Run-time simulation model for Li-ion battery using in-circuit extracted mass transport parameters

Abstract

A run-time model for Li-ion battery, which can be modified or updated when the battery is operating in the circuit, based on, in-circuit extraction of required mass transport parameters is presented. The modeling approach is based on the segmented diffusion modeling and in-circuit parameter extrac­tion. Lithium-ion batteries are finding large application demand in many areas and at different power levels. LG18650, 2.6Ah, Li-ion cell is used as the sample cell in the study. A comparison of the model behavior is made with test data obtained from an LG18650 cell. The comparative study between the model behavior and experimental data, for a constant current charge rate and pulse discharge scenario are carried out and the results are presented. An analytical approach for obtaining the expected variation in the capacitance parameter values of the run-time equivalent circuit model, with change in state of charge (SoC) of the battery is arrived at. The percentage root mean square error between the model prediction and experimental data is 0.63% for the run-time simulation at C/10 charge rate.