Selected topics of molten salt electrochemistry

This review article describes some selected novel molten salt electrochemical processes which have been challenged by the author and his co-workers. Metallic Na is produced with high current efficiency by the electrolysis of molten NaCl-ZnCl(2) or NaOH using beta-alumina diaphragm. Two methods of chlorine recovery from HCl gas are possible by electrochemical processes in molten LiCl-KCl. A novel SiH(4) production method has been proposed by the use of Si electrode in a molten LiCl-KCl-LiH system. N(2) gas is cathodically reduced to form N(3-) ion in molten LiCl-KCl, which encourages the author to develop new applications, e.g., Li-N(2) thermally regenerative fuel cell and thermogalvanic cell. Electrochemical implantation of nitrogen to form various metal nitrides is possible by the use of anodic reaction of N(3-) ion in a molten LiCl-KCl-Li(3)N system. Electrochemical implantation and displantation can be applied to form transition metal-rare earth alloys in molten LiCl-KCl containing rare earth chloride. As non-conventional electrochemical reactions, discharge erectrolysis to form fine metal or carbon particles and electrochemical plantation of Zr on ceramics are described. Finally, the synthesis of new room temperature molten salt, EMIF . 2.3HF and its physical and chemical properties are described.