ZnO/rGO/C composites derived from metal–organic framework as advanced anode materials for Li-ion and Na-ion batteries

A novel ZnO/reduced graphene oxide/carbon (ZnO/rGO/C) composite is synthesized by pyrolysis of Zn-based metal–organic framework where graphene oxide and the glucose are imported as carbon sources. As a result, ZnO nanoparticles dispersing on a uniform reduced graphene sheet with a thin carbon layer construct a unique structure, which can prevent the aggregation of ZnO, enhance the electronic conductivity, and offer a robust scaffold during electrochemical processes. Compared to the bare ZnO and ZnO/rGO, the obtained ZnO/rGO/C composite can exhibit a high reversible capacity (~ 830 mA h g⁻¹ after 100 cycles, approximately 85% of theoretical capacity), and superior rate capability as anodes for Li-ion battery. Additionally, the electrochemical property of ZnO-based materials for Na-ion batteries is also proposed for the first time. It demonstrates that the as-synthesized ZnO/rGO/C composite also delivers an outperformance cyclic stability and considerable reversible capacity (~ 300 mA h g⁻¹ after 100 cycles). This simple methodology can be further extended to other energy storage applications.