Experimental Investigation of Water-Cooled Heat Pipes in the Thermal Management of Lithium-Ion EV Batteries

Abstract

In this work, an experimental study was conducted to investigate the thermal performance of a heat pipe thermal management system for electric vehicle lithium-ion batteries. The battery cells were represented by two proxy cells with a heat source ranging from 10 to 35 W/cell. The evaporator of the heat pipes was in close contact with the battery cell surface, and the condenser was subjected to the forced convection of circulating water. The performance was characterized by the maximum surface temperature, temperature difference, total thermal resistance and Nusselt number at the condenser side. The effects of heat inputs, length of the condenser and water flowrate were also investigated. A condenser length in the range of 100–150 mm and water flowrate showed insignificant effects on the battery surface temperature and the total thermal resistance. Heat pipes were also observed to be able to reduce the battery surface temperature by 39.1% on average. They are also capable of maintaining the surface temperature below 50 °C and temperature differential below 5 °C if the heat generation of the battery cell is less than 20 W.