CN105826086B - Flexible all-solid-state supercapacitor and preparation method thereof based on SiC nanowire array - Google Patents

Abstract

A method for preparing a flexible all-solid-state supercapacitor based on a SiC nanowire array, the supercapacitor includes a flexible positive electrode, a solid electrolyte, a diaphragm, and a flexible negative electrode, which includes the following specific steps: the present invention solves the above technical problems. The technical solution is: the preparation method of the flexible super solid capacitor of the SiC nanowire array includes the following specific steps: (1) growing silicon carbide or nitrogen-doped or aluminum-doped silicon carbide nanometers on flexible carbon cloth or graphene film The line array is used as the positive and negative electrodes of the supercapacitor, and it is cut into a suitable size; (2) The mass percentage is 30~50% polyvinyl alcohol, 30~50% phosphoric acid and 20~40% water in 70~ Stir and mix evenly at 90°C to make the electrolyte; (3) Coat the electrolyte on the surface of the flexible positive and negative electrodes respectively, and wait for the bulk electrolyte to form in the air environment; (4) Put a diaphragm stack between the flexible positive and negative electrodes Press them together and let them stand to dry to get a flexible all-solid supercapacitor. The performance of this solid-state supercapacitor does not change significantly under bending and twisting.

Description

Flexible all-solid supercapacitor based on SiC nanowire array and its preparation method

technical field

The invention relates to a method for preparing a flexible all-solid-state supercapacitor of a SiC nanowire array, and belongs to the technical field of preparation of electrochemical energy storage devices.

technical background

Electronic device technology is developing towards miniaturization, integration and flexibility. Compared with traditional electronic devices, flexible electronic devices have important application prospects in portable and wearable electronic products, aerospace, biomedicine, information, energy and other fields. In August 2013, flexible technology has been selected by foreign media as one of the top ten technological advances in the world. In order to meet the wide application requirements of these flexible electronic products, energy storage devices must not only have greater energy and power density, but also have excellent flexibility and processability to meet the requirements of the rapid development of flexible integrated circuit technology and manufacturing processes in the future. .

Supercapacitor is a new type of high-efficiency energy storage device based on electrode materials to store charges. Its performance is between that of traditional electrostatic capacitors and batteries. It has outstanding advantages such as high energy density, long cycle life, fast charging and discharging, and wide operating temperature range. , mainly using the electric double layer and redox pseudocapacitance to store electrical energy, and is expected to be widely used in consumer electronics, automobiles and other fields. With the introduction of new electrode materials with nanostructures into supercapacitors, the unique physical and chemical properties of nanomaterials have gradually improved the performance of supercapacitors, and the design of flexible all-solid supercapacitor electrode materials with array structure, high conductivity, and high specific surface area more and more possible.

SiC has good chemical corrosion resistance, high strength, high hardness, high temperature resistance and unique excellent electrical and optical properties. It is an ideal new semiconductor material for researching microelectronic devices and optoelectronic devices. Silicon carbide nanowire arrays doped with nitrogen and aluminum are expected to be good electrode materials for supercapacitors due to their good electrical conductivity and high specific surface area.

Contents of the invention

The technical problem to be solved by the present invention is to provide a method for preparing a flexible solid-state supercapacitor based on SiC nanowire arrays based on the excellent physical and chemical properties of silicon carbide nanowire arrays and silicon carbide nanowire arrays doped with nitrogen and aluminum .

The technical scheme adopted by the present invention to solve the above-mentioned technical problems is: the preparation method of the flexible super solid capacitor of the SiC nanowire array comprises the following specific steps:

(1) Growing silicon carbide or nitrogen-doped or aluminum-doped silicon carbide nanowire arrays on flexible carbon cloth or graphene film as the positive and negative electrodes of supercapacitors, and cutting them into appropriate sizes;

(2) Stir and mix 30-50% polyvinyl alcohol, 30-50% phosphoric acid or sulfuric acid and 20-40% water at 70-90° C. to make electrolyte;

(3) The electrolyte is coated on the surface of the flexible positive and negative electrodes respectively, and the bulk electrolyte is formed in the air environment;

(4) A separator is placed between the flexible positive and negative electrodes and stacked together, and the flexible all-solid-state supercapacitor can be obtained by standing and drying.

The membrane used in the step (4) is a hydrophilic membrane.

Compared with the prior art, the present invention has the advantages of:

Compared with the reported capacitors without doped SiC nanowire arrays, the present invention enables the fabrication of flexible all-solid-state supercapacitors doped with nitrogen and aluminum

Description of drawings

Fig. 1 is the structural schematic diagram of the supercapacitor device that the present invention makes;

Fig. 2 is the cyclic voltammetry curve of the SiC supercapacitor prepared in Example 1 of the present invention at different scan rates;

Fig. 3 is the constant current charge and discharge curve of the SiC supercapacitor prepared in Example 1 of the present invention;

Fig. 4 is a comparison chart of cyclic voltammetry curves of the SiC supercapacitor prepared in Example 1 of the present invention without bending, bending 90 degrees, 180 degrees and twisting 60 degrees, 120 degrees, 240 degrees;

Fig. 5 is the cyclic voltammetry curve of the SiC supercapacitor prepared in Example 2 of the present invention at different scan rates;

Fig. 6 is the constant current charge and discharge curve of the SiC supercapacitor prepared in Example 2 of the present invention;

Detailed ways

The present invention will be further described in detail below with reference to the embodiments of the accompanying drawings.

Embodiment one

(1) First grow nitrogen-doped silicon carbide nanowire arrays on carbon cloth by chemical vapor deposition, (2) cut them into appropriate sizes, and use them as positive and negative electrodes, (2) prepare PVA/H ₃ PO ₃ water Gel solution, and then drop the drop on the carbon cloth with SiC nanowires, spin coat a layer of the hydrogel solution and dry; (3) place the water-soluble diaphragm on the two electrodes obtained in the previous step - Between the positive and negative materials of the solid electrolyte, they are symmetrically pasted together, and the device assembly is completed after standing and drying. The cyclic voltammetry curves of the prepared supercapacitors at different scan rates are shown in Figure 2. From top to bottom, the scan rates are: 30, 20, 10, 5, 2v/s; The constant current charge and discharge curves are shown in Figure 3. The charge and discharge current densities from left to right are: 28, 14, 7, 2, 1mA/cm ^-2 . The cyclic voltammetry curves of bending 90 degrees, 180 degrees and twisting 60 degrees, 120 degrees, 240 degrees are shown in Figure 4. It can be seen that the performance of this solid supercapacitor does not change significantly under the conditions of bending and twisting.

Embodiment two

(1) First grow aluminum-doped silicon carbide nanowire arrays on carbon cloth by chemical vapor deposition, (2) and cut them into appropriate sizes, as positive and negative electrodes, (2) prepare PVA/sulfuric acid hydrogel solution , and then drop the drop on the carbon cloth with SiC nanowires, spin coat a layer of the hydrogel solution and dry; (3) put the water-soluble separator on the two electrodes obtained in the previous step-solid electrolyte In the middle of the positive and negative electrode materials, they are symmetrically attached together, and the device assembly is completed after standing and drying. The cyclic voltammetry curves of the prepared supercapacitors at different scan rates are shown in Figure 5. From top to bottom, the scan rates are: 20, 10, 5, 2, 1v/s; The constant current charge and discharge curves are shown in Figure 6, and the charge and discharge current densities from left to right are: 70, 35, 15, 5, 2mA/cm ^-2 .

Claims (4)

1. a kind of preparation method preparing the flexible all-solid-state supercapacitor based on SiC nanowire array, the ultracapacitor Including flexible positive electrode, solid electrolyte, diaphragm and flexible negative electrode comprising step in detail below：

(1) solid electrolyte is respectively applied on flexible positive and negative electrode surface, waits for that solid electrolyte is molded in air environment；

(2) it is put into diaphragm between flexible positive and negative electrode to overlap together, standing and drying, you can obtain flexible all solid state super electricity Container；

The positive and negative electrode used in the step (1) be the N doping being grown on flexible carbon cloth or graphene film or aluminium mix Miscellaneous nanometer silicon carbide linear array.

2. a kind of system preparing the flexible all-solid-state supercapacitor based on SiC nanowire array according to claim 1 Preparation Method, which is characterized in that the solid electrolyte used in the step (1) is the polyethylene that mass percent is 30~50% Alcohol, 30~50% phosphoric acid and 20~40% water are uniformly mixed manufactured hydrogel at 70~90 DEG C.

3. a kind of system preparing the flexible all-solid-state supercapacitor based on SiC nanowire array according to claim 1 Preparation Method, which is characterized in that the diaphragm used in the step (2) is hydrophily diaphragm.

4. a kind of system preparing the flexible all-solid-state supercapacitor based on SiC nanowire array according to claim 1 Preparation Method, which is characterized in that the flexibility, which refers to entire device, to be bent in 0~180 degree, distorted within the scope of 0~360 degree Performance does not change.