Thin layer electrolyte impregnation into porous anode-supported fuel cell by ultrasonic spray pyrolysis

Abstract

An ultrasonic spray pyrolyzed thin layer electrolyte impregnates into a porous anode and extends the depth of triple phase boundaries (TPBs) to several times that of the dense thin layer thickness. This process, without an anode functional layer, improves the conventional repeated impregnation that results in anode porosity blocking and difficult extending to the anode/electrolyte interface. A (La0.75Sr0.2Ba0.05)(0.175)Ce0.825O1.981 (LSBC) electrolyte thin layer (iLSBC) is deposited on a porous La0.3Sr0.7TiO3 (LST) anode by ultrasonic spray pyrolysis using 0.1 M LSBC precursor at a substrate temperature of 450 degrees C, while controlling the solution flow rate and spray volume. The spray pyrolyzed iLSBC/LST half cells co-fired at 1350 degrees C/6 h exhibit no evident second phase in the X-ray diffraction analysis. The depth profile of iLSBC/LST indicates an approximately 2.75 mm-thick layer with the Ce element line scanning showing a significantly higher impregnation depth. Slight lattice distortion among the impregnated region may be due to the iLSBC diffusion, resulting in the extension of the TPB area and length. The half-cell reaches a low imped-ance and achieves a power density of 377 mW/cm(2) at 750 degrees C. (C) 2021 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.