Facile fabrication of three-dimensional hierarchical CuO nanostructures with enhanced lithium storage capability
Three-dimensional hierarchical CuO nanostructures with uniform flower-like and urchin-like morphologies have been successfully prepared by a facile, cheap and environmentally friendly solvothermal method. The as-prepared flower-like CuO is constructed by nanopetals, which are composed of nanoparticles, and the urchin-like CuO with a hollow structure is composed of tightly arranged nanorods. As anode materials for lithium-ion batteries, the flower-like CuO material exhibits a high initial discharge capacitance (1457.2 mA h g−1 at 100 mA g−1), good rate capability and excellent cycling stability. The superior electrochemical performance is mainly attributed to the hierarchical structure and the nanosize of the nanoparticles composing the nanopetals, which benefit electron and Li ion transportation, and provide large electrode–electrolyte contact area. The extra capacity of the samples may be due to the partial reversible formation and decomposition of the gel-like SEI film on the surface of the electrode and pseudocapacitance.