Manufacturing method of graphene/manganese dioxide super-capacitor electrode

Abstract

A manufacturing method of a graphene / manganese dioxide super-capacitor electrode belongs to the functional carbon material manufacturing field. The manufacturing method comprises the following steps of manufacturing a graphene / manganese dioxide compound without a template and other surfactants, wherein the graphene / manganese dioxide compound is composed of the graphene and manganese dioxide nanoparticles uniformly loaded between graphene layers, and a diameter of the manganese dioxide nanoparticles is 10-20 nm; and then manufacturing the graphene / manganese dioxide compound into a super-capacitor electrode. The graphene / manganese dioxide supercapacitor electrode manufactured in the method is placed in a 1mol / L NaSO4 electrolyte. A capacitance of a super capacitor measured under a 1.6 V potential window is 380-540F / g, and the capacitance is 85-90% of an initial value after 1000 cycles under 100mV / s.

Description

technical field [0001] The invention belongs to the field of preparation of functional carbon materials, in particular to a preparation method of a graphene / manganese dioxide super capacitor electrode. Background technique [0002] Because supercapacitors have the advantages of high power density, excellent cycle life, good memory-free effect, and low maintenance costs, they can be used as devices to replace batteries in new energy storage. Due to graphene's unique two-dimensional structure and inherent physical properties (exceptionally high electrical conductivity and large surface area), graphene-based materials have great potential for applications in supercapacitors. [0003] Graphene is a two-dimensional sp 2- Hybrid carbon sheet, because of its very good theoretical high specific surface area, low density, good chemical stability and high conductivity, can be used as a supercapacitor. The ultra-thin graphene wall can form a three-dimensional graphene structure, and ...

AI Technical Summary

Problems solved by technology

[0005] At present, the synthesis of manganese dioxide / graphene composites is usually carried out in aqueous solution, but due to the poor wettability of manganese dioxide and carbon and the high surface energy of nanoparticles, it is difficult to enter the nanostructured manganese dioxide soluble salt. Between the layers of graphene, they tend to cluster in water instead of combining with graphene, which leads to the fact that the nanostructured manganese dioxide cannot contact the electrolyte and cannot produce a pseudocapacitive effect

The inability to produce pseudocapacitive effect is the reason why the capacitance value of the manganese dioxide supercapacitor in the prior art is far lower than its theoretical supercapacitance value

This agglomerated nanostructured manganese dioxide also greatly reduces the surface energy of the nanoparticles, which reduces the electrochemical activity of manganese dioxide, thereby reducing the chemical reaction rate between the electrolyte and the manganese dioxide active material and the interaction of electrolyte ions. Diffusion speed, which eventually slows down the charging and discharging speed of the supercapacitor

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