Thermal behavior investigation of the battery pack for aircraft engine initial startup to consider preheating method at subzero temperature.

Lithium-ion batteries have high energy density, excellent life cycle, and low self-discharge characteristics, but their performance is sensitive to temperature. In particular, the performance of lithium-ion batteries is degraded, and the internal resistance increased may prevent the battery from operating such as charged or discharged at subzero temperatures. Therefore, the study of thermal stability of lithium-ion batteries at low temperatures is as important as the battery thermal safety problem at high temperatures. In this paper, an analysis of preheating methods for battery packs designed for aircraft engine startup in low-temperature environments is conducted. The battery pack was designed by the design constraints that assumed ambient of −32 °C. The preheating is carried out using external heating for operation of the battery pack in low-temperature environments. Sixteen resistance heaters are installed inside the battery pack, which consists of 112 cylindrical lithium-ion cells. In addition, for effective heating of cylindrical battery cells, the battery cells are inserted inside the aluminum square battery tray, and the resistance heaters are attached sides of the battery tray for heating it. The thermal analysis when the designed preheating method was applied was carried out to review thermal distributions such as temperature uniformity of batteries according to heating. The heating volume of the resistance heater and the modification of the aluminum tray was considered, and the modified design method provided additional cell temperature homogeneity within the battery pack, resulting in thermal management strategy to use the battery pack in low temperatures. [ABSTRACT FROM AUTHOR]