Impregnated nickel anodes for reduced-temperature solid oxide fuel cells based on thin electrolytes of doped LaGaO3

Highly active Ni-cermet anodes for thin La0.9Sr0.1Ga0.8Sr0.2O3-δ (LSGM) electrolyte solid oxide fuel cells are fabricated by impregnating aqueous nickel nitrate solutions into porous LSGM backbones, followed by calcinations at 700 °C. High Ni loadings, e.g., VNi = 7.9%, are mandatory for obtaining well-interconnected Ni coatings on the internal surfaces of the supporting LSGM structures, where good chemical compatibility is confirmed by the X-Ray diffraction patterns. The polarization resistances are impressively low for the VNi = 7.9% anodes in humidified hydrogen, ranging from 0.008 Ω cm2 at 650 °C to 0.011 Ω cm2 at 550 °C. Thin LSGM electrolyte fuel cells, impregnated with Ni anodes and Sm0.5Sr0.5CoO3−δ–Ce0.8Sm0.2O1.9 (SSC – SDC) cathodes, exhibit superior power densities at reduced temperatures, e.g., 1.60 and 1.05 W cm−2 at 650 and 550 °C, respectively. ► Dual-scale porous Ni–LSGM composites are fabricated using impregnation method. ► Low ASR values of 0.011 Ω cm2 are obtained at 550 °C for the Ni–LSGM composite anodes. ► Power densities of 1.05 W cm−2 are obtained at 550 °C for LSGM-electrolyte fuel cells.