Strontium segregation in a La _0.6 Sr _0.4 Co _0.2 Fe _0.8 O _3−δ (LSCF) electrode reacts with Cr and S in a solid oxide fuel cell (SOFC), which can cause cell performance deterioration.

Zinc–air batteries are one of the most excellent of the next generation energy devices. However, their application is greatly hampered by the slow kinetics of oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) of air electrode. It is of great importance to develop good oxygen electrocatalysts with long durability as well as low cost. Here, A-site deficient (SmSr)_0.95Co_0.9Pt_0.1O₃ perovskites have been studied as potential OER electrocatalysts prepared by EDTA–citrate acid complexing method. OER electrocatalytic performance of (SmSr)_0.95Co_0.9Pt_0.1O₃ was also evaluated. (SmSr)_0.95Co_0.9Pt_0.1O₃ electrocatalysts exhibited good OER activities in 0.1 M KOH with onset potential and Tafel slope of 1.50 V and 87 mV dec⁻¹, similar to that of Ba_0.5Sr_0.5Co_0.8Fe_0.2O₃ (BSCF-5582). Assembled rechargeable Zn–air batteries exhibited good discharge potential and charge potential with high stability, respectively. Overall, all results illustrated that (SmSr)_0.95Co_0.9Pt_0.1O₃ is an excellent OER electrocatalyst for zinc–air batteries. Additionally, this work opens a good way to synthesize highly efficient electrocatalysts from A-site deficient perovskites.

Due to the insufficient stability and expensive price of commercial precious metal catalysts like Pt/C and IrO₂, it is critical to study efficiently, stable oxygen reduction reaction as well as oxygen evolution reaction (ORR/OER) electrocatalysts of rechargeable Zn-air batteries. PrBa_0.5Sr_0.5Co_1.5Fe_0.5O₅ (PBSCF) double perovskite was adopted due to its flexible electronic structure as well as higher electro catalytic activity. In this study, PBSCF was prepared by the citrate-EDTA method and the optimized amount of PBSCF-Pt/C composite was used as a potential ORR/OER bifunctional electrocatalyst in 0.1 M KOH. The optimized composite exhibited excellent OER intrinsic activity with an onset potential of 1.6 V and Tafel slope of 76 mV/dec under O₂-saturated 0.1 M KOH. It also exhibited relatively competitive ORR activity with an onset potential of 0.9 V and half-wave potential of 0.78 V. Additionally, Zn–air battery with PBSCF composite catalyst showed relatively good stability. All these results illustrate that PBSCF-Pt/C composite is a promising bifunctional electrocatalyst for rechargeable Zn-air batteries.