Mixed ion and electron conductive composites for single component fuel cells: I. Effects of composition and pellet thickness

Electrochemical performances of single component fuel cells (SCFCs) based on mixed ion and electron conductors have been studied as a function of composition and pellet thickness by polarization curves and electrochemical impedance spectroscopy. The electronic conductor of LNCZO shows conductivities of 21.7 and 5.3 S cm−1 in H2 and in air, respectively. SCFC using 40 wt. % of LNCZO and 60 wt. % of ion conductive SDC-Na2CO3 with a thickness of 1.10 mm shows the highest power density of 0.35 W cm−2 at 550 °C. The performance is correlated to the mixed conduction properties (ionic and electronic, p and n-type) and the microstructure of the functional SCFC layer.

► SCFCs are assembled by mixed ion and electron conductive composites. ► The performances are influenced by the composition and thickness of the pellets. ► A maximum power density of 350 mW cm−2 is achieved at 550 °C. ► The performance is correlated with the mixed conduction (ionic and electronic, p and n-type) properties and the porous microstructure.