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 mu m) 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 degrees 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 degrees C, confirming dense and gas-tight GDC electrolytes. A promising polarization resistance of 0.15 Omega.cm(2) was obtained from the cold-sintered Ni-GDC anode at 750 degrees C.