Effect of mixed acid media on the positive side of the hybrid zinc-cerium redox flow battery
Related Research Unit(s)
|Journal / Publication||Electrochimica Acta|
|Publication status||Published - 20 Sep 2014|
|Link to Scopus||https://www.scopus.com/record/display.uri?eid=2-s2.0-84906075951&origin=recordpage|
The electrochemical activity of the Ce3+/4+ reaction in the presence of various mixed acid electrolytes containing methanesulfonic acid (MSA) as the base electrolyte along with hydrochloric, nitric and sulfuric acid was investigated as a function of acid concentration and reaction temperature on a Pt disk electrode. Cyclic voltammetry in 0.6 mol L-1 cerium and 4 mol L-1 MSA with 0.5 - 1 mol L-1 hydrochloric acid showed that the reversibility and kinetics of the Ce3+/4+ reaction were significantly enhanced compared to that containing MSA only. Higher diffusion coefficients (D) and exchange current densities (jo) were also obtained for the mixed acid media containing sulfuric and nitric acid, but in this case the reversibility of the reaction was not that improved. Higher concentrations of hydrochloric, nitric and sulfuric acid (>1 mol L -1) made the oxidation of Ce3+ very hard to delineate from the cyclic voltammograms because of the side reactions occurring at such high potentials. The exchange current density (jo), obtained through polarization resistance and electrochemical impedance spectroscopy measurements (EIS), increased with temperature over the range 25 to 55 °C. The EIS results showed that the solution resistance of the mixed electrolytes is considerably lower than that of the unmixed electrolyte facilitating the charge transfer reaction. Nonetheless, solubility issues arose at high Ce4+ concentrations (state of charge > 60%) and elevated temperatures (>40°C). © 2014 Elsevier Ltd.
- Cerium, Mixed acid media, Redox flow battery
Electrochimica Acta, Vol. 141, 20.09.2014, p. 255-262.
Research output: Journal Publications and Reviews (RGC: 21, 22, 62) › 21_Publication in refereed journal › peer-review
Nikiforidis, G & Daoud, WA 2014, 'Effect of mixed acid media on the positive side of the hybrid zinc-cerium redox flow battery', Electrochimica Acta, vol. 141, pp. 255-262. https://doi.org/10.1016/j.electacta.2014.06.142
Nikiforidis G, Daoud WA. Effect of mixed acid media on the positive side of the hybrid zinc-cerium redox flow battery. Electrochimica Acta. 2014 Sep 20;141:255-262. https://doi.org/10.1016/j.electacta.2014.06.142