The only car on the market today that uses batteries and a gasoline-powered generator to recharge those batteries while the car moves is the GM Volt. While the Volt is a highly-efficient vehicle when on battery power alone, its not any more efficient than the average car when the gas generator is on. A breakthrough from the University of Maryland may change that in the future.
The innovation is a small gasoline fuel cell that would need to be only 10cm per side to generate the same power as the gasoline generator found under the hood of the Volt today. The small fuel cell would be able to use gasoline, diesel, or natural gas to create power to drive an electric system using batteries.
The key to small fuel cell breakthrough is that the researchers have been able to reduce the operating temperature of the fuel cell from 900°C to about 650°C. Their ultimate goal is to get them down to 350°C. That temperature reduction makes the fuel cell much cheaper to construct and easier to package and insulate safely in a car. In the future, extended range EVs like the Volt may be able to use this cell for much more efficient driving.
[via Technology Review]