简介：Inthispaper,carbonmicrospherepreparedbyhydrothermaltreatmentwasactivatedbyKHCO3athightemperature,andemployedasthecatalystforVO2+/VO2+redoxreactionforvanadiumredoxflowbattery(VRFB).CarbonmicrospherecanbeetchedbyKHCO3duetothereactionbetweenthepyrolysisproductsofKHCO3andcarbonatoms.Moreover,KHCO3activationcanbringmanyoxygenfunctionalgroupsoncarbonmicrosphere,furtherimprovingthewettabilityofcatalystandincreasingtheactivesites.Theelectrocatalyticpropertiesofcarbonmicrospherefromhydrothermaltreatmentareimprovedbyhightemperaturecarbonization,andcanfurtherbeenhancedbyKHCO3activation.Amongcarbonmicrospheresamples,theVO2+/VO2+redoxreactionexhibitsthehighestelectrochemicalkineticsonKHCO3activatedsample.ThecellusingKHCO3activatedcarbonmicrosphereasthepositivecatalystdemonstrateshigherenergyefficiencyandlargerdischargecapacity,especiallyathighcurrentdensity.TheresultsrevealthatKHCO3activatedcarbonmicrosphereisanefficient,low-costcarbon-basedcatalystforVO2+/VO2+redoxreactionforVRFBsystem.