electric cars battery draws in oxygen from the surrounding air.

Scientists say the revolutionary 'STAIR' (St Andrews Air) battery could now pave the way for a new generation of electric cars, laptops and mobile phones.

The cells are charged in a traditional way but as power is used or 'discharged' an open mesh section of battery draws in oxygen from the surrounding air.

This oxygen reacts with a porous carbon component inside the battery, which creates more energy and helps to continually 'charge' the cell as it is being discharged.

By replacing the traditional chemical constituent, lithium cobalt oxide, with porous carbon and oxygen drawn from the air, the cell is much lighter than current batteries.

And as the cycle of air helps re-charge the battery as it is used, it has a greater storage capacity than other similar-sized cells and can emit power up to 10 times longer.

Professor Peter Bruce of the Chemistry Department at the University of St Andrews, said: "The benefits are it's much smaller and lighter so better for transporting small applications.

"The size is also crucial for anyone trying to develop electric cars as they want to keep weight down as much as possible.

"Storage is also important in the development of green power. You need to store electricity because wind and solar power is intermittent."