Publication

NMSL Lab

Publication

Two-dimensional molybdenum diselenide nanosheets as a novel electrode material for symmetric supercapacitors using organic electrolyte
Author
Parthiban Pazhamalai, Karthikeyan Krishnamoorthy, Surjit Sahoo, Sang-Jae Kim
Journal
Electrochimica Acta
Page
591-598
Year
2019

Abstract

Two-dimensional transition metal chalcogenides have gained much consideration as electrode materials in electrochemical energy storage devices. In this work, we successfully prepared 2H-MoSe2 sheets and investigated their charge-storage performance in organic electrolyte via fabrication of symmetric supercapacitor (SSC). The formation of 2H-MoSe2 nanosheets was confirmed using X-ray diffraction, X-ray photoelectron spectroscopy, high-resolution transmission electron microscope, Raman spectrum and mapping analyses, respectively. The cyclic voltammetric analysis revealed the presence of pseudocapacitive nature of charge-storage in the MoSe2 SSC with a specific cell capacitance of 25.31 F g−1 obtained at a scan rate of 5 mV s−1. The charge-discharge analysis revealed that the MoSe2 SSC possesses a high specific cell capacitance of 16.25 F g−1 (obtained at a current density of 0.75 A g−1), an energy density of 20.31 Wh kg−1 and excellent cyclic stability with capacitance retention of about 87% over 10,000 cycles. The MoSe2 SSC delivered an excellent power density of 7.5 kW kg−1 obtained from the CD profiles measured using a current density of 5 A g−1. The energy/power density of the MoSe2 SSC device is comparable or even higher with the reported SSCs using 2D materials such as graphene sheets, siloxene sheets, and MXene sheets, respectively. Electrochemical impedance spectroscopic analysis (Nyquist and Bode plots) were used to understand the capacitive nature and charge-transfer kinetics of the MoSe2 SSC in organic electrolyte. Furthermore, we have also demonstrated the real-time application of the MoSe2 SSC as an indication of their candidature towards the development of next-generation energy storage devices.