Graphene-like WS2/nitrogen and phosphorus do-coped graphene electrochemical sodium storage composite electrode preparation method

Abstract

The present invention discloses a graphene-like WS2 / nitrogen and phosphorus do-coped graphene electrochemical sodium storage composite electrode preparation method, which comprises: S1, dispersing graphene oxide in water, adding a quaternary phosphonium salt, uniformly mixing, sequentially adding ammonium thiotungstate and hydrazine, and uniformly mixing; and S2, carrying out a hydrothermal reaction on the mixed dispersion system obtained in the step S1, cooling, collecting the solid product through centrifugation, washing, drying, and carrying out a heat treatment in a nitrogen or argon atmosphere so as to prepare the graphene-like WS2 / nitrogen and phosphorus do-coped graphene composite nanometer material; and S3, adopting the composite nanometer material obtained in the step S2 as the electrochemical sodium storage active substance to prepare the composite electrode. According to the present invention, graphene oxide, ammonium thiotungstate and hydrazine are adopted as the raw materials, and the quaternary phosphonium salt assisted hydrothermal and heat treatment method and other methods are used to successfully prepare the graphene-like WS2 / nitrogen and phosphorus do-coped graphene electrochemical sodium storage composite electrode; and the method has advantages of simpleness, convenience, and easy industrial application expanding.

Description

technical field [0001] The invention belongs to the technical field of new energy materials and energy storage and conversion, and in particular relates to a graphene-like WS 2 Preparation method of nitrogen / phosphorus co-doped graphene electrochemical sodium storage composite electrode. Background technique [0002] New energy vehicles are an important development direction of the future automotive industry, and power batteries are one of the core components of new energy vehicles. At present, lithium-ion batteries are the most promising high-energy battery system. However, with the advent of the era of electric vehicles and smart grids, global lithium resources will not be able to effectively meet the huge demand for power lithium-ion batteries, which will further push up the price of lithium-related materials, increase battery costs, and ultimately hinder new energy. industry development. Therefore, it is critical to develop other related energy storage technologies th...

AI Technical Summary

Problems solved by technology

For the liquid-phase synthesis method, the water solubility of inorganic phosphate is very good, but because the phosphate or hydrogen phosphate itself is negatively charged, it is difficult to adsorb on the graphene oxide with the same load; and the phosphorus in the phosphate - The bond energy of the oxygen bond is relatively large, and it needs to be broken at high temperature, so the doping degree of phosphorus in the phosphorus-doped graphene prepared by using phosphate or hydrogen phosphate as the phosphorus source is not high

Although organic phosphine such as butyl phosphate and triphenylphosphine are not strong in phosphorus-carbon bonds and are easy to break, because organic phosphorus has poor solubility in water and does not have a positive charge, it cannot be combined with negatively charged ones in aqueous solution. Graphene oxide and thiotungstate produce strong electrostatic interaction, resulting in poor composite material or uneven doping

If the reaction is carried out in an organic solvent, and the solubility of thiotungstate in an organic solvent is relatively poor, it will not only be difficult to react, but also produce more organic waste and pollute the environment

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