Hydrothermally prepared α-MnSe nanoparticles as a new pseudocapacitive electrode material for supercapacitor

Transition metal chalcogenides become emerging materials as electrodes for electrochemical energy storage devices. In this study, we are reporting the preparation of alpha-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 alpha-MnSe nanoparticles. The electrochemical analysis such as cyclic voltammetry and electrochemical impedance spectroscopy suggested the mechanism of charge-storage is due to the pseudocapacitive nature of alpha-MnSe electrode. The alpha-MnSe electrode delivered a specific capacitance of 96.76 F g(-1) from galvanostatic charge-discharge obtained at a constant current density of 0.1 mA cm(-2) with a corresponding energy density of 8.60 Wh kg(-1) and better cyclic stability over 2000 cycles. Further, the electrochemical performance of the alpha-MnSe symmetric supercapacitor device shows that the specific capacitance is about 23.44 F g(-1) at a current density of 0.1 mA cm(-2), with a potential window of 0.8 V. The superior electrochemical performance of alpha-MnSe highlights the potential use as electrode material in energy storage sector. (c) 2018 Elsevier Ltd. All rights reserved.