Synthesis and electrochemical properties of NaV3O8 nanoflakes as high-performance cathode for Li-ion battery

Abstract

In the current work, NaV₃O₈ nanoflakes were fabricated by a novel two-step approach using VO₂(B) nanoflakes as a sacrificial template. The as-prepared NaV₃O₈ was characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results showed that NaV₃O₈ sintered at 400 °C had a suitable degree of crystallinity and demonstrated uniform nanoflake morphology, 100–200 nm in width, 500–800 nm in length and 30–50 nm in thickness. When used as a cathode material for Li-ion batteries, it showed good cyclic performance (a discharge capacity of 210 mA h g⁻¹ remained after 30 cycles at 30 mA g⁻¹ and no capacity fading occurred over 100 cycles at 150 mA g⁻¹). The rate capability was 113.4 mA h g⁻¹ and 91.5 mA h g⁻¹ in 6 C and 10 C, respectively. XRD patterns of NaV₃O₈ electrodes at different voltages revealed a single-phase reaction mechanism and small crystal volume change (∼3%) during the lithium intercalation/deintercalation processes.