Effect of cold sintering on the sintering shrinkage matching of NiO-GDC anode with GDC electrolytes in making anode-supported solid oxide fuel cells

Abstract

This study presents the co-sintering of anode-supported GDC/NiO-GDC Solid Oxide Fuel Cells (SOFCs) prepared by the Cold Sintering Process (CSP). A layer (<100 μm) of GDC electrolyte powders was first spread on a circular piece of filter paper cut at the die punch diameter size, then put on a relatively thick, porous NiO-GDC anode powder before CSP. The bi-layer was first cold-sintered at room temperature (RT), a very rare case in the literature, and then post-sintered at 1100 °C, which was much lower than the ones reported in the literature by using conventional furnaces. In the end, GDC electrolyte densities were found to be between 95 and 97% of their theoretical value while the NiO-GDC anode was sintered to gain mechanical strength but remained porous as desired. SOFCs constructed from these cold-sintered GDC/NiO-GDC bilayers exhibited an open circuit potential of 0.85 V at 750 °C, confirming dense and gas-tight GDC electrolytes. A promising polarization resistance of 0.15 Ω.cm2 was obtained from the cold-sintered Ni-GDC anode at 750 °C.