A novel A/B-sites co-substitution strategy was introduced to enhance the performance and durability of Ruddlesden–Popper perovskite Sr₃Fe₂O_7−δ (SF)-based air electrodes for reversible protonic ceramic cells (RePCCs).

Simultaneous Sr-deficiency and Nb-substitution in SF result in Sr_2.8Fe_1.8Nb_0.2O_7−δ (D-SFN), offering improved structural stability under RePCC conditions by suppressing the formation of Sr₃Fe₂(OH)₁₂ phase.

The introduction of Sr-deficiency enhances oxygen vacancy concentration in D-SFN, promoting efficient oxygen transport within the material and contributing to excellent activity in RePCCs.

引入了一种新颖的 A/B 位点共取代策略，以提高用于可逆质子陶瓷电池 (RePCC) 的Ruddlesden-Popper 钙钛矿 Sr ₃ Fe ₂ O _{7−δ (SF) 基空气电极的性能和耐用性。}

SF中同时缺乏Sr和取代Nb会产生Sr _2.8 Fe _1.8 Nb _0.2 O _{7−δ (D-SFN)，通过抑制Sr 3} Fe ₂ (OH) ₁₂相的形成，在RePCC条件下提高结构稳定性。

Sr 缺乏的引入提高了 D-SFN 中的氧空位浓度，促进了材料内氧的有效传输，并有助于 RePCC 的优异活性。