Essential technologies on the direct cooling thermal management system for electric vehicles

As the increasing concern of degradation or thermal runaway of lithium-ion batteries, direct cooling system on electric vehicles draws much attention and has been broadly researched. Although satisfactory energy efficiency and thermal performance can be achieved according to current appliances, in-depth discussion of system design and modeling is still necessary for providing mature applications. Herein, a comprehensive review of direct cooling system is presented, and essential components on the overall design are introduced as 4C chain (construction of the system, component modeling, cooling plate design, and coolant selection). Construction, coolant, cooling plate, and component modeling are presented independently for discussing the research progress, where detailed information is provided contributing to the selection of essential components. Moreover, the typical applications on electric vehicles of direct cooling are also investigated, and more productions are under research. Apart from system designing, the environmental fitness is also considered and the defects are summarized for system optimization. Considering to achieve future innovative application, digital twin model-based method is delivered for providing the guidance of prospective direct cooling system design, and the method enhances the potential to achieve better thermal management based on digital technologies and cloud-control platform. Based on the innovative development of cloud-controlling platform design and electronic and electrical architecture, the cloud battery controlling provides the chances for online elaborate model-based operation and precise model-based controlling strategy for novel direct cooling system. Novelty Statement A comprehensive review on the general construction of system is presented, and essential components of direct cooling system are also summarized for optimizing the system efficiency. The article highlights the research profile of direct cooling system, namely 4C (construction of the system, component modeling, cooling plate design, and coolant selection) chain. Considering the future applications, the prospect of potential optimization is assumed for providing the guidance of future researched, and combination with digital twin models is one of probable methods where the results can be generalized to the battery thermal systems.