Numerical-experimental method to devise a liquid-cooling test system for lithium-ion battery packs

Abstract

The liquid-cooling system (LCS) of lithium-ion battery (LIB) pack is crucial in prolonging battery lifespan and improving electric vehicle (EV) reliability. This study purposes to control the battery pack's thermal distribution within a desirable level per a new-designed LCS. Both the special experimental platform and LCS model coupled with EV dynamic model are established to pinpoint the optimal matching parameters of components and the system's operational control-strategies. The results show that the deviation between experiment and simulation is within 3.0 % under conventional conditions. Higher flowrate and lower inlet temperature lead to lower battery temperature, while delaying the cooling intervention could reduce power consumption of 20 % around. The multi-objective optimization is conducted to further slash power consumption at 2750 W, and battery temperature at 30.83 °C during normal 1C discharge, by using response surface method combined with genetic algorithm II. Moreover, the present optimization also demonstrates a well-balanced solution between the battery temperature and power consumption under drive cycle. Combined with experiment and simulation, this work is valuable for one to design an excellent LCS for LIB packs of EV.