The numerical and experimental investigation of the transient behaviours of a lithium-ion pouch battery cell under dynamic conditions

Abstract

In this paper, the transient model of a high energy density Lithium-ion pouch battery cell is developed under dynamic conditions. The battery cell has a capacity of 73 Ah and volumetric energy density of 642 Wh L−1. This is one of the few studies included the electro-thermal behaviour of high energy density battery under transient conditions by using second ordered model. The transient model indicated that the state of charge (SOC) decreased by 7 % at the end of the WLTP driving cycle and this value is good agreement with the experimental data. Moreover, the developed model provides an accurate prediction of the terminal voltage with a R2 value of 0.99 and a maximum relative error of 2.0 %. Furthermore, the proposed model predicts the electro-thermal characteristics more precisely and the heat generation rate and the entropic term can also be determined without using measurement device. The calculated total heat emitted from battery is about 6W at 1 C-rate for constant current and the heat generation rate is a peak value of ±1.75 105 Wm−3 under dynamic conditions. By using the estimated heat generation rate, more effective cold plates will be designed for thermal management of high energy density battery cells.

Keywords

• Transient model
• Pouch cell
• Heat generation
• Dynamic conditions