sheet unit; the electrode sheet unit from bottom to top is composed of: a composite electrode coupled with a transition metal phosphide nanosheet and a laser-induced graphene foam, and a solid-state electrolyte; the serpentine wire is composed of: The material is laser-induced graphene foam. 4 . The flexible and extensible supercapacitor array based on the principle of mechanical buckling according to claim 3 , wherein the serpentine wires make the energy storage chip units form series, parallel or mixed connections. 5 . 5. The flexible and extensible supercapacitor array based on the principle of mechanical buckling according to claim 3, wherein the transition metal phosphide nanosheets are zinc, manganese, cobalt, nickel, iron, copper phosphide nanosheets One or more of; the solid electrolyte is one or more of PVA/KCl, PVA/KOH, PVA/H ₂ SO ₄ , PVA/H ₃ PO ₄ , PVA/LiCl, PVA/LiOH ; The material of the flexible substrate of the silicone resin film is polydimethylsiloxane and copolyester. 6 . The flexible and extensible supercapacitor array based on the principle of mechanical buckling according to claim 5 , wherein the thickness of the flexible substrate of the silicone resin film is 100 μm; the laser-induced graphene foam electrode of the interdigital structure is 100 μm. 7 . The thickness of the array is 100 μm; the length of the transition metal phosphide thin nanosheet is 100 nm and the thickness is 4 nm; the thickness of the solid electrolyte is 10 μm; the size of the rigid substrate is 1 cm*1 cm* 0.05 cm. 7. A preparation method of a flexible and extensible supercapacitor array based on the principle of mechanical buckling, characterized in that, comprising the following steps: Step S1: using spin coating technology to prepare a silicone resin film flexible substrate; Step S2: using double-sided adhesive tape to fix multiple rigid substrates on the flexible silicone resin film in a dispersed array arrangement; Step S3: sticking the polyimide film on the substrate, and reducing the polyimide film with a carbon dioxide laser to form a laser-induced graphene foam electrode array with an interdigital structure; the laser-induced graphene foam electrode with an interdigital structure The array includes an energy storage chip structure fixed on a rigid base and a serpentine wire connecting the energy storage chip units; Step S4 : preparing ultrathin nanosheets of transition metal oxides by a hydrothermal method, and converting them into thin nanosheets of transition metal phosphides by high-temperature reduction, and then depositing thin nanosheets of transition metal phosphides by spraying and using a mask On the structure of the energy storage sheet, a composite electrode of the transition metal phosphide thin nanosheet coupled with the laser-induced graphene foam is formed; Step S5: depositing a solid electrolyte on the composite electrode coupled with the transition metal phosphide thin nanosheet and the laser-induced graphene foam; Step S6 : forming a silicone resin film encapsulation layer on the surface of the laser-induced graphene foam electrode array of the interdigital structure by spin coating technology. 8 . The method for preparing a flexible and extensible supercapacitor array based on the principle of mechanical buckling according to claim 7 , wherein: the material of the rigid substrate is SiO ₂ or Si; the transition metal phosphide thin nanosheets are One or more of zinc, manganese, cobalt, nickel, iron, copper phosphide nanosheets; the solid electrolyte is PVA/KCl, PVA/KOH, PVA/H ₂ SO ₄ , PVA/H ₃ PO ₄ , one or more of PVA/LiCl, PVA/LiOH; the material of the silicone resin film flexible substrate is polydimethylsiloxane and copolyester. 9 . The method for preparing a flexible and extensible supercapacitor array based on the principle of mechanical buckling according to claim 7 , wherein the serpentine wire makes the structure of the energy storage sheet to be connected in series, in parallel or in mixed connection. 10 .

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