摘要
A La_(0.5)Ba_(0.5)MnO_(3-δ) oxide was prepared using the sol-gel technique.Instead of a pure phase,La_(0.5)Ba_(0.5)MnO_(3-δ) was discovered to be a combination of La_(0.7)Ba_(0.3)MnO_(3-δ) and BaMnO_(3).The in-situ production of La_(0.7)Ba_(0.3)MnO_(3-δ)+BaMnO_(3) nanocomposites enhanced the oxygen vacancy(Vo)formation compared to single-phase La_(0.7)Ba_(0.3)MnO_(3-δ) or BaMnO_(3),providing potential benefits as a cathode for fuel cells.Subsequently,La_(0.7)Ba_(0.3)MnO_(3-δ)+BaMnO_(3) nanocomposites were utilized as the cathode for proton-conducting solid oxide fuel cells(H-SOFCs),which significantly improved cell performance.At 700 C,H-SOFC with a La_(0.7)Ba_(0.3)MnO_(3-δ)+BaMnO_(3) nanocomposite cathode achieved the highest power density(1504 mW·cm^(-2))yet recorded for H-SOFCs with manganate cathodes.This performance was much greater than that of single-phase La_(0.7)Ba_(0.3)MnO_(3-δ)or BaMnO_(3) cathode cells.In addition,the cell demonstrated excellent working stability.First-principles calculations indicated that the La_(0.7)Ba_(0.3)MnO_(3-δ)/BaMnO_(3) interface was crucial for the enhanced cathode performance.The oxygen reduction reaction(ORR)free energy barrier was significantly lower at the La_(0.7)Ba_(0.3)MnO_(3-δ)/BaMnO_(3) interface than that at the La_(0.7)Ba_(0.3)MnO_(3-δ) or BaMnO_(3) surfaces,which explained the origin of high performance and gave a guide for the construction of novel cathodes for H-SOFCs.
基金
supported by the National Natural Science Foundation of China(Grant Nos.52272216 and 51972183)
the Hundred Youth Talents Program of Hunan,and the Startup Funding for Talents at University of South China
the support from the Hunan University Student Innovation and Entrepreneurship Training Program(Grant No.S202210555343)。
