Solvothermal synthesis of Al₂Se₃/rGO nanocomposites with excellent electrochemical performance in supercapacitor

As a supercapacitor material, transition metal selenide (TMS) can be synthesised in a cost-effective and simple manner. However, it suffers from low-rate capacities and poor cyclic stability due to their easy aggregation and structural instability during charge and discharge cycles. Herein, we report the synthesis of aluminum selenide (Al₂Se₃) nanorods over reduced graphene oxide (rGO) nanosheets as a novel material using the solvothermal method. The successful formation of Al₂Se₃/rGO nanocomposite was confirmed via XRD (X-ray diffraction), SEM (scanning electron microscopy), and XPS (X-ray photoelectric spectroscopy) and was also investigated for its optical characteristics and electrochemical performance. The optimised Al₂Se₃/rGO sample with 5 wt% and 10 wt% rGO exhibited high specific capacitances of 701.83 Fg⁻¹ and 1138.1 Fg⁻¹, respectively. Moreover, Al₂Se₃/10%rGO nanocomposite as a positive electrode achieves energy densities of 39.57 Wh/kg and power densities of 0.006 kW/kg at current densities 2.5 A/g along with stability up to 2000 cycles, suggesting it to be a significant technological candidate in the future. This work highlights an effective and feasible approach to engineer or construct TMS/rGO nanocomposites for charge storage applications.