Single crystalline ammonium vanadium oxide bronze NH4V4O10 nanobelts were synthesized by the hydrothermal treatment of H2C2O4·2H2O and NH4VO3 at 140°C for 48h. The NH4V4O10 nanobelts were characterized using a combination of techniques including X-ray diffraction, transmission electron microscopy, selected area electronic diffraction, scanning electron microscopy and X-ray photoelectron spectroscopy techniques. The as-obtained nanobelts are several microns long, typically 30–40nm wide, and 10–20nm thick. The electrochemical properties of the nanobelts were tested in cells with metallic lithium as the negative electrode, the first discharge capacity of 171.8mAhg−1 was achieved.