Intelligent Energy in the UK has developed a working iPhone 6 with a hydrogen fuel cell built into the chassis, The Telegraph reported.
According to the report, the fuel cell sits alongside the normal iPhone 6 lithium-ion battery, and is refilled through the headset jack.
In future, the company said it expects there to be a slot on smartphones where a cartridge is inserted.
The Telegraph reported that Intelligent Energy’s technology is patented, and that the company is said to be working closely with Apple.
Talk of cartridge-based hydrogen fuel cell systems for cellphones is not new, though.
STMicroelectronics said in 2008 that its miniature fuel cell had been in development since 2005, and was due to hit the market by 2010.
STM’s products were also designed to be part of a hybrid system where the phone runs off a lithium-ion battery, which in turn is charged by the fuel cell.
BIC, the company known for its disposable pens, was set to manufacture cartridges for STM’s technology. Each cartridge could provide 3 to 5 recharges of a traditional battery.