Recent progress in nanostructured electrodes for solid oxide fuel cells deposited by spray pyrolysis

Low-temperature solid oxide fuel cells (LT-SOFCs), operating below 650 degrees C, are attracting a great interest due to their long-term stability and potential application for stationary and portable power generation. Much effort is being devoted to investigating new electrode materials because the electrode polarization resistance remains a serious limitation to the performance. Nanostructured electrodes offer the possibility of increasing the SOFC efficiency at low temperatures. Among the different electrode preparation techniques, spray pyrolysis deposition is a versatile, economic and industrially scalable method to grow electrodes directly on the electrolyte, reducing preparation steps and time. Recent progresses in this field are summarized here, especially highlighting the wide variety of different microstructural strategies used to improve the electrode performance, i.e. nanocomposite cathodes graded cathodes, infiltrated cathodes and cathodes with active/functional layers. Finally, the current existing challenges and the future working directions for further enhancing the properties of new nanostructured electrodes are discussed.