Facile synthesis of nanocage Co3O4 for advanced lithium-ion batteries

•Co-MOF is converted to nanocage Co3O4 by two-step thermal annealing.•As-obtained nanocages are composed of Co3O4 nanoparticles with porous nature.•Nanocage Co3O4 exhibits good rate capability and cycling stability as LIB anode.

A facile two-step annealing process is applied to synthesize nanocage Co3O4, using cobalt-based metal-organic framework as precursor and template. The as-obtained nanocages are composed of numerous Co3O4 nanoparticles. N2 adsorption–desorption isotherms show that the as-obtained Co3O4 has a porous structure with a favorable surface area of 110.6 m2 g−1. Electrochemical tests show that nanocage Co3O4 is a potential candidate as anode for lithium-ion batteries. A reversible specific capacity of 810 mAh g−1 was obtained after 100 cycles at a high specific current of 500 mA g−1. The material also displays good rate capability, with a reversible capacity of 1069, 1063, 850, and 720 mAh g−1 at specific current of 100, 200, 800, and 1000 mA g−1, respectively. The good electrochemical performance of nanocage Co3O4 can be attributed to its unique hierarchical hollow structure, which is maintained during electrochemical cycling.

Graphical abstractHierarchical Co3O4 nanocages are synthesized via a two-step annealing process. When applied as an anode material for LIBs, high capacity, good cycling stability, and high rate capability is observed.Figure optionsDownload full-size imageDownload as PowerPoint slide