Low temperature processing and characterization of novel ceria based electrolyte composition Ce_0.8−xGd_0.1Bi_0.1Ti_xO_2−δ (x = 0.05,0.1) for intermediate temperature SOFC application

Doped ceria based ceramic system is a potential candidate as a solid electrolyte for intermediate or low temperature solid oxide fuel cells. The Gadolinium Doped Ceria (GDC) shows better performance, but the high temperature sintering required for GDC cause cerium ion reduction, which may further enhance electrical conductivity instead of ionic conductivity. This reduction can be lowered by doping GDC system with tri or tetra valent ions. This study emphasizes the preparation and characterization of bismuth and titanium doped GDC system using solution combustion method. Samples with two different dopant concentrations were prepared by the same method and its ionic conductivity is compared. Both the samples show fluorite structure under X-ray diffraction analysis and the micrographs are agglomerated with less voids in them. The Raman and X-ray Photoelectron Spectroscopy results confirm the presence of oxygen vacancies in the prepared samples. The impedance spectroscopy study shows that the sample with low dopant concentration has better ionic conductivity of the order of 10^− 3 S/cm. The applications of SOFC, especially as an auxiliary power unit that supports batteries in electric vehicles will help to reduce the use of combustion engine vehicles in everyday life, which further reduces environmental pollution.