Bimetallic ZIF-derived polyhedron ZnCo2O4 anchored on the reduced graphene oxide as an anode for sodium-ion battery

Polyhedron ZnCo2O4 derived from the appropriate oxidation of bimetallic ZIF (Co2/3Zn1/3(MeIm)(2)) is anchored on the reduced graphene oxide (rGO) nanosheets via a hydrothermal method. ZnCo2O4 is uniformly distributed in the structure of polyhedron and the polyhedron ZnCo2O4 firmly is decorated on the rGO nanosheets according to the results of element mapping and scanning electron microscope (SEM). With a discharge/charge voltage from 0.01 to 3.0V, the polyhedron ZnCo2O4@rGO composite electrode displays good cycling performance with a discharge capacity of 134mAhg(-1) after 300 cycles for sodium-ion batteries, which is better than polyhedron ZnCo2O4. Good cycling performance and high reversible capacity can be ascribed to benign conductive environment and flexible supporting of reduced graphene oxide.