A novel porous CuO nanorod/rGO composite as a high stability anode material for lithium-ion batteries

The porous copper oxide (CuO)/reduced graphene oxide (rGO) composite was synthesized by a facile hydrothermal procedure using urea as a foaming agent. The CuO nanorods possessed vermicular pore channel with diameter of 4   nm and aspect ratio of 5:1, and were homogeneously grown on the surface of rGO sheets. The vermicular pore channel offered more sites for the storage and insertion of Li ions , as well as accelerated electrolyte diffusion and Li-ion transport. The electrochemical properties of the CuO/rGO nanocomposite as the anode material for lithium-ion battery were studied. It is found that the as-synthesized CuO/rGO nanocomposite showed an initial reversible capacity of 819   mA   h/g and the specific capacity of 480   mA   h/g after 50 cycles at a current density of 70   mA/g, which is due to the unique porous structure of CuO with high surface area and the presence of rGO that could improve lithium-ion mobility, shorten the distance for Li + diffusion, facilitate the transport of electrons and accommodate the large volume changes. With these outstanding performance, the CuO/rGO nanocomposite hold great promise as an advanced anode material for lithium-ion batteries.