Thermal runaway management of Li ion battery using PCM: A parametric study

Abstract

• The surface temperature of the Li-ion battery cell has been studied to maintain it below the safe operating temperature. • A parametric study for Li-ion cell has been conducted for different PCMs, PCM volume, charging/ discharging rates and ambient temperatures. • Use of PCMs reduced the surface temperature of the Li-ion battery cell. • An ambient temperature higher than that of the melting point of PCM is not recommended for its detrimental effect on the surface temperature of the cell. The paper reports an experimental and numerical study to manage the thermal runaway with in the safe operating temperature of Li-ion battery in terms of variation in its surface temperature subjected to different operating conditions. A parametric study has been conducted at different charging rates (1C, 2C, and 3C), and the cell's surface temperature is measured and examined. The study has incorporated three different Phase Change Materials (PCM) which are Eicosane, Paraffin wax, and Capric acid. The effect of varying thicknesses (5 mm, 10 mm) of PCM around the cell has been studied. The ambient temperature has been varied to examine its effect on the surface temperature of the cell. The results showed, using PCM around the battery cell reduced the cell's surface temperature by 21.5% compared to the cell without PCM for the case of discharging at a 3C rate. Between Eicosane and Paraffin wax, the earlier performance is better than the latter owing to its higher latent heat. The cell with Eicosane reached a peak temperature of 313 K compared to 316 K for cell with RT 42. The surface temperature of the cell remained unaffected by the change in the thickness of the PCM layer surrounding the cell from 5 mm to 10 mm but the melting fraction decreased by 35% and 25% at a 3C discharge rate for Capric acid and Eicosane, respectively. The ambient condition of the cell is very crucial; it is found that at higher temperatures of the surrounding, the effect of the PCM is detrimental to the cell.