Formation of tungsten trioxide with hierarchical architectures arranged by tiny nanorods for lithium ion batteries

Abstract

WO₃ with hierarchical flower-like architectures has been obtained by calcination of WO₃·0.33H₂O, which is initially prepared via a hydrothermal method with formic acid as a structure directing agent. For the hierarchical flower-like structure, each flower petal is composed of a number of tiny nanorods and the smooth degree of the surface is tuned by the additive amount of HCOOH. As the hierarchical architecture shortens the diffusion paths of the electrolyte ions, improves the dynamic performance and supplies more active sites, the samples exhibit high discharge capacities and long cycling life. Especially, high discharge capacities of 1284.5 mA h g⁻¹, 904.1 mA h g⁻¹, 829.3 mA h g⁻¹, 576.8 mA h g⁻¹ and 861 mA h g⁻¹ are achieved when the current densities are 100 mA g⁻¹, 200 mA g⁻¹, 250 mA g⁻¹, 500 mA g⁻¹ and 100 mA g⁻¹, respectively.