Featured Research

from universities, journals, and other organizations

Keeping electric vehicle batteries cool

Date:
July 12, 2012
Source:
Fraunhofer-Gesellschaft
Summary:
Heat can damage the batteries of electric vehicles – even just driving fast on the freeway in summer temperatures can overheat the battery. An innovative new coolant conducts heat away from the battery three times more effectively than water, keeping the battery temperature within an acceptable range even in extreme driving situations.

CryoSolplus is a dispersion that can absorb three times as much heat as water, and can prevent batteries from overheating.
Credit: © Fraunhofer UMSICHT

Heat can damage the batteries of electric vehicles -- even just driving fast on the freeway in summer temperatures can overheat the battery. An innovative new coolant conducts heat away from the battery three times more effectively than water, keeping the battery temperature within an acceptable range even in extreme driving situations.

Related Articles


Batteries provide the "fuel" that drives electric cars -- in effect, the vehicles' lifeblood. If batteries are to have a long service life, overheating must be avoided. A battery's "comfort zone" lies between 20°C and 35°C. But even a Sunday drive in the midday heat of summer can push a battery's temperature well beyond that range.

The damage caused can be serious: operating a battery at a temperature of 45°C instead of 35°C halves its service life. And batteries are expensive -- a new one can cost as much as half the price of the entire vehicle. That is why it is so important to keep them cool. Thus far, conventional cooling systems have not reached their full potential: either the batteries are not cooled at all -- which is the case with ones that are simply exchanged for a fully charged battery at the "service station" -- or they are air cooled. But air can absorb only very little heat and is also a poor conductor of it. What's more, air cooling requires big spaces between the battery's cells to allow sufficient fresh air to circulate between them. Water-cooling systems are still in their infancy. Though their thermal capacity exceeds that of air-cooling systems and they are better at conducting away heat, their downside is the limited supply of water in the system compared with the essentially limitless amount of air that can flow through a battery.

More space under the hood

In future, another option will be available for keeping batteries cool -- a coolant by the name of CryoSolplus. It is a dispersion that mixes water and paraffin along with stabilizing tensides and a dash of the anti-freeze agent glycol. The advantage is that CryoSolplus can absorb three times as much heat as water, and functions better as a buffer in extreme situations such as trips on the freeway at the height of summer. This means that the holding tank for the coolant can be much smaller than those of watercooling systems -- saving both weight and space under the hood. In addition, CryoSolplus is good at conducting away heat, moving it very quickly from the battery cells into the coolant. With additional costs of just 50 to 100 euros, the new cooling system is only marginally more expensive than water cooling. The coolant was developed by researchers at the Fraunhofer Institute for Environmental, Safety and Energy Technology UMSICHT in Oberhausen.

As CryoSolplus absorbs heat, the solid paraffin droplets within it melt, storing the heat in the process. When the solution cools, the droplets revert to their solid form. Scientists call such substances phase change materials or PCMs. "The main problem we had to overcome during development was to make the dispersion stable," explains Dipl.-Ing. Tobias Kappels, a scientist at UMSICHT. The individual solid droplets of paraffin had to be prevented from agglomerating or -- as they are lighter than water -- collecting on the surface of the dispersion. They need to be evenly distributed throughout the water. Tensides serve to stabilize the dispersion, depositing themselves on the paraffin droplets and forming a type of protective coating. "To find out which tensides are best suited to this purpose, we examined the dispersion in three different stress situations: How long can it be stored without deteriorating? How well does it withstand mechanical stresses such as being pumped through pipes? And how stable is it when exposed to thermal stresses, for instance when the paraffin particles freeze and then thaw again?" says Kappels. Other properties of the dispersion that the researchers are optimizing include its heat capacity, its ability to transfer heat and its flow capability. The scientists' next task will be to carry out field tests, trying out the coolant in an experimental vehicle.


Story Source:

The above story is based on materials provided by Fraunhofer-Gesellschaft. Note: Materials may be edited for content and length.


Cite This Page:

Fraunhofer-Gesellschaft. "Keeping electric vehicle batteries cool." ScienceDaily. ScienceDaily, 12 July 2012. <www.sciencedaily.com/releases/2012/07/120712111713.htm>.
Fraunhofer-Gesellschaft. (2012, July 12). Keeping electric vehicle batteries cool. ScienceDaily. Retrieved January 29, 2015 from www.sciencedaily.com/releases/2012/07/120712111713.htm
Fraunhofer-Gesellschaft. "Keeping electric vehicle batteries cool." ScienceDaily. www.sciencedaily.com/releases/2012/07/120712111713.htm (accessed January 29, 2015).

Share This


More From ScienceDaily



More Matter & Energy News

Thursday, January 29, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Tesla 'Insane Mode' Gives Unsuspecting Passengers the Ride of Their Life

Tesla 'Insane Mode' Gives Unsuspecting Passengers the Ride of Their Life

RightThisMinute (Jan. 29, 2015) — If your car has an "Insane Mode" then you know it&apos;s fast. Well, these unsuspecting passengers were in for one insane ride when they hit the button. Tesla cars are awesome. Video provided by RightThisMinute
Powered by NewsLook.com
Now Bill Gates Is 'Concerned' About Artificial Intelligence

Now Bill Gates Is 'Concerned' About Artificial Intelligence

Newsy (Jan. 29, 2015) — Bill Gates joins the list of tech moguls scared of super-intelligent machines. He says more people should be concerned, but why? Video provided by Newsy
Powered by NewsLook.com
Two Stunt Pilots Perform Incredibly Close Flyby

Two Stunt Pilots Perform Incredibly Close Flyby

Rumble (Jan. 29, 2015) — Two pilots from &apos;Escuadrilla Argentina de Acrobacia Aιrea&apos; perform an incredibly low altitude flyby stunt during a recent show exhibition in Argentina. Check it out! Video provided by Rumble
Powered by NewsLook.com
'Brand Blocker' Glasses Blur Ads in Real Time

'Brand Blocker' Glasses Blur Ads in Real Time

Buzz60 (Jan. 28, 2015) — A team of college students design and build a pair of goggles that will obscure any corporate branding from your field of vision. Jen Markham (@jenmarkham) has the story. Video provided by Buzz60
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins