Effect of O-Site Doping on Triple Conductive Perovskite Air Electrodes: A DFT Calculation

Abstract

Proton ceramic electrochemical cell (PCEC) is a promising technology for energy storage and conversion. However, the performance of its air electrode materials remains unsatisfactory. To improve the ORR/OER catalytic activity of air electrodes, most studies focus on doping elements at the A/B sites of perovskite materials, while O-site doping is rarely explored. We propose that O-site doping in air electrode materials could be a highly effective strategy. Using a triple-conductive perovskite, BaFeO 3−δ , as the base material for the air electrode, we investigated the effects of F or Cl or Br doping at the O-site via first-principles density functional theory (DFT) calculations. First, we systematically analyzed the proton migration pathways in BaFeO 3−δ with oxygen vacancies and determined key parameters governing proton migration. Subsequently, different concentrations of F/Cl/Br were doped at the O-site, and the proton migration pathways were recalculated. By comparing the average proton migration energy barriers before and after O-site doping, we evaluated the structural and property changes induced by F/Cl/Br doping. Additionally, we also calculated the ORR/OER catalytic pathways before and after anion doping, revealing the fundamental mechanisms by which anion doping enhances catalytic activity. This research offers powerful theoretical support for designing high-performance air electrodes for PCECs.