Changes in LSC and LSCF Cathode Crystallographic Parameters Measured by Electrochemical in situ High-Temperature XRD

摘要

The solid oxide fuel cell symmetrical cells with porous cathodes for intermediate temperature applications have been studied under electrochemical polarization and oxygen feeding conditions using high-temperature in situ XRD (HT-XRD) method. Changes in the lattice parameters of La_(0.6)Sr_(0.4)CoO_(3-δ) and La_(0.6)Sr_(0.4)Co_(0.2)Fe_(0.8)O_(3-δ) were observed depending on the temperature (T), electrode potential (E) and oxygen partial pressure (p_(O2)) applied. At fixed T and p_(O2), the cathode potential noticeably influences the crystallographic cell volume, thus, i.e., the oxygen stoichiometry, explained by the partial reduction of electrochemically labile Co-ionic centers in La_(0.6)Sr_(0.4)CoO_(3-δ) (LSC) and the La_(0.6)Sr_(0.4)Co_(0.2)Fe_(0.8)O_(3-δ) (LSCF) under study. Noticeably higher effect of cathode potential on the cell volume has been established at lower p_(O2).