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New batteries could cut electric car charging times

Published: 01st September, 2016 at 00:00
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Ionic redox transistor batteries hope to bump EV charging efficiency from 0.4 miles per minute to “tens of miles per minute.”

Charging your eco-friendly electric vehicle can be a slow process, but engineering researchers at Ohio State University are working on a new material that could make charging your battery considerably faster.


By testing the charging rate of current electric cars, the researchers, led by professor Vishnu-Baba Sundaresan, discovered that at their best estimations it takes eight hours to charge a car long enough to travel for 200 miles (0.4 miles per minute), whereas that distance can be covered by petrol engines for only one minute at the pump. This problem is caused by the way charge is stored in batteries, but by developing smart plastic membranes surrounded by a liquid electrolyte, they hope to make new ionic redox transistor batteries, which could bump up its storage capacity to give tens of miles per minute.

Existing lithium batteries already contain plastic membranes, but Sundaresan’s membranes are different and smarter. By doping polypyrrole, researchers can insert pores, which allow charged particles called ions to pass through them. These smart pores open wide when the battery is being charged or being used to power the car, but close when it is not being used, a bit like a fishing net where the holes shrink after the fish have been caught.

“For long road trips, you could empty out the used electrolyte and refill the battery to get the kind of long driving range we are accustomed to with internal combustion engines,” explains Sundaresan.

Another problem with lithium batteries is that they self-discharge (slowly go flat) as ions leak between the membranes, causing the electrical energy to drain away. That’s annoying if it happens slowly, and dangerous if it happens too fast. There have been numerous stories in the news recently where the heat given out by leaking lithium batteries has caused hoverboards, iPhones and even Boeing 787 Dreamliners to catch fire. Sundaresan believes that, when used with a specially designed electronic control unit, the new batteries could prevent this kind of thermal runaway.

The Ohio team is now working to make their dream of a safer, faster charging battery a reality. If they succeed, it would certainly generate a buzz in the electric vehicle industry.


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