Study On Preparation And Performance Of Supercapacitor Electrodes Based On Carbon-Based Composites

Supercapacitors have the advantages of high power density,fast charging speed,wide operating temperature range and long cycle life,making the research on supercapacitors more and more important.Electrodes,membranes and electrolytes are the three important components of supercapacitors.Among them,electrodes are the most critical factors affecting the overall performance of supercapacitors.Therefore,how to prepare supercapacitor electrodes with excellent comprehensive performance,low price and environmental friendliness has been key topics for researchers.In order to develop supercapacitor electrodes with excellent performance,composite materials have attracted great attention from researchers.In general,the composite electrode combines carbon with transition metal oxide or conductive polymer to create a synergistic effect between the materials and improve the comprehensive performance of the composite electrode.In this article,carbon materials are used as the base material,and the carbon materials are combined with conductive polymers or transition metal oxides to prepare composite electrodes.The specific research contents are as follows:(1)First,the melamine sponge is subjected to a conductive treatment using reduced graphene oxide(RGO),and then high-quality polypyrrole(PPy)is supported on the melamine sponge by chemical oxidative polymerization.High-quality PPy not only provides good conductivity for composite electrodes but also provides high specific capacitance.The effect of the oxidant(ammonium persulfate)concentration on the properties of the final composite electrode was investigated by varying the oxidant concentration.When the oxidant concentration is 0.2 M,the electrical properties of the jflexible composite electrode achieve best.At this time,the loading of polypyrrole was 11.3 mg,the electrical properties was tested in a 1 M sodium sulfate solution,and the area specific capacitance reached 3189 mF cm-2.At the same time,after completing 2000 cycles of testing,its electrical performance still maintained 85%of the initial state,indicating that the flexible electrode has good cycle stability.(2)NiCo2O4-CNFs composite electrodes were prepared by electrospinning and subsequent heat treatment.Carbon fiber was used as the conductive matrix of active material.NiCo2O4 particles were uniformly dispersed on carbon fiber.This structure provided good electricity performance for NiCo2O4-CNFs composite electrode.The composite electrode has a mass specific capacitance of 836 F g-1 at a current density of 5 A g-1,and the cycle stability of the NiCo2O4-CNFs2 electrode at a current density of 10 A g-1 was tested,after 2000 cycles of testing,it still maintains the 80.9%specific capacitance of the initial state,indicating that the obtained composite electrode not only has a good specific capacitance but also has excellent cycle stability.