Experimental and Numerical Investigation of Thermal Energy Management with Reciprocating Cooling and Heating Systems for Li-Ion Battery Pack

This work investigated the thermal management of Li-ion battery packs by using reciprocating cooling and heating systems with different reciprocating periods and air velocities. The accuracy of the 3D model was validated through the comparison of the temperature curves between experimental and numerical data. Results show that the reciprocating cooling and heating systems can reduce the temperature nonuniformity and maximum temperature of cells significantly. For the reciprocating cooling system, it can increase the minimum temperature in cells. The maximum average surface temperature difference curve is a concave parabola that first decreases and then increases with the increase of the reciprocating period. The strategy by increasing the reciprocating period has little influence on lowering the maximum average surface temperature of cells. As for the reciprocating heating system, the reciprocating period has little effect on the variation of temperature for cells when the reciprocating period is higher than 10s. The temperature difference curve inside of a cell with a different reciprocating period is a parabola too. The maximum average temperature inside of each cell increases with the increase of air velocity, but the increase rate tends to be reduced. For small air velocities, the average temperature inside of each cell increases linearly with the increase of time, but for high air velocities, it increases quadratically.