The Peltier heating of the aluminium cathode and the Peltier cooling of the platinum/graphite anode in the aluminium electrolysis cell

We present first experimental evidence for the reversible heating of the aluminium cathode and the corresponding cooling of the aluminium anode during electrolysis in cryolite-alumina melts. We find that the heating/cooling varies linearly with the current, as expected from theory. We present next experimental evidence for the reversible cooling of the reversible oxygen gas electrode in contact with an electrolyte of cryolite and aluminium fluoride saturated with alumina. The Peltier effect, or the degree of cooling, varies again linearly with the current. When the experiment is repeated with a carbon electrode, there is a small heating effect. An irreversible effect masks the cooling in the case of the carbon electrode. The results give a qualitative support of our previous results for the Seebeck coefficient for the singe electrodes.