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中温固体氧化物燃料电池阳极基底及负载型电解质薄膜的研制

阎景旺; 董永来; 于春英; 江义   

  1. 中国科学院大连化学物理研究所 大连 116023
  • 收稿日期:2000-08-29 修回日期:2000-09-25 出版日期:2001-09-20 网络出版日期:2001-09-20

Fabrication and Characterization of Anode Substrates and Supported Electrolyte Thin Films for Intermediate Temperature Solid Oxide Fuel Cells

YAN Jing-Wang; DONG Yong-Lai; YU Chun-Ying; JIANG Yi   

  1. Dalian Institute of Chemical Physics; Chinese Academy of Sciences; Dalian 116023; China
  • Received:2000-08-29 Revised:2000-09-25 Published:2001-09-20 Online:2001-09-20

摘要: 在用固相反应法合成电解质材料La0.9Sr0.1Ga0.8Mg0.23-δ(LSGM)的基础上,研制出中温固体氧化物燃料电池LSGM+NiO阳极基底;考察了阳极基底孔隙率、孔径分布及电导率随组成变化的规律;研究了阳极基底组成、微观结构、制备工艺等对负载型LSGM电解质薄膜成膜过程及质量的影响和负载型电解质薄膜在还原气氛中的结构稳定性;采用湿化学物理方法及等静压烧结工艺成功地制备出了厚度为20~50μm的负载型致密LSGM电解质薄膜.研究表明;NiO含量为60%的阳极基底具有适宜的烧结收缩率、孔隙率与孔径分布,且比表面积与比孔容积均较大,适合作为SOFC的阳极.随着NiO含量的增加,还原后阳极基底的电导率有所增大.其中低NiO含量的阳极基底在还原后的初生态,其电导率在交变信号的诱导下发生弛豫现象而迅速增大,并由离子导电性转变为金属导电性.而高NiO含量的阳极基底,其还原后的电导率随测量时间的延长变化很小,并从一开始就表现出金属导电的性质.采用无约束烧结程序制备的负载型LSGM电解质薄膜,表面为粗大的片状晶粒,还原后在晶界处产生裂纹.而采用等静压烧结程序制备的负载型LSGM电解质薄膜,表面为细小、形状规则的晶粒, 晶界结合紧密, 且还原后晶界无裂纹出现.

关键词: 温固体氧化物燃料电池, 阳极基底, 电解质薄膜, LSGM

Abstract: LSGM+NiO anode substrates for intermediate temperature solid oxide fuel cells were fabricated and the
relationships between porosity, pore radii distribution, electrical conductivity of the substrate and its composition were studied. Effects
of the substrate composition, microstructure, fabrication process on the formation process, quality and structure stability of the supported
LSGM thin films were investigated. Based on these works, we successfully made a dense supported LSGM thin film with a thickness of 20-50μm
using a costly effective wet chemical-physics method. Anode substrate with 60% NiO possesses preferable sintering-shrinkage rate, porosity and pore
radii distribution. Its specific pore surface area and specific pore volume are also larger. Electrical conductivity of reduced anode substrates
increases with NiO content in the substrates. Electrical conductivity of reduced anode substrates with low NiO content increases rapidly with ac
impedance measuring time and changes from electronic conduction to ionic conduction. Electrical conductivity of substrates with high NiO content
changes very slow with measuring time, showing metal conducting property and very high electrical conductivity from the beginning. On the surfaces
of supported LSGM thin films fabricated by non-restraint sintering method, large flat grains can be seen and cracks appear along grain boundaries after
reduction in H2. On the surfaces of supported LSGM thin films fabricated by isostatic-pressure sintering method, just small grains with even crystal
sizes which contact with each other tightly can be seen and after reduction in H2, no cracks appear on grain boundaries.

Key words: intermediate temperature solid oxide fuel cell, anode substrate, electrolyte thin film, LSGM

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