The effect of pore-former morphology on the electrochemical performance of solid oxide fuel cells under combined fuel cell and electrolysis modes

The effect of the pore-former used in the Ni-YSZ fuel electrode on the electrochemical performance of solid oxide cells is studied. Three cells with the configuration of Ni-YSZ/YSZ/Nd2NiO4+δ-YSZ were fabricated with different pore-formers, such as graphite, PMMA (polymethyl methacrylate) or an equal...

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Detalles Bibliográficos
Autores: Laguna-Bercero, M. A., Hanifi, Amir R., Menand, Lucile, Sandhu, Navjot K., Anderson, Neil E., Etsell, Thomas H., Sarkar, Partha
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2018
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/181407
Acceso en línea:http://hdl.handle.net/10261/181407
Access Level:acceso abierto
Palabra clave:Tubular
Nickel
Zirconia
Microstructure
Pore-former
SOFC
SOEC
Descripción
Sumario:The effect of the pore-former used in the Ni-YSZ fuel electrode on the electrochemical performance of solid oxide cells is studied. Three cells with the configuration of Ni-YSZ/YSZ/Nd2NiO4+δ-YSZ were fabricated with different pore-formers, such as graphite, PMMA (polymethyl methacrylate) or an equal mixture of both, which were added to the Ni-YSZ support during the fabrication process. The results show that the Ni-YSZ support containing graphite leads to a more porous support and formation of coarser pores in the vicinity of the electrolyte. This leads to a reduction in the triple phase boundary (TPB) length with a corresponding increase of activation polarization and, as a consequence, the overall cell performance decreases in both fuel cell and electrolysis modes. The cell having PMMA delivered the highest performance under both operation modes (818 and −713 mAcm−2 were obtained in SOFC and SOEC modes at 800 °C), due to finer pores next to the electrolyte. The cell having the mixture of both pore-formers delivered intermediate results. All the cells show similar concentration polarization values meaning that even the least porous cell (PMMA) provided sufficient porosity for gas flow. In addition, long term reversible experiments were performed, showing no degradation for a period above 400 h.