The Cadillac Provoq concept, announced at this year's Consumer Electronics Show in Las Vegas and shown in Detroit, is another example of General Motors’ E-Flex propulsion system, this time combining a new fifth-generation fuel-cell system and a lithium-ion battery pack. The concept can go 300 mi (480 km) on a single fill of hydrogen, with 280 mi (450 km) coming from hydrogen and 20 mi (32 km) on battery electric energy.
“The Provoq is a marriage of our Cadillac brand, which is our leader for innovation and technology, with effectively our most advanced powertrain or propulsion system,” said Nick Zielinski, Vehicle Chief Engineer for Advanced System Integration.
The concept is a relatively compact crossover with a 180.3-in (4580-mm) length, 72.8-in (1850-mm) width, and 67.0-in (1703-mm) height on a 114.4-in (2906-mm) wheelbase. Powertrain components were located to minimize intrusion into passenger and cargo room and allow a 60/40-split folding rear seat.
The underhood General Motors-developed fuel-cell stack is half the size of its predecessor but is more powerful. “The size reduction is the result of changes to the materials inside the stack,” said Zielinski. “We changed from polyester composite material to metallic cells to make then thinner.” The proprietary material, along with its coating, was developed with an unnamed metal supplier.
A pair of 10-ksi (690-bar) composite storage tanks beneath the rear cargo floor holds 13.2 lb (6 kg) of hydrogen to feed the fuel-cell stack, which generates up to 88 kW of continuous power. The lithium-ion battery pack can store up to 9 kW•h of electrical energy and provides up to 60 kW additional power. Electricity generated by the fuel cell is distributed to a 70-kW drive system for the front wheels and 40-kW in-wheel hub motors on the rear wheels. Its 0-60 mph (0-97 km/h) time of 8.5 s is a more than 30% improvement over the previous-generation fuel-cell system, and top speed is 100 mph (160 km/h).
A solar panel in the roof helps power onboard accessories such as the interior lights and audio system. Front grille louvers close at highway speeds to enhance aerodynamics and open at low speed to provide maximum cooling to the fuel-cell stack. Other exterior highlights are a full underbody aerodynamic cover, left and right charging ports in the front fender vents for plug-in range extension, flush door handles, and a low-drag roof rack. The concept’s 21-in wheels are located by MacPherson-strut front and multilink rear suspensions and are wrapped in custom Michelin tires incorporating low-rolling-resistance Green-X technology for an extended vehicle range.
The instrument cluster has reconfigurable LCD displays for readouts including fuel-cell and vehicle performance info. “Green” interior highlights include a headliner wrapped in a recyclable soy-based material, carpet made of recycled polyester and jute, seat and instrument panel leather free of harmful chemicals, and carbon-fiber-like Xorel material for the door and instrument panels.