Self-assembled triple-conductive La2Ni1 − xCe2xO4+δ cathodes for proton-conducting solid oxide fuel cells

Abstract

Research into novel cathodes for proton-conducting solid oxide fuel cells (H-SOFCs) attracted significant interest, primarily driven by the need for lower operating temperatures. In this study, doping the Ruddlesden–Popper (R–P) oxide La₂NiO_4+δ (LNO) with Ce led to the formation of LNCO, which exhibited a two-phase structure consisting of LNO and La₂Ce₂O₇ (LCO). This unique composition endowed La₂Ni_1−xCe_2xO_4+δ (LNCOx) with triple conductivity, effectively expanding electrochemical active sites across the entire cathode. Consequently, H-SOFCs employing the novel composite La₂Ni_0.8Ce_0.4O_4+δ (LNCO04) cathode demonstrated significant improvements in catalytic activity and durability, achieving an impressive maximum power density of 1516 mW cm⁻² at 700 °C. Notably, this performance surpasses that of most LNO-based cathodes previously reported in earlier studies, underscoring the substantial promise of LNCO oxide as a proton-conductive cathode material for H-SOFCs.