Modeling studies on battery thermal behaviour, thermal runaway, thermal management, and energy efficiency

Thermal management is crucial to the safe operation of, and the achievement of normal/optimal performance of, electric vehicle (EV) batteries. A thermal management system is responsible for maintaining the operational temperature and temperature uniformity across a battery stack (during battery operation and/or stand-by) either by active cooling or by electric heating. The main concern with the thermal behaviour of room-temperature batteries (e.g. lithium-ion batteries) is the possible significant temperature increase (e.g. during high power extraction) which may cause thermal runaway, while for some batteries (e.g. lithium/polymer-electrolyte batteries), the operating temperature of which is above ambient temperature, another concern is the long heat-up time before start-up and the reduced total energy efficiency. In this paper, we discuss the thermal management aspect of electric vehicle batteries, including the examination of battery thermal behaviour, the design of suitable thermal management systems, and the evaluation of battery energy efficiency and the possibility of the occurrence of thermal runaway due to battery abuse.