Bi6Te2-xRxO13 (R=Ti, Si, Ce) Systems: A Investigation for Fuel Cell Applications

Abstract

In recent years, the increase of economic and environmental problems related to energy generation has increased researches at renewable energy sources. Among others, the fuel cells excel as promising alternative technology of electricity generation and materials science is an ally in the search for better and more efficient materials for this application. In particular, solid-state ionic conductors represent functional materials with promising advantages for fuel cells, as is the case of Bi2O3-based oxygen ion conductors, however, they need to have its cubic phase stabilized at room temperature. This paper presents a study of the Bi6Te2-xRxO13 (R = Ti, Si and Ce) systems for such an application. Solid state reaction was used to materials synthesis. The 3Bi2O3:2TeO2 system present two phases, an orthorhombic one (Bi6Te2O15) stable at room temperature and another high temperature cubic (Bi6Te2O13). Experiments of substitution of Te ions by Ti, Si and Ce ions using the Bi6Te2- xRxO13 matrix were done intending to stabilize the cubic phase at room temperature and the results are presented as well as discussed here