Thin-film solid oxide fuel cells on porous nickel substrates with multistage nanohole array

A novel support/electrode/catalyst structure for a low-temperature thin-film solid oxide-fuel cell SOFC is fabricated using a two-step replication process. This so-called "multistage nanoporous" nickel substrate has channels connecting both sides of the substrate. The channel diameter gradually changes from about 20 nm to about 200 nm through the thickness. During fabrication, an anodic aluminum oxide (AAO) with a multistage nanopore structure is used as a template. The multistage pore structure is then filled with PMMA syrup to obtain the negative geometry. The filled PMMA syrup is UV cured, and the subsequent removal of AAO in a basic solution completes the negative structure. The final structure is obtained by nickel electroplating on the negative structure followed by the removal of the negative structure in an organic solvent. A thin-film SOFC with a 200 nm thick yttria stabilized zirconia (YSZ) is fabricated on the nanoporous substrate and the cell is operated at a low temperature range, between 370-550 degrees C. The maximum output power density of 7 mW/cm(2) is obtained at 400 S C. (c) 2006 The Electrochemical Society.