In Operando Electrochemical High-Temperature X-Ray Diffraction Study of Ni-Ce0.9 Gd0.1O2-δ Redox Properties

Abstract

A new in operando measurement cell has been developed for simultaneous monitoring of electrochemical (EC) properties and crystallographic structure using high temperature (HT) X-ray diffraction analysis (XRD) of solid oxide fuel cell (SOFC) anodes at working conditions. The influence of oxide ion flux on crystallographic structure of Gd0.1Ce0.9O2- d (GDC) in Ni-GDC cermet anode as well as impact of Ni ⇌ NiO redox cycles on the performance of anode has been studied. Influence of temperature, pO2 in gas stream and oxide ion flux through the membrane on the GDC lattice parameters was observed. Decrease of electrode polarization, i.e. increase of oxide ion flux lead to decrease of unit cell volume of the GDC lattice. The observed diminishing of GDC lattice parameter caused by oxide ion flux at -0.9 V was approximately same as the change caused by 50 degree of temperature decrease.