A wet-chemical route for the preparation of Ni-BaCe_0.9Y_0.1O_{3 - δ} cermet anodes for IT-SOFCs

Nano-sized BaCe_0.9Y_0.1O_{3 - δ} (BCY10) protonic conductor powders were used to prepare Ni-BCY10 cermets for anode-supported intermediate temperature solid oxide fuel cells. A new wet-chemical route was developed starting from Ni nitrates as precursors for NiO. BCY10 powders were suspended in a Ni nitrate aqueous solution that was evaporated to allow NiO precipitation on the BCY grains, obtaining NiO-BCY10 cermets. To obtain the final Ni-BCY10 anodes, pellets were reduced in dry H₂ at 700 °C. The structural and microstructural properties of the pellets were investigated using X-ray diffraction analysis and field emission scanning electron microscopy. A homogeneous dispersion of perovskite and nickel phases was observed. The chemical stability of the anodes was evaluated under wet H₂ and CO₂ atmosphere at 700 °C. The electrical properties of the Ni-BCY10 pellets were evaluated using electrochemical impedance spectroscopy measurements. The Ni-BCY10 cermet electrodes showed large electronic conductivity, demonstrating percolation through the Ni particles, and low area specific resistance at the BCY10 interface. These characteristics make the cermet suitable for application in BCY-based protonic fuel cells. The developed chemical route offers a simple and low-cost procedure to obtain promising high performance anodes.