Journal
JOURNAL OF POWER SOURCES
Volume 555, Issue -, Pages -Publisher
ELSEVIER
DOI: 10.1016/j.jpowsour.2022.232400
Keywords
SOFC; Long-term degradation; PLD diffusion barrier layer; Post-mortem characterisation; YSZ-CGO interdiffusion; Cathode destabilisation
Ask authors/readers for more resources
This article investigates the electrolyte-cathode interfaces in solid oxide fuel cells and presents advanced post-mortem characterization of different cell types. It is found that the barrier layer deposited by pulsed laser deposition (PLD) remains stable, prevents the formation of insulating phases, and avoids fracture, in contrast to the screen-printed barrier layers.
Electrolyte-cathode interfaces are critical regions of solid oxide fuel cells where important degradation phe-nomena are localized due to cation interdiffusion and reactivity. State-of-the-art barrier layers deposited by screen-printing are not fully blocking, resulting in the formation of insulating phases such as SrZrO3. This article is the continuation of a previous work where a dense gadolinium doped ceria (CGO) barrier layer deposited by pulsed laser deposition (PLD) was optimized and deposited on large-area cells (80 cm2) (Morales et al., 2018) [1]. Those cells, together with reference cells made with CGO screen-printed barrier layers were operated in the same stack for 14000 h during two years. In this work, advanced post-mortem characterisation of the cells is presented showing important microstructural differences between the two types of cell. Operated reference cells present formation of SrZrO3 and cathode demixing, as observed in previous works. Moreover, the generation of a fracture parallel to the barrier layer inside the electrolyte is reported, which is compatible with the coalescence of Kirkendall voids formed at the diffusion front of the Gd/Ce cations into the electrolyte. In contrast, the PLD barrier layer remains stable, avoids the formation of insulating phases and prevents the formation of the mentioned fracture.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available