An innovative and facile synthesis route of(La,Sr)_(2)FeO_(4+δ)–La_(0.4)Sr_(0.6)FeO_(3−δ)composite as a highly stable air electrode for reversible solid oxide cell applications

Achieving thermal cycle stability is an imperative challenge for the successful commercialization of solid oxide cell(SOC)technology.Ruddlesden‒Popper(R‒P)oxides,whose thermal expansion coefficient(TEC)is compatible with common electrolytes,are promising candidates for SOC applications.However,the two-dimensional conduction characteristic of R‒P oxides leads to insufficient catalytic activity,which hinders their performance.Here,we propose a win‒win strategy for self-assembly decoration by employing a one-pot method to address this issue.By using a single perovskite oxide(La_(0.4)Sr_(0.6)FeO_(3))to modify R‒P oxide(La_(0.8)Sr_(1.2)FeO_(4+δ)),we enhanced the electrochemical performance without compromising the stability of the composite electrode.The strategic incorporation of a 10 mol%perovskite phase at 800℃ resulted in a significant 49%reduction in the polarization resistance(R_(p)),an impressive 86%increase in the maximum power density under power generation mode,and a notable 33%increase in the electrolysis current density under electrolysis mode.Furthermore,the perovskite-decorated R‒P oxide composite also exhibited high thermal and chemical stability,with negligible performance degradation observed under both thermal cycling and charge/discharge cycling conditions.Our results demonstrate that such dual-phase composites,which are simultaneously produced by a onestep process with outstanding catalytic activity and stability,can be considered an effective strategy for the advancement of SOCs.