New technology may give electric cars more mileage

In an effort to give electric car drivers more km per minute of charging, engineers led by an Indian-origin researcher have designed a thin plastic membrane that stops rechargeable batteries from discharging when not in use and allows for rapid recharging.

According to Vishnu-Baba Sundaresan, assistant professor of mechanical and aerospace engineering, today's hybrid and electric cars are hitting the performance limit because of how charge is stored in conventional batteries.

He believes that the new membrane technology might be the only way to push past that limit until a new category of battery electrodes are developed.

The best eco-car makers appear to have hit a performance limit and that limit is 0.4 miles -- less than half a mile of driving -- per minute of charging.

"Put another way, today's very best eco-friendly cars can travel around 200 miles after an eight-hour charge, while gas-powered cars can cover the same distance after only one minute spent at the pump," the authors said.

The researchers hope their new technology can boost electric car batteries to provide up to tens of miles per minute of charge.

"That's still an order of magnitude away from the equivalent measure in gasoline, but it's a place to start," said Sundaresan.

Sundaresan and doctoral student Travis Hery are working on a battery in which energy is stored in a liquid electrolyte -- which people can recharge or empty out and refill as they would refill a gas tank.

For everyday commuting, the electrolyte can be simply regenerated by plugging it into a power outlet overnight or while parked at the garage.

"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," Sundaresan noted.

The same technology could prevent self-discharge in supercapacitors, which give high power and rapid recharge capability to some electric cars, buses and light rail transit systems.

The research was published in the journal Energy & Environmental Science.

--IANS

na/bg