Comparative capacitive performance of MnSe encapsulated GO based nanocomposites for advanced electrochemical capacitor with rapid charge transport channels

Abstract

In this work, series of manganese selenide (MnSe) and graphene oxide (GO) nanocomposites are prepared via a well-known hydrothermal route to investigate the impact of varying content of GO (5, 10, 15, and 20%) on the electrochemical properties of MnSe-GO composites. Phase and structural investigations of the as-prepared samples were carried out by using XRD. SEM analysis showed the successful formation of flakes-like morphology of MnSe wrapped on GO sheets, providing a conductive pathway for transmission of electrolyte ions. When tested thoroughly for supercapacitor electrodes in a three-electrode configuration, all electrodes revealed a pair of redox peaks originating from Mn2+/Mn3+ due to faradaic redox reactions owing to their pseudocapacitive behavior. Amongst all samples, the optimum electrochemical performance was achieved with the aid of 5% GO composite with MnSe, which exhibited a capacitance of 180 F g−1 with the lowest charge transfer resistance. For practical aspects, we designed and fabricated an asymmetric supercapacitor (ASC), which delivered a capacitance of 56.25 F g−1, an energy density of 31.25 Wh kg−1 at a power density of 6779.20 W kg−1. Remarkably, our fabricated ASC made of MnSe-GO//AC displayed an outstanding cycling performance with its initial capacitance retention of 86.3% when tested for 5000 successive charge-discharge cycles. Thus, based on the comparative results of MnSe based GO composites for energy storage, the performance of the MnSe nanomaterial can be further enhanced by using different carbon-based nanomaterials, a promosing approach to fabricate materials for future energy conversion and storage devices.