Rational design of bifunctional catalysts towards oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is vital for reversible Zn-air batteries. Here, we highlight the surface functionalized perovskite, oxygen vacancies-rich Ce_0.9Gd_0.1O_2-δ (GDC) decorated Pr_0.5Ba_0.5CoO_3-δ (PBC), as a novel bifunctional electrode for Zn-air batteries. Surface decoration by GDC can not only introduce abundant electrochemically active oxygen vacancies for ORR and OER, but also improve the structure stability of perovskite against practical operation. Density functional theory calculations further reveal that O₂ and H₂O molecules readily adsorb on GDC surface rather than PBC surface. The resulting 20 wt.% GDC decorated PBC catalyst delivers a significantly higher bifunctionality than the pristine PBC. As a proof-of-concept, an assembled Zn–air battery using 20 wt.% GDC decorated PBC electrode demonstrates a considerable peak power density and a long cycling life. This study offers a facile and effective approach to design air electrode of rechargeable Zn-air batteries.

合理设计双功能催化剂，以进行氧还原反应（ORR）和氧释放反应（OER）对于可逆锌空气电池至关重要。在这里，我们重点介绍了表面功能化钙钛矿，富氧空缺的Ce _0.9 Gd _0.1 O2 _-δ（GDC）装饰的Pr _0.5 Ba _0.5 CoO3 _-δ（PBC），作为用于锌空气电池的新型双功能电极。GDC的表面装饰不仅可以为ORR和OER引入大量的电化学活性氧空位，还可以提高钙钛矿在实际操作中的结构稳定性。密度泛函理论计算进一步揭示了O ₂和H ₂O分子容易吸附在GDC表面而不是PBC表面上。所得的20重量％的GDC修饰的PBC催化剂提供了比原始PBC明显更高的双官能度。作为概念证明，使用20 wt。％GDC装饰的PBC电极组装的Zn-空气电池展示出可观的峰值功率密度和较长的循环寿命。这项研究为设计可充电锌空气电池的空气电极提供了一种简便有效的方法。