Improvement of Lithium Storage Performance of Molybdenum Trioxide by a Synergistic Effect of Surface Coating and Oxygen Vacancies

3D hierarchical flower-like carbon coated MoO3−x nanosheets (denoted as MoO3−x NS@C) have been successfully fabricated by a simple hydrothermal method. When used as anode for Li-ion batteries, the MoO3−x NS@C electrode exhibits excellent cycle performance and outstanding rate capabilities. The charge capacity can reach 1025 mAh g−1 over 150 cycles, and 62% of the charge capacity is retained when the current density increases to 2000 mA g−1. The improved lithium storage performance of MoO3−x NS@C is attributed to the synergistic effect of oxygen vacancies and the carbon coating, which not only enhance the electric conductivity and Li-ion diffusion coefficient but also lead to superior structural stability and cyclability of the MoO3−x NS@C electrode during repeated lithiation/delithiation process.