Hierarchical porous Co3O4 nanocages with elaborate microstructures derived from ZIF-67 toward lithium storage

Increasing the complexity of external or internal structure of hierarchical nanomaterials is essential to improve the specific capacity and stability of anode for lithium ion batteries (LIBs). Three types of porous Co 3 O 4 nanocubes (concave-cube, yolk-shell cube and porous cube) with novel hollow structures were synthesized straightforwardly by annealing zeolitic imidazolate framework (ZIF-67) under varied temperatures of 350 °C, 450 °C and 550 °C, respectively. Consequently, the resulting concave, core-shell and porous Co 3 O 4 nanocubes exhibited superior specific capacities of 1009, 1148 and 696 mA h g −1 , respectively, at a current density of 200 mA g −1 after 200 cycles. Even at a high current density of 10 A g −1 , the core-shell Co 3 O 4 nanocube still showed a large reversible capacity of 317 mA h g −1 . The complex hierarchical texture, porous shell and core, and well-defined hollow structure of the Co 3 O 4 nanocubes were contributed greatly to the good lithiation/delithiation reversibility, ultralong cycling stability and enhanced rate capability.