Experimental study to optimize the thermal performance of Li-ion cell using active and passive cooling techniques

Abstract

Lithium Ion (Li-ion) batteries have been utilized generally in electrical vehicles and different applications because of their no memory effect, high specific energy, high energy density, and high efficiency. However, these batteries generate a large amount of heat when they are charged and discharged at a higher C-rate which eventually leads them toward thermal runaway. To extend the lifespan, effectiveness, and capacity of Li-ion batteries, a suitable Battery Thermal Management System (BTMS) is necessary. In this research work, the effect of active and passive cooling techniques (i.e., natural convection cooling, forced cooling, and phase change material (PCM) cooling) are studied on the charging and discharging of Li-ion cell at higher C-rate. Lauric acid is used as Organic PCM for cooling of single cell and its thermophysical properties are obtained using differential scanning calorimetry (DSC). In the absence of natural convection cooling, experimental findings demonstrated that the highest cell temperature during discharging at 3C, 2C, and 1C was 69 °C, 60 °C, and 38.7 °C respectively. The maximum increase in cell temperature using natural convection cooling, forced cooling, and PCM cooling is 39.9 °C, 20.1 °C, and 20.8 °C as compared to the absence of natural convection at 3C discharge rate. The PCM cooling has shown a temperature reduction of 7.2 %, 25.3 % and 31 % as compared to lack of natural convection using a discharge rate of 1C, 2C, and 3C. Experimental results proved that PCM cooling was most effective and capable of controlling the cell temperature without any external power and assisting the Li-ion cells to operate within a safe temperature range.