For this scheme to be effective, the molten salt must contain a high concentration of metal cations or oxygen anions to ensure a low resistance. Luckily, many high energy density metals form molten salts which can serve as low resistance layers for cation transport. In addition, the cation solid electrolyte should also be chemically stable to the molten metal. This presents a significant challenge, but it may be easier to design a stable liquid metal-cation conductor interface than a stable molten metal-oxide-ion conductor interface.