Optimising anode supported BaZr1-xYxO3-¿ electrolytes for solid oxide fuel cells: Microstructure, phase evolution and residual stresses analysis

Yttrium-doped BaZrO3 is a promising electrolyte for intermediate-temperature protonic ceramic fuel cells. In the anode-supported configuration, a slurry containing the electrolyte is deposited on the surface of a calcined porous anode and sintered. Differences in sintering behaviour and thermal expa...

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Detalles Bibliográficos
Autores: Fernández-Muñoz, Sol, Alba, María D., Ramírez Rico, Joaquín., Chacartegui, Ricardo
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2024
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/364965
Acceso en línea:http://hdl.handle.net/10261/364965
Access Level:acceso abierto
Palabra clave:Fuel-cell
Electrolyte
Residual stress
Sintering
Proton conductors
fuels
Descripción
Sumario:Yttrium-doped BaZrO3 is a promising electrolyte for intermediate-temperature protonic ceramic fuel cells. In the anode-supported configuration, a slurry containing the electrolyte is deposited on the surface of a calcined porous anode and sintered. Differences in sintering behaviour and thermal expansion coefficients for the anode and electrolyte result in elastic residual stresses that can impact the long-term stability of the cell during cyclic operation. Half-cells using BaZr0.8Y0.2O3-¿ as the electrolyte were fabricated using the solid-state reaction sintering method under various sintering conditions. Comprehensive microstructure and residual stress analyses as a function of processing parameters were performed using two-dimensional X-ray diffraction, Rietveld refinement, and scanning electron microscopy, before and after the half-cells were reduced under hydrogen, giving a complete picture of phase, microstructure, and stress evolution under thermal and reduction cycles like the actual operation of the cell. Our results reveal that a temperature of 1400 ¿C and shorter soaking times might be advantageous for obtaining phase-pure and thin yttrium-doped BaZrO3 electrolytes with improved microstructure and the presence of compressive residual stress. These findings offer valuable insights into optimising the fabrication process of BaZrO3-based electrolytes, leading to enhanced performance and long-term stability of anode-supported protonic ceramic fuel cells operating at intermediate temperatures.