项目名称： 基于晶界偏析调控的CeO2基电解质微结构工程及相关机理研究

项目编号： No.51502136

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 一般工业技术

项目作者： 葛林

作者单位： 南京工业大学

项目金额： 21万元

中文摘要： 掺杂CeO2被认为是中低温SOFC电解质材料的重要候选之一。处于低温及中温区间的CeO2基电解质，材料电阻主要来源于晶界。由溶质偏析所引发的晶界空间电荷效应和由杂质汇聚所导致的晶界电荷阻挡效应是晶界电阻的两大主要来源，因此晶界溶质/杂质的偏析与清扫一直都是CeO2基电解质领域研究的重要课题之一。申请人在最近的研究工作中发现添加ZnO可有效地促进偏析的溶质和杂质SiO2发生反应，借助此反应将有望实现两种晶界电阻效应的“共清扫”。本课题拟在利用此类“共清扫”反应调控晶界溶质及杂质偏析的基础上，深入研究晶界微观结构组成特性与离子传输能力间的联系，以进一步揭示晶界相浸润/非浸润（wetting/dewetting）特性转变机制，阐明晶界溶质偏析规律，为实现晶界偏析相分布形态的精确控制奠定理论基础，并为高性能CeO2基电解质的制备提供可靠的理论指导。

中文关键词： 固体氧化物燃料电池；陶瓷电解质；离子电导；晶界偏析

英文摘要： Doped ceria has been regarded as one of the most promising candidate electrolytes for intermediate-temperature (IT) and low-temperature (LT) solid oxide fuel cells. The grain-boundary resistivity dominates the overall resistivity of doped ceria at low and intermediate temperatures. The barrier-layer effect caused by impurity precipitation and the space-charge effect caused by dopant segregation are the main factors which lead highly resistive grain-boundaries; hence the segregation and scavenging of the grain-boundary dopant/impurities has always been one of the important issues in the field of ceria-based electrolytes. Recently, applicant found that the addition of ZnO can promote the reaction between the segregated dopant and the impurity SiO2, which may “co-scavenging” two kinds of barrier effect. Based on the control of grain-boundary dopant/impurities segregation via “co-scavenging” reaction, this project focuses on the relationship between the ion transmission capacity and the component/property of grain-boundary, aimed to reveal the converting mechanisms about the wetting/dewetting configurations of grain-boundary phases and illustrate the principles of grain-boundary dopant segregation; these research will establish a theoretical basis for the precise control of the distributions of grain-boundary segregated phases, and will provide reliable theories for the fabrication of high-performance ceria-based electrolytes.

英文关键词： solid oxide fuel cells;ceramic electrolyte;ionic conduction;grain-boundary segregation