1 research outputs found
Synthesis and characterisation of a green NiO/La(Sr)PO4−δ cermet anode for phosphate based solid oxide fuel cells
Cermets are commonly used as anode in fuel cells. Ni/La(Sr)PO4−δ has not been synthesized before and it could be a good anode for hightemperature
protonic fuel cells. In this article, the preparation of Ni/La(Sr)PO4−δ by combustion synthesis using nitrates, ammonium phosphate and
urea is described. In this preliminary work, we are more concerned to understand the calcined powder reduction pattern with in situ Electrochemical
Impedance Spectroscopy (EIS) experiments. The as-prepared powder is structurally analysed by XRD, also after each calcination treatment in air
and in reducing atmosphere, and before and after the electrical measurements were carried out. The electrical characteristics of a green pellet of
NiO/La(Sr)PO4−δ are studied by impedance spectroscopy as a function of temperature (50–800 ◦C) in a reducing atmosphere (10−20 atm). The
reducing process of NiO to Ni is also followed by EIS. Finally, the morphology of this composite material analysed by EIS was observed by means
of SEM/EDX. The morphology of this composite material indicates the presence of two compatible phases. One corresponds to the La(Sr)PO4
phase and the second one to a Ni phase, according to EDX data. The low electrical conductivity values indicate that nickel agglomerates are not
totally percolated in the calcined pellet as it was expected. Higher conductivity values are expected when total Ni percolation occurs after sintering.Peer reviewe