NiO polyhedron nanocrystals have been synthesized using a single source of nickel chloride through a calcination reaction. The electrochemical results displayed that the obtained sample is an outstanding anode material for lithium ion batteries (LIBs). The sample maintains a high specific capacity of 645.5 mAh g-1 at current density of 1000 mA g-1 after 100 cycles. Even at high current density of 4000 mA g-1, the NiO polyhedron nanocrystals still deliver a capacity of 459.6 mAh g-1. The high specific capacity, long stable cyclic property and good rate capability make the NiO polyhedron nanocrystals a good candidate anode material for high-performance LIBs.