The AC impedance method, also known as electrochemical impedance spectroscopy (EIS), serves as an analytical technique for investigating hydration reaction mechanisms in electrochemical systems. This methodology involves applying small-amplitude sinusoidal AC voltage perturbations at varying frequencies to an electrochemical system while measuring the corresponding alternating current response. Alternatively, direct measurement of system impedance (or admittance) can be conducted to analyze hydration mechanisms. By establishing the correlation between perturbation signals and electrode system responses, the AC impedance characteristics of electrochemical systems can be determined. Based on these characteristics, an equivalent circuit model can be proposed according to the system’s intrinsic properties, thereby enabling the exploration of kinetic processes within the electrochemical system. Through analysis of AC impedance responses—particularly variations in equivalent circuit component parameters (including charge transfer resistance, double-layer capacitance, and diffusion coefficients during charge transfer)—kinetic parameters of the electrochemical system can be effectively estimated.