Synthesis and characterization of Co-doped Lanthanum Nickelate perovskites for solid oxide fuel cell cathode material

L. Chávez-Guerrero, M. Hinojosa-Rivera, B. Medina-Lott, R-N. Vannier, A. Ringuedé, M. Cassir

Abstract


In the perovskite structures widely investigated and used as Solid Oxide Fuel Cells (SOFC) cathodes, oxygen reduction is mainly limited to the triple phase boundary (TPB), where oxygen (air), electrode and electrolyte are in contact. It is possible via the sol-gel modified Pechini method to: 1) control the material grain size, which can increase TPBs, 2) produce a homogenous material and 3) obtain a cathode material in a faster way compared with the solid state route. LaNi$_x$Co$_{1-x}$O$_3$ ($x = 0.3$, 0.5, 0.7) were synthesized by the modified Pechini method. The perovskite phase formation began at 350$^{\circ}$C and the presence of pure LaNi$_{0.7}$Co$_{0.3}$O$_3$
LaNi$_{0.5}$Co$_{0.5}$O$_3$ and LaNi$_{0.3}$Co$_{0.7}$O$_3$ structures was evidenced by High Temperature X-ray diffraction (HT-XRD) measurements. Scanning Electron Microscopy (SEM) micrographs showed that the microstructure evolves with the amount of cobalt from a coalesced to an open structure. Electrochemical impedance spectroscopy (EIS) on symmetrical cells LaNi$_x$Co$_{1-x}$O$_3$/YSZ (yttria-stabilized zirconia)/LaNi$_x$Co$_{1-x}$O$_3$ showed that the highest ASR (area specific resistance) is obtained with $x = 0.3$, whereas ASR values are similar for $x = 0.5$ and 0.7 at temperatures higher than 600$^{\circ}$C. At temperatures lower than 600$^{\circ}$C, ASR is the lowest for LaNi$_{0.5}$Co$_{0.5}$O$_3$, showing that this composition with intermediate porosity appears as a good choice for an intermediate-temperature solid oxide fuel cell (SOFC).

Keywords


Wet chemistry; SOFC cathode; Co content; microstructure; area-specific resistance

Full Text:

PDF

Refbacks

  • There are currently no refbacks.


REVISTA MEXICANA DE FÍSICA, year 67, issue 2, March-April 2021. Bimonthly Journal published by Sociedad Mexicana de Física, A. C. Departamento de Física, 2º Piso, Facultad de Ciencias, Universidad Nacional Autónoma de México, Ciudad Universitaria, Alcaldía Coyacán, C.P. 04510 , Ciudad de México. Apartado Postal 70-348. Tel. (+52)55-5622-4946, https://rmf.smf.mx/ojs/rmf, e-mail: rmf@ciencias.unam.mx. Chief Editor: José Alejandro Ayala Mercado. INDAUTOR Certificate of Reserve: 04-2019-080216404400-203, ISSN: 2683-2224 (on line), 0035-001X (print), both granted by Instituto Nacional del Derecho de Autor. Responsible for the last update of this issue, Technical Staff of Sociedad Mexicana de Física, A. C., Fís. Efraín Garrido Román, 2º. Piso, Facultad de Ciencias, Universidad Nacional Autónoma de México, Ciudad Universitaria, Alcaldía Coyacán, C.P. 04510 , Ciudad de México. Date of last modification, March 1st., 2021.

The responsibility of the materials published in Revista Mexicana de Física rests solely with their authors and their content does not necessarily reflect the criteria of the Editorial Committee or the Sociedad Mexicana de Física. The total or partial reproduction of the texts hereby published is authorized as long as the complete source and the electronic address of the publications are cited.

There is no fee for article processing, submission or publication.

Revista Mexicana de Física by Sociedad Mexicana de Física, A. C. is distributed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License