Preparation and properties of LSB-doped GDC electrolytes for intermediate temperature solid oxide fuel cells

摘要

A novel LSB-doped GDC (LGDC) electrolyte has been developed. Ce0.8Gd0.2O1.9 (GDC) and Bi0.775La0.225O1.5 (LSB) have been synthesized by a citric acid-nitrate sol-gel method and a conventional solid-state reaction method, respectively. A series of LGDC are fabricated by mixing nanosized GDC powder with 1, 3, 10, 15, and 20wt% of LSB at the sintering temperature of 1300 degrees C. The X-ray diffraction results indicate that all the LGDC electrolytes are single phase without any other impurity phases exist. The relative density of LGDC electrolytes firstly increases and then decreases when increasing the proportion of LSB. The ionic conductivity of 3LGDC (1.47x10(-2)Scm(-1)) is similar to 75% higher than that of GDC (8.38x10(-3)Scm(-1)) at 600 degrees C. The maximum power density of the single cells based on 10LGDC co-fired at 1300 degrees C can reach 655mWcm(-2) at 700 degrees C. This maximum power density is similar to 110% higher than that of the GDC-based cell. The introduction of LSB significantly improve the open cell voltages (OCVs) of the single cells. Moreover, the long-term stability is maintained up to more than 100h, demonstrating high stability of the LGDC electrolytes. Hence, we trust that this LGDC electrolytes can be chosen to a promising electrolyte for high-performance IT-SOFCs.