LAUSR

The solid oxide electrolysis cell (SOEC) and its developement are in an increasing focus, because of its high efficiency and eco‐friendliness in storing energy by converting electrical energy into hydrogen. Recently, research has been conducted to decrease the operation temperature of SOECs below 750 °C to overcome high system costs and rapid degradation rate at high operation temperatures. Although La0.6Sr0.4Co0.2Fe0.8O3–δ (LSCF) is a promising oxygen electrode for SOEC, when the operating temperature is reduced, the reaction kinetics of the LSCF oxygen electrode is significantly decreased due to high activation energy of the oxygen ion transport. To address this issue, we developed a composite oxygen electrode of LSCF combined with Gd and Nd double doped ceria (GNDC). Due to excellent oxygen ion transport nature of GNDC, the SOEC with the LSCF‐GNDC oxygen electrode yielded impressive current density of ∼1,174 mA cm−2 at 1.3 V at 750 °C along with excellent stability. These results demonstrated that the novel LSCF‐GNDC composite is promising as an efficient and durable oxygen electrode for SOEC applications.