One-step synthesis of ZnO@C nanospheres and their enhanced performance for lithium-ion batteries

• ZnO@C nanospheres have been synthesized using zinc and acetylacetone as raw materials through a one-step co-pyrolysis method.
• Hollow carbon nanospheres can be obtained after removing of the internal ZnO in HCl solution.
• The ZnO@C nanospheres give a reversible capacity of 440 mA h g−1 at a current density of 100 mA g−1 after 50 cycles.

ZnO@C nanospheres with an average diameter of 200 nm have been synthesized using zinc (Zn) and acetylacetone as raw materials through a one-step co-pyrolysis method. The electrochemical properties of the ZnO@C nanospheres as an anode material are examined. The ZnO@C nanospheres give a reversible capacity of 440 mA h g−1 at a current density of 100 mA g−1 after 50 cycles. The improved electrochemical performance can be ascribed to the carbon shells, which not only serve as good electronic conductors but also act as good protective layers (preventing the pulverization) during lithiation/delithiation process. In addition, after removing of the internal ZnO in HCl solution, hollow carbon nanospheres can be obtained.