Accelerated Phase Transition of Pr2NiO4 in the Presence of GDC Interlayer

Abstract

Praseodymium Nickelate (Pr2NiO4) has the potential to be a cathode for commercial solid oxide fuel cells (SOFCs) due to its high activity towards oxygen reduction. However, when Gd-doped Ceria (GDC) is used as an interlayer to prevent cathode-electrolyte interaction, phase transitions in Pr2NiO4 are accelerated. The accelerated phase transition in Pr2NiO4 decreases the stability of the cell, leading to faster degradation rates in performance over the lifetime of the cell. Identifying how the GDC interlayer affects phase transition will increase the effectiveness of Pr2NiO4 as an SOFC cathode. In this work, the accelerated phase transition of Pr2NiO4 in the presence of GDC will be investigated by: (1) thermo-annealing mixtures of Pr2NiO4/GDC powders at varying compositions and temperatures and, (2) constructing and analyzing cells with Pr2NiO4-GDC composite electrodes and GDC interlayers. XRD will be used to analyze the resulting phase transitions of the annealed powders and of the operated cells. Identifying structural and operational dependencies of this mechanism may help us develop approaches to increase the long-term stability of SOFCs with Pr2NiO4 as cathode material. Keywords: Nickelate, Doped ceria, phase transition, solid oxide fuel cell