Binding ZnO nanorods in reduced graphene oxide via facile electrochemical method for Na-ion battery

Alternating voltage electrochemical dispersion, as a green and facile electrochemical technique, has been successfully developed to design ZnO nanorods/reduced graphene oxide (ZnO/RGO) composite. The morphology of ZnO can be induced to form rod-like structure in this composite via the introduction of GO in the electrolyte solution. Meanwhile, GO can be reduced to RGO during the electrochemical process without adding extra reducing agent, which can enhance the electrical conductivity of ZnO/RGO composite and accommodate the volume change of ZnO. Moreover, ZnO nanorods are well embedded on the surface of RGO with the present of COZn bridge bonds. This COZn formed in the electrochemical preparation can be helpful to contact ZnO nanorods and RGO, which accelerate electron transport rate and enhance structural stability of ZnO/RGO electrode. As-prepared ZnO/RGO composite as an anode for sodium-ion batteries (SIBs) displays much higher capacity, rate performance and cycling behavior than those of pure ZnO material, especially shows ultra-long cycle life (91.9% capacity retention at 500 mA g⁻¹ after 1000 cycles).