Co3O4–C core–shell nanowire array as an advanced anode material for lithium ion batteries

We report on the synthesis of a Co3O4–C core–shell nanowire array and its application as an anode material for lithium ion batteries. The core–shell nanowire array is prepared by combining a facial hydrothermal synthesis and direct current magnetron sputtering. The amorphous carbon layer with a thickness of 18 nm is homogeneously coated on the surface of the porous Co3O4 nanowire. The Co3O4–C core–shell nanowire array delivers an initial discharge capacity of 1330.8 mA h g−1 at 0.5 C and maintains a high reversible capacity of 989.0 mA h g−1 after 50 cycles, much higher than the unmodified Co3O4 nanowire array (490.5 mA h g−1). The improved electrochemical performance can be attributed to the introduction of a thin carbon layer, which improves the electrical conductivity and structure stability of the Co3O4 nanowire array.