Modeling of Lithium Ion Batteries Employing Grand Canonical Monte Carlo and Multiscale Simulation

Abstract

In the current investigation modeling of two half cells (LiMn2O4 cathode and carbon anode) followed by modeling of the complete cell of the battery employing Grand Canonical Monte Carlo simulations to evaluate open circuit potential and energetic of the process involved had been carried out. Current model takes into account the effect of electrolyte and temperature variations on various battery parameters like open circuit potential, cell current, cell voltage and free energy of Li+ intercalation/deintercalation. Estimation of open circuit potential (OCV) of Lithium ion batteries becomes vital as it is a crucial parameter in (i) estimating diffusion coefficient of lithium in the electrode material during charge/discharge process, (ii) obtaining entropy of the reaction and internal energy calculations and (iii) understanding thermal runaway problems. The strong dependence of OCV with the state of charge (SOC) of the battery and temperature makes the prediction more difficult. To avoid computational tediousness, Grand Canonical Monte Carlo technique coupled with multiscale simulation is employed to predict experimental OCV of LiMn2O4 cathode material in the presence of electrolyte solution.