Cooling performance and optimization of a new hybrid thermal management system of cylindrical battery

To enhance the temperature uniformity of liquid cooling system, an effective strategy was proposed based on liquid cooling and micro heat pipe array (MHPA) for prismatic batteries. But whether this hybrid battery thermal management system (BTMS) still works effectively for cylindrical lithium-ion batteries needs to be verified and its optimal design has not been worked due to complex factors and paraments of hybrid BTMS. In this paper, a novel hybrid BTMS for the cylindrical batteries is proposed based on MHPA and liquid cooling, whose cooling performance is investigated experimentally and numerically. The result shows that compared with the module without MHPA, the maximum temperature of the hybrid module is reduced by 34.11 % and the temperature difference is decreased from 3.66 °C to 0.66 °C, in 1C discharging progress. Even in 3C, the maximum temperature and temperature difference decreased to 41.03 °C and 2.16 °C, respectively. To optimize the energy density and cooling performance, multi-objective optimization is applied based on the Non-dominated Sorting Genetic Algorithm Ⅱ (NSGA-Ⅱ) coupled with the Response Surface Methodology (RSM). According to the Pareto-optimal solution, the energy density of the optimized BTMS can increase 13.75 % to 122.39 Wh/kg with the cooling performance changed lightly, compared with the original module.