No abstract

Today's Li-ion battery stringent requirements include high electric currents, large format cells and possibly the use of carbon based current collectors, which would enhance the electrochemical-thermal non-uniformities in the cell. Although a number of models have been implemented in order to study such non-uniformities, no efforts have been made to describe the distribution of side reaction rates and their effect on aging distribution. To fill that gap, we developed a pseudo-3D porous electrode electrochemical model that incorporates via first principles the solid-electrolyte interphase (SEI) growth on the anode, which is thought to be a dominant aging mechanism. The model was used to simulate the cyclic behavior of a large format (40 Ah) Li-ion polymer pouch cell with the assumption of a carbon based positive current collector. It was found that SEI growth localization would form in the electrode thickness and planar dimensions during discharging, but would be destroyed during the subsequent charging, so that the associated aging would be uniform upon cycling. This suggests that computationally efficient lumped models could be used to describe the cell aging process associated with the SEI growth on the graphitic anode, which would be ideal for onboard implementations such as in electric vehicle applications.

No abstract

SUMMARY The thermal behavior of a Li‐ion battery module that belongs to the battery system of an actual electric vehicle prototype was numerically investigated. Realistic driving loads and passive cooling conditions were considered. A combination of a vehicle dynamics model, an equivalent electric circuit battery model, and a 3D finite‐element thermal model was used in the analysis. Temperature and electric potential measurements, performed at the cell and module levels, were first used for model calibration. Electric currents, associated with the ARTEMIS driving cycles, were then calculated and applied in the battery model to predict the heat sources for the thermal model. It was found that the temperature increase corresponding to urban transportation requirements in European countries is tolerable. Nevertheless, road and highway applications would result in a temperature increase that accelerates cell ageing, and an active cooling strategy is required. Copyright © 2012 John Wiley & Sons, Ltd.

No abstract