
Influence of layer numbers on the structural and electrical performance of cobalt-free SrFe0.5Ti0.5O3-δ cathode for ntermediate-temperature solid oxide fuel cell application
Author(s) -
Nurul Akidah Baharuddin,
Wan Nor Anasuhah Wan Yusoff,
Andanastuti Muchtar,
Mahendra Rao Somalu,
Nafisah Osman,
Mustafa Anwar
Publication year - 2019
Publication title -
iop conference series. earth and environmental science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.179
H-Index - 26
eISSN - 1755-1307
pISSN - 1755-1315
DOI - 10.1088/1755-1315/268/1/012132
Subject(s) - materials science , van der pauw method , cathode , cobalt , layer (electronics) , sintering , scanning electron microscope , electrical resistivity and conductivity , electrolyte , cobalt oxide , oxide , analytical chemistry (journal) , nanotechnology , composite material , electrode , metallurgy , hall effect , electrical engineering , chemistry , chromatography , engineering
The influence of layer numbers on the structural and electrical performance of SrFe 0.5 Ti 0.5 O 3-δ cobalt-free cathode was studied. The SrFe 0.5 Ti 0.5 O 3-δ cathode films fabricated using screen-printing technique with different layer numbers sintered at 1300 °C for 2 h were characterised using field-emission scanning electron microscopy (FESEM) for structural analysis and four-point van der Pauw method for direct current electrical conductivity (σ DC ). FESEM micrographs confirmed that the SrFe 0.5 Ti 0.5 O 3-δ cobalt-free cathode films (fabricated with different layer numbers) adhered well on the samarium doped ceria electrolyte surface. The porous films were also uniform without crack formation. The thicknesses of the as-fabricated cathode films were 9.0 ± 0.5, 25.6 ± 1.0, 54 ± 0.6, 71.2 ± 1.4 and 92.2 ± 1.6 μm for layer numbers 1 (1×), 4, 7, 10 and 13 times (13×), respectively. The electrical performance of SrFe 0.5 Ti 0.5 O 3-δ cobalt-free cathodes was reported within the operating temperature ranging from 550 °C to 800 °C as the targeted application was the intermediate temperature solid oxide fuel cell. The layer numbers (thickness) dependence of σ DC suggested a mechanism of long electron pathway at the surface and through the films due to the increase in pores. While the sintering temperature is kept constant, increasing in the number of layers increased the pores accordingly. Hence, the lowest σ DC value at 800 °C (2.45 S cm − 1) is obtained for SrFe 0.5 Ti 0.5 O 3-δ cathode films with high number of layers (13×). The highest σ DC value (16.46 S cm − 1) was recorded for a single layer (1×) SrFe 0.5 Ti 0.5 O 3-δ cathode film. Although the conductivity value was still far from the desired theoretical conductivity of 100 S cm − 1, this result was better than that of the literature that reported the same composition, thereby showing that the quality of cathode film was improved.