车用锂离子电池直冷热管理系统用冷媒研究进展

电动汽车用直冷系统是未来电动汽车热管理系统的可行解决方案之一，在整车减重、改善温度一致性等方面具备较大潜力。冷媒是直冷热管理系统的重要组成，影响直冷系统制冷能力、效率、安全性等因素。选择高效、匹配的冷媒对直冷热管理系统设计格外重要。梳理了近年来电动汽车直冷热管理系统用冷媒的研究进展。首先，基于电动汽车工况阐述了锂离子电池的热特性需求与直冷热管理系统特性；其次，系统分析了常用冷媒特性的定义与表征；然后，详细介绍了单质冷媒与混合冷媒的研究进展；最后，总结了冷媒亟待解决的问题与未来展望，并为新一代直冷热管理系统用冷媒的发展提出了可行的研究方向。 

Review on refrigerant for direct-cooling thermal management system of lithium-ion battery for electric vehicles

The direct-cooling thermal management system is one of the feasible solutions for the future advanced thermal management system of electric vehicles, which has great potential in terms of vehicle weight reduction and temperature consistency management. Refrigerants are the critical components for direct-cooling thermal management system that directly impact the refrigeration capacity, efficiency and safety. Selecting an effective and suitable refrigerant is especially important for direct-cooling thermal management systems. In this paper, the refrigerants for the direct-cooling thermal management system in recent years is reviewed. First, the thermal management requirements of the lithium-ion batteries and the performance of the direct-cooling thermal management systems are introduced based on electric vehicle applications. Then the definitions and characteristics of commonly used refrigerants are systematically analyzed. The next part introduces the research progress of the pure refrigerants and mixed refrigerants in detail. Finally, the problems and future prospects of the refrigerants are summarized, and feasible research directions for refrigerants in thefuture direct-cooling thermal management systems are proposed.