Effects of different coolants and cooling strategies on the cooling performance of the power lithium ion battery system: A review

As the power lithium-ion batteries are applied to provide energy for electric vehicles, higher requirements for battery thermal management system (BTMS) have been put forward. The operating temperature, reliability, safety and cycle life of batteries is the key points that people concern. The liquid cooling system is considered as an efficient cooling method, which can control the maximum temperature of the battery and the temperature difference between the batteries in a reasonable range to prolong the cycle life of the battery. This review summarizes the latest research papers of battery liquid cooling system from three aspects, including the performance of coolant, classification of liquid cooling system and design of battery pack. In terms of coolants, the properties and applications of different liquids such as water and oil, as well as different additives such as nanoparticles, are compared. For the classification of liquid cooling system, the difference between active and passive cooling, internal and external cooling, direct and indirect cooling are introduced. As for the design of battery pack, the series, parallel and series-parallel configurations are introduced and the advantages and disadvantages of the different configurations are analyzed. The differences in the design scheme between direct and indirect cooling system are compared. The influences on the cooling performance of battery pack with different parameter design of the cooling plate and the cooling jacket of indirect cooling system are discussed in depth.