All ETDs from UAB

Advisory Committee Chair

Renato P Camata

Advisory Committee Members

Shane A Catledge

Amber L Genau

David J Hilton

Gregg M Janowski

Mary E Zvanut

Document Type

Dissertation

Date of Award

2019

Degree Name by School

Doctor of Philosophy (PhD) College of Arts and Sciences

Abstract

Solid oxide fuel cells are electrochemical systems that convert chemical energy into electricity using ion-conducting oxide ceramics as electrolytes. These devices are widely considered as an important technology in addressing the future demands for low-carbon electrical power generation. Oxide ceramics in which the active ionic species is the proton ion (H+), are of particular current interest because they exhibit ionic conductivities that are two-to-three orders of magnitude higher than ceramics that rely on transport of oxide ions (O2−). Accordingly, these so-called protonic oxide conductors are being investigated vigorously in a variety of bulk and thin film configurations. A major goal of these efforts is to elucidate the ionic conduction processes that enable the high protonic conductivity observed in these materials in the 500°-750°C temperature range. This dissertation seeks to contribute to this effort by investigating the ionic transport properties of thin films of the perovskite barium zirconate doped with trivalent cations. Doped barium zirconate has drawn considerable attention recently not only due to its high protonic conductivity but also because of its high chemical stability in typical fuel cell operating environments. Our focus is to study the protonic conductivity of barium zirconate thin films doped with the little explored cations Gd3+(gadolinium) and Yb3+(ytterbium). In addition, we also seek to investigate the effect of microstructure in the protonic conduction of these thin films doped with Gd and Yb.

Share

COinS