Effect of sintering procedures in development of LiCoO2-cathodes for the molten carbonate fuel cell

LiCoO2-powder was synthesized from carbonate precursors by calcination in air. Greentapes were tape-cast using a non-aqueous slurry and 10 μm plastic spheres as pore formers. Sintering was carried out in air at 850–950°C and in argon/air at 500/750°C. The two sintering procedures led to very different sub-micron morphologies, with the primary particles being much smaller in the latter case. The electrochemical performance at 650°C, in terms of overpotential at 160 mA/cm2, for the air- and argon/air-sintered electrodes was 57 and 81 mV, respectively. The potential drop due to contact resistance between electrode and current collector was estimated to be 100 and 70 mV, respectively. The electrode materials were characterized by scanning electron microscopy (SEM), Hg-porosimetry, the BET-method (N2-adsorption), X-ray diffractometry (XRD), flame atomic absorption spectrometry (F-AAS), carbon analysis and a van der Pauw conductivity measurement set-up.