The plan is for Toyota to provide BMW with drivetrain and hydrogen storage solutions. The German automaker will use them to build a prototype vehicle by 2015 and possibly enter production around 2020, according to Japan's Nikkei.
As you probably know, fuel cells typically convert hydrogen into electricity to power vehicles, allowing them to run five times longer than battery electric cars. Moreover, it takes just a few minutes to fill a tank with hydrogen, whereas charging a battery requires several hours.
Source: Automotive News