Overcoming chromium poisoning in solid oxide cells through multiscale perovskite engineering.

Li, Min; Liu, Huixian; Bu, Yunfei; Wang, Xiang; Wang, Haoran; Chen, Jiawei; Li, Jiawei; Zhao, Yantao et al. · Nat Commun · 2026

basic_science · Level V

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Abstract

Chromium poisoning and sluggish oxygen kinetics limit oxygen electrodes in reversible solid oxide cells. We introduce a triple barrier design that integrates lattice stabilization by Ba to suppress SrO segregation, BaCoO<sub>3</sub> nanodomains that trap chromium, and surface acidity tuning via trace Mo at the B site in La<sub>0.6</sub>Sr<sub>0.1</sub>Ba<sub>0.35</sub>Co<sub>0.2</sub>Fe<sub>0.78</sub>Mo<sub>0.02</sub>O<sub>3</sub>₋<sub>δ</sub>. The electrode reaches 0.058 Ω·cm<sup>2</sup> polarization resistance at 750 °C, 70.4 percent lower than LSCF, delivers 1.352 W·cm⁻<sup>2</sup> at 800 °C, and 2.08 A·cm⁻<sup>2</sup> at 1.5 V. Under 0.5 A·cm⁻<sup>2</sup> with a chromium source, single cells operate stably for about 1000 hours. Quantitative characterization and thermodynamic analysis show suppressed SrCrO<sub>4</sub> formation and shallow chromium ingress, consistent with BaCoO<sub>3</sub> mediated trapping and Mo moderated surface basicity. Density functional theory at operating temperature and pressure indicates Ba and Mo together weaken CrO<sub>3</sub> adsorption. The design reconciles high activity with chromium tolerance and is transferable to related oxygen electrodes.