“…A solid composite electrolyte composed of a molten salt phase, such as mixed hydroxides or carbonates, and an oxygen ion conducting porous solid phase, such as samarium doped ceria (SDC) has been used in solid oxide fuel cells (SOFCs) [16,[21][22][23][24][25]. The conductivity of this kind of composite electrolyte in an intermediate temperature (IT, 400-700 • C) range is much higher than the conventional solid electrolyte used in SOFC [26] and the molten electrolyte in molten carbonate fuel cell (MCFC).…”