Abstract
Transition metal chalcogenides become emerging materials as electrodes for electrochemical energy
storage devices. In this study, we are reporting the preparation of a-MnSe nanoparticles using a one-pot
hydrothermal method and examined its use as an electrode material for supercapacitors. Physicochemical
characterizations such as X-ray diffraction, laser Raman, and field emission scanning electron
microscopic analyses revealed the formation of a-MnSe nanoparticles. The electrochemical analysis such
as cyclic voltammetry and electrochemical impedance spectroscopy suggested the mechanism of chargestorage
is due to the pseudocapacitive nature of a-MnSe electrode. The a-MnSe electrode delivered a
specific capacitance of 96.76 F g1 from galvanostatic charge-discharge obtained at a constant current
density of 0.1mA cm2 with a corresponding energy density of 8.60Wh kg1 and better cyclic stability
over 2000 cycles. Further, the electrochemical performance of the a-MnSe symmetric supercapacitor
device shows that the specific capacitance is about 23.44 F g1 at a current density of 0.1mA cm2, with a
potential window of 0.8 V. The superior electrochemical performance of a-MnSe highlights the potential
use as electrode material in energy storage sector.