Current drawbacks of proton-conducting ceramic materials: How to overcome them for real electrochemical purposes

Complex oxides exhibiting predominantly protonic transportation represent a promising electrolyte material for electrochemical devices that satisfy clean, sustainable, and safe energy technologies (electricity generation, hydrogen production, energy storage, and carbon dioxide utilization). Although impressive laboratory-scale results have been achieved for small-scale protonic ceramic devices (cells), they have yet to be manufactured on a commercial scale owing to a number of outstanding issues related both to nanolevels- and macro-levels. In the present review, these issues are discussed along with their possible solutions and opportunities for future technological breakthroughs. It is clear that emerging synergies between fundamental science and applied technologies will facilitate rapid progress in the development of protonic ceramic electrochemical cells.