Diffusion induced concave Co3O4@CoFe2O4 hollow heterostructures for high performance lithium ion battery anode

A facile and effective approach to prepare Co3O4/CoFe2O4 hollow cubes with uniform size and complex interior architectures is proposed via annealing of metal-cyanide-bridged hybrid coordination polymers (HCPs). The synergistic effect of the hybrid metal oxides and the rational design of the architecture endow these heterostructures with good lithium storage property and charge carrier transfer kinetics. In the hybrid materials, CoFe2O4 offers high theoretical capacity and Co3O4 provides stability at high current densities, leading to the significant enhancement in lithium storage properties comparing to the pure CoFe2O4. For example, Co3O4/CoFe2O4 heterostructures annealed at 800 degrees C exhibit a high capacity of 511 mA h g(-1) at a current density of 8.0 A g(-1) and a reversible capacity of 515 mA h g(-1) during the 500th cycle at a current density of 5.0 A g(-1). (C) 2016 Elsevier BY. All rights reserved.