Investigation of the Effect on Thermal Performance Using Organic Phase Change Material in Battery Cooling Systems

The thermal performance of lithium-ion battery under passive cooling (organic PCM) is investigated experimentally. Coconut oil, soy wax and palm wax are used as organic PCM. This study investigates the temperatures at the anode, cathode and midpoint of the battery in natural convection and the effects of passive cooling method on three different organic PCMs located around Li-ion battery during different discharges (1C, 2C and 3C). The results with PCM are also compared with the cases without PCM and the effects of organic PCMs on battery thermal performance are determined. According to the experimental results, it is determined that at the highest discharge rate, coconut oil completely melted, palm wax is in mushy phase region and soy wax does not change phase. Depending on discharge rates, in the case without PCM, while the maximum battery surface temperatures range from 30.7 °C to 48.8 °C, these temperatures range from 25.5 °C to 42.6 °C for coconut oil, 24.8 °C to 41.8 °C for soy wax, and 25 °C to 40.5 °C for palm wax. Battery cooling performance is better in palm wax. In addition, when the surface temperatures of the battery are compared with organic PCMs temperature, it is identified that there is very little difference. These findings indicate that passive cooling can also reduce battery operating temperature and the use of organic PCMs can make positive contributions to battery thermal performance.