Investigations of Ni/(Sc)YSZ cermets for solid oxide cells (SOCs) were performed by electrochemical impedance spectroscopy (EIS), under varying experimental conditions and upon redox cycling, using three different designs of symmetric cells. The deconvolution and fitting of the obtained impedance spectra was performed using a combination of distribution of relaxation times (DRT) and complex non-linear least squares fitting routine (CNLS). The exhibited behaviours allowed the attribution of each contribution to a specific process, and correlated with production methods and microstructural parameters. Initial degradation results for both Ni/ScYSZ and Ni/YSZ based anodes under very high steam content are also reported. ©2010 COPYRIGHT ECS - The Electrochemical Society