Ionic conductivity and transport mechanism in Sm-doped CeO2 ceramics prepared from ionic gelation-derived oxide powders

IF 5.5 3区材料科学 Q1 ELECTROCHEMISTRY

Electrochimica Acta Pub Date : 2025-06-17 DOI:10.1016/j.electacta.2025.146725

B.M.G. Melo , D. Nicheva , V. Ilcheva , V. Boev , G. Avdeev , T. Petkova , S․Soreto Teixeira , L.C. Costa

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引用次数: 0

Abstract

Rare-earth-doped ceria is being investigated for applications, such as solid oxide fuel cells (SOFCs), oxygen sensors, thermobarrier coatings, among others. In all these applications, finely dispersed starting powders are essential for preparing ceramics with parameters that meet technological requirements.

In the present work, Sm-doped CeO₂ ceramics were prepared by ionic gelation (IG) and subsequent thermal treatment. Ionic solutions of sodium alginate and metal nitrates (Ce(NO₃)₃.H₂O, Sm(NO₃)₃.H₂O) were gelled, followed by a thermal treatment at 500 °C for 4 h to obtain powders. After, they were pressed into pellets and sintered at 1400 °C to form dense ceramics.

The as prepared Ce_1-xSm_xO_2-x/2 (x = 0.1, 0.2, 0.3, 0.4, 0.5) materials were characterized morphologically and structurally by scanning electron microscopy (SEM), X-ray diffraction (XRD) and infrared spectroscopy (IR). XRD analysis confirms samarium incorporation in the CeO₂ lattice, evidenced by diffraction peaks shifts.

The ceramics relative density, a key factor for the reliable performance of electrolyte materials was also analyzed.

AC impedance analysis was performed to study the ionic conductivity of the obtained ceramics.

The impedance data were modeled using equivalent circuits to study the ionic conductivity and the electrolyte materials transport mechanisms. The bulk, grain boundary and total conductivity were analyzed and compared to all compositions. The intrinsic grain boundary conductivity and space-charge layer properties were further studied using a Mott-Schottky approximation to investigate the doping effect.

This study demonstrates the potential of ionic gelation for the synthesis of Sm-doped CeO₂ ceramics with controlled structural and electrochemical properties, making them suitable for SOFCs applications.

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离子凝胶衍生氧化物粉末制备的sm掺杂CeO2陶瓷的离子电导率和输运机制

稀土掺杂的二氧化铈在固体氧化物燃料电池（sofc）、氧传感器、热障涂层等方面的应用正在研究中。在所有这些应用中，精细分散的起始粉末对于制备参数符合工艺要求的陶瓷是必不可少的。本文采用离子凝胶（IG）法制备了sm掺杂的CeO2陶瓷，并对其进行了热处理。海藻酸钠与金属硝酸盐（Ce(NO3)3）的离子溶液。将H2O， Sm(NO3)3.H2O)凝胶化，500℃热处理4 h得到粉末。之后，将它们压成颗粒，在1400℃下烧结，形成致密的陶瓷。采用扫描电子显微镜（SEM）、x射线衍射仪（XRD）和红外光谱（IR）对制备的Ce1-xSmxO2-x/2 （x=0.1, 0.2, 0.3, 0.4, 0.5）材料进行了形貌和结构表征。XRD分析证实了在CeO2晶格中掺杂了钐，衍射峰移位证明了这一点。分析了影响电解质材料可靠性能的关键因素——陶瓷相对密度。通过交流阻抗分析，研究了所得陶瓷的离子电导率。利用等效电路对阻抗数据进行建模，研究离子电导率和电解质材料的输运机制。对各组分的体积、晶界和总电导率进行了分析和比较。利用Mott-Schottky近似进一步研究了掺杂效应的本征晶界电导率和空间电荷层性质。该研究证明了离子凝胶法制备具有可控结构和电化学性能的sm掺杂CeO 2陶瓷的潜力，使其适合SOFCs应用。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Electrochimica Acta 工程技术-电化学

CiteScore

11.30

自引率

6.10%

发文量

1634

审稿时长

41 days

期刊介绍： Electrochimica Acta is an international journal. It is intended for the publication of both original work and reviews in the field of electrochemistry. Electrochemistry should be interpreted to mean any of the research fields covered by the Divisions of the International Society of Electrochemistry listed below, as well as emerging scientific domains covered by ISE New Topics Committee.