Porous CuO/reduced graphene oxide composites synthesized from metal-organic frameworks as anodes for high-performance sodium-ion batteries

Currently, metal-organic frameworks (MOFs) and their derivates have attracted great interest as a new kind of electrode material for energy storage devices, mainly due to their designable framework structures, abundant pore structures, adjustable pore and particle sizes. In this work, porous CuO/reduced graphene oxide (RGO) composites were obtained through the pyrolysis of Cu-based MOFs/graphene oxide under microwave irradiation, and investigated as anode materials for sodium-ion batteries (SIBs). CuO/RGO composites exhibit a maximum specific capacity of 466.6 mA h g⁻¹ after 50 galvanostatic charge/discharge cycles at a current density of 100 mA g⁻¹. Even at a high current density of 2 A g⁻¹, a capacity of 347.6 mA h g⁻¹ is still maintained with stable cycling. The superior electrochemical performance, which is better than those of CuO-based electrodes reported previously, makes the CuO/RGO composites to be applied promisingly as anodes for high-performance SIBs.