LSM (La_0.8Sr_0.2MnO_3-δ)–Inconel Inert Anode Current Collector for Solid Oxide Membrane (SOM) Electrolysis

Abstract

An innovative inert anode current collector is successfully developed and used in solid oxide membrane (SOM) electrolysis experiments. In these experiments, an oxygen-ion-conducting yttria-stabilized zirconia (YSZ) membrane separates a liquid silver anode from a molten fluoride flux containing magnesium oxide. During electrolysis at 1423 K, magnesium cations in the flux are reduced at a stainless steel cathode and removed in the vapor phase employing argon bubbling and condensed in a separate chamber. Meanwhile, oxygen anions are transported out of the flux through the YSZ membrane to the liquid silver anode where they are oxidized producing oxygen gas. The inert anode current collector is immersed in the liquid silver anode. The current collector employs a sintered strontium-doped lanthanum manganite (La0.8Sr0.2MnO3-δ or LSM) bar, an Inconel alloy 601 rod, and a liquid silver contact in between. During the SOM electrolysis experiments, the current collector exhibited excellent electrical, thermal, mechanical, and chemical stabilities in oxygen as well as the liquid silver environment.