Synthesis of reduced graphene oxide (rGO)/dysprosium selenide (Dy2Se3) composite electrode for energy storage; flexible asymmetric supercapacitor

Abstract

In recent years, the requirement for flexible electrode materials has attracted scientific attention for developing flexible supercapacitors. The present work reports the porous reduced graphene oxide/dysprosium selenide (rGO/Dy2Se3) composite thin films preparation, employing successive ionic layer adsorption and reaction (SILAR) method. This work offers thorough information about the structure, morphology, and elemental analysis of prepared rGO/Dy2Se3 composite, as well as its electrochemical properties such as specific capacitance (Cs), charge transfer resistance, electrochemical stability, etc. The rGO/Dy2Se3 composite electrode achieved a Cs of 289 F g−1 at a 5 mV s−1 scan rate with 89% retention up to 5000 galvanostatic charge-discharge (GCD) cycles due to synergy between properties of Dy2Se3 and rGO. A flexible solid-state asymmetric supercapacitor (FSSAS) rGO-Dy2Se3/LiClO4-PVA/MnO2) device delivered Cs of 107 F g−1 at a 5 mV s−1 and a specific energy of 45 Wh kg−1 at a power of 9 kW kg−1. The FSSAS device retained 91% of its capacitance at a 160° bending angle. These findings show that Dy2Se3 anchored on rGO using SILAR method is a promising candidate for supercapacitors.