Synthesis of ultralong (NH4)2V6O16•1.5H2O nanobelts for application in supercapacitors

Ultralong (NH4)(2)V6O16 center dot 1.5H(2)O nanobelts were synthesised by a combination of sol-gel and hydrothermal methods. The chemical composition, morphology and microstructure of products were characterised by X-ray powder diffraction, Fourier transform infrared spectroscopy, field emission SEM and TEM respectively. Typical (NH4)(2)V6O16 center dot 1.5H(2)O nanobelts are several hundreds of micrometres in length, 50-100 nm in thickness and 200-500 nm in width. It is indicated that SO42- ions are critical to the formation of ultralong nanobelts. Electrochemical performance shows that (NH4)(2)V6O16 center dot 1.5H(2)O nanobelts can exhibit a specific capacitance as high as 220 F g(-1) at 0.05 A g(-1) over a potential range of -0.1-0.9 V in 1M NaNO3 due to their high conductivity and ion diffusion rate. This work provides new insights for the growth of ultralong NH4V3O8 nanobelts and their application in supercapacitors.