Thermal management of Li-ion battery by using eutectic mixture of phase-change materials

Abstract

Lithium-ion batteries have a wide range of applications in portable electronic devices, global positioning systems, and the automobile industry due to their remarkable attributes like high energy density, long life cycle, higher efficiency, low self-discharging, and worthier operational performance. Although under different vigilant operating parameters, lithium-ion batteries generate a significant amount of heat, which deteriorates their performance and can lead to thermal runaway. To mitigate this issue and to improve safety, battery life, capacity, and overall performance, a robust thermal management system is very necessary. This study scrutinizes the effect of a passive cooling method using phase-change materials and their eutectic mixture on a 2600 mAh lithium-ion battery pack during the charging and discharging at various C-rates (1C, 1.5C, and 2C). Phase-change materials used in the experimentation are salt hydrates namely calcium nitrate tetrahydrate and zinc nitrate hexahydrate and their eutectic mixture contains 55 % calcium nitrate tetrahydrate and 45 % zinc nitrate hexahydrate. Experimental results reveal that without the usage of any phase-change material, the highest temperature was recorded at a 2C rate due to high current, with cell 5 recording a temperature of 60.98 °C. Zinc nitrate hexahydrate reduced the temperature by 18.98 °C to maintain it at 42 °C, and calcium nitrate tetrahydrate led to a temperature drop of 14.48 °C, maintaining it at 46.50 °C. The eutectic mixture caused a temperature reduction of 21.97 °C, maintaining it at 39.01 °C. The results of this study illustrate that the implementation of eutectic mixture as a phase-change material diminishes both the maximum surface temperature and the temperature gradient. This implies its efficacy as a viable material for the cooling of battery packs.