Ru-doped lanthanum ferrite as a stable and versatile electrode for reversible symmetric solid oxide cells (r-SSOCs)
2022; Elsevier BV; Volume: 555; Linguagem: Inglês
10.1016/j.jpowsour.2022.232399
ISSN1873-2755
AutoresMartina Marasi, Leonardo Duranti, Igor Luisetto, Emiliana Fabbri, Silvia Licoccia, Elisabetta Di Bartolomeo,
Tópico(s)Magnetic and transport properties of perovskites and related materials
ResumoIn the current scenario of innovative energy systems, reversible solid oxide cells (r-SOCs) are widely recognized as promising devices, thanks to their high conversion efficiency in both power-to-fuel and fuel-to-power modes. A crucial aspect for their scale-up is the development of multi-functional compounds that can work as either air or fuel electrodes. The most reliable alternative to conventional materials for r-SOCs are perovskite oxides. Sr-substituted lanthanum ferrites (LSF) show large mixed ionic and electronic conductivity (MIEC) and versatile catalytic activity upon B-site doping. Nevertheless, their poor stability in highly reducing environments precludes their widespread application. In this work, 5 mol% Ru-doped lanthanum ferrite La0.6Sr0.4Fe0.95Ru0.05O3-δ (LSFR05) is investigated as a multi-functional electrode for reversible and symmetric solid oxide cells (r-SSOCs). Ru-doping promotes LSF stability, retaining a higher lattice oxygen content. Upon reduction, LSFR05 exhibits exsolution of uniformly dispersed catalytically active Fe–Ru nanoparticles. All-perovskite symmetric cells showed remarkably high power density as H2–SOFC at 850 °C (602 mW cm−2), while in CO2-SOEC mode a current density output of 1.39 A cm−2 at 1.5 V was obtained. With a standard 70:30 CO2:CO gas composition, the cell showed a polarization resistance as low as 165 mΩ cm2. The complete SOFC-SOEC reversibility was successfully assessed for over 200 h.
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