J. mater. chem. A J. mater. chem. A High performance La₂NiO_4+<i>δ</i> oxygen and Ni–Ce_0.9Gd_0.1O_{2−<i>δ</i>} fuel electrodes for thin film reversible solid oxide cells Riaz Adeel Sirvent Juande Zueco-Vincelle Juan Buzi Fjorelo Panisset Silvère Stangl Alexander Rapenne Laetitia Baiutti Federico Mermoux Michel Laguna-Bercero Miguel Angel Tarancón Albert Burriel Mónica 2025 research-article