AI 中文总结
研究 BaCeO₃ 基电解质应用受限问题，通过第一性原理计算等，揭示小半径、高电负性 A 位掺杂剂在增强钙钛矿电解质质子传输及稳定性上的协同作用，证明 A 位 Ca 掺杂优势并阐明机制，为高性能电解质设计提供指导。
AI 中文摘要
基于 BaCeO₃ 的电解质在质子传导固体氧化物燃料电池中的化学稳定性差，限制了其实际应用。常用的 B 位掺杂策略虽能改善质子传输，但稳定性提升有限。近期实验表明 A 位 Ca 掺杂可同时增强这两种性能。通过对 Ca 掺杂 BaCeO₃ 的第一性原理计算和机理分析，确定了小半径、高电负性 A 位掺杂剂在钙钛矿电解质中控制质子传输和化学稳定性的协同作用。结果证明了 Ba 基电解质中 A 位 Ca 掺杂的优势，阐明了相关掺杂剂影响质子传输和化学稳定性的机制，为高性能质子传导电解质的设计提供了指导。
英文摘要
The practical application of BaCeO$_3$-based electrolytes is limited by their poor chemical stability in proton-conducting solid oxide fuel cells. Commonly employed B-site doping strategies typically improve proton transport with limited improvement in stability. Recent experiments show that A-site Ca doping can simultaneously enhance both properties. Here, through first-principles calculations and mechanistic analysis of Ca-doped BaCeO$_3$, we identify the synergistic roles of small-radius, high-electronegativity A-site dopants in governing proton transport and chemical stability in perovskite electrolytes. We show that the higher electronegativity of A-site dopant weakens the A-O ionic bonding, facilitating oxygen-vacancy formation and enhancing proton uptake by increasing the basicity. This weakened A-O interaction also suppresses the formation of impurity phases and reduces the adsorption strength of acidic gases such as CO$_2$ and SO$_2$. The lattice contraction induced by the smaller ionic radius improves thermal stability and can enhance proton diffusion in systems where proton transfer is the rate-limiting step. Furthermore, we find that Ca surface segregation can mitigate grain-boundary resistance effects. Our results demonstrate the advantages of A-site Ca doping in Ba-based electrolytes, clarify the mechanisms by which small-radius, high-electronegativity dopants influence proton transport and chemical stability, and provide guidance for the design of high-performance proton-conducting electrolytes.
Comments15 pages and 11+4 figures. The version that accepted for publication in Phys. Rev. B
