Design of Thermal Management Systems for Battery Electric Vehicles

The optimal choice of a lithium-ion battery (LIB) cell for a specific battery electric vehicle (BEV) application is complex, extending from cell chemistry selection by way of electrical interconnection through to the thermal design and integration of the battery energy storage. In late stages of the development process, small concept adjustments to comprehensive interactive properties affect all decisions previously made. Here, specific attention is paid to the battery thermal management system (BTMS) because it affects all subordinate system levels and is therefore crucial in finding an optimal concept solution. During the conventional development process, many iterations are made in the absence of an overall approach. An efficient procedure is required that supports the development process in finding the optimum solution taking into account the effects of and trade-offs between all system levels. This work proposes an approach to obtaining a reliable electrical and thermal design of LIB systems in the concept phase, taking into consideration the special requirements of automotive applications. The focus is a full concept development process including cell selection, mechanical, electrical and thermal battery system design and the design of the BTMS including its possible connection to the vehicle thermal management system (VTMS).