Inhibition of Ni Grain Growth in Ni-BCY Anode Substrate for Solid Oxide Fuel Cell

摘要

The growth of Ni grains in sintered 60wt%Ni-BCY anode supports for solid oxide fuel cells and their electrical conductivities were evaluated. The critical grain growth was confirmed in a Ni-BCY disk sintered at a temperature higher than 1450°C, resulting in a large degree of decline in electrical conductivity. In addition, reducing the Ni content in Ni-BCY did not effectively suppress the Ni grain growth. Addition of GDC into the Ni-BCY (Ni-BCY-GDC) was found to effectively inhibit the Ni grain growth after sintering at 1450°C, which remarkably enhanced the electrical conductivity compared with those of the Ni-BCY supports. Adding GDC into BCY simultaneously suppressed the grain growth of the BCY. The grain sizes of Ni are in a linear relationship with grain size over volume fraction (r/f) of the oxide phase, implying that the Ni grain growth was prevented by the pinning pressure from the oxide grains.