%0 Journal Article
%A Wolf, Stephanie E.
%A Vibhu, Vaibhav
%A Tröster, Eric
%A Vinke, Izaak C.
%A Eichel, Rüdiger-A.
%A de Haart, L. G. J.
%T Steam Electrolysis vs. Co-Electrolysis: Mechanistic Studies of Long-Term Solid Oxide Electrolysis Cells
%J Energies
%V 15
%N 15
%@ 1996-1073
%C Basel
%I MDPI
%M FZJ-2022-02891
%P 5449
%D 2022
%X High-temperature electrolysis using solid oxide electrolysis cells (SOECs) is an innovative technology to temporarily store unused electrical energy from renewable energy sources. However, they show continuous performance loss during long-term operation, which is the main issue preventing their widespread use. In this work, we have performed the long-term stability tests up to 1000 h under steam and co-electrolysis conditions using commercial NiO-YSZ/YSZ/GDC/LSC single cells in order to understand the degradation process. The electrolysis tests were carried out at different temperatures and fuel gas compositions. Intermittent AC- and DC- measurements were performed to characterize the single cells and to determine the responsible electrode processes for the degradation during long-term operation. An increased degradation rate is observed at 800°C compared to 750°C under steam electrolysis conditions. Moreover, a lower degradation rate is noticed under co-electrolysis operation in comparison to steam electrolysis operation. Finally, the post-test analyses using SEM-EDX and XRD were carried out in order to understand the degradation mechanism. The delamination of LSC is observed under steam electrolysis conditions at 800°C, however, such delamination is not observed during co-electrolysis operation. In addition, Ni-depletion and agglomeration are observed on the fuel electrode side for all the cells.
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:000839683000001
%R 10.3390/en15155449
%U https://juser.fz-juelich.de/record/908877