Electrochemical performance of La0.65Sr0.35MnO3 oxygen electrode with alternately infiltrated Sm0.5Sr0.5CoO3-δ and Sm0.2Ce0.8O1.9 nanoparticles for reversible solid oxide cells

La 1-x Sr x MnO 3 is a well-known oxygen electrode for reversible solid oxide cells (RSOCs). However, its poor ionic conductivity limits its performance in redox reaction. In this study, we selected Sm 0.5 Sr 0.5 CoO 3-δ (SSC) as catalyst and Sm 0.2 Ce 0.8 O 1.9 (SDC) as ionic conductor and sintering inhibitor to co-modify the La 0.65 Sr 0.35 MnO 3 (LSM) oxygen electrode through an alternate infiltration method. The infiltration sequence of SSC and SDC showed an influence on the morphology and performance of LSM oxygen electrode, and the influence was gradually weakened with the increasing infiltration time. The polarization resistance of the alternately infiltrated LSM-SSC/SDC electrode was 0.08 Ω cm 2 at 800 °C in air, which was 3.36% of the LSM electrode (2.38 Ω cm 2 ). The Ni-YSZ/YSZ/LSM-SSC/SDC single cell attained a maximum power density of 1205 mW cm −2 in SOFC mode at 800 °C, which was 8.73 times more than the cell with LSM electrode. The current density achieved 1620 mA .cm −2 under 1.5 V at 800 °C in SOEC mode and the H 2 generation rate was 3.47 times of the LSM oxygen electrode. • LSM oxygen electrode was alternately infiltrated by SDC and SSC nanoparticles. • SDC nanoparticles showed an inhibitory effect on the coalescence of the SSC particles. • The ORR and OER catalytic activities of LSM oxygen electrode was improved. • SSC and SDC nanoparticles enhanced the hydrogen generation rates of LSM-based SOEC.