Nb2O5 nanospheres/surface-modified graphene composites as superior anode materials in lithium ion batteries

Uniform Nb2O5 nanospheres/surface-modified graphene (SMG) composites for anode materials in lithium ion batteries were synthesized by hydrothermal method. The microstructure and morphology of composites were investigated by X-ray diffraction, scanning electron microscopy and transmission electron microscope techniques. The experimental results showed that Nb2O5 nanospheres were tightly and uniformly grown on the surface of SMG nanosheets. Nb2O5 nanospheres/SMG composites exhibited an impressive reversible capacity of 404.6 mA h g−1 at the current density of 40 mA g−1 after 100 cycles, and an excellent rate capacity of 345.5 mA h g−1 at the current density of 400 mA g−1.