Evaluation of the electrocatalytic performance of a novel nanocomposite cathode material for ceramic fuel cells

Abstract

Cathode materials are pivotal in advancing ceramic fuel cell (CFC) technology. However, they still suffer from insufficient oxygen reduction reaction (ORR) activity and a high thermal expansion coefficient (TEC). In this study, we develop a thermodynamically stable self-ordered nanocomposite cathode material with the unique composition, BaCo0.5Ce0.3Fe0.1Yb0.1O3-δ (BCCFYb). Upon calcination, the precursor material separates into a host cubic and ancillary rhombohedral phase. We compare the performance of the triple ionic and electronic (O2−/H+/e−) conducting BCCFYb to that of cobalt-rich oxide-ion and electron (O2−/e−) conducting BaCo0.833Yb0.167O3-δ (BCYb), cerium-rich proton and electronic (H+/e−) conducting BaCe0.75Fe0.25O3-δ (BCF), and Co–Ce-rich triple ionic and electronic (O2−/H+/e−) conducting BaCo0.833Yb0.167O3-δ - BaCe0.75Fe0.25O3-δ (BCYb-BCF) traditional composite materials. The BCCFYb demonstrates a low TEC, good operational stability, and superior cathodic performance in both oxygen ion- and proton-conducting CFC modes, making it a promising cathode material for ceramic fuel cells.