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

A Ni 3 Al intermetallic compound was added to the cathode to decrease the solubility of Ni in a Li/K eutectic molten salt. The solubility of Ni/Ni 3 Al 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 (62Li 2 CO 3 –38K 2 CO 3 ) at 650 °C. A significant decrease in Ni precipitation was observed over a long term operation using a Ni/(4%, 7%, 10%) Ni 3 Al stabilized cathode. Al is easily oxidized and forms an Al 2 O 3 film on the surface. This Al 2 O 3 film can inhibit corrosion of the electrode. The solubility of the Ni–Al oxidized electrodes containing Ni 3 Al and NiO decreased with increasing amounts of Ni 3 Al added and with increasing sintering temperature. The solubility decreased to 1.57 ppm, which is 1/10 that of the pure NiO cathode.