摘要
固体电极对于制备可实现高效能源转换和气体排放控制的固体氧化物器件具有重要意义。固体氧化物电极广泛用于固体氧化物燃料电池和电解池,然而其高温可靠性不完全令人满意。由铂(Pt)和氧化钇稳定的氧化锆(yttria stabilized zirconia,YSZ)制成的复合电极Pt/YSZ已广泛应用在氧气和氮氧化物(NOx)气体传感器上,即使在恶劣条件下其也表现出良好稳定性。常规Pt/YSZ电极Pt含量较高,增加了材料成本。本文旨在开发一种基于Pt、钆掺杂的氧化铈(10 mol%gadolinia doped ceria,GDC10)和氧化钇稳定的氧化锆(5 mol%yttria stabilized zirconia,5YSZ)的三组分固体电极,同两组分的Pt/YSZ电极相比,三组分电极Pt/5YSZ/GDC10的极化电阻和Pt含量都较低。在该三组分电极中,5YSZ可强化电极同5YSZ电解质间的连接,电极最佳组分(Pt/5YSZ/GDC10)配比为1:1:1。通过引入适当石墨,可以进一步降低电极铂含量,同时可以达到更低的极化电极电阻。石墨最佳添加量在10-30wt.%。电极进行SDC20浸渍处理可显著提升其电性能。浸渍后的电极对温度变化更敏感,活化能为100-120 k J·mol^(-1)。电极同电解质共烧与二者单独烧结相比,前者的电极电阻稍高。
Solid electrodes are of importance to fabricate solid oxide cells for high efficiency energy conversion and emission control purpose. Oxide electrodes are widely studied for solid oxide fuel cells （SOFCs） and electrolysis cells （SOECs）, though their reliability are not fully satisfactory at elevated temperature. On the other hand, the composite electrodes made of platinum and yttria stabilized zirconia （YSZ） have been widely used in oxygen and nitrogen oxides （NOx） sensors for emission control, showing satisfactory endurance under harsh conditions. The normal Pt/YSZ electrodes contains relatively high Pt content, meaning higher material cost. The study thus aims at developing a three-component solid electrode consisting of platinum, 10 mol% gadolinia doped ceria （GDC10） and 5 mol% yttria stabilized zirconia （5YSZ）, which can realize reduced both polarization resistance and platinum load, compared to the binary electrodes of Pt/YSZ. In these three-component electrodes, 5YSZ in electrode can enhance the contact with 5YSZ based electrolyte and the optimal ratio of Pt/5YSZ/GDC10 is 1 ： 1 ： 1. The platinum load can be further reduced by properly introducing graphite while even lower electrode resistance can be reached. The optimal graphite content lies in the range of 10-30wt%. Electrode impregnation improve electrode performance remarkably. The impregnated electrode in general is more sensitive to temperature change with the activation energy of 100-120 kJ·mol^-1. The co-fired electrode along with electrolyte has slightly higher resistance compared to its separately fired counterpart.
作者
孙小毛
林今
邢学韬
龚靖博
周友
牟树军
刘长军
刘兴勇
胡强
Xiaomao Sun;Jin Lin;Xuetao Xing;Jinbo Gong;You Zhou;Shujun Mu;Changjun Liu;Xingyong Liu;Qiang Hu(School of Chemical Engineering,Sichuan University Of Science ＆ Engineering,Zigong 643000,China;Department of Electrical Engineering,Tsinghua University,Beijing 100084,China;National Institute of Clean and low carbon energy,Beijing 102211,China;School of Chemical Engineering,Sichuan University,Chengdu 610065,China;Sichuan Energy Internet Research Institute,Tsinghua University,Chengdu 610000,China)
出处
《陶瓷学报》
CAS
北大核心
2018年第3期345-353,共9页
Journal of Ceramics
基金
received financial supports from Innovation Seedling Projects of Zigong City (2017CXM02)
Key R&D Program of Sichuan Province (2017GZ0391)
National Key Research and Development Program (2016YFE0102600)
