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

• Published in: Renewable energy 2022-02, Vol.185, p.1167-1176
• Main Authors: Zapata-Ramírez, Víctor, Rosendo-Santos, Paula, Amador, Ulises, Ritter, Clemens, Mather, Glenn C., Pérez-Coll, Domingo
• Format: Article
• Language: English
• Subjects: Cobalt-free air electrode; Electrochemical stability; Fuel-cell performance; SOFC; Spray pyrolysis
• ISSN: 0960-1481; 1879-0682
• DOI: 10.1016/j.renene.2021.12.121

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 SrFeO3-δ and SrFe0.9Mo0.1O3-δ prepared by a Pechini method confirmed that SrFeO3-δ 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 cm2 for SrFeO3-δ and SrFe0.9Mo0.1O3-δ at 700 °C, respectively, in comparison to their analogues synthesised by the Pechini method (0.55 and 0.42 Ω cm2), 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