Co-Sintering of Anode, Electrolyte, and (Ce 0.9 Gd 0.1 )O 2− δ Barrier Layer to Enhance Performance of Electrolyte-Supported Solid Oxide Fuel Cells

This study demonstrates the effectiveness of a low-temperature co-sintering approach for electrolyte-supported solid oxide fuel cells (SOFCs), conducted without using any sintering aid that could reduce the ionic conductivity of YSZ. Highly milled gadolinium-doped ceria ((Ce 0.9 Gd 0.1 )O 2− δ , CGO) and yttria-stabilized zirconia–nickel oxide (YSZ–NiO) powders played a critical role in promoting YSZ densification. Intensive milling significantly enhanced the shrinkage of both CGO and YSZ–NiO composite powders, which assisted the densification of the YSZ layer positioned between the CGO and YSZ–NiO layers. This process enabled the formation of dense and gas-tight YSZ and CGO layers at unusually low sintering temperatures, down to 1250 °C. Such a low sintering temperature suppresses the interdiffusion of cations between the YSZ and CGO layers and reduces the ohmic resistance. The co-sintered anode structure exhibited a fine-grained, well-connected morphology, uniform nickel dispersion, and excellent interfacial bonding between the anode and YSZ electrolyte, which improved the overall anode performance. Symmetric half-cell impedance analysis accurately predicted full-cell performance, confirming the reliability and effectiveness of this low-temperature co-sintering strategy.