Multiple cycle chromium poisoning and in-situ electrochemical cleaning of LSM-based solid oxide fuel cell cathodes
Zhikuan Zhu, Michelle Sugimoto, Uday B. Pal, Srikanth Gopalan, Soumendra N. Basu
Abstract
Electrochemical cleaning, a recently proposed mitigation strategy for chromium poisoning in solid oxide fuel cell (SOFC) cathodes, involves rapid in-situ removal of Cr2O3 deposits from LSM-YSZ cathodes accompanied by a recovery of a large fraction of the cell performance originally lost due to Cr poisoning. By operating the cell briefly as a solid oxide electrolyzer cell (SOEC), the cleaning method effectively reverses the Cr deposition reactions, reforming Cr-containing vapor species, thereby freeing up electrochemically active sites and restoring cell performance. In practice, this method can be periodically applied to the system after a specified amount of degradation due to chromium poisoning has occurred. The current study investigates the efficacy of this method by cycling a single cell through a stage of accelerated poisoning followed by electrochemical cleaning for a total of three times. Current-voltage measurements demonstrate repeated loss in performance due to Cr poisoning and recovery in performance due to electrochemical cleaning, reinforcing the utility of this cleaning method over the lifetime of the cell operation.