INNOVATIVE COOLING TECHNIQUES FOR THERMAL MANAGEMENT AND TEMPERATURE UNIFORMITY IMPROVEMENT OF LITHIUM-ION BATTERIES

Lithium-ion (Li-ion) batteries have found widespread applications in developing clean energy transportation and are one of the best candidates for electric and hybrid electric vehicles. One of the major challenges of Li-ion batteries is their temperature rise due to heat generation inside the battery cells during high-powered cycles; this leads to the cells' life reduction. In the last several years, significant progress has been made on innovative cooling techniques for thermal management temperature uniformity improvement of Li-ion batteries. Three-dimensional transient thermal analysis of an air-cooled module that contains prismatic Li-ion cells next to a special kind of aluminum pin fin heat sink whose heights of pin fins increase linearly through the width of the channel in the airflow direction was carried out. The cumulative effects of using a pin fin heat sink and porous metal foam on the thermal management of a Li-ion battery pack were investigated. Internal cooling that uses electrolytes as a coolant inside rectangular microchannels in the positive and negative electrodes was proposed to optimize the thermal management of Li-ion battery packs. The effects of the size of the microchannels on the thermo-electrical performance of the battery cell as well as the effects of the electrolyte flow inlet temperature and velocity were studied. A Lattice Boltzmann Method (LBM) simulation was carried out to simulate the effects of embedded microchannels inside the electrodes on the electrolyte transport in the porous electrodes as well as their effects to lead the generated gases during thermal runaway out of the battery cell. A thermal LBM was employed to predict electrolyte flow, heat transfer, and internal heat generation inside the positive porous electrode.