Abstract The present study describes the rational engineering, preparation and characterisation of new mixed ionic-electronic conductors (MIECs) having great potential for application in solid oxide fuel cells (SOFCs) based on proton-conducting electrolytes. The developed MIECs are derived from promising Ba(Ce,Zr)O3-materials doped with iron as a transition element: BaCe0.7–xZr0.2Y0.1FexO3–δ (x = 0–0.7, Δx = 0.1). The comprehensive analysis of the functional properties (crystal structure, densification, microstructure, defect structure, thermal expansion behaviour, electrical conductivity) indicate that a moderate iron content is beneficial in order to achieve a certain compromise. In detail, the gradual Fe-doping results in an enhancement of transport properties (including, ionic-electronic conductivity level) and deterioration of mechanical characteristics (an increase of average thermal expansion coefficient values). The composition with x = 0.6, identified as more optimal, was used as a cathode for an intermediate-temperature SOFC; this cathode displays a satisfactory polarisation resistance level, 0.21 Ω cm2 at 700 °C, without the use of any additional electroactivation technique. The obtained results indicate that BaCe 0.7–xZr0.2Y0.1FexO3–δ MIECs having one of the highest chemical compatibility with state-of-the-art proton-conducting electrolytes can be considered as advanced electrodes for designing new solid oxide electrochemical devices with prolonged and stable operation mode.

中文翻译：

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BaCe0.7–xZr0.2Y0.1FexO3–δ 源自质子传导电解质：一种为固体氧化物燃料电池设计化学相容阴极的方法

摘要 本研究描述了新型混合离子电子导体 (MIEC) 的合理工程、制备和表征，该导体在基于质子传导电解质的固体氧化物燃料电池 (SOFC) 中具有巨大的应用潜力。开发的 MIEC 源自有前途的 Ba(Ce,Zr)O3 材料，掺杂铁作为过渡元素：BaCe0.7–xZr0.2Y0.1FexO3–δ (x = 0–0.7, Δx = 0.1)。对功能特性（晶体结构、致密化、微观结构、缺陷结构、热膨胀行为、电导率）的综合分析表明，适度的铁含量有利于实现一定的折衷。详细地说，逐渐的 Fe 掺杂导致传输特性的增强（包括，离子电子电导率水平）和机械特性恶化（平均热膨胀系数值增加）。x = 0.6 的组合物被确定为更佳，用作中温 SOFC 的阴极；该阴极在 700 °C 下显示出令人满意的极化电阻水平，0.21 Ω cm2，无需使用任何额外的电激活技术。获得的结果表明 BaCe 0.7–xZr0.2Y0.1FexO3–δ MIECs 与最先进的质子传导电解质具有最高的化学相容性之一，可以被认为是用于设计新的固体氧化物电化学装置的先进电极。和稳定的运行模式。用作中温 SOFC 的阴极；该阴极在 700 °C 下显示出令人满意的极化电阻水平，0.21 Ω cm2，无需使用任何额外的电激活技术。获得的结果表明 BaCe 0.7–xZr0.2Y0.1FexO3–δ MIECs 与最先进的质子传导电解质具有最高的化学相容性之一，可以被认为是用于设计新的固体氧化物电化学装置的先进电极。和稳定的运行模式。用作中温 SOFC 的阴极；该阴极在 700 °C 下显示出令人满意的极化电阻水平，0.21 Ω cm2，无需使用任何额外的电激活技术。获得的结果表明 BaCe 0.7–xZr0.2Y0.1FexO3–δ MIECs 与最先进的质子传导电解质具有最高的化学相容性之一，可以被认为是用于设计新的固体氧化物电化学装置的先进电极。和稳定的运行模式。