THE EFFECTS OF NICKEL-OXIDE CATHODE DISSOLUTION ON MOLTEN CARBONATE FUEL-CELL LIFE

The dissolution of lithiated nickel oxide cathodes results in a transport of nickel into the fuel cell matrix and can result in an electronic short circuit between the electrodes. A theoretical analysis was developed for this process, accounting for the dissolution, diffusion, transference, and convection of nickel. Experimental data obtained on post-test nickel content in matrices and shorting time were found to be correlated by this theory, except for a current density effect that was underpredicted. This poor prediction of the current density effect is postulated to be caused by cation segregation during cell operation. These results enable the estimation of matrix nickel content and shorting time as a function of cell design and operating conditions.