전기화학적 모델을 이용한 리튬이온 배터리셀의 주파수 분석

Abstract

A battery frequency domain analysis is conducted using electrochemical dy namics. Electrochemical Impedance Spectroscopy (EIS) is a powerful technique to obtain information about electrochemical systems. To utilize EIS from the electrochemical dynamics point of view, it is necessary to induce it through an electrochemical battery model. In this study, the most widely known Pseudo 2-dimensional (P2D) model among electrochemical models was analyzed. Based on the analysis, a reduced-order model of the P2D model called Single Particle Model (SPM) was also implemented. For the P2D model, the nonlinearity of the relational expression is severe when calculating the state gradient. Also, numer ically, there are many meshes in terms of space, so the amount of computation is burdensome. To overcome these problems, the SPM which efficiently reduced the P2D model was employed to derive the EIS-based analytic solution. In sum mary, this paper proposes a method that can utilize the impedance measurement method through in-depth analysis of the electrochemical model.