A highly efficient Sb-doped La0.5Sr0.5FeO3-δ cathode for protonic ceramic fuel cells

Abstract

The La0.5Sr0.5FeO3-δ (LSF) material is modified with Sb doping to improve the performance of conventional LSF cathode for protonic ceramic fuel cells (PCFCs). The Sb cations can be inserted into the LSF lattice to develop a new composition La0.5Sr0.5Fe0.9Sb0.1O3-δ (LSFSb), which reduces the formation energy of oxygen vacancies and lowers the proton migration energy of the Sb-doped material when compared to the Sb-free LSF. Additional experimental findings reveal that Sb doping enhances the proton/oxygen transport and surface exchange kinetics. The fuel cell with the LSFSb cathode has a substantially higher peak power density of 933 mW cm−2 at 700 °C than the LSF cell, which only reaches 606 mW cm−2 under the same testing conditions. Using the LSFSb composite cathode further improved the fuel-cell performance, resulting in a promising fuel cell performance of 1388 mW cm−2, which is high for LSF-based PCFCs, thus demonstrating that LSFSb is a suitable cathode for PCFCs.