The four-door luxury saloon employs a low-temperature proton exchange membrane (LT PEM) fuel cell stack and carbonfibre hydrogen tanks together with a plug-in lithium-ion battery and a pair of electric motors to achieve an overall zero-emission range of up to 311 miles.
Mounted up front in the space usually taken up by the A7’s more traditional combustion engines, the fuel cell employed by the A7 h-tron comprises over 300 cells, each of which is a polymer membrane separated by a platinum-based catalyst. It operates in a voltage range between 230 and 360 volts.
The fuel stack is supported by a plug-in 8.8kW/h lithium-ion battery mounted within the floor of the boot. It boasts a recharge time of two hours on a regular 240-volt mains and also stores recuperated kinetic energy, helping to extend the overall range up a claimed 31 miles. Refilling the hydrogen supply, meanwhile, takes two minutes.
The new Audi uses two electric electric motors – one mounted up front and one at the rear. They developed nominal 114bhp and 199lb ft each, providing the A7 h-tron with a combined 228bhp and 398lb ft of torque.
With drive sent to all four wheels, Audi claims the 1950kg A7 h-tron accelerates from 0-62mph in 7.8sec and reaches a top speed of 113mph.
Audi's technical chief Ulrich Hackenberg said hydrogen power would form part of an increasing varied drivetrain landscape in the future: "This is the most forward-looking concept from our research and development team. The A7 h-tron is unique in many regards.