Rapid Reactive Laser Processing of Protonic Ceramics

Abstract

Protonic ceramics possess low transport activation energies, which allow for high ionic conductivity at low operating temperatures (250–600°C). The protonic ceramic energy devices such as protonic ceramic fuel cells, protonic ceramic electrolyzers, solid state ammonia synthesis cells, hydrogen or water sensors, steam permeable membrane reactors, and hydrogen permeable membrane reactors, etc., have attracted significant attention recently. It has been recognized that the processing of protonic ceramics with high phase purity and controlled microstructure is equally significant compared with the development of new materials. Though the recently discovered solid state reactive sintering method has been proven as an effective method for processing of protonic ceramics from cost-effective raw materials such as oxides and carbonates, the traditional long-term (more than 10 hours) furnace sintering at high temperatures (>1400°C) is still inevitable. In this work, by combining the selective laser sintering/melting technique and the solid state reactive sintering technique, we developed a new rapid laser reactive processing method for selectively and instantaneously processing protonic ceramics with well-engineered microstructures and high phase purity. More than 10 perovskite oxides and cermets have been successfully fabricated for using as the protonic electrolyte and highly porous protonic electrode scaffolds.