La_0.6Sr_0.4Co_0.2Fe_0.8O_3-δの酸素イオン欠損量におよぼす応力の影響

抄録

La_0.6Sr_0.4Co_0.2Fe_0.8O_3-δ (LSCF) is a mixed ionic-electronic conductor and one of the candidates to be used for oxygen separation membrane and cathode material for solid oxide fuel cell. The ionic conductivity of LSCF, which is still by several orders of magnitude lower than its electronic conductivity, needs to be further improved for higher performance of those devices. This study investigates a variation of oxygen deficiency of LSCF under uniaxial compression. An electrochemical cell consisting of YSZ (yttria stabilized zirconia )/LSCF/YSZ with glass sealing was prepared. The coulometric titration method was employed. The result demonstrated that the oxygen deficiency decreased by 0.0058 under 80 MPa of stress. The estimation based on the mechanical and thermo-chemical-mechanical properties, the oxygen deficiency could decrease by ~0.006 when the uniaxial compressive stress of 100 MPa is applied, which shows a relatively good agreement with the experimental result.