Hierarchical hybrid ZnFe2O4 nanoparticles/reduced graphene oxide composite with long-term and high-rate performance for lithium ion batteries

Abstract

Hierarchical hybrid nanostructure of mesoporous ZnFe2O4 nanoparticles anchored on reduced graphene oxide (ZnFe2O4 NPs/rGO) has been successfully developed in this research via a fast low-temperature refluxing method and a subsequent-annealing treatment in N2. The unique mesoporous network structures of ZnFe2O4 NPs supported by flexible rGO sheets offer sufficient electrode-electrolyte contact, shorten Li+ ions diffusion distance, and thus greatly facilitate the electrochemical reactions via accommodating the volume change efficiently during cycling. Meanwhile, the conductive rGO matrix in the hybrid composite also ensures rapid electron transport to avoid the serve pulverization. Just based on such beneficial synergistic effect, the well-designed hierarchical hybrid ZnFe2O4 NPs/rGO composites present excellent lithium storage performance with high reversible discharge capacity, long-term cycle stability and superb high-rate capability when used as an anode for LIBs. A stable discharge capacity of as high as about 1106.7 mAh g−1 is well maintained even after 400 cycles at the current density of 200 mA g−1. We think this facile strategy could be further extended to the fabrication of other graphene-based electrodes for advanced energy applications.