Modeling and characterization of the mass transfer and thermal mechanics of the power lithium manganate battery under charging process

摘要

Based on the electric charge conservation laws, the mass transfer and the energy conservation, a coupled electrochemical-thermal model of the Lithium battery is established and validated by the experiment data. And then the coupled model is applied to investigate the electrochemical and thermal characteristics of the power Lithium manganate battery at 1C charging ratio and the obtained results include the electrolyte concentration distribution trend, the current density distribution rule, Fick diffusion of the Lithium ions, etc. This results show that the temperature of electrolyte region is significantly higher than that of the regions near to the positive and negative electrode during charging process due to the transfer of Lithium ions in the electrolyte region. Meanwhile, the concentration of active substance particles and the electrolyte concentration can be employed to characterize the polarization size. When charging rates are 0.5C, 1.0 C and 1.5C, the charge times of power Lithium manganate battery are 7200s, 3600s and 2700s, respectively. The maximum and minimum internal temperatures at the end of the charging process are 307.2K/305.8K, 328.2K/323.6K and 341.2K/332.7K, respectively. The appropriate increase of the heat dissipation in the middle of the battery is useful for the reduction of the central temperature inside the battery. (C) 2019 Elsevier Ltd. All rights reserved.