Electrochemical impedance spectroscopy (EIS) is one of the most powerful experimental methods to study electrochemical systems, and has been extensively used in the analysis of lithium battery systems, especially to determine kinetic and transport parameters, understand reaction mechanisms, and to study degradation effects in past two decades. In this paper, the electrode polarization process in lithium ion batteries which includes three basic physical and chemical processes, namely, electronic transport process, ionic transport process and electrochemical reaction process, is briefly described, and the EIS characteristics of each transport and reaction stage of the three basic physical and chemical processes are discussed, especially the mechanism of inductance formation and contact impedance is expounded in detail. Moreover, porous electrode theory and its application in lithium ion batteries are reviewed, and emphasis is put upon the principle and method of numerical simulation of impedance with physics-based lithium-ion batteries models. Furthermore, the typical EIS characteristics and the attribution of each time constant of the electrode materials for lithium ion batteries such as graphite, silicon, simple binary transition metal oxides, LiCoO₂, spinel LiMn₂O₄, LiFePO₄, spinel Li₄Ti₅O₁₂ and transition metal oxides are also discussed. Finally, the challenges currently faced by EIS are identified and possible directions and approaches in addressing these challenges are suggested.

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