Hollow MXenes-based metal oxide composite material and preparation method and application thereof

Abstract

The invention discloses a hollow MXenes-based metal oxide composite material. The hollow MXenes-based metal oxide composite material comprises the following components: V2CTx MXenes, reduced grapheneoxide and metal oxide. The V2CTx MXenes are obtained by treating a substrate material with an etching agent, a layer expanding agent and an ionic liquid. The reduced graphene oxide is used as an intermediate layer material and has the effects of connecting, inhibiting stacking and inducing growth. The morphology of the metal oxide NiMoO4 is of a petal wrinkle-shaped structure, and pseudocapacitance is provided. The microstructure of the composite material has a carbon shell 'embedded' hollow structure. The key technology of the preparation method is as follows: the microstructure is regulatedand controlled by adopting a non-constant centrifugal condition and an ionic liquid. When the material is used as a supercapacitor, the supercapacitor is charged and discharged in a range of-0.2 V to0.35 V, and when the discharge current density is 1 A / g, the specific capacitance is 1000-1100 F / g. The specific capacitance performance can still reach 88-89% of the original specific capacitance performance after 3000 cycles under the current density of 10 A / g. And excellent electrochemical characteristics and chemical stability are achieved.

Description

technical field [0001] The invention relates to the technical field of supercapacitors, in particular to the application of a hollow MXenes-based metal oxide composite material and a preparation method thereof in the field of supercapacitors. Background technique [0002] Due to the non-renewable nature of fossil fuels, energy is threatened with depletion. The greenhouse effect caused by the massive consumption of fossil fuels has swept the world, and the environmental pollution has become increasingly serious. The development and utilization of clean energy and the improvement of energy storage technology have become important goals to solve the problems of common concern in today's society. Clean and renewable energy such as wind energy, hydro energy, hydrogen energy, solar energy, etc. are seriously affected by nature, resulting in the intermittent and decentralized use of these energy sources. Affected by external factors, these energy conversion efficiency is low and ...

AI Technical Summary

Problems solved by technology

Although this technical solution can solve the stacking problem to a certain extent, it still cannot solve the following problems:

[0008] 1. Due to the lack of Faraday reaction, it is impossible to achieve a substantial improvement in the performance of supercapacitors;

[0009] 2. Since the MXenes material is prepared at a constant centrifugal speed at a constant speed (4000 r / min), the resulting material has problems such as insufficient fluffiness in the macroscopic appearance of the material, insignificant layering effect of the microscopic appearance, and material loss.

[0011] 1. The technical solution is still to prepare MXenes materials at a constant centrifugal speed of 5000 rpm, resulting in more impurities in the final material;

[0012] 2. The obtained material is only the Co 3 o 4 -Simple recombination of MXenes with reduced graphene oxide (rGO) leads to Co 3 o 4 Severe agglomeration occurs on the surface of MXenes, and the introduced graphene has an effect on the Co on the surface of MXenes 3 o 4 The microscopic morphology of MXenes did not play a role in catalytic regulation, that is, the high specific surface area and favorable transport channel advantages of MXenes were not fully utilized, and the ideal electrochemical performance was not obtained in the end.

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