Hydrogen-powered Audi A7 h-tron concept could make production

Audi is pursuing a production future for the hydrogen-powered four-wheel-drive Audi A7 h-tron, company chiefs have hinted following the car's unveiling at the Los Angeles Motor Show.

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/497 kilometres.

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/50km. 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 0-100kph in 7.8sec and reaches a top speed of 113mph/180kph.

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. 

"It is the first performance fuel cell vehicle, but it's important to know that CO2 emissions are zero. This is outperforming the competition. It is a bold statement for the potential of fuel cells and a benchmark innovation."

The A7 h-tron is the German car maker’s third hydrogen-powered prototype, following on from the earlier A2 H2 and Q5 HFC.