Battery Thermal Management Systems are necessary for the overall efficiency and life cycle of vehicle as well safety of passengers and vehicle, as elevated operating temperatures have adverse effect on the efficiency, life cycle and safety of the Li-ion battery packs. The operating temperature prescribed by many studies for improved performance and better life cycle of Li-ion batteries is around 25°C. In some worst case scenarios, high operating temperature may lead to thermal runaway in the battery, causing immense amount of heat generation, even leading to an explosion. To avoid all these dangerous events, battery thermal management is utilized to regulate the temperature of the battery pack. In this thesis, a novel battery thermal management system based on liquid cooling principle is proposed. The system involves dual purpose cooling plate for prismatic Li-ion batteries, which can maintain the temperature under normal conditions as well as mitigate the heat generated during thermal runaway. An experiment was performed on the prismatic Li-ion battery to measure the heat generation trends. The battery was discharged at 5C to replicate aggressive conditions. The data for maximum heat flux generated in the Li-ion battery was obtained. An estimated amount of heat generated during thermal runaway was calculated. A conjugate heat transfer method was used to simulate the cooling plates for normal operation and thermal runaway. The plates were simulated with two flow rates for normal operation and three flow rates for thermal runaway. Three different designs of cooling plates were compared on the basis of surface temperature, pressure drop and flow rate. The final design was selected based on the comparison with the rest of the cooling plates. The selected cooling plate can: • Maintain the temperature of battery below 25°C during normal operation. • Dissipate the maximum possible heat generated during thermal runaway and bring the temperature to less than 80°C. • M (open full item for complete abstract)