On Thursday, Sept. 22, Advanced Thermal Solutions, Inc. (ATS), a leading-edge engineering and manufacturing company focused on the thermal management of electronics, will host the New England Section of Society of Automotive Engineers International (SAE NE) for a tour of its Norwood campus and a presentation by ATS founder, President, and CEO Dr. Kaveh Azar.
Dr. Azar’s discussion is entitled, “Battery Thermal Management – The Gateway to the Successful Operation of Electric Vehicles.” He will review the role of temperature in the longevity and performance of nickel metal hydride (NiMH) and lithium-ion electric vehicle batteries; drawing analogies between battery temperature and the junction temperature of modern electronics. As Dr. Azar notes, “Both play an identical role in successful operation of their respective systems.”
There will be a discussion of the analytical methods and design criterion for predicting battery temperature and establishing safe temperature limits. Dr. Azar will present high-level possibilities for thermal management in the electric vehicle sphere as well as cooling options that are deployed for battery thermal management. Current cooling designs can be active or passive. There are forced air, liquid cooling, natural convection and conduction systems used by manufacturers.
Several thermal solutions that engineers have incorporated include increasing the thermal density of the battery, using phase-change material to store transient heat loads and graphite-impregnated paraffin waxes as gap fillers. It is also important for the designs to control temperature distribution across the battery to avoid degradation of cells.
Thermal management is crucial in the design of electric vehicle batteries because temperature has a direct correlation on battery life and performance. It will affect the battery’s ability to store and deliver a charge, weaken polymer- or fiber-based cell dividers, and could potentially lead to thermal runaway.
“The engineers who will design the next hybrid vehicle battery packs will need to be cognizant of the growing need for thermal management,” read a recent article on coolingZONE. “The increased need for thermal protection, due to safety considerations; the reduced thermal capacity, due to lesser mass; and the reduced workable volume are among the challenges to be faced. The hybrid vehicle we may soon drive must have reliable and intelligent cooling systems to cool down their high-density battery packs.”
Why is this topic of particular relevance now?
Electric vehicle sales worldwide have jumped 57 percent from 2015 to 2016, according to data reported by Bloomberg New Energy Finance. The article referenced a Bloomberg report stating that electric vehicle sales could be as much as 47 percent of the automotive market by 2040 (dependent on factors such as oil prices). In the U.S., manufacturers have been urged by President Barack Obama’s EV Everywhere challenge to make electric cars as affordable and convenient as gas-powered vehicles by 2022.
Like cell phone technology in the past two decades, electric vehicles have the potential for widespread usage and to wide-ranging effects inside and outside of the automotive industry. The “digitization of the transport system” will effect, among others, oil companies, car dealerships, maintenance services, and utility suppliers.
“If it is hard to predict when phase change in complex systems begins, it is even harder to predict where it ends,” said Michael Leibreich and Angus McCrone, the authors of the Bloomberg article. “No list of potential impacts of the ‘Transformation of Transportation’ can be complete. However, one thing is for sure: if our predictions for the uptake of electric vehicles are anything like correct, there is no part of the global economy which will not, in some way, be affected.”
Currently, electric vehicles cost an average of $30,000 and travel 100 miles or less on a single charge. Tesla (Model 3) and Chevrolet (Bolt EV) have both promised electric vehicles that will travel 200 miles on a charge within the year. Other car makers, such as Volkswagen and BMW, have announced plans to turn a large portion of their production to electric vehicles in the next few years as well.
While the changes in infrastructure and the length of time that most car owners keep a vehicle (11 years on average) have limited electric vehicle sales to this point, according to Christopher Mims of the Wall Street Journal, the next vehicle that most consumers purchase is likely to be electric.
Mims explained, “It is the nature of disruptive technological shifts that it seems like nothing is changing—until it seems as if everything is changing at once. Electric vehicles have been a long time coming, but they now represent such a clear and present threat to the gasoline engine that Mr. Fox, of the service-station association, now recommends that members signing long-term contracts for fuel include an option to renegotiate if more than 10 percent of a state’s fleet goes electric.”
Electric vehicles offer a smooth drive with better acceleration, less moving parts requiring less maintenance, better air quality, and a better platform for autonomous driving, said Bloomberg. Electric vehicles are the future and that means designing better, longer-lasting, higher-performing batteries will be the future as well.
Cooling those batteries will be critical. As Dr. Azar will explain, without proper thermal management the electric vehicle battery will be inefficient and unable to provide the performance that consumers demand.
The Sept. 22 event is free for SAE NE members and $5 for non-members. It runs from 6-9:15 p.m. with tours of the ATS campus from 7-8:00 p.m. and Dr. Azar’s presentation at 8:00. Register online at http://www.sae.org/servlets/sectionEvent?PAGE=getSectionEvents&OBJECT_TYPE=SectionEventAdmin&HEIR_CODE=MS045#249128&saetkn=w1aFMMls8Y or contact SAE member Jeff Mobed at email@example.com or 508-367-6565.