Lowering the sintering temperature of solid oxide fuel cell electrolytes by infiltration

Abstract

A dense electrolyte with a relative density of over 95% is vital to prevent gas leakage and thus the achievement of high open circuit voltage in solid oxide fuel cells (SOFCs). The densification process of ceria based electrolyte requires high temperatures heat treatment (i.e. 1400-1500 °C). Thus, the minimum co-sintering temperatures of the anode-electrode bilayers are fixed at these values, resulting in coarse anode microstructures and consequently poor performance. The main purpose of this study is to densify gadolinia doped ceria (GDC), a common SOFC electrolyte, at temperatures lower than 1400 °C. By this aim, an approach involving the infiltration of polymeric precursors into porous electrolyte scaffolds, a method commonly used for composite SOFC electrodes, is proposed. By infiltrating polymeric precursors of GDC into porous GDC scaffolds, a reduction in the sintering temperature by at least 200 °C is achieved with no additives that might affect the electrical properties. Energy dispersive x-ray spectroscopy line scan analyses performed on porous GDC scaffolds infiltrated by a marker solution (polymeric FeOx precursor in this case) reveals a homogeneous infiltrated phase distribution, demonstrating the effectiveness of polymeric precursors.

Effect of electrolyte thickness manipulation on enhancing carbon deposition resistance of methane‐fueled solid oxide fuel cell

“…SOFC membrane is required to have tight electrolyte layer to avoid fuel crossover as supported by Sındırac et al 26 which found that dense electrolyte structure was able to provide good gas‐tightness property, preventing fuel crossover. Thus, nitrogen gas permeation test was performed to examine the effect of electrolyte thickness with different co‐sintering temperature toward the tightness property of that membrane.…”

“…The increment of sintering temperature promoted the fusion and bonding of the cermet particles which led to the higher value of mechanical strength and gave advantage in term of the toughness of the HFs. 12 SOFC membrane is required to have tight electrolyte layer to avoid fuel crossover as supported by Sındırac et al 26 which found that dense electrolyte structure was able to provide good gas-tightness property, preventing fuel crossover. Thus, nitrogen gas permeation test was performed to examine the effect of electrolyte thickness with different co-sintering temperature toward the tightness property of that membrane.…”

Effects of electrospraying parameters on deposition of La0.3Sr0.7Fe0.7Cr0.3O3−δ cathode layer on GDC

“…Ethylene glycol (C 2 H 6 O 2 , Merck >99.0%) was then slowly added into this solution until all polymerization and evaporation processes were completed. Finally, the precursor solution was diluted with ethylene glycol monobutyl ether (C 6 H 14 O 2 , Merck >99%) (1:1 weight ratio) to reduce the surface tension and also to enhance the wetting properties of the polymeric precursor 49–51 . This last reagent was added to the solution to reach the desired final salt concentration of ions (i.e., .004 and .01 M).…”

Microstructural investigation of the effect of electrospraying parameters on LSCF films

“…Further, the effect of the use of this i n t e r n a t i o n a l j o u r n a l o f h y d r o g e n e n e r g y 4 5 ( 2 0 2 0 ) 3 5 1 3 9 e3 5 1 4 8 new solvent is discussed by looking into how it affects the resulting cathode layer coating micro-structure. In the recent years, some significant and promising results were achieved via methods which used polymeric precursor method with this solvent couple [50,52]. Therefore, it is well worth to investigate this solvent couple, whether it can be successfully used in ESD.…”