Effect of cerium addition to Ni–Cr anode electrode for molten carbonate fuel cells: Surface fractal dimensions, wettability and cell performance

Abstract

The geometrical and chemical effects of cerium (Ce) addition to Ni–Cr anode electrode in molten carbonate fuel cells (MCFCs) were investigated by measuring the fractal dimensions and wettability of four types of anode electrode with Ce added up to 5 wt.%. In addition, their cell performances were investigated through a single cell operation test and their results were explained based on the wettability of the anode electrodes. The addition of Ce to the anode electrode increased the fractal dimensions and wettabilities of the electrodes. Despite the even larger electrical resistivity of Ce compared to that of Ni and Cr, the electrical resistances of the Ce-added anode electrodes were slightly increased with increasing level of Ce addition. This might be ascribed to the greater wettability of the Ce-added anode electrode that enhanced the cell performance. Therefore, the greater wettability of the Ce-added anode electrode might compensate for its relatively larger electrical resistance. Considering these results, more stable cell operation with a longer potential lifespan was achieved with the Ce (3 wt.%)-added, Ni (90 wt.%)–Cr (7 wt.%) anode electrode, compared to those of the Ce-free Ni–Cr anode electrode.