Electrochemical oxidation of phytic acid-polypyrrole/carbon fiber composite material and its preparation method and application

Abstract

The invention discloses a phytic acid electrochemical oxidation-polypyrrole / carbon fiber composite material and its preparation method and application in a super capacitor. The composite material comprises a modified carbon fiber composite material obtained by electrochemical oxidation of phytic acid, and its carbon fiber The surface is covered with a polypyrrole film, and the mass ratio of the polypyrrole film and the modified carbon fiber composite material is ≥2.8:10. The preparation method includes electrochemically oxidizing carbon fiber composite materials with phytic acid; and depositing a polypyrrole film on the surface of the carbon fiber. In the phytic acid electrochemical oxidation-polypyrrole / carbon fiber composite material of the present invention, the polypyrrole film is evenly and tightly wrapped on the surface of the carbon fiber to form a "perfect film layer", so that the composite material has good structural stability, high specific capacitance and flexibility. It is a foldable polypyrrole-based composite material with excellent performance and can be widely used as an electrode material for supercapacitors, especially for flexible supercapacitors, with high use value and good application prospects.

Description

technical field [0001] The invention belongs to the field of supercapacitor electrode materials, and relates to a phytic acid electrochemical oxidation-polypyrrole / carbon fiber composite material, a preparation method thereof, and an application in a supercapacitor. Background technique [0002] Supercapacitors include flexible supercapacitors, among which flexible supercapacitors have the advantages of small size, light weight, good flexibility, good deformability, high specific capacitance and power density, and are recognized as one of the most powerful power sources in wearable electronics. . Flexible supercapacitors can be integrated into different materials suitable for curved surfaces of the human body or other non-planar surfaces. In addition, it can withstand deformations at almost any angle, making it more suitable for long-term applications and therefore causing minimal disruption to the wearer's daily life. In order to match flexible supercapacitors, energy sto...

AI Technical Summary

Problems solved by technology

[0004] In recent years, researchers have attempted to load polypyrrole membranes on different substrate materials, including traditional metal mesh (foam nickel, copper foam, etc.) and graphene oxide, among which metal mesh, oxide When graphene is used as the substrate material, there are the following defects: (a1) Since both metal mesh and graphene oxide are inflexible materials, it is difficult to prepare polypyrrole-based composites with good flexibility and structural stability, which is not conducive to polypyrrole-based composites. Composite materials are widely used in supercapacitors, especially flexible supercapacitors; (a2) when metal mesh and graphene oxide are used as carriers, there are prone to defects with few surface active sites, and it is difficult to form a uniform and compact "perfect film layer" (a3) When metal mesh and graphene oxide are used as carriers, it is difficult to suppress the volume expansion of polypyrrole membranes caused by ion doping and dedoping, and there may even be a tendency to promote volume expansion. Pyrrol-based composite materials have defects such as poor structural stability and poor charge-discharge cycle performance; (a4) The price of metal mesh and graphene oxide is relatively high, which is not conducive to reducing the cost of use, and there is a risk of polluting the environment

However, in the actual research process of the inventors of the present application, it has been found that the following defects still exist when these carbon materials are used as supports for loading polypyrrole membranes: (b1) the surface functional groups of these carbon materials have little content, and when combined with the polypyrrole membrane When , it is difficult to form a strong chemical bond, and it is easy to form a large gap between the two, thereby affecting the transmission of electrolyte ions; (b2) the surface of these carbon materials is usually hydrophobic, and it is difficult for pyrrole monomers to disperse evenly on the surface of carbon materials , so it is easy to cause the natural agglomeration of pyrrole monomers, which eventually leads to a large amount of polypyrrole film accumulation on the surface of the carbon material, and forms faults and vacancies on the surface of the carbon material, resulting in a decrease in the energy density of the material

The more prominent problem is that the gap between the polypyrrole film and the carbon material, the accumulated polypyrrole film, and the existence of these adverse factors will reduce the structural stability of the material, which in turn will affect the overall recycling of the material. Will increase the use and maintenance costs of materials

In addition, in the actual research process of the inventors of the present application, it is also found that when carbon fiber materials are used as carriers to support polypyrrole membranes, attempts are made to modify polypyrrole membranes, such as doping, high-temperature activation, etc., although the composite The overall conductivity of the material has been improved to a certain extent, but it is still difficult to establish a firm connection between the polypyrrole film and the substrate, so it is difficult to form a uniform and compact "perfect film" on the surface of the carbon fiber material

It can be seen that in the prior art, in the polypyrrole-based composite material with carbon fiber material as the carrier, it is difficult to form a uniform and compact "perfect film" on the surface of the carbon fiber material, and there are still structural instability, low specific capacitance, and charge-discharge cycle. Defects such as poor performance

So far, there have been no related reports on "how to form a 'perfect film' on the surface of carbon fiber materials"

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