NaV₆O₁₅Nanoflakes with Good Cycling Stability as a Cathode for Sodium Ion Battery

Developing high-capacity cathode material is still a big challenge for room temperature Na-ion batteries. Herein, NaV 6 O 15 nanoflakes are synthesized by a facile two-step method, in which (NH 4 ) 0.5 V 2 O 5 nanoflakes are first achieved by a hydrothermal approach and then transferred to NaV 6 O 15 by a solid state reaction. The as-prepared materials are well characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). When used as a cathode for Na-ion battery, the NaV 6 O 15 electrode exhibits good electrochemical performance with a high initial discharge capacity of 147.7 mAh g −1 at 15 mA g −1 and a capacity retention of 92.2% after 30 cycles during 1.5 ∼ 4.0 V. The good electrochemical properties of NaV 6 O 15 nanoflakes are mainly due to their rigid structure and stable two-dimensional nanoflake morphology.