Record-low sintering-temperature (600 degrees C) of solid-oxide fuel cell electrolyte

Abstract

One of the major problems arising with Solid-Oxide Fuel Cell (SOFC) electrolyte is conventional sintering which requires a very high temperature (> 1300 degrees C) to fully densify the electrolyte material. In the present study, the sintering temperature of SOFC electrolyte is drastically decreased down to 600 degrees C. Combinational effects of particle size reduction, liquid-phase sintering mechanism and microwave sintering resulted in achieving full density in such a record-low sintering temperature. Gadolinium doped Ceria (GDC) nano-particles are synthesized by co-precipitation method, Lithium (Li), as an additional dopant, is used as liquid-phase sintering aid. Microwave sintering of this electrolyte material resulted in decreasing the sintering temperature to 600 degrees C. Micrographs obtained from Scanning/Transmission Electron Microscopy (SEM/TEM) clearly pointed a drastic growth in grain-size of Li-GDC sample (similar to 150 nm) than compared to GDC sample (< 30 nm) showing the significance of Li addition. The sintered Li-GDC samples displayed an ionic conductivity of similar to 1.00 x 10(-2) S cm(-1) at 600 degrees C in air and from the conductivity plots the activation energy is found to be 0.53 eV. (C) 2016 Elsevier B.V. All rights reserved.