Improving the electrochemical performance of LaPrNiO4+δ as an oxygen electrode for intermediate temperature solid oxide cells by varying the architectural design

• Published in: Journal of electroanalytical chemistry (Lausanne, Switzerland) Vol. 849; p. 113373
• Main Authors: Khamidy, N.I., Laurencin, J., Djurado, E.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15-09-2019; Elsevier Science Ltd; Elsevier
• Subjects: Chemical Sciences; Composition; Configurations; Electric double layer; Electrochemical analysis; Electrochemical impedance spectroscopy; Electrode materials; Electrode polarization; Electrodes; Electrolytes; Electrolytic cells; Electrostatic discharges; Electrostatic spray deposition; Intermediate temperature solid oxide cell; Oxygen electrode; Rare-earth nickelates; Screen printing; Spray deposition; Intermediate temperature solid oxide cell; Electrostatic spray deposition; Oxygen electrode; Rare-earth nickelates; Electrochemical impedance spectroscopy
• ISSN: 1572-6657; 1873-2569
• DOI: 10.1016/j.jelechem.2019.113373

Rare earth nickelate, LaPrNiO4+δ (LPNO), is one of the most suitable oxygen electrode materials for Intermediate Temperature Solid Oxide Cells (IT-SOC). By using Electrostatic Spray Deposition (ESD) and Screen Printing (SP), various architectural designs of electrodes are fabricated on Ce0.9Gd0.1O2-δ (GDC) electrolyte. Three electrode configurations are investigated based on a single Active Functional Layer (AFL), a double layer of the same composition which is an AFL topped by a current collecting layer (CCL) and a triple layer which is mainly the double layer with an LPNO/GDC composite interface. For each configuration, the electrode response and properties are analyzed by using Electrochemical Impedance Spectroscopy (EIS), X-ray diffraction and Scanning Electron Microscopy (SEM). The electrochemical properties are discussed as a function of the electrode design, microstructure, and composition with the presence of a higher order nickelate such as (La,Pr)3Ni2O7-δ. The electrochemical performance is enhanced thanks to better adhesion of the electrode onto the electrolyte, the presence of an LPNO/GDC composite interface, a more homogeneous distribution of fine grains, and a flatter electrode surface. A significant decrease in the polarization resistance (Rpol) is measured from 0.72, 0.50, and down to 0.20 Ω cm2 at 600 °C from single to triple layer, respectively.
LaPrNiO4+δ (LPNO) oxygen electrode for intermediate temperature solid oxide cells is designed using screen printing (SP) and electrostatic spray deposition (ESD). The electrode performance is improved as the configuration evolves from single layer deposited by ESD to double layer and then triple layer. The triple layer electrode presents an excellent performance with the polarization resistance of 0.20 Ω cm2 at 600 °C. [Display omitted]
•Electrosprayed LPNO AFL is characterized by particles at the nanometer scale.•Designing interfaces play a key role in the performance of LPNO oxygen electrode.•(La,Pr)3Ni2O7-δ is beneficial for the electrochemical activity of the electrode.•Ball milled powder for SP enhances the homogeneity of the CCL.•The TL configuration performs 4 times better than the SL ESD.