Kiymaz D.Kiymaz A.Tekoglu S.Mayr F.Dincalp H.Zafer C.2024-07-222024-07-22202200406090http://akademikarsiv.cbu.edu.tr:4000/handle/123456789/12406In a supercapacitor, determining the cells’ internal dynamics and limiting factors on the efficiency is essential for device designs. In this context, electrochemical impedance spectroscopy is a powerful tool in investigating device kinetics. This study explained the performance improvement in nanostructured MnO2 electrodes from a diffusion perspective. Firstly, we reported morphological features of flower-like nanosheet MnO2 and nanowire MnO2 with identical crystal structure (α-MnO2 phase) and capacitance-voltage properties. Then, the factors limiting the bias voltage-dependent capacitance efficiency were explained via electrochemical impedance spectroscopy by setting up a three-electrode system. Both resistance and capacitance vs. frequency plots provided important information on ion diffusion and charge transfer mechanisms. © 2022 Elsevier B.V.EnglishCapacitanceCharge transferCrystal structureEfficiencyElectrochemical electrodesElectrochemical impedance spectroscopyManganese oxideNanowiresSupercapacitorChemical solution depositionDevice designElectrochemical-impedance spectroscopiesHollanditesInternal dynamicsMorphological featuresNano sheetNano-structuredPerformanceTransport kineticNanosheetsArticle10.1016/j.tsf.2022.139535