Impedance spectroscopy study of Nd2NiO4+δ, LSM and platinum electrodes by micro-contact technique

The impedance spectra of Nd2NiO4+δ, La1−xSrxMnO3 and platinum pin-shaped electrodes pressed on the surface of an electrolyte pellet (Yttria Stabilized Zirconia) have been recorded as a function of temperature, in air atmosphere, under zero dc conditions. Such an electrode configuration was used to study the characteristics of the air electrode reaction with respect to the nature of the electrode material, the geometry of the electrode–electrolyte contact being the same for all electrodes. The impedance data were analyzed and the results evidence different oxygen reduction mechanisms depending on the nature of the oxide, Mixed Ionic and Electronic Conducting (MIEC) oxide for the nickelate, bad ionic but electronic conductor for the manganite and metallic for the platinum.