Síntese e caracterização dos compostos de BaCo0,4Fe0,4Zr0,1Y0,1O3-δ e BaCo0,4Fe0,3Zr0,1Y0,1Er0,1O3-δ para aplicação como cátodo em célula a combustível de óxido sólido com condutividade protônica

Abstract

Solid oxide fuel cells (SOFC) generate electrical energy through electrochemical processes and represent a sustainable alternative to fossil fuels. However, the high operating temperature of these devices (800-1000°C) affects the availability of candidate materials to be used, in addition to increasing processing requirements, resulting in higher manufacturing costs. Seeking to overcome this problem, researchers have turned their attention to the development of proton ceramic fuel cells (PCFC), which can operate at temperatures around 600°C. Recently, studies have focused on proton cathodes with triple conductivity for O-2, H+ ions and electrons, which have the capacity to increase the electrode/electrolyte electrochemical reaction sites, enhancing the cell efficiency. In this segment, the BaFe0.4Co0.4Zr0.1Y0.1O3-δ (BCFZY) compound has emerged as a promising candidate to act as a triple conductivity cathode. In this study, cathodes of BCFZY and BaCo0.4Fe0.3Zr0.1Y0.1Er0.1O3-δ (BCFZYE) were fabricated using the mixed oxide synthesis route. The best conductivity and activation energy values occurred in an oxidizing atmosphere, with values around 0.12 S/cm and 0.04 eV for both studied compounds. The erbium-containing compound showed more favorable results in a nitrogen atmosphere under humid conditions. An ASR value of 0.04 Ω.cm2 was obtained for the studied compounds, indicating low polarization resistance for the transport of electric species