Influence of particle size and agglomeration in solid oxide fuel cell cathodes using manganite nanoparticles

TL;DR

This study investigates how particle size and agglomeration affect the performance of La0.8Sr0.2MnO3 nanoparticle cathodes in solid oxide fuel cells, highlighting the importance of particle deagglomeration and sintering conditions.

Contribution

It demonstrates that particle deagglomeration improves cathode performance and explores the complex relationship between particle size, agglomeration, and sintering temperature.

Findings

Deagglomeration enhances cathode performance.

Largest sintering temperature correlates with lowest resistance.

Performance dependence on particle size varies with synthesis route.

Abstract

In this work we studied the influence of particle size and agglomeration in the performance of solid oxide fuel cell cathodes made with nanoparticles of La0.8Sr0.2MnO3. We followed two synthesis routes based on the Liquid Mix method. In both procedures we introduced additional reagents in order to separated the manganite particles. We evaluated cathodic performance by Electrochemical Impedance Spectroscopy in symmetrical (CATHODE/ELECTROLYTE/CATHODE) cells. Particle size was tuned by the temperature used for cathode sintering. Our results show that deagglomeration of the particles, serves to improve the cathodes performance. However, the dependence of the performance with the size of the particles is not clear, as different trends were obtained for each synthesis route. As a common feature, the cathodes with the lowest area specific resistance are the ones sintered at the largest temperature. This result indicates that an additional factor related with the quality of the cathode/electrolyte sintering, is superimposed with the influence of particle size, however further work is needed to clarify this issue. The enhancement obtained by deagglomeration suggest that the use of this kind of methods deserved to be considered to develop high performance electrodes for solid oxide fuel cells.