Developing high-performance cathode materials for intermediate-temperature solid oxide fuel cells (SOFCs) is crucial to advance SOFC technology. This study explores the application of an entropy engineering strategy to the A-site of ferrite spinel oxides to develop high-performance cathode materials. We synthesized a high-entropy spinel oxide, (Mg_0.2Fe_0.2Co_0.2Ni_0.2Cu_0.2)Fe₂O₄, and compared its performance with its lower-entropy counterparts, CoFe₂O₄ and (Mg_0.333Co_0.333Ni_0.333)Fe₂O₄. Experimental results and density functional theory (DFT) calculations revealed that (Mg_0.2Fe_0.2Co_0.2Ni_0.2Cu_0.2)Fe₂O₄ exhibits superior electrochemical performance owing to its suitable electronic structure, diverse surface metal cations, and abundant surface oxygen vacancies. When applied as the cathode in an anode-supported SOFC, the cell achieves a peak power density of 787.15 mW cm⁻² at 800 °C and demonstrates excellent long-term stability over 100 hours of operation. These findings highlight the potential of A-site entropy engineering as a promising approach to enhance the performance and stability of SOFC spinel oxide cathodes.

中文翻译：

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用于开发高性能 SOFC 阴极的尖晶石氧化物 A 位熵工程新策略


开发用于中温固体氧化物燃料电池（SOFC）的高性能阴极材料对于推进SOFC技术至关重要。本研究探讨了熵工程策略在铁氧体尖晶石氧化物 A 位的应用，以开发高性能正极材料。我们合成了高熵尖晶石氧化物 (Mg _0.2 Fe _0.2 Co _0.2 Ni _0.2 Cu _0.2 )Fe ₂ O ₄ ，并将其性能与其低熵对应物 CoFe ₂ O ₄和 (Mg _0.333 Co _0.333 Ni _0.333 ) 进行了比较四氧化_二铁。实验结果和密度泛函理论（DFT）计算表明（Mg _0.2 Fe _0.2 Co _0.2 Ni _0.2 Cu _0.2 ）Fe ₂ O ₄由于其合适的电子结构、多样的表面金属阳离子和丰富的表面氧空位而表现出优异的电化学性能。当用作阳极支持的SOFC中的阴极时，该电池在800℃下实现了787.15 mW cm ^-2的峰值功率密度，并在100小时的运行中表现出优异的长期稳定性。 这些发现凸显了 A 位熵工程作为增强 SOFC 尖晶石氧化物阴极的性能和稳定性的一种有前途的方法的潜力。