The V5+ electrolyte solution from vanadium redox flow batteries was studied by variable temperature 17O and 51V Nuclear Magnetic Resonance (NMR) spectroscopy and DFT based computational modeling. It was found that the V5+ species exist as hydrated penta co-ordinated vanadate ion, i.e. [VO2(H2O)3]1+. This hydrated structure is not stable at elevated temperature and change into neutral H3VO4 molecule via a deprotonation process. H3VO4 species is also knowingly unstable, leading to the observed V2O5 precipitation in V5+ electrolyte solutions.
Revised: March 26, 2012 |
Published: April 1, 2011
Citation
Vijayakumar M., L. Li, G.L. Graff, J. Liu, H. Zhang, Z. Yang, and J.Z. Hu. 2011.Towards Understanding the Poor Thermal Stability of V5+ Electrolyte Solution in Vanadium Redox Flow Batteries.Journal of Power Sources 196, no. 7:3669-3672.PNNL-SA-75255.doi:10.1016/j.jpowsour.2010.11.126