Charge transport kinetics in flower like α-MnO2 nano-sheet and α-MnO2 nanowire based supercapacitors
Articles > Article · 2022
Authors: Deniz Kiymaz, Aykut KIYMAZ, Serpil Tekoglu, Felix Mayr, Haluk Dincalp, Ceylan ZAFER
Thin Solid Films, Journal Indexed in SCI Expanded, International, WoS, 2022, vol 762, pp 139535-139535
DOI: 10.1016/j.tsf.2022.139535
Summary
In 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.