Experimental study on cooling performance of flat heat pipe for lithium-ion battery at various inclination angels

The temperature prediction of lithium-ion battery cells under different working conditions is still a significant challenge. A heat pipe-based air cooling system is presented for thermal management of the lithium-titanite (LTO) cell. Experimental studies are done on the thermal efficiency performance of a flat copper heat pipe on the LTO cell. The effects of the various inclinations (0˚ to 90˚) on the heat pipe resistance are analyzed as well. It was found that increasing the inclination angle of the heat pipe has a critical effect on the cooling process and thermal resistance of the heat pipe since it directly influences the operation of the condensed working fluid. Results indicate that by increasing the inclination angle of heat pipe from 0˚ to 90˚ degree, the temperature difference for evaporator and condenser reduced from 5.26 ℃ to 5.04 ℃, which leads to a thermal resistance reduction of 0.02 K/W. Moreover, the backside temperature of the cell experienced a 1.3 ℃ reduction.