Potassium Vanadate Nanobelt as a High-Capacity Cathode Material for Li-ion Battery

Abstract

In this paper, a potassium-deficient K0.66V3O8 with nanobelt morphology was synthesized by a facile and large-scale hydrothermal method and its electrochemical performance as cathode material for Li- ion battery was investigated. As indicated by the scanning electron microscopy (SEM), the nanobelts show a width of ~80 nm and a length of less than one micrometer. Cyclic voltammetry (CV) test indicates good reversible Li ion insertion/extraction behavior. When used as a cathode material for Li- ion battery, the nanobelts exhibit a high initial discharge capacity of 268.9 mAh g-1 during 1.5~4.0 V at 15 mA g-1. After capacity fading in the first several cycles, it maintains the capacity of 180 mAh g-1. At 75 mA g-1, the K0.66V3O8 nanobelts still show the reversible capacity of 197.5 mAh g-1 with the capacity retention of 70.8% after 25 cycles.