Byutilizinghardtemplatemethodtoadjustthemesoporelength,andalkaliactivationtogeneratemicropores,twohierarchicalporouscarbons(HPCs)wereprepared.Withcontrollingoftheirmesoporelengthandtheactivationconditions,thecomplexsystemcomposedbyHPCsandelectrolytewassimplifiedandtheeffectofmesoporelengthontheperformanceofHPCsaselectrodesinsupercapacitorswasinvestigated.Itisfoundthatwiththemesoporelengthgettingsmaller,theorderedareagetssmallerandthaggregationoccurs,whichiscausedbythehighsurfaceenergyofsmallgrains.HPCwithlongpore(HPCL)exhibitsadonut-likemorphologywithwell-definedorderedmesoporesandaregularorientationwhileinHPCwithshortpores(HPCS),shortmesoporesareonlyorderlydistributedinsmallregionsLongerorderedchannelsformunobstructedwaysforionstransportintheparticleswhileshorterchannels,onlyorderlydistributedinsmallareas,resultsinblockedpaths,whichmayhindertheelectrolytionstransport.Duetotheunobstructedstructure,HPCLexhibitsgoodratecapabilitywithacapacitancretentionrateover86%ascurrentdensityincreasingfrom50mA/gto1000mA/g.ThespecificcapacitanceofHPCLderivedfromthecyclicvoltammetrytestat10mV/sisupto201.72F/g,whilethespecificapacitanceofHPCSisonly193.65F/g.
