Study on graphene oxide modified by oligomers of p-phenylenediamine for supercapacitors

Inordertoobtainhighspecificcapacitanceoftheelectrodeusedforsupercapacitorsbasedon newcarbonmaterials,grapheneoxide(GO),fromgraphiteoxidizedbychemicals,wasmodifiedbyoligomers of p-phenylenediamine in an autoclave.The changes of molecular structure of pphenylenediamineoligomersinethanolsolutionunderdifferentheatingprocessesweretestedbyUV-vis spectroscopy.Thestructure,morphology,electricalstorageperformanceandcyclestabilityofthecompositewerecharacterizedbyX-raydiffraction,fieldemissionscanningelectronmicroscopy,andcyclic voltammetry.Theresultsimplythatoligomersof p-phenylenediaminecaneffectivelyexpandthelayer spacingofGO,andthecompositeshowsarandomstackingmanner.Oligomersof p-phenylenediamine, heatedat60℃ for48h,havethegreatesteffectonthemodificationofGO.Specificcapacitanceofthe
compositeis453F/g,andtheretentionisabove98% after600cycles.Furthermore,aprototypesupercapacitorwasfabricatedinaCR2032cellcase.Calculatedbytheactivesubstance,theenergydensityof thecellis6.8 W·h/kg,and the power density is516.3 W/kg.And the retention is90% of its originalcharging/dischargingprocessafter1000cycles.Theresultsimplythatgrapheneoxidemodified byoligomersofp-phenylenediaminewillhaveagoodpotentialapplicationinenergystorage.