Preparation and power performance of single chamber SOFC based on LAMOX electrolyte

• Main Authors: Yu-Chen Chen, 陳育誠
• Other Authors: Dah-Shyang Tsai
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/15567790821316887942

碩士 === 國立臺灣科技大學 === 化學工程系 === 97 === Our purpose intends to develop SOFC single cell based on LAMOX electrolyte. In this study, La1.8Dy0.2Mo2-xWx (LDMW), 10mol% Gd doped CeO2 (GDC10), GDC10-Ni cermet composite and La0.6Sr0.4Co0.8Fe0.2 (LSCF6482) are electrolyte, cathodic diffusion barrier layer, anode and cathode respectively. Those anode- supported single cells were tested on the basis of single-chamber design. 350 sccm methane-air mixture supplied for electrochemical reactions was introduced into reactor. The effects on open circuit voltage (OCV) and maximum power density (MPD) via adjusting anode ratio, Rmix(the amount of CH4 / the amount of O2) and composition as well as thickness of electrolyte were investigated in this thesis. Materials microstructure and chemical compatibility were examined by SEM and XRD. XRD patterns show that no impurity phase forms between electrolyte and NiO at 1523K. Porosity in electrodes and similar configuration in each single cell can be seen in SEM image. As to the effect on OCV and MPD, the single cell supported by GDC : NiO (in wt%) = 40 :60 exhibits higher MPD than that of other ratios. For this single cell, the best performance takes place at 898K. Its OCV and MPD are 0.77V and 193mW cm-2 respectively. As to the effect on Rmix, the MPD of Rmix = 1 prevail to that of Rmix =2. Thickness and composition also deeply affect OCV and MPD. When electrolytes thickness are around 70μm, OCV of single cells increase with tungsten content in electrolyte yet MPD decrease with it. Working temperature increases with tungsten content in electrolyte as well. On the other hand, thinner electrolytes (~30μm) are applied on single cells, OCV of single cells still increase with W content in electrolyte. Additionally, their values are lower than that of thicker electrolyte. La1.8Dy0.2Mo1.6W0.4 and La1.8Dy0.2Mo1W1 single cells with thinner electrolytes promote MPD when temperature are 823K, 848K and 873K for La1.8Dy0.2Mo1.6W0.4 and 823K, 848K, 873K, 898K, 923K, 948K for La1.8Dy0.2Mo1W1. However, their performances are not better when temperatures are higher than 898K for La1.8Dy0.2Mo1.6W0.4 and 973K for La1.8Dy0.2Mo1W1.