Formation of hollow Co3O4 nanocages with hierarchical shell structure as anode materials for lithium-ion batteries

Two kinds of unusually hollow and porous Co3O4 nanocages with high complexity in shell architecture and high surface areas of 58.8 and 43.8 m(2) g(-1) are synthesized by a straightforward pyrolysis of zeolitic imidazolate framework (ZIF-67) rhombic dodecahedrons as self-sacrificing template under different temperature. The two types complex hollow Co3O4 nanocomposites utilized as anode materials for Lithium ion batteries (LIBs) manifested the initial discharge capacities as high as 2169 and 1928 mA h g(-1) and initial Coulombic efficiency under a specific current of 100 mA g(-1), which could still show a high reversible capacity of 915 and 668 mA h g(-1) after 100 cycles. The two electrodes materials also exhibited rate capability of 322 and 169 mA h g(-1) at a large specific current of 2 A g(-1). The hollow architecture, complex shell structure, high surface area and ultrafine building blocks might give rise to the high specific capacities. Moreover, the simple synthesis route rendered it to be a potential and promising electrode materials for rechargeable LIBs.