Mesoporous zinc ferrite/graphene composites: Towards ultra-fast and stable anode for lithium-ion batteries

Mesoporous zinc ferrite (ZnFe2O4)/graphene composites are synthesized using a facile ambient-pressure method, i.e., co-precipitation of metal cations onto graphene oxide followed by solid state reaction to yield ZnFe2O4 nanoparticles anchored on reduced graphene oxide. The resultant ZnFe2O4/graphene composites have large specific surface area with mesopores, and the size of the ZnFe2O4 nanoparticles is less than 20 nm. When the composites are employed as an anode material for lithium-ion batteries, it exhibits superior electrochemical performances in term of high reversible capacity, good cyclic performance and excellent rate capability. Its reversible discharge capacities can be maintained at 870 mAh/g at 1.0 A/g for 100 cycles and consecutively 713 mAh/g at 2.0 A/g for another 100 cycles. Moreover, other graphene-based composites containing ferrites, such as cobalt ferrite and nickel ferrite, are also synthesized with this generic strategy which is promising for large-scale production of lithium-ion battery anode materials.