Crystal structure of perovskite oxides and its correlation with transport properties for solid oxide fuel cells

NAPOLITANO, FEDERICO R.; TROIANI, HORACIO E.; FIGUEROA, SANTIAGO J. A.; ARCE, MAURICIO D.; SALETA, MARTÍN E.; A. SERQUIS; BASBUS, JUAN F.; CUELLO, GABRIEL J.; MOGNI, LILIANA V.

Curitiba

Congreso; 24 ABCr meeting; 2019

Associação Brasileira de Cristalografia

The development of clean energy technologies requires to improve the efficiency of electrical systems. For several years, our group has been studying materials based on non-stoichiometric oxides to be used in devices for generating clean and sustainable energy such as solid oxide cells (SOC) in their fuel or electrolyzer modes (SOFC or SOEC). ABO3 perovskites oxides provides a very versatile structure, where a large variety of atoms can be included into the A or B sites through distortions of the ideal cubic structure. This characteristic allows the tuning of particular properties that could be relevant for certain applied interest. Due to the strong relationship between the crystallographic structure and the defects with the electronic and transport properties of these materials, it is necessary to explore them with numerous complementary techniques, and simulating operating conditions in order to correlate their characteristics with the properties of interest (properties of transport, thermal, electrochemical, etc.). In this talk I will show some examples of systems in which the correlation between the micro / nanostructural aspects (determined by the processing parameters) and the physical properties that determine the efficiency of some SOC components. In particular, I will present some results regarding two systems: La0.4Sr0.6Ti1-yCoyO3-δ (LSTC) and BaCe0.4Zr0.4Y0.2O3-δ (BCZY) perovskites, which present interesting correlations between the crystallographic and electronic structure with the catalytic activity. LSTC is a good candidate for symmetrical SOC electrodes [1] and BCZY, which is proposed as a potential PC-SOFC electrolyte [2] due to its high bulk protonic conductivity.Figure 2: Simultaneous data acquisition of BCZY: Conductivity (above) and lattice parameter (below) obtained from Impedance Spectroscopy (IS) and Synchrotron-XRD simultaneous measurements as function of temperature.The results include in-situ and in-operando measurements of these oxides both in the laboratory and in large facilities such as synchrotron or neutron sources. All these studies are necessary to find the ideal combination of materials (and synthesis processes) that optimize their performance and long-term stability, to be used in applications.