Quantitative Characterization of the Microstructure-Property Relationships in Ni and MIEC Nanocatalyst-Infiltrated Ni/YSZ Anodes

Abstract

The performance of solid oxide fuel cell (SOFC) anodes infiltrated with different nanocatalysts are compared. In traditional Ni/YSZ cermet anodes, reactions occur at triple phase boundaries (TPBs). Infiltration of Ni nanoparticles increases the TPB density. However, unless the added TPBs created by infiltration have electronically conducting pathways to the percolated Ni in the Ni/YSZ cermet, the added TPBs are not electrochemically active. Different strategies to activate these added TPBs by providing such a conducting pathway, have been explored. These include, spreading the Ni nanoparticles to form a percolating network at temperature, co-infiltration of Ni with GDC, a mixed ionic and electronic conducting (MIEC) phase, and doping the YSZ in the Ni/YSZ cermet to promote electronic conductivity between the Ni nanoparticles. Electrochemical I-V and EIS studies of full and symmetric cells, SEM analysis of fracture cross-sections of infiltrated cells, and FIB-SEM based 3-D reconstruction of the infiltrated microstructures will be discussed.