Study of a novel microstructured air electrode/electrolyte interface for solid oxide cells

• FLM technique was applied to modify the surface of an IT-SOC electrolyte. • Patterned SDC electrolyte presented a well-spaced and distributed pillar shape microstructure. • Different grain size, high surface/area ratio and mixed oxidation states were detected. • Pillar shape microstructure improved electrical and chemical performance over time. • A correlation between microstructure and superficial mixed oxidation states is proposed. Solid Oxide Cells (SOCs) are promising high temperature electrochemical devices to obtain clean energies from renewable sources. Their high operating temperatures (800–1000 °C) contribute to the degradation of the cell components. Intermediate Temperature SOCs (IT-SOCs) appear as an alternative to decrease the operating temperatures (600–800 °C) and avoid cell degradation, nevertheless, the electrochemical performance is affected by energy dissipation, principally by the air electrode overpotentials. This work presents the surface modification of Ce 0.80 Sm 0.20 O 2-δ (SDC) electrolyte by Femtosecond Laser Micromachining (FLM) to increase the surface/area ratio and therefore improve the electrochemical performance. A pattern with an equally spaced pillar shape microstructure was obtained and characterized. (La 0.60 Sr 0.40 ) 0.95 Co 0.20 Fe 0.80 O 3-δ (LSCF) powder was used as porous air electrode to determine the electrochemical benefits of the pattern. Polarization resistance (R p ) of air electrode in patterned sample was about five times lower than in flat one at 600 °C and after 45 h, which suggested an improvement in the electrical and chemical features over time. These enhancements could be explained by the synergistic effect among surface/area ratio, nano-microcrystalline domains and superficial Ce 3+ concentration in the patterned electrolyte. R p values are higher than those reported for best air electrodes, however, FLM has proven its benefits in electrochemical performance.