对称型固体氧化物燃料电池ReBaMn_(2)O_(5+δ)基电极材料结构与性能的理论预测与实验验证  

Structure and Performance of ReBaMn_(2)O_(5+δ)based Electrodes for Symmetric Solid Oxide Fuel Cells

作　　者：张敏[1] 张旸[1] 杜志鸿[1,2] 赵海雷 ZHANG Min;ZHANG Yang;DU Zhihong;ZHAO Hailei(School of Materials Science and Engineering,University of Science and Technology Beijing,Beijing 100083,China;Beijing Municipal Key Lab for Advanced Energy Materials and Technologies,Beijing 100083,China)

机构地区：[1]北京科技大学材料科学与工程学院,北京100083 [2]新能源材料与技术北京市重点实验室,北京100083

出　　处：《硅酸盐学报》2024年第6期1799-1809,共11页Journal of The Chinese Ceramic Society

基　　金：国家重点研发计划(2018YFB1502202)。

摘　　要：为获得高性能ReBaMn_(2)O_(5+δ)对称电极材料,本工作通过第一性原理计算分析了不同稀土元素(La,Pr,Nd,Sm,Gd,Y)对材料结构和性能的影响。计算结果表明LaBaMn_(2)O_(5+δ)不易形成层状钙钛矿结构,Gd Ba Mn_(2)O_(5+δ)的结合能最高,对应结构稳定性最好,而Nd Ba Mn_(2)O_(5+δ)则具有较小的Mn 3d和O_(2)p轨道之间的能量差、以及较低的O_(2)p轨道中心与Fermi面的能量差,对应材料较高的电导率和优异的催化活性。选用La,Nd和Gd作为A位元素进行实验研究。结果表明,LaBaMn_(2)O_(5+δ)难以形成单相钙钛矿,但成功合成了具有层状结构的Nd Ba Mn_(2)O_(5+δ)和Gd BaMn_(2)O_(5+δ),其在氧化和还原气氛下均保持良好的结构稳定性。相比于Gd Ba Mn_(2)O_(5+δ),Nd Ba Mn_(2)O_(5+δ)在空气和5%(体积分数) H2/Ar中均具有较高的电导率。且Nd Ba Mn_(2)O_(5+δ)电极在空气和氢气气氛下的极化阻抗均小于GdBaMn_(2)O_(5+δ),表现出更强的催化活性。以NdBaMn_(2)O_(5+δ)为对称电极,300μm的La_(0.8)Sr_(0.2)Ga_(0.8)Mg0.2O_(3)–δ为电解质制备的对称全电池,在850℃下最大功率密度达到335 mW·cm^(-2)。Introduction Compared with conventional solid oxide fuel cell,using one material as both the cathode and anode to construct a symmetrical solid oxide fuel cell(SSOFC)configuration can simplify the fabrication processes and reduce the cost,while mitigating the chemical incompatibility and thermal mismatching issues.A-site double perovskite PrBaMn_(2)O_(5+δ),with a matched thermal expansion coefficient with electrolytes,good structural stability in both oxidizing and reducing atmospheres as well as a modest catalytic activity is a promising symmetrical electrode.However,PrBaMn_(2)O_(5+δ)has a low electrical conductivity in reducing atmosphere and an inferior catalytic activity towards fuel oxidation.To address these issues,a lattice doping strategy was employed to regulate the charge carrier and oxygen vacancy concentrations,as well as the energy band structure.In addition,theoretical calculation could predict the properties of the material,and screen doping elements for high-performance material.The A site elements have a great impact on the properties of material in terms of structure,conductivity,and catalytic activity.In this paper,first-principles calculation was employed to investigate the effect of A-site Re(rare-earth)element species(i.e.,La,Pr,Nd,Sm,Gd,and Y)on the structure and properties of ReBaMn_(2)O_(5+δ)materials,and the calculated results were verified by experimental data.Methods The Cambridge sequential total energy package(CASTEP)module in Material Studio software was utilized to calculate the binding energy,formation energy from oxides,and density of states(DOS)of LaBaMn_(2)O_(5+δ)(LBM),PrBaMn_(2)O_(5+δ)(PBM),NdBaMn_(2)O_(5+δ)(NBM),SmBaMn_(2)O_(5+δ)(SBM),GdBaMn_(2)O_(5+δ)(GBM),and YBaMn_(2)O_(5+δ)(YBM)materials,respectively.The selected materials were prepared by a sol-gel method.The phase structure of the synthesized powder was examined by X-ray diffraction(XRD).The electrical conductivities of the samples were measured by the DC four-terminal method in air and 5%H2/Ar atmosphere,respe

关 键 词：对称性固体氧化物燃料电池 第一性原理计算 A位双钙钛矿 稀土元素 

分 类 号：O646[理学—物理化学]