2019 Volume 127 Issue 1 Pages 1-4
A new electrochemical oxygen separation pump was developed by using c-axis-oriented La9.66Si5.3B0.7O26.14 (c-LSBO), which has high oxide-ionic conductivity (>10−3 S cm−1) up to 300°C. Interfacial resistance between the electrode and c-LSBO was investigated to realize the full potential of LSBO as an oxygen separation material. The formation of a Sm-doped CeO2 (SDC) thin film (thickness: 300 nm) between the electrode and c-LSBO was effective for suppressing the interfacial resistance. Furthermore, a mixed conductive La0.6Sr0.4Co0.78Ni0.02Fe0.2O3−δ (LSCFN) was applied to the electrode for enhancing the oxygen reduction/evolution activity on the electrode. The LSCFN/SDC/c-LSBO symmetric cell showed an oxygen permeation flux of 3.5 mL cm−2 min−1 (1.0 A cm−2) at 600°C under an applied DC voltage of 1.5 V; this value was 67 times that of Pt/c-LSBO. This oxygen pump based on the LSCFN/SDC/c-LSBO symmetric cell would find promising application in oxygen separation at intermediate temperatures. Further reduction of the interfacial resistance and polarization resistance of the electrode may decrease the operating temperatures to below 400°C.