Tailoring cobalt-free La_(0.5)Sr_(0.5)FeO_(3-δ)cathode with a nonmetal cation-doping strategy for high-performance proton-conducting solid oxide fuel cells

A nonmetal doping strategy was exploited for the conventional La_(0.5)Sr_(0.5)FeO_(3-δ)(LSF)cathode,allowing high performance for proton-conducting solid oxide fuel cells(H-SOFCs).Unlike previous studies focusing on the utilization of metal oxides as dopants,phosphorus,which is a nonmetal element,was used as the cation dopant for LSF by partially replacing Fe ions to form the new La_(0.5)Sr_(0.5)Fe_(0.9)P_(0.1)O_(3-δ)(LSFP)compound.The H-SOFC using the LSFP cathode showed a two-fold peak power density as compared to that using the LSF cathode.Both experimental studies and first-principle calculations were used to unveil the mechanisms for the high performance of the LSFP cells.