Dual-shelled Cu2O@Cu9S5@MnO2 hollow spheres as advanced cathode material for energy storage

Abstract

In this study, dual-shelled Cu2O@Cu9S5@MnO2 hollow spheres with high surface area and porosity are developed as cathode material for electrochemical energy storage. Initially, Cu2O spheres are prepared via a hydrothermal method, which act as templates for subsequent procedure of forming hollow spheres with core(Cu2O)-shell(Cu9S5) structure. Subsequently, porous MnO2 shells is deposited on Cu2O@Cu9S5 hollow spheres to form dual-shelled hollow spheres. In alkaline aqueous electrolyte, at a current density of 0.1 A g−1, Cu2O@Cu9S5@MnO2 exhibits a high specific capacitance of 129.9 F g−1 with 99.6% capacity retention over 4000 cycles. In terms of rate capability, capacitance retention of Cu2O@Cu9S5@MnO2 at a current density of 3 A g−1 is 71.0% of the initial capacitance measured at a current density of 0.1 A g−1. Cu2O@Cu9S5@MnO2 delivers a promising high rate and highly capacitive cathode material for alkaline supercapacitors, due to its hollow architecture and its synergistic mixed oxide core-dual-shell composition.