Investigation of extruded heat sink assisted air cooling system for lithium-ion capacitor batteries

High-working temperature and non-uniform temperature evolution of high-power lithium-ion capacitor (LiC) batteries lead to thermal reliability problems. Therefore, the development of a robust cooling system is indispensable to control the heat generation of the cell. In this work, the cooling performance of an active cooling system has been investigated using three thermal management systems. In this regard, in the first step, the temperature evolution of the LiC cell under natural convection is monitored by the thermocouple. In the next step, an extruded heat sink is added to the cell to investigate the thermal performance of this passive thermal management system (TMS). In the last phase of this study, an air-cooling system is added to the passive TMS to study the performance of the hybrid passive-active cooling system. A prominent feature of the proposed TMS is the uniform temperature distribution of the LiC cell. A continuous intense charge-discharge current rate of 150 A is applied to the LiC battery without any pause for 1400s, to obtain the temperature evolution of the cell. According to the results, starting at a constant initial temperature of 23 °C, the monitored temperature by the thermocouple reaches to 55.3 °C, which is above the safety limit recommended by the manufacturer. Moreover, by adding the extruded heat sink to the cell, the temperature of the cell shows 41.1 °C, which is not still in the safe range. However, the added active air-cooling system can control the temperature below 30 °C. This means that the proposed extruded heat sink assisted air-cooling system reduces the temperature by 27% compared to the only heat sink mode, which shows the reliability of the proposed hybrid TMS

Keywords:Lithium-ion capacitor (LiC), Thermal management system (TMS), Active cooling system, Air cooling, Extruded heat sink