Electrochemical behavior simulation of high specific energy power lithium-ion batteries based on numerical model

Based on COMSOL Multiphysics, a three-dimensional electrochemical-thermal coupling model of lithium-ion battery is constructed. The electrochemical distribution characteristics of the electrode and its evolution law are studied. The results show that the solid-liquid potential shows a large gradient change at the junction between the positive and negative electrode and tabs; the distribution of the maximum and minimum values of the overpotential near the side of tabs or the center of the electrode and the absolute value of the negative distribution characteristic is relatively large. At the end of discharge, the negative electrode almost comes to the state of complete de-lithium, which causes the potential to increase suddenly, and the battery voltage to reach the discharge cut-off voltage in advance. The state of charge (SOC) of the positive electrode is only 0.89; the electrode utilization distribution exhibits a non-uniform distribution characteristic perpendicular to the thickness of the electrode, and changes continuously during the discharge process.