Carbonclothmodifiedbyhydrothermaltreatmentinammoniawaterisdevelopedasthepositiveelectrodewithhighelectrochemicalperformanceforvanadiumredoxflowbatteries.TheSEMshowsthatthetreatmenthasnoobviousinfluenceonthemorphologyofcarboncloth.XPSmeasurementsindicatethatthenitrogenousfunctionalgroupscanbeintroducedonthesurfaceofcarbonclothsuccessfully.TheelectrochemicalperformanceofV(IV)/V(V)redoxcoupleonthepreparedelectrodeisevaluatedwithcyclicvoltammetryandlinearsweepvoltammetrymeasurements.TheN-dopedcarbonclothexhibitsoutstandingelectrochemicalactivityandreversibilitytowardV(IV)/V(V)redoxcouple.TherateconstantofV(IV)/V(V)redoxreactiononcarbonclothcanincreaseto2.27×10-4cm/sfrom1.47×10-4cm/safternitrogendoping.ThecellusingN-dopedcarbonclothaspositiveelectrodehaslargerdischargecapacityandhigherenergyefficiencycomparedwiththecellusingpristinecarboncloth.TheaverageenergyefficiencyofthecellusingN-dopedcarbonclothfor50cyclesat30mA/cm2is87.8%,4.3%largerthanthatofthecellusingpristinecarboncloth.ItindicatesthattheN-dopedcarbonclothhasapromiseapplicationprospectinvanadiumredoxflowbatteries.