This article reported the electrochemical performance of a microspheres carbon/MnO2 (CMS/MnO2 ) composite prepared by an inGsituselfGlimitingdeposition methodunderhydrothermalcondition.The morpholoG giesandstructuresoftheprepared materialswerecharacterizedbyscanelectron microscopy (SEM),transmisG sionelectron microscopy (TEM),XGraydifraction (XRD)andthermogravimetricanalysis (TGA),andthe electrochemicalbehaviorsweretestedby meansofcyclicvoltammetry (CV),chargeGdischargetestsandelectroG

chemicalimpedancespectroscopy (EIS),respectively.Theresultsrevealthat MnO2 homogeneouslygrow onto thesurfaceofCMStoformahydrangeaGlikemicrostructure.MnO2 hasatypicalKGBirnesiteGtypecrystalstrucG tureandthecontentofMnO2inthecompositeis62wt% andaspecificcapacitanceof266F/gwasobtained.

Upontheprolongedsynthetictime,thespecificcapacitanceofresultantCMS/MnO2 materialsincreasedand thenlevelsof,because MnO2 nanoshetscoatedandgrownonthesurfaceofCMSstepbystep.