Russell Bloomfield presents at SPE’s first ever Electric & Autonomous Vehicle conference.

The Society of Plastics Engineers (SPE) hosted its inaugural Electric & Autonomous Vehicle (EAV) conference in Troy, Michigan, in May 2022. Russell Bloomfield, application development engineer for Envalior, presented a session about Engineering Plastics Developed for EV Thermal Management Systems (TMS) during the two-day conference attend by more than 700 industry professionals.

Bloomfield’s presentation focused on key thermal management system design challenges often faced by designers, how to select advanced material solutions for these important systems, and PPS coolant performance.

At the beginning of the presentation, Bloomfield pointed out how electric vehicles are here to stay and as vehicle electrification accelerates, thermal management is becoming even more important. E-powertrain efficiency, safety and lifetime is dependent on thermal management of key components such as the batters, e-motors, and fuel cell stacks.

Key design challenges of thermal management systems

Engineering plastics play an essential role for EV thermal management systems applications. Designers often face the following challenges when creating thermal management system applications:

• Time: Battery thermal management systems must run continuously, even when vehicles are charging.
• Temperature: More precise temperature control is needed to avoid safety risks.
• Complexity: Design flexibility needed for more complex thermoplastic components.

Safety risk escalates quickly when proper temperature is not maintained. When EV battery temperatures exceed 65°C the rush for thermal runaway conditions and battery combustion rapidly grows. This is a growing concern as the number of electric vehicles in operation increases. There is less margin for error with narrower optimal temperature range compared to ICE battery overheating can create thermal runaway fire safety risks.

Time is a challenge too because temperature must be maintained even as the electric vehicle charges, thus, longer lifecycle increases the importance of hydrolysis resistance and weld line strength. As the coolant aging time increases, water glycol coolant hydrolysis resistance and ion leaching control are increasingly important for optimal TMS, along with material weld line strength after aging. 

Materials properties and selection

PPS offers the best overall performance, PPA and other polyamides can be considered so long as they meet aging and temperature requirements. 

Envalior is a system solution supplier by providing a full TMS material product portfolio. Our Xytron G4080HR PPS and ForTii MX15HR deliver excellent Water Glycol resistance.  At high temperature, Xytron G4024T PPS and G4080HR PPS deliver 4 times greater mechanic retention as compared to PPA. Plus, Xytron G4080HR has the highest stable hydrolytic-resistance, plus it has a stable weld line strength even post coolant exposure.

“I’m very excited about the broad material portfolio that Envalior has developed for BEV thermal management systems,” explained Bloomfield. “Notable within our portfolio is the Xytron PPS material which offers best-in-class property retention after long-term coolant exposure. The foundation for this performance edge is the proprietary manner by which we compound the glass fiber reinforcement into the polymer matrix. The novel compounding benefits not only the weld line strength retention of the material, but also helps deliver the Xytron materials’ extremely low ion leaching performance which serves the fuel cell market as well.”

All of Xytron’s Key Properties are back-up with intensive, long-term data-packages, and our fundamental know-how of interfacial technology differential us to other PPS players.