A new approach to storing electrical energy can store more energy than gasoline in the same volume, and could help extend the range of electric vehicles. But some experts say other approaches are more practical.

Batteries produce electricity from a closed chemical system that is eventually exhausted. Fuel cells use a constant supply of fuel, so they are continually topped up. Licht's cell has features of each.


Its negative electrode, or anode, is made from vanadium boride, which serves double-duty as a fuel too. But unlike the flowing fuel of a fuel cell, the material is held internally, like the anode material of a battery.

The vanadium boride reacts with a constant stream of oxygen, as in a fuel cell, provided by the positive electrode, or cathode. This brings in a supply of air from outside.

The cell has a theoretical energy capacity of 27 kilowatt hours per litre, compared to 9.7 kilowatt hours per litre for gasoline. But both approaches are limited by practical factors to smaller figures.