Stability & aging studies of Pr-based nickelates as cathodes for SOFC

This book is dedicated to stability and ageing studies of Praseodymium based nickelates as cathodes for Solid Oxide Fuel Cells (SOFCs). With this respect Ln2NiO4+δ (Ln=La Pr or Nd) compounds with the K2NiF4 type structure act as alternative cathode materials for IT-SOFC due to their mixed ionic and electronic conductivity (i.e. MIEC properties). Pr2NiO4+δ shows excellent electrochemical properties at intermediate temperature (i.e. low polarization resistance Rp value Rp = 0.03 Ω.cm² at 700 °C) while La2NiO4+δ exhibits higher chemical stability. So the properties of La2-xPrxNiO4+δ nickelates were investigated with the aim to find best compromise between chemical stability and electrochemical performances. As an interesting point even after complete dissociation of Pr2NiO4+δ into PrNiO3-δ Pr4Ni3O10+δ and Pr6O11 the polarization resistance does not show significant change. So finally two new materials PrNiO3-δ and Pr4Ni3O10+δ were investigated as SOFCs cathode showing very promising results for Pr4Ni3O10+δ in symmetrical cell (Rp (Pr4Ni3O10+δ) = Rp (Pr2NiO4+δ) = 0.15 Ω.cm² at 600 ° C) and single cell (1.6 W.cm-2 at 800 °C).