In a nutshell, scientists from Southampton University used an alternating current, powered by a transformer, to recreate a bolt of electricity by passing 200,000 volts across an 11-inch gap. This generated the same heat, light and charge produced by a bolt of lighting, which was then used to charge the battery on a Nokia 925 phone. Continue reading for a video and more information.
According to The Daily Mail, "Neil Palmer from the university passed the extremely high voltage across a gap between two conducting tubes in order to generate the bolt. The charge was then passed through a second, controlling transformer, connected to the phone's battery.