Investigation of shrinkage behavior of Ni–Fe bimetallic anode tube support and the densification of electrolyte using co-sintering temperature

NiO–Fe2O3/gadolinium-doped CeO2 (GDC), NiO–Fe2O3/yttria-stabilized ZrO2 (YSZ) anode supported fuel cells were fabricated at co-sintering temperatures of anode-electrolyte from 1250 °C to 1400 °C. The volumetric shrinkage of the anode-electrolytes and the porosity of the anode tube were studied systematically at different temperatures. 1300 °C is the marginal temperature to obtain sufficient electrocatalytic activity of electrodes, and a higher temperature is needed to suppress gas leakage through the scandia-stabilized zirconia (ScSZ) electrolyte. At each co-sintering temperature from 1250 °C to 1400 °C, the porosity of NiO–Fe2O3/GDC anode tubes is nearly 10% higher than that of NiO–Fe2O3/YSZ anode tubes. SEM results exhibited the anode-supported electrolyte tends to be more dense as co-sintering temperature increasing to 1400 °C from 1250 °C. However, the high co-sintering temperature of 1400 °C will result in low porosity of anode which negatively affected the power density.

► The OCV of the cells is linearly related to the tube diameter shrinkage degree, it reaches 1.1 V which basically equals to the Nernst voltage prepared at 1400 °C.
► At each co-sintering temperature from 1250 °C to 1400 °C, the porosity of NiO–Fe2O3/GDC anode tubes is nearly 10% higher than that of NiO–Fe2O3/YSZ anode tubes.
► In one-step sintering of anode tubes (/GDC or/YSZ) and ScSZ electrolyte, their volumetric shrinkage, porosity, and power performance were studied systematically at different temperatures.