Investigation into Cathodic Reduction Process of Yb(Iii) Ion in (Lif-Ybf3)Eut.-Yb2o3 Molten Salt System

The electrochemical behavior of Yb3+ ions is investigated through cyclic voltammetry and chronoamperome-try/potentiometric methods on the surface of a W/Ni working electrode in a (LiF-YbF3)eut-Yb2O3 molten salt system. The results show that the reduction of Yb3+ ions is completed by two-step quasi-reversible processes of Yb3+/Yb2+ and Yb2+/Yb on the W and Ni cathodes in LiF-YbF3 and (LiF-YbF3)eut-Yb2O3 molten salt systems at 1223 K; and the diffusion coefficients of Yb3+ are 5.45 x 10-4 cm2 s-1 and 3.75 x 10-3 cm2 s-1, respec-tively. The addition of Yb2O3 can improve the electrochemical activity of Yb3+ in the LiF-YbF3 system. The crystallization of Yb3+ ions are through three-dimensional instantaneous and continuous nucleation on the W and Ni electrodes in the (LiF-YbF3)eut-Yb2O3 molten salt system, respectively. The reduction activity of Yb2+ ions on the Ni cathode is stronger than on the W cathode, which is beneficial to alloying. The Ni2Yb alloy can be prepared by constant voltage electrolysis with Ni as a consumable cathode in the (LiF-YbF3)eut-Yb2O3 molten salt system.