The crystal structure and ionic conductivity of layered composite of SDC-YSZ-SDC

摘要

Research on the preparation of ceria based material for electrolyte of solid oxide fuel cell has been conducted. The Sm_(0.2)Ce_(0.8)O_(1.9) (SDC) was prepared by sol-gel method and the layered composites of SDC with Y_(0.08)Zr_(0.92)O_(3-δ) were prepared by screen printing method. This research aims to study the crystal structure and its conductivity character. XRD measurement equipped with Le Bail refinement shows that SDC is crystallized in cubic structure with space group of Fm3m. The addition of YSZ into SDC does not change its crystal structure. However, the cell parameter of SDC is reduced from 5.434036(2) A to 5.433(0) A. At 600°C, SDC has electronic conductivity that indicates the presence of electrons migration that can promotes short circuit during fuel cell operation. The combination of SDC with YSZ forming a layered composite of SDC-YSZ-SDC could reduce the electronic conductivity, even though its ionic conductivity is also become lower than single SDC at the same temperature.