INTEGRATED FABRICATION PROCESS FOR SOLID OXIDE FUELCELLS USING HYBRID PLASMA SPRAYING

Abstract

This study was aimed at developing a novel integrated fabrication process for solid oxide fuel cells (SOFC) with hybrid plasma spraying (HYPS). HYPS makes it possible to obtain not only very dense yttria stabilized zirconia (YSZ) films as solid electrolytes, but also porous Ni-YSZ cermets as fuel electrodes and porous La1-xSrxMnO3 (LSMO) films as air electrodes. The quality of each film was examined individually and the electrical conductivity of the Ni-YSZ and LSMO electrodes was measured. The fabrication of the entire SOFC by using exclusively HYPS was then demonstrated. Initially, a 2 mm thick fuel electrode of Ni-YSZ cermet was formed on a boron-nitride substrate, which could be easily removed alter deposition. The electrolyte (YSZ) and the air electrode (LSMO) were then successively deposited on the self-supporting cermet. By this method, the sintering step necessary in the conventional SOFC processing can be omitted, and SOFC cells can be fabricated using only spraying process. The technical feasibility of the novel SOFC processing was clearly demonstrated by an excellent cell performance. It showed an open circuit voltage (O.C.V.) value of 1.01 V and a power density of 7.3 × 103 W/m2.