Facile Synthesis of Hollow Polyhedral (Cubic, Octahedral and Dodecahedral) NiO with Enhanced Lithium Storage Capabilities

A facile sacrificial-template method combined with a post annealing treatment was developed to synthesize uniform hollow polyhedral (cubic, octahedral and dodecahedral) NiO materials. The electrochemical and lithium-ion battery performances of the shape controlled hollow polyhedral NiO materials were examined, providing us with a description of the structure-performance correlations of hollow polyhedral anodes. The lithium-ion battery performance was found to be highly dependent on the hollow polyhedral NiO morphology. The hollow dodecahedral NiO (HD-NiO) electrode exhibited excellent cycling stability, high reversible capacity and good rate capacity compared to the other two NiO samples. At a current density of 0.1 A g−1, the hollow dodecahedral NiO electrode displayed an especially high capacity of 980 mAh g−1 after 100 cycles, which was much higher than that of the hollow cubic and octahedral NiO electrodes. Most important of all, when assembled with LiCoO2 to construct a full lithium-ion battery (HD-NiO//LiCoO2), the HD-NiO electrode exhibited a reversible capacity of 627 mAh g−1 at a current density of 0.1 A g−1 in the potential range of 1.0-3.8 V. These results clearly demonstrate that hollow polyhedral NiO has potential as an anode material in next generation lithium-ion battery systems with improved storage capacities.