Exploring the effect of a GDC adhesion layer on the performance and durability of Ni-GDC fuel electrode supported solid oxide electrolysis cells

Ni-GDC (Gadolinium-doped ceria) fuel electrode supported cells (FESC) are a promising alternative that could supersede Ni-GDC electrolyte supported cells (ESC) and Ni-YSZ FESC, given the perspectives of enhanced performance and long-term durability. One challenge in achieving competitive performance is the electrode-electrolyte interface. In this work, the reduction of the co-sintering temperature below 1300 °C and the addition of an adhesion layer (a layer between the fuel electrode and electrolyte) are used to improve the overall performance. Cells containing dense and porous adhesion GDC layers were fabricated and tested, demonstrating that a better interface contact reduces the interfacial polarization resistance associated with Ce-Zr interdiffusion. Additionally, a cell with a GDC fuel electrode was tested, showcasing high initial performance at 800 °C (0.38 Ω cm 2 ) for a nickel free functional layer. A cell with a dense GDC adhesion layer co-sintered at 1200 °C identified electronic conductivity of the support as a challenge when sintering at low temperatures. A long-term steam electrolysis test in galvanostatic mode at −0.5 A/cm 2 , unveiled a fast degradation rate (450 mV/kh) of a cell containing a dense GDC adhesion layer. The observed difference between this test and the long-term stability measured for Ni-GDC FESC without an adhesion layer warrants further analysis.