Synthesis and characterisation of novel oxyanion doped materials for use in solid oxide fuel cells

Smith, Alaric (2014). Synthesis and characterisation of novel oxyanion doped materials for use in solid oxide fuel cells. University of Birmingham. Ph.D.

Preview

Smith14PhD.pdf
PDF
Download (8MB)

Abstract

In this thesis the work presented focused on the doping of oxyanions, borate, silicate, sulfate and phosphate, into different materials with the perovskite structure for use as electrolytes or cathodes in solid oxide fuel cells.
Phosphate and sulfate doping was shown to have been carried out successfully on gallium doped barium and strontium scandates. They all adopted the cubic perovskite structures with the presence of oxyanions confirmed by Raman spectroscopy. These samples were found to have improved stability to CO2 atmospheres with increasing gallium content.
Phosphate doping was also carried out on doped barium cerates and was found to lower the conductivity while not leading to improved stability. Oxyanion doped barium stannates were investigated and showed a lower conductivity on oxyanion doping and borate doped samples showed an improved stability in reducing atmospheres.
Following on from earlier work on silicate doping in perovskite cathode materials silicon doping was carried out on (Ca/Sr)2MnFe1-xSixO6-δ which resulted in the formation of cubic perovskites with a mixed oxidation state on the B site. Conductivity and area specific resistance data were collected for the samples showing an initial improvement on silicon doping for two of the series.

Type of Work:

Thesis (Doctorates > Ph.D.)

Award Type:

Doctorates > Ph.D.

Supervisor(s):