TY - GEN
T1 - Anodic Behaviour of Ni-Fe-Cu electrode In Molten Fluoride Salts
AU - Saevarsdottir, Gudrun
AU - Singh, Kamaljeet
AU - Haarberg, Geir Martin
AU - Bourmaud, Milane
AU - Padamata, Sai Krishna
N1 - Funding Information: The authors would like to thank Aksel Alstad (NTNU), Jon Hjaltalin Magnusson (Arctus Metals), Gudmundur Gunnarsson, Gudbjorg Oskarsdottir and Rauan Meirbekova (IceTech), that supplied the anode material. Special thanks to the Alcoa Foundation which funded this work, (2019:223136). Publisher Copyright: © 2022 ECS - The Electrochemical Society.
PY - 2022
Y1 - 2022
N2 - The anodic behaviour of NixFeyCuz alloy at different sodium- and potassium-cryolite based electrolyte compositions was examined by chronopotentiometry, galvanostatic polarisation, and linear sweep voltammetry at 1098 K. Steady-state anodic polarisation curves show anodic overpotential in electrolyte with molar ratio CR=(NaF+KF)/AlF3=1.4 is significantly less than in electrolyte with CR=1.3. Short-term galvanostatic polarisation curves indicate the potential difference between the anode and reference electrode (Al) was stable in electrolytes with CR=1.4 and potassium ratio KR=KF/(KF+NaF)=0.3 and CR=1.4 KR=0.35. Linear sweep voltammetry method indicates the presence of a diffusion controlled reaction at a potential below onset of oxygen evolution, which can likely be attributed to oxide formation. The diffusion coefficient obtained from linear sweep voltammetry and chronopotentiometry are within a similar range. Tafel curves confirm the presence of a reaction below the potential of oxygen evolution, but indicate a similar overpotential level for the oxygen evolving reaction as for carbon anodes.
AB - The anodic behaviour of NixFeyCuz alloy at different sodium- and potassium-cryolite based electrolyte compositions was examined by chronopotentiometry, galvanostatic polarisation, and linear sweep voltammetry at 1098 K. Steady-state anodic polarisation curves show anodic overpotential in electrolyte with molar ratio CR=(NaF+KF)/AlF3=1.4 is significantly less than in electrolyte with CR=1.3. Short-term galvanostatic polarisation curves indicate the potential difference between the anode and reference electrode (Al) was stable in electrolytes with CR=1.4 and potassium ratio KR=KF/(KF+NaF)=0.3 and CR=1.4 KR=0.35. Linear sweep voltammetry method indicates the presence of a diffusion controlled reaction at a potential below onset of oxygen evolution, which can likely be attributed to oxide formation. The diffusion coefficient obtained from linear sweep voltammetry and chronopotentiometry are within a similar range. Tafel curves confirm the presence of a reaction below the potential of oxygen evolution, but indicate a similar overpotential level for the oxygen evolving reaction as for carbon anodes.
KW - Inert anodes
KW - aluminium electrolysis
KW - metallic electrodes
KW - oxygen-evolving electrodes
UR - https://www.scopus.com/pages/publications/85140244140
U2 - 10.1149/10914.0075ecst
DO - 10.1149/10914.0075ecst
M3 - Conference contribution
T3 - ECS Transactions
SP - 75
EP - 86
BT - ECS Transactions
PB - Institute of Physics Pub
T2 - 242nd ECS Meeting
Y2 - 9 October 2022 through 13 October 2022
ER -