Li-Ion Battery Pack Thermal Management: Liquid Versus Air Cooling

Abstract

The Li-ion battery operation life is strongly dependent on the operating temperature and the temperature variation that occurs within each individual cell. Liquid-cooling is very effective in removing substantial amounts of heat with relatively low flow rates. On the other hand, air-cooling is simpler, lighter, and easier to maintain. However, for achieving similar cooling performance, a much higher volumetric air flow rate is required due to its lower heat capacity. This paper describes the fundamental differences between air-cooling and liquid-cooling applications in terms of basic flow and heat transfer parameters for Li-ion battery packs in terms of QITD (inlet temperature difference). For air-cooling concepts with high QITD, one must focus on heat transfer devices with relatively high heat transfer coefficients (100–150 W/m2/K) at air flow rates of 300–400 m3/h, low flow induced noise, and low-pressure drops. This can be achieved by using turbulators, such as delta winglets. The results show that the design concepts based on delta winglets can achieve QITD of greater than 150 W/K.

Battery Thermal Management System for Electric Vehicles: A Brief Review

“…On the other hand, in hybrid vehicles and 100% electric vehicles with high battery power demand, the most widespread system is liquid cooling due to the ability to keep the battery at the ideal temperature even in situations of extreme battery usage and high heat release. In a comparative assessment carried out by Han et al [15], it was demonstrated that while the liquid cooling system has a rating of 500 W/K, the air-cooling system is around 70 W/K.…”

“…High thermal conductivity, mostly applied for high cooling demand [2][3][4][5][6][7][8][9][10][11][12][13][14][15]. complexity, high cost, heavy, must store the fluid, viscosity, potential leaks, additives for anti-freeze & Boiling [2][3][4][5][6][7][8][9][10][11][12][13][14][15].…”

“…Currently, the temperature control of batteries in electric vehicles is done through the use of the battery thermal management system (BTMS). This system is responsible for ensuring that the battery works in the proper temperature range and keeps the temperature between the cells as homogeneously as possible [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15].…”

Minimum Race-Time Planning-Strategy for an Autonomous Electric Racecar

“…Here and in the following, T F1 = T F1,I . The symbol T M,∞ denotes the temperature of the surroundings of the specific component M. This temperature can be assumed to be equal to the mean value of the inflowing and effluent cooling liquid temperature [20].…”

Electric and Thermal Model of Li-ion battery pack with cylindrical components

“…The low heat air capacity causes its temperature to rise when used to cool series-connected cells. Thus, the outermost cells are not well cooled, leading to an uneven temperature distribution [9]. These limitations can be addressed by taking some measurement when building the battery pack, such as the battery size and the arrangement of the cells.…”