Modified carbon cloth as positive electrode with high electrochemical performance for vanadium redox flow batteries

(整期优先)网络出版时间:2016-04-14
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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.