Electrochemical performance of Ni-based anodes for solid oxide fuel cells

The catalytic activity of Ni-based anodic materials was investigated in complete solid oxide fuel cells (SOFCs) by electrochemical analysis. Button cells, consisting of supporting yttria-stabilized zirconia (YSZ) electrolyte layer, (La1-xSrx)(y) MnO3 (LSM) cathode and (cermet) Ni0.5Co0.5-YSZ anode were employed. Powders for anodes were obtained by wet impregnation. This procedure allowed easy production of composite electrodes with homogeneous distribution of phases and controlled microstructure. Two electrodes impedance spectroscopy was carried out at different temperatures and partial pressures of reacting gases in order to evaluate contribution of each component to overall cell losses. Current-voltage characteristic curves were also collected. Feeding with CH4 was tested and compared to H2. No deterioration of cell performance due to carbon formation at anode was observed over a test period of 100 h.