Advances and challenges of R744 based thermal management systems in electric vehicles

The global transition to electric vehicles is essential for reducing transportation-related carbon emissions. Despite this, the limited driving range, primarily caused by the high energy consumption of thermal management systems, remains a significant barrier to the widespread adoption of EVs. Concurrently, international regulations are phasing out conventional refrigerants with high global warming potential, leading to the use of natural refrigerants, such as carbon dioxide (R744). R744 meets environmental standards and exhibits favorable thermodynamic performance. The current state of R744-based thermal management in EVs advancements in transcritical R744 heat pumps technologies, operational challenges and optimization strategies were comprehensively reviewed in this work. The review also included an overview of the present landscape and prospects for R744-based TMS in next-generation electric vehicles. It could be concluded that future thermal management strategies of EVs can be based on integrated R744-based solutions, featuring further advanced add-ons, such as AI-based control strategies.