The use of α-MnOOH nanosheets as battery-type electrode for supercapacitor applications

This study investigated MnOOH nanosheets, which were synthesized at different manganese molarities on 3D-nickel foam by hydrothermal synthesis, for use as battery-type electrodes. The crystal structures and morphologies of the MnOOH nanosheets were determined by using X-ray diffraction, field emission scanning electron microscopy, energy dispersion X-ray spectroscopy, Raman Spectroscopy and X-ray photoelectron spectroscopy. Cyclic voltammetry, galvanostatic charge discharge and electrochemical impedance spectroscopy analysis of the MnOOH nanosheets were performed in 1 M of a KOH aqueous electrolyte solution. The specific capacity values obtained from GCD measurements taken at a current density of 0.5 A g-1 from samples called Mn-0.2, Mn-0.5, Mn-1 and Mn-2-according to their manganese molarities-were 230, 557, 766 and 493 C g-1, respectively. Furthermore, the Mn-1 sample, which had the highest specific capacitance value, showed excellent cycle stability by retaining 79% of the initial specific capacity after 10000 charge-discharge cycles. © Springer Science+Business Media, LLC, part of Springer Nature 2019.