| Autor: |
Buckley, D. Noel, Bourke, Andrea, Oboroceanu, Daniela, Lenihan, Catherine, Al Hajji Safi, Maria, Quill, Nathan, Miller, Mallory A., Savinell, Robert F., Wainright, Jesse S., Sasikumar S P, Varsha, Rybalchenko, Maria, Amini, Pupak, Lynch, Robert P. |
| Zdroj: |
ECS Transactions; September 2022, Vol. 109 Issue: 10 |
| Abstrakt: |
The electrochemical kinetics of the VII/VIIIredox reaction on carbon electrodes is enhanced by anodic treatment of the electrode and inhibited by cathodic treatment. Contrastingly, the kinetics of the VIV/VVredox reaction is inhibited by anodic treatment of the electrode and enhanced by cathodic treatment. The observed effects are attributed to oxygen-containing species on the surface of carbon electrodes and it is likely that enhancement of both VII/VIIIand VIV/VVoccurs on the same (meso) state of the electrode. Oxidation of this active meso state leads to inhibition of VIV/VVwhile reduction of the active meso state leads to inhibition of VII/VIII.We have investigated the thermal stability of VFB catholytes using a standard methodology. The induction time for precipitation of V2O5decreases exponentially with increasing temperature or VVconcentration but increases exponentially with increasing sulphate concentration. Arrhenius plots show two linear regimes, at 45–70 °C and 30–45 °C, respectively. We model this behavior to estimate acceleration factors for testing of electrolyte stability over a range of test and use temperatures. Group V additives (phosphate and arsenate) are effective for improving the thermal stability of VFB catholytes. |
| Databáze: |
Supplemental Index |
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