Introducing an Electrochemical Impedance Spectroscopy Methodology based on Volterra Filters

The paper proposes a novel Electrochemical Impedance Spectroscopy methodology that takes into account the nonlinearties present in the battery. For this purpose, the current-voltage relationship of the cell is modeled in discrete domain as a Volterra filter and the linear part of the nonlinear model is efficiently estimated using Orthogonal Periodic Sequences. Preliminary experimental results involving six lithium-ion cells show the soundness of the proposed approach also in comparison with the classical method.