Ternary Ni–Co–Fe Exsolved Nanoparticles/Perovskite System for Energy Applications: Nanostructure Characterization and Electrochemical Activity

The exsolution of Ni–Co–Fe from a Sr0.93(Ti0.3Fe0.56Ni0.07Co0.07)O3−δ perovskite (STFNC) is explored as a strategy to produce electrochemically active electrodes for symmetric-SOFC (S-SOFC). It was found that a nanostructured NiCoFe ternary alloy phase, with approximately equal amounts of each metal, can be formed by this method. The STFNC electrode is studied via electrochemical impedance spectroscopy, showing a really interesting potential as S-SOFC electrode: the anode polarization resistance was 1.12 Ω·cm2 in a wet 10%H2 atmosphere at 700 °C (exsolving in situ the NiCoFe phase), and the cathode polarization resistance at 700 °C in air was 0.054 and 0.042 Ω·cm2, before and after exsolution, respectively.