The U.S. Patent and Trademark Office published on Thursday Apple's patent application for a hydrogen fuel cell technology. This will purportedly allow a mobile device such as an iPhone to have a week-long battery life.The application was submitted in March this year but was only published Thursday. The details can be accessed here.

The new technology supports earlier reports that showed Apple's interest in hydrogen technology. There are, for instance, two previous patents in 2010 entitiled "Fuel Cell System to Power a Portable Computing Device" and "Fuel Cell System Coupled to a Portable Computing Device," reported by Apple Insider.

The newest patent explains the existence of a fuel cell stack that generates power as well as cartridge systems and several connectors. Based on these, one can expect fuel that is converted to electrical power rather than the usual battery packs, according to Mashable. Indeed, the patent application cited several sources of fuel that include sodium borohydride and liquid hydrogen.

Some experts, however, doubt whether the patent will be implemented in the near future. This can be attributed to the difficulty in designing fuel cartridges because it will eat up valuable design space or the challenge in having users adopt recharging by fuel rather than through USB, according to Apple Insider. 

Still, the fuel cell concept is viable. One need only look at a working iPhone 6 prototype announced this month that runs on a hyrdogen-powered battery developed by British firm Intelligent Energy. The company claims that it has successfully created electricity by combining hydrogen and oxygen, the Telegraph reported. Intelligent Energy is reportedly working closely with Apple. But it is not clear whether its technology is the same as the one contained in Apple's recent patent application.