Economical preparation and characterization of dual-ion conducting fuel cell

Abstract

The composites consisted of oxygen ion conductive (La0.75Sr0.2Ba0.05)0.175Ce0.825O1.891 (LSBC) and proton conductive BaZr0.1Ce0.7Y0.2O3-d (BZCY) prepared by solid state reaction and impregnation are sintered to form composite and phase gradient membranes, respectively. The conductivity of (100-x)LSBC-xBZCY composite membranes exhibit non-ohmic in air and semiconductive diode behavior in Ar/5%H2 higher than 500 degrees C. The elemental concentration gradient of Ba, Ce and O at grain boundaries of LSBC/BZCY corresponds to the inter-diffusion and Schottky barrier formation. The Schottky barrier of dual phase boundary (DPB) may be beneficial for dual-ion conduction. The microstructures of sintered and polished (100-x)LSBC-xBZCY surface exhibit convex hard LSBC and concave soft BZCY. The percolated 70LSBC-30BZCY of the composite membrane obtains the power density of 20.51 mW/cm2. The phase gradient membrane of BZCY impregnated LSBC presents the higher power density of 40.6 mW/cm2 (700 degrees C). The new two-phase composite and phase gradient membranes generate more simple and compact layer structure than sandwiched solid oxide fuel cell. Such two-phase dual-ion membranes provided by our economical process can be considered to develop new single membrane fuel cells possibly. (c) 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.