Nanostructured LnBaCo2O6-d (Ln = Sm, Gd) with layered structure for Intermediate Temperature SOFC cathodes

TL;DR

This study introduces nanostructured layered LnBaCo2O6-d perovskites as promising intermediate temperature SOFC cathodes, demonstrating improved electrochemical performance through novel synthesis and pore size optimization.

Contribution

First synthesis and evaluation of nanostructured LnBaCo2O6-d cathodes with porous templates for SOFCs, showing enhanced electrochemical properties.

Findings

Sm-based cathodes outperform Gd-based ones.

Smaller template pores lead to better performance.

Nanostructuring reduces area-specific resistance.

Abstract

We evaluated for the first time the use of nanostructured layered perovskites of formulae LnBaCo2O6-d with Ln = Sm and Gd (SBCO and GBCO, respetively) as SOFC cathodes, finding promising electrochemical properties in the intermediate temperature range (~700{\deg}C). The synthesis of these nanomaterials, not reported before, was achieved by using porous templates to confine the chemical reagents in regions of about 200 nm and 800 nm. The performance of nanostructured SBCO and GBCO cathodes for the oxygen reduction reaction was analyzed in symmetrical cells using Gd2O3-doped CeO2 (GDC) as electrolyte. For this purpose, nanostructured SBCO and GBCO cathodes were deposited on both sides of the electrolyte by a simple thick-film procedure and evaluated by Electrochemical Impedance Spectroscopy technique under different operating conditions. We found that cathodes synthesized using smaller template pores exhibited better performance. Besides, SBCO cathodes displayed lower area-specific resistance than GBCO ones.