Advanced research on rechargeable Lithium-ion batteries has allowed for large format and high-energy batteries to be largely used in Battery Electric Vehicles (BEVs). For transportation applications, beside limitations of driving range, long charging time is still considered as an important barrier for a wide use of BEVs. The increase of the charging current amplitude may however subject the battery to stressful situations and can significantly increase the temperature of the battery. These phenomena reduce the battery’s lifetime and performances and in worst-case scenario, thermal runaway can occur. To avoid this, there is a need for an optimized thermal management in order to keep the battery in a safe and beneficial range of operating conditions.
Firstly, in this PhD dissertation a two-dimensional electrical-thermal model has been developed to predict the cell temperature distribution over the surface of the battery. This model requires less input parameters and still has high accuracy. In addition, a novel estimation tool has been developed for estimation of the thermal model parameters. Furthermore, the thermal behavior of the proposed battery has been investigated at different environmental conditions as well as during the abuse conditions for assessment of thermal stability of the battery.
Taking into account the harsh thermal distribution, an advanced three-dimensional electrochemical-thermal model has been developed in order to investigate the impact of the cell design on the thermal, voltage and current distributions in order to avoid high non-homogenous distribution. The developed model allows us to optimize the cell design, in order to achieve the longest lifetime and high performances of battery cell.
Finally, different thermal management strategies such as liquid cooling and passive cooling using phase change material embedded in an aluminium-foam (liquid-solid phase change) have been investigated and compared in depth by applying real BEV drive cycles. The main objective of this study is to decrease the complexity, the weight, the volume and the cost and to maintain high safety according to the best strategy.
Promotor: Prof. Dr. Joeri Van Mierlo, Prof. Dr. Hamid Gualous, Prof. Dr. Noshin Omar