Facile synthesis of metal-organic framework-derived Co3O4 with different morphologies coated graphene foam as integrated anodes for lithium-ion batteries

A facile strategy to fabricate the composites including metal-organic framework (MOF)-derived Co3O4 with different morphologies and graphene foam (GF) is proposed in this work. The resulting Co3O4/GF materials can be directly employed as integrated anodes of lithium-ion batteries, and their electrochemical performances are significantly superior to pure Co3O4 in specific capacities, long-cycle stabilities and rate performances. The enhanced properties originate from the synergistic interaction between GF and MOF-derived metal oxides, where GF provides high conductivity, large specific surface area and excellent mechanical property, whereas metal oxides contribute to high electrochemical activities. The effect of Co3O4 morphologies in the composites on the electrochemical properties is also discussed. Benefitting from the unique structure feature, the leaf-Co3O4/GF integrated electrode delivers a high capacity of 986 mA h g(-1) after 250 cycles at a current density of 100 mA g(-1), which is better than those observed in the block- and rod-Co3O4/GF samples. Even measured at 2 A g(-1), the leaf-Co3O4/GF electrode still shows a capacity of around 340 mA h g(-1). The relatively high electrochemical behaviors are attributed to the unique leaf-like structure of Co3O4 in the composite. (C) 2018 Elsevier B.V. All rights reserved.