The dissolution behavior of Ni–Ni/Al intermetallic electrode in Li/K = 62/38 mixed molten carbonate

A Ni3Al intermetallic compound was added to the cathode to decrease the solubility of Ni in a Li/K eutectic molten salt. The solubility of Ni/Ni3Al used as a cathode was examined by measuring the concentrations of Ni and Al ions in alkali metal carbonate. The electrolyte consisted of a mixture of lithium carbonate and potassium carbonate (62Li2CO3–38K2CO3) at 650 °C. A significant decrease in Ni precipitation was observed over a long term operation using a Ni/(4%, 7%, 10%) Ni3Al stabilized cathode. Al is easily oxidized and forms an Al2O3 film on the surface. This Al2O3 film can inhibit corrosion of the electrode. The solubility of the Ni–Al oxidized electrodes containing Ni3Al and NiO decreased with increasing amounts of Ni3Al added and with increasing sintering temperature. The solubility decreased to 1.57 ppm, which is 1/10 that of the pure NiO cathode.