In situ exsolved Co–Fe nanoparticles on the Ruddlesden-Popper-type symmetric electrodes for intermediate temperature solid oxide fuel cells

Abstract Maintaining the original advantages of symmetrical solid oxide fuel cells (SSOFCs), the electrochemical performance can be further enhanced by new quasi-symmetrical solid oxide fuel cells. Herein, highly active Ruddlesden-Popper oxides Co-doped LaSr3Fe3O10-δ are investigated as possible symmetric electrodes for SSOFCs, and in situ exsolution of Co–Fe nanoparticles can be homogenously observed on the backbone of this catalyst after high temperature hydrogenation. Spin coated gadolinium doped ceria (GDC) buffer layer onto both sides of the YSZ electrolyte is used to avoid the side reaction of YSZ electrolyte and the symmetric electrodes. LaSr3Fe2CoO10-δ showed more excellent electrochemical performance with the high maximum power density of 351.4 mW cm−2 and the electrode polarization resistance of 0.2894 Ω cm2 at 800 °C. Moreover, no sign of degradation with this SSOFCs during 100 h long-time testing is observed at 700 °C, indicating that the LaSr3Fe2CoO10-δ symmetrical electrode exhibits good redox reversibility. The high stability and catalytic activity of Ruddlesden-Popper oxides can provide more promise related applications for SSOFCs.