First-principles molecular dynamics study on the behaviors of Cs in a mixed system of liquid metal and LiCl–KCl molten salt†

The structure and dynamic properties of Cs in the mixed system of LiCl–KCl molten salt and a liquid metal (Bi and Pb) electrode are investigated through first-principles molecular dynamics simulation. It is found that the dynamic properties of different ions in molten salt could be significantly affected when the liquid metal electrode is coupled and this influence varies with the type of liquid metal applied. The microstructures of the mixed systems of molten salt and liquid metal electrode: MS–Cs–Bi, MS–CsCl–Bi, MS–Cs–Pb, and MS–CsCl–Pb, are also investigated by the bond angle distribution function, Voronoi tessellation analysis, five-fold symmetry parameter, and bond-orientational order parameter. The comparison study of the microstructures of the mixed systems when different liquid metal electrodes are applied provides information on the liquid metal electrode selection when conducting electrolysis. The present study represents the first demonstration of the study of a mixed system of salt and liquid electrode for practical applications and would be greatly beneficial to the development of pyroprocessing of spent nuclear fuel.