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.