Graphene-based composite material as well as preparation method and application thereof

Abstract

The invention discloses a graphene-based composite material and a preparation method and application thereof. The method comprises the steps: 1, feeding a mixed solution obtained by mixing manganese salt, urea and diethylene glycol containing PVP to a reaction kettle to be subjected to a hydrothermal reaction, then filtering, washing, drying and roasting an obtained reaction product to obtain a manganese-based oxide; (2) putting the manganese-based oxide into a high-temperature reactor, continuously heating the reactor, feeding protective gas, and introducing first gas containing the protective gas and hydrogen into the high-temperature reactor after a first preset temperature is reached, so as to obtain a manganese oxide template; (3) putting the manganese oxide template into a high-temperature reactor and continuously heating; introducing the shielding gas at the same time, and after a second preset temperature is reached, introducing a second gas containing the shielding gas and a carbon source or containing the shielding gas, the carbon source and a nitrogen source into the high-temperature reactor, so as to deposit and form graphene or nitrogen-doped graphene on the manganeseoxide template, thereby obtaining the graphene-based composite material.

Description

technical field [0001] The invention belongs to the technical field of carbon materials, and in particular relates to a graphene-based composite material and its preparation method and application. Background technique [0002] As an important strategic emerging industry of the country, the graphene industry has great application prospects in new energy, chemical industry, electronic information, biomedicine and other fields, and will play an important role in the new round of domestic industrial transformation and innovation-driven development. Graphene has excellent characteristics such as fast electron mobility, high strength, good electrical / thermal conductivity, high light transmittance, and small mass. It is widely used in new energy, petrochemical, electronic information, composite materials, biomedicine, wearable devices and energy Applications in traditional and emerging fields such as environmental protection are expected to trigger changes in related industries. ...

AI Technical Summary

Problems solved by technology

[0004] (1) Graphene oxide functional group defects: In most methods for preparing graphene composite materials, the graphene used is obtained by reducing graphene oxide, which will inevitably introduce some oxygen-containing functional groups, and the reaction temperature in some composite material synthesis methods is low , it is difficult to decompose the oxygen-containing functional groups, and the residual oxygen-containing functional groups react with the electrolyte during the battery cycle, which not only reduces the first effect of the battery, affects the battery cycle life, but also brings safety hazards

[0005] (2) Insufficient performance of transition metal oxides: Although the theoretical capacity is high, transition metal oxides have poor conductivity, high irreversible capacity, obvious volume effect during charge and discharge, and powdering of electrode materials, resulting in poor cycle stability and low capacity. Fast attenuation and other issues restrict its industrial application

[0006] (3) Large-scale preparation of graphene: The traditional oxidation-reduction method is limited by the long production cycle, the generation of a large amount of waste acid and waste liquid, and safety and environmental protection issues, while the reaction conditions of the epitaxial growth method are relatively harsh, and the single crystal silicon carbide substrate The cost is too high, graphene is difficult to separate from the substrate, and it is difficult to prepare graphene materials in large quantities, and the prospect of industrial production is not great

[0007] Therefore, the existing technology for preparing graphene-based composites needs to be improved

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