Fabrication and characterization of a tubular solid oxide fuel cell with impregnated perovskite electrodes

The tubular cells were produced by a simple and inexpensive method, suitable for mass production. A porous YSZ backbone was co-cast with a thin layer of YSZ electrolyte over it. After rolling in tubular shape and co-sintering, the porous backbone was impregnated with functional perovskite materials, the nickel doped lanthanum calcium titanate LCNT (La0.43Ca0.37Ni0.06Ti0.94O3- γ) for the fuel side and the lanthanum strontium ferrite LSF (La0.8Sr0.2FeO3) for the air electrode. The LCNT perovskite was proposed as the alternative fuel electrode due to its mixed ionic and electronic conductivity (MIEC) properties and catalytical activity supplemented by exsolved Ni nanoparticles. The electrochemical poling at high potential, so-called 'switching', can increase the activity of LCNT due to facilitated reduction and exsolution. After switching at 2.1 V for 2 min, the tubular cell performance in fuel cell mode increased threefold. The impedance analysis indicated a reduction of ohmic and polarisation resistance on the whole frequency range and facilitated electrode kinetics under applied voltage.