Preparation of graphene-encapsulated mesoporous metal oxides and their application as anode materials for lithium-ion batteries

Graphene-encapsulated mesoporous metal oxides (e.g. Co3O4, Cr2O3 and NiO) as novel anode materials for lithium-ion batteries were simply synthesized by adjusting the pH of mesoporous metal oxides and graphene oxide suspensions to set values (e.g. 5–6 for metal oxides, 7–8 for graphene oxide) and mixing the two suspensions in the presence of reducing agents. These composites synthesized by this facile method exhibited superior electrochemical performance, including remarkably high capacity, high rate capability and excellent cycle performance. The improved performance may be attributed to the high dispersion of mesoporous particles separated by graphene nanosheets and the high electrical conductivity of graphene.