A British firm has developed what it claims to be the world's first hydrogen-powered smartphone battery, capable of keeping an iPhone 6 charged for up to seven days. Intelligent Energy created a working prototype for Apple's latest flagship phone, using the headphone socket as a port to refuel the hydrogen.

It is believed that the company has been working closely with Apple in order to develop the battery technology. Apple is yet to respond to a request for comment from IBTimes UK as to whether it is considering using hydrogen fuel cells within its devices in the future.

The miniaturised fuel cell fits into the iPhone 6 without having to alter the device in any significant way. The most discernible difference to standard models is the inclusion of a small vent on the back cover that allows water vapour to escape. Future versions of the hydrogen-powered battery will utilise a disposable cartridge that could be easily fitted into the bottom of future smartphones, negating the need to recharge the device through traditional methods.

"To our knowledge, this has never been done before," Henri Winand, chief executive of Intelligent Energy, told The Telegraph. "We have now managed to make a fuel cell so thin we can fit it to the existing chassis without alterations and retaining the rechargeable battery. This is a major step because if you are moving to a new technology you have to give people a path they are comfortable with."

Intelligent Energy believes that the technology could be rolled out commercially within two years, depending on how interested partners are with pursuing it.