In electric vehicles (EVs), battery thermal management system (BTMS) plays an essential role in keeping the battery working within the optimal operating temperature range and preventing thermal runaway. Many cooling mediums have been conducted into BTMS to transfer, absorb, or dissipate the heat generated from the batteries. Thermal conductivity, heat transfer coefficient, cooling performance, cost, poison, environment, system size, and equipment needed are critical factors in choosing the ideal heat transfer coolant for the BTMS. This review paper concentrates on the novel and echo-friendly heat transfer coolant mediums investigated for BTMS and has been rarely documented in the literature. In the scope of this review, traditional BTMS coolant mediums including air, water, phase change material (PCM), and hybrid coolants are considered, and their optimization techniques have been discussed. Additionally, a comprehensive review is provided on novel techniques and novel materials that have the possibility of enhancing the thermal performance of the battery pack on the one hand, as well as the potential of integration into BTMS with higher safety and less (weight, volume, cost, toxicity, and power consumption) compared to the classical heat transfer coolant mediums on the other hand. Finally, evaporative, mist, spray, and nanofluid techniques are found as promising cooling techniques. In terms of environmental, availability, and non-toxicity aspect, jute has the highest possibility of being integrated into BTMS. This study will give the opportunity to see the latest research investigating novel cooling mediums, which will lead to further improvement for BTMS.