A Simplified Electrochemical Model of Lithium-ion Battery Considering Liquid Overpotential

This paper proposes a simplified electrochemical model for lithium-ion batteries considering liquid phase overpotential (LOP2D). It has great significance for the analysis and prediction of dynamic battery characteristics, battery status evaluation, battery management etc. Based on the porous electrode theory and concentrated solution theory, the diffusion and migration of lithium ions are considered. Moreover, the finite difference method is used to solve the process of solid-phase lithium-ion diffusion. Finally, this paper compares terminal voltage change with time between the simplified electrochemical model and P2D model under different current density. The results show that the LOP2D model provides a more straightforward mathematical expression with fewer computational terms and higher computational accuracy, which is of great value in practical applications such as battery SOC estimation, ageing analysis, overcharge and over-discharge control, and thermal analysis.