Alternate Current Impedance Spectroscopy (ac-is or Is) of a Ceria Impedance Spectra of Mixed Conductors: a 2d Study of Ceria 2

In this paper we develop an analytical framework for the study of 2 electrochemical impedance of mixed ionic and electronic conductors 3 (MIEC). The framework is based on first-principles and it features 4 the coupling of electrochemical reactions, surface transport and bulk 5 transport processes. We utilize this work to analyze two-dimensional 6 systems relevant for fuel cell science via finite element method (FEM). 7 Alternate Current Impedance Spectroscopy (AC-IS or IS) of a ceria 8 symmetric cell is simulated near equilibrium condition (zero bias) for a 9 wide array of working conditions including variations of temperature 10 and H2 partial pressure on a two-dimensional doped Ceria sample 11 with patterned metal electrodes. The model shows agreement of IS 12 curves with the experimental literature with the relative error on the 13 impedance being consistently below 2%. Important two-dimensional 14 effects such as the effects of thickness decrease and the influence of 15 variable electronic and ionic diffusivities on the impedance spectra 16 are also explored. 17