La2NiO4+δ infiltrated into gadolinium doped ceria as novel solid oxide fuel cell cathodes: Electrochemical performance and impedance modelling

• Published in: Journal of power sources 2015-10, Vol.294, p.473-482
• Main Authors: Nicollet, C., Flura, A., Vibhu, V., Rougier, A., Bassat, J.M., Grenier, J.C.
• Format: Article
• Language: English
• Subjects: ALS model; Chemical Sciences; Composite cathode; Electrochemical impedance spectroscopy; Infiltration process; Lanthanum nickelate; Material chemistry; SOFC cathode
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2015.06.077

This paper is devoted to the study of composite cathodes of La2NiO4+δ infiltrated into a Gd-doped ceria backbone. Porous Gd-doped ceria backbones are screen printed onto yttria-stabilized zirconia or Gd-doped ceria dense electrolytes, and infiltrated with a La and Ni nitrate solution (2:1 stoichiometry ratio). The influence of the preparation parameters on the polarization resistance, such as the concentration of the infiltration solution, the amount of infiltrated phase, the annealing temperature, the thickness of the electrode, and the nature of the electrolyte, is characterized by impedance spectroscopy performed on symmetrical cells. The optimization of these parameters results in a decrease of the polarization resistance down to 0.15 Ω cm2 at 600 °C. Using the Adler-Lane-Steele model, the modelling of the impedance diagrams leads to the determination of the ionic conductivity as well as the surface exchange rate of the infiltrated electrode. [Display omitted] •Infiltration of La2NiO4+δ into gadolinia doped ceria backbone reported for the first time.•Interest of such infiltrated electrodes comes from a high specific area of the electrocatalyst.•Polarization resistances as low as 150 mΩ cm2 at T = 600 °C have been measured.•Surface exchange reaction rates and effective ionic conductivity are calculated from EIS data.