Optimisation of high-performance, cobalt-free SrFe1-xMoxO3-δ cathodes for solid oxide fuel cells prepared by spray pyrolysis

[EN] Strontium-ferrite-based perovskites as cobalt-free cathodes for intermediate-temperature solid oxide fuel cells (IT-SOFCs) have been analysed employing structural, stability and electrochemical studies. Neutron diffraction of SrFeO and SrFeMoO prepared by a Pechini method confirmed that SrFeO u...

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Detalles Bibliográficos
Autores: Zapata-Ramírez, Víctor, Rosendo-Santos, Paula, Amador, Ulises, Mather, Glenn C., Pérez-Coll, Domingo
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2022
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/287392
Acceso en línea:http://hdl.handle.net/10261/287392
Access Level:acceso abierto
Palabra clave:SOFC
Cobalt-free air electrode
Spray pyrolysis
Electrochemical stability
Fuel-cell performance
Descripción
Sumario:[EN] Strontium-ferrite-based perovskites as cobalt-free cathodes for intermediate-temperature solid oxide fuel cells (IT-SOFCs) have been analysed employing structural, stability and electrochemical studies. Neutron diffraction of SrFeO and SrFeMoO prepared by a Pechini method confirmed that SrFeO undergoes a phase transition from tetragonal to cubic symmetry at 300–400 °C, whereas Mo-doping stabilises cubic symmetry in the range RT-900 °C. Spray-pyrolysed electrodes offered significantly lower area-specific resistances of 0.2 and 0.11 Ω cm for SrFeO and SrFeMoO at 700 °C, respectively, in comparison to their analogues synthesised by the Pechini method (0.55 and 0.42 Ω cm), and lower grain size, as confirmed by scanning electron microscopy. Thermal cycling and ageing studies indicated a more robust response for the spray-pyrolysed electrodes, in particular the Mo-doped phase, which achieved a stable electrode-polarisation resistance <0.1 Ω cm for 10 heating/cooling cycles and 100 h of ageing at 700 °C. Anode-supported single cells with a thin CeGdO electrolyte produced performances of 0.5 and 0.9 W cm at 700 and 800 °C, respectively. SrFeMoO deposited by spray pyrolysis is, thus, proposed as a promising cobalt-free cathode for IT-SOFC based on its good structural stability and highly competitive electrochemical performance.