表面偏析在固体氧化物燃料电池阴极/电解质界面形成和反应中的作用  

Role of Surface Segregation in the Cathode/Electrolyte Interface Formation and Reactions of Solid Oxide Fuel Cells

作　　者：何帅 邹远锋 蒋三平 HE Shuai;ZOU Yuanfeng;JIANG Sanping(Foshan Xianhu Laboratory of the Advanced Energy Science and Technology Guangdong Laboratory,Foshan 528216,Guangdong,China)

机构地区：[1]先进能源科学与技术广东省实验室佛山分中心暨佛山仙湖实验室,广东佛山528216

出　　处：《陶瓷学报》2023年第3期434-446,共13页Journal of Ceramics

基　　金：深圳市协同创新科技计划国际科技合作项目(GJHZ 20210705142006020)。

摘　　要：电极/电解质界面对高温固体氧化物燃料电池(SOFC)等电化学固态器件的性能和耐久性起着至关重要的作用。SOFC与液态电解质电池相比,SOFC的多孔电极和致密电解质之间的界面接触是不连续的,并且有显著的固体与固体(Solid-to-Solid,StS)接触特性。这种StS的接触特性在SOFC的表面偏析、电极/电解质界面和电极相界面反应性等现象中起到了关键作用,尤其是对于作为O_(2)还原反应、具有高混合离子和电子电导率和高活性等特点的钴基钙钛矿阴极材料。然而,对这些表界面现象的机理研究绝大部分集中在高温电极/电池烧结过程中所发生的钴基钙钛矿电极与氧化钇稳定的氧化锆(YSZ)基电解质之间的高反应活性现象。电极直接组装技术的开发避免了传统高温烧结带来的相关不利问题,同时科研人员进一步研究了在SOFC运行条件下的免烧结电极/电解质界面形成和反应现象。简要回顾了在SOFC运行条件下具有电子导电La_(0.8)Sr_(0.2)MnO_(3)和混合离子和电子导电的La_(0.6)Sr_(0.4)Co_(0.2)Fe_(0.8)O_(3-δ)免烧结钙钛矿电极与YSZ和掺钆氧化铈(GDC)电解质之间的极化、表面偏析和界面形成的基本原理和内在联系等的研究进展。明晰并理解电极/电解质界面的基本原理对于开发高性能和耐用的SOFC技术具有普遍且重要的意义。Electrode/electrolyte interface plays a critical role in determining the performance and durability of solid state devices,such as high temperature solid oxide fuel cells(SOFCs).Different from that in aqueous electrolyte cells,the interface between porous electrode and dense electrolyte is generally not continuous and typically shows the characteristics of solid-to-solid(StS)contact.Such StS contact is of critical role in surface segregation polarization,electrode/electrolyte interfaces and interphase reactivity of electrodes of SOFCs.This is particularly true for the cobaltite based perovskite materials,due to their high mixed ionic and electronic conductivity and high activity as cathodes for O_2 reduction reaction of SOFCs.However,the studies of such fundamental issues are largely limited by the high activity of cobaltite-based perovskites with yttria-stabilized zirconia(YSZ)based electrolyte during the high temperature electrode/cell sintering stages.Recently,direct assembly techniques were developed to study the electrode/electrolyte interface formation and reactions under SOFC operating conditions,which avoids the detrimental issues associated with the conventional high temperature sintering.This article is aimed to briefly review the advances in the fundamental understanding and intrinsic relationship between the polarization,surface segregation and interface formation under SOFC operation conditions on electronic conducting La_(0.8)Sr_(0.2)MnO_(3) and mixed ionic and electronic conducting La_(0.6)Sr_(0.4)Co_(0.2)Fe_(0.8)O_(3-δ)perovskite model electrodes and YSZ and gadolinium-doped ceria(GDC)electrolytes.The fundamental understanding of the electrode/electrolyte interface has general and significant implications for the development of high performance and durable SOFCs.

关 键 词：固体氧化物燃料电池 阴极 电极/电解质界面 表面偏析 极化 

分 类 号：TQ174.75[化学工程—陶瓷工业]