About this Research Topic
Consumer demand for Hybrid-Electrical Vehicles (HEV) and Electrical Vehicles (EV) has been increasing due to their benefits of high energy efficiency and lower emissions. These vehicles, together with the electrification development trend, continue to gain global attention. The introduction of different components, materials, lubricant operating environments, and the demands on efficiency and durability necessitate making lubricant-additive technologies compatible with these advanced systems. A distinguishing feature of the HEV is the intermittent on-off control of the internal combustion (IC) engine based on the in-use power requirement of the vehicle. This results in overall cooler operating temperatures of the IC engine and more frequent starts of the hybrid engine. Accordingly, sludge and varnish production in the lubricant is significantly higher for the hybrid engine system due to these stop-and-go switching modes. Second, the lubricant must be compatible with more electrical components such as the battery, motors, hardware materials, for corrosion management and to adequately dissipate heat. In addition, the requirement of the lubricant to have low viscosity in order to maximize energy efficiency, while still maintaining protection of hardware such as driveline and bearing components, must be properly balanced with new additive technology. Therefore, advanced lubrication technology is crucial in maintaining the high efficiency and reliability of HEV and EV vehicles. Original Equipment Manufacturers (OEMs) have requested the adoption of dedicated lubricants or driveline fluids to protect and ensure the smooth functioning of the electrified drivetrain parts. Transmission and driveline fluids tailored to hybrids and EVs must have the right electrical properties, ensure corrosion protection, and be compatible with insulating materials. They need to meet appropriate thermal cooling requirements, offer bearing protection, and provide oxidation and sludge control.
This Research Topic will focus on research and development trends related to advanced automotive lubricants and thermal cooling fluids used in Hybrid/EV vehicles. Future developments in advanced transmission and driveline fluids will aim to minimize friction loss and to maximize component durability. Automotive lubricants in the future are expected to differ dramatically from those of today to meet the high-performance demand for future Hybrid/EV vehicles, advanced hybrid engines and driveline components. Also, further advancement in automotive lubricants will require more reliable and efficient methods of evaluation of lubricant performance in modern engine and driveline systems. Foreseeably, the future will embrace the design and implementation of "smart" tribo-systems that will automatically control critical lubricant parameters, thereby optimizing lubricant and subsystem performance. The end goal of this Research Topic is to showcase the current and future development trends of advanced Hybrid/EV vehicles and their lubricants, while at the same time highlight significant progress in the areas of energy efficiency, driveline reliability, cooling system advancement, and thermal management requirements.
We call for high-quality papers in this Research Topic which will focus on, but are not limited to, the following topics:
• Advanced Hybrid/EV automotive lubricant development for meeting lubrication and thermal management requirements
• Development of tribo-systems for evaluation of advanced automotive lubricants and advanced material performance for modern hybrid engines and driveline systems
• Characterizing the lubrication/tribological environments (such as shear, temperatures, loads, contaminants, etc) in advanced HEV/EV operating systems
• Tribochemistry for understanding tribological characteristics of automotive lubricants in their advanced engineering applications
• Bench test evaluation and interpretation of the performance of automotive lubricant and thermal management systems
• Analysis of friction and wear performance in modern automotive engines or advanced hybrid driveline components
• Analysis of lubrication and cooling processes during tribo-systems for automotive hybrid/EV applications
• Future trends for automotive Hybrid/EV system lubrication and thermal management requirements
Dr. Simon Tung is the founder of Innovation Technology Consulting Inc., a company investigating a broad range of green energy technology, consulting on transportation energy, fuel, and lubricant requirements, and providing business coaching for OEM clients. All other Topic Editors declare no competing interests with regards to the Research Topic subject.
Keywords: Lubricants, Automotive Tribology, Hybrid Electric Vehicles, Thermal Management, Driveline Lubrication
Important Note: All contributions to this Research Topic must be within the scope of the section and journal to which they are submitted, as defined in their mission statements. Frontiers reserves the right to guide an out-of-scope manuscript to a more suitable section or journal at any stage of peer review.