Development of an isotopic oxygen exchange setup operating under high pressure: preliminary measurements performed on Ln$_2$NiO$_{4+\delta}$ (Ln=La, Pr, Nd, MIEC) oxides

Aurélien Flura (1) , Jérôme Laurencin (2) , Sébastien Fourcade (1) , Fabrice Mauvy (1) , Vaibhav Vibhu (3) , Jean-Paul Salvetat (4) , Julie Mougin (2) , Jean-Marc. Bassat (1)

1 ICMCB - Institut de Chimie de la Matière Condensée de Bordeaux
2 LITEN - Laboratoire d'Innovation pour les Technologies des Energies Nouvelles et les nanomatériaux
3 IEK-9 - Institute of Energy and Climate Research - Fundamental Electrochemistry
4 PLACAMAT - Plateforme Aquitaine de Caractérisation des Matériaux

MIEC (Mixed Ionic Electronic Conductors) used as oxygen electrodes in Solid Oxide Cells are characterized by both high oxygen diffusion (D) and surface exchange (k) coefficients. To date, the reported measurements have been performed at ambient pressure and even below. However, to reach a higher efficiency at the system level, it would be helpful to operate the Solid Oxide Electrolysers under high pressure. A preliminary study is therefore mandatory, to assess the oxygen reduction/oxidation and the transport properties of the electrodes materials when submitted to high pressure. Then, an innovative setup able to operate up to a total pressure of 50 bar has been developed. Its technical characteristics will be described here. This setup has been used to characterize the properties of nickelates with MIEC properties. Oxygen exchanges have been performed in the range 500 < T°C < 700, under p(O$_2$) ~ 6.5 bars. Preliminary results (oxygen over-stoichiometry, D* and k* coefficients) obtained on Ln$_2$NiO$_{4+\delta}$ (Ln=La, Pr, Nd) oxides are presented and discussed.

Domaines: Matériaux

Aurélien Flura, Jérôme Laurencin, Sébastien Fourcade, Fabrice Mauvy, Vaibhav Vibhu, et al.. Development of an isotopic oxygen exchange setup operating under high pressure: preliminary measurements performed on Ln$_2$NiO$_{4+\delta}$ (Ln=La, Pr, Nd, MIEC) oxides. ECS Transactions, 2021, 103 (1), pp.1319-1330. ⟨10.1149/10301.1319ecst⟩. ⟨hal-03343009⟩