Operando odd random phase electrochemical impedance spectroscopy for in situ monitoring of the anodizing process

Electrochemical impedance spectroscopy (EIS) is a versatile technique to characterize electrochemical systems satisfying causality, linearity and stationarity requirements. Odd Random Phase multisine EIS (ORP-EIS) can measure time-varying impedances for non-stationary processes. In this work, operando ORP-EIS introduced monitor the anodizing of aluminum, which nonlinear process, by superimposing AC perturbation signal on DC potential. Results show that does not disturb growth oxide film. Moreover, makes it possible follow barrier layer provides an opportunity investigate processes like ion adsorption, incorporation movements through during anodizing. These cannot be studied conventional EIS.