Preparation and characterization of carbon-coated NaVPO₄F as cathode material for rechargeable sodium-ion batteries

By Lu, Yao; Zhang, Shu; Li, Ying; Xue, Leigang; Xu, Guanjie & Zhang, Xiangwu
Published in Journal of Power Sources NULL 2014

Abstract

Sodium vanadium fluorophosphate (NaVPO₄F), a material candidate for sodium-ion battery cathodes, was synthesized via a high-temperature solid-state reaction approach. Different amounts of carbon coating were introduced in NaVPO₄F to improve its electrochemical performance. The structure and morphology of the resultant cathode materials were examined by scanning electron microscopy and X-ray diffraction. The effects of carbon coating on the electrochemical performance were evaluated by cyclic voltammetry, charge–discharge curve, cycling performance and electrochemical impedance spectroscopy. The highest capacity achieved for this material was 97.8 mAh g⁻¹ and the best capacity retention was 89% at the 20th cycle. Results demonstrated that appropriate amount of carbon coating could effectively improve the electrochemical performance of NaVPO₄F, and carbon-coated NaVPO₄F could offer promising future for sodium-ion battery cathode materials.

Read Article » Back