Lithium storage behaviors of KNb 3 O 8 nanowires for rechargeable batteries

Abstract KNb3O8 is a kind of layered niobium oxide material. In this work, it is the first time for KNb3O8 to be investigated as anode active material for lithium-ion batteries. KNb3O8 nanowires are successfully prepared by a feasible electro-spinning technique followed with a subsequent heat treatment. The KNb3O8 nanowires exhibit a high charge capacity of 325.2 mA h g−1 at current density of 50 mA g−1. At a higher rate of 500 mA g−1, the charge capacity of KNb3O8 nanowires can still be maintained at 155.9 mA h g−1. In order to further investigate the electrochemical properties of KNb3O8 nanowires, cyclic voltammetry and electrochemical impedance spectroscopy are used to reveal the diffusion kinetics in KNb3O8. In addition, the electrochemical reversibility of KNb3O8 is also demonstrated by in-situ XRD investigation. All the results indicate that KNb3O8 nanowires may be a potential anode material for rechargeable lithium-ion batteries.