4. Conclusion and emerging issues

ALD is becoming an extraordinary and evolving tool for the functionalization of materials and interfaces in many fields and, more recently, in energy devices where many extensions are becoming possible. MIEC cathodes and anodes for SOFC devices face significant challenges due to the complexity of fabrication with three or more precursors. Nevertheless, some studies are promising and new perspectives are envisaged. Epitaxial catalysts for the direct oxidation of methane in both SOFC and MCFC cells could become a strategic topic in the near future. In a similar field, new ceramic-based electrolyte materials for PCFCs could be manufactured by ALD, increasing the reactivity of this device, which operates at temperatures below 500°C. In the case of MCFCs, the protection of bipolar plates, cathode and anode could be improved against corrosion by homogeneous, dense films manufactured by ALD; this...