High electrical conductivity and crystal structure of the solid oxide cell electrode Pr4Ni3O10-δ

Pr4Ni3O10-delta is a promising air electrode for solid oxide fuel cells and electrolysers with comparable performance to Pr4Ni3O10-delta but with improved thermodynamic stability at a cell operating temperature of 600 degrees C-800 degrees C. To fully understand and integrate Pr4Ni3O10-delta into commercial devices there are several aspects that remain to be addressed. This study provides a systematic analysis of the synthesis kinetics, crystal structure, oxygen content and electrical conductivity providing clear paths for the development of Pr4Ni3O10-delta-based low temperature solid oxide electrochemical devices with enhanced performance and stability. We prove that the material can reach a remarkable electrical conductivity of 235 Scm(-1) at 700 degrees C in air, much higher than the previously reported values of 86 Scm 1 and 56 Scm(-1), rising to 278 Scm(-1) at 450 degrees C. High resolution neutron powder and in-situ X-ray diffraction confirmed that Pr4Ni3O10-delta crystallises in the monoclinic P2(1)/a space group, and that no phase transitions were observed on heating to 1000 degrees C in air. An electrical conductivity anomaly was found at similar to 300 degrees C and is attributed to a subtle change in the local structure of the material, potentially associated with changes in the oxygen content.