Phase change material selection using simulation-oriented optimization to improve the thermal performance of lithium-ion battery

Battery thermal management system (BTMS) is highly essential to maintain battery temperature in Electric Vehicles. The phase change material (PCM) based BTMS is highly effective due to its high latent heat and can also be used without any power consumption. The present work aims to propose the most suitable PCM used for BTMS. Six commercially available PCMs are studied with the battery pack at three different charging rates low (1C), moderate (2C), and high (3C), and three different ambient conditions, i.e., cold (20 degrees C), moderate (30 degrees C), and hot (40 degrees C) conditions. As critical thermal parameters, the maximum battery temperature (T-max) and maximum temperature difference (Delta T-max) are studied. As both T-max and Delta T-max are required to be minimum to increase the performance of the battery, a method of Multi-attribute decision making (MADM) named Weighted Product Method (WPM) is used in the present study. At different charging rates 1C, 2C, and 3C, PCMs RT31, RT35, and RT42 are found as most suitable, respectively. While, RT24, RT35, and RT50 are found as most suitable PCM at the ambient temperature of 20 degrees C, 30 degrees C, and 40 degrees C, respectively. It is found out from the result that ambient temperature should be given more consideration than charging rate in PCM selection. These PCMs are found suitable on a battery performance basis; however, if a safe range of lithium-ion batteries (60 degrees C) is considered, it is noticed that only RT42 and RT50 successfully maintain battery temperature below 60 degrees C at each operating condition. Finally, it is concluded that PCM with melting temperature lower than ambient temperature and quite higher than ambient temperature is not effective, but PCM with melting temperature 5-10 degrees C more than ambient temperature can provide better battery performance.

Automated summary

Battery thermal management system using phase change material (PCM) is crucial in maintaining battery temperature in Electric Vehicles. This study proposes the most suitable PCM for BTMS by analyzing different commercially available PCMs under various charging rates and ambient conditions. The study finds that the PCM selection should prioritize ambient temperature rather than charging rate, and identifies specific PCMs that can successfully maintain battery temperature within a safe range.