Method for preparing nano MnO2 composite electrode for high-conductivity super-capacitor

Abstract

A method for preparing nano MnO2 composite electrode for a high-conductivity super-capacitor includes the steps of taking a multi-walled carbon nanotube, adding the multi-walled carbon nanotube to mixed acid formed by sulfuric acid and nitric acid, wherein the molar ratio of the sulfuric acid and the nitric acid is 3:1, heating the mixed acid to 60 DEG C and stirring the mixed acid in a centrifugal mode, washing the mixed acid repeatedly with deionized water until the PH value of supernatant is 7, drying the multi-walled carbon nanotube for use, preparing electrolyte with the concentration between 0.1g / L and 2g / L, using stainless steel net electrodes as a cathode and an anode, applying direct-current voltage of 0.05-1V / cm2 across the cathode and the anode, depositing for 10-50min, obtaining a stainless steel net absorbing the multi-walled carbon nanotube, preparing a MnSO4 solution or a MnNO3 solution of 0.1mol / L as electrolyte, taking the stainless steel net to prepare an electrode, wherein the electrode serves as a positive pole and a platinum electrode serves as a negative pole, carrying out electrodeposition at a constant current of 0.5-50mA / cm2, keeping the temperature at 90 DEG C, and obtaining the nano MnO2 composite electrode after depositing for 5-30min. The method can conveniently and accurately control current density, electrolysis time, the type, components, the concentration, the PH value and other parameters of the electrolyte, and has the advantages of being simple to operate and low in cost.

Description

technical field [0001] The invention relates to a kind of nanometer MnO for supercapacitor with high conductivity 2 Preparation method of composite electrode. Background technique [0002] With the rapid development of the world economy, oil resources are becoming increasingly scarce, environmental pollution is becoming more and more serious, and the demand for renewable and environmentally friendly power sources is growing rapidly. Supercapacitors are a new type of green energy storage device that has developed rapidly this year. It has the characteristics of high energy, high power, and long life. It has the characteristics of wide operating temperature, high reliability, and fast charge and discharge. [0003] The research on manganese oxide supercapacitor electrode materials has become one of the research hotspots in the field of supercapacitors. Manganese oxides have attracted much attention due to their advantages of multi-valence, high theoretical specific capacita...

AI Technical Summary

Problems solved by technology

However, MnO 2 It is a semiconductor with low conductivity and poor cycle reversibility, which seriously limits the electrode material used as a supercapacitor charge and discharge performance

Therefore, when manganese dioxide is used as an electrode material to prepare an electrode, there is a shortcoming that it must be supplemented by adding a conductive material to make up for its poor conductivity.

[0004] MnO 2 As an active material for supercapacitor electrodes, it has the characteristics of high theoretical specific capacity, but due to its low electrical conductivity, it is difficult to exert its high theoretical specific capacity.

In order to improve MnO 2 Electrode conductivity, the existing process methods are all based on MnO 2 The powder is mixed with high conductivity material to improve MnO 2 The purpose of electrode conductivity, but the mixed high conductivity material is difficult to disperse evenly in the electrode, cannot form electron diffusion channels, and cannot better improve MnO 2 Electrode conductivity

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