0D-2D Cu2O microspheres@rGO composite for enhanced sodium storage

Abstract

A cuprous oxide microspheres@reduced graphene oxide (Cu2O@rGO) composite is successfully prepared and used as an anode active material for sodium-ion batteries. In the hybrid structure, large-sized 0D Cu2O microspheres (∼500 nm) are distributed on highly conductive 2D rGO layers. The Cu2O@rGO electrode delivers a high reversible capacity of 273.2 mAh g−1 at a current density of 50 mA g−1 after 100 cycles, significantly higher than regular-sized (less than100 nm) Cu2O/rGO composite (185.9 mAh g−1) and bare Cu2O particles (95.8 mAh g−1). Even at 1 A g−1, Cu2O@rGO still demonstrates a capacity of 189 mAh g−1 after 1000 cycles. The enhanced electrochemical performance of Cu2O@rGO might be ascribed to the continuous and stable 3D network structure, which is transformed from the unique large-sized 0D-2D architecture after cycling. The as-fabricated hybrid structure shows great potentials in energy storage applications.