However, it is not currently possible to fulfil all mobility requirements with a single electric vehicle concept. Those who drive predominantly or even exclusively in urban areas do not place as much emphasis on vehicle range but very much like the idea of lower noise levels and emissions. For such customers, a battery-electric vehicle is an attractive solution.
Those who also wish to cover long distances on country roads and motorways combined with low noise levels, no local emissions and short refuelling times have a viable alternative in the shape of the fuel-cell electric vehicle.
Mercedes-Benz Concept BlueZERO, measuring 4.22 m in length, 1.89 m in width and 1.59 m in height, offers decisive design advantages over electric cars based on conventional vehicle platforms and designed only for use in combination with internal combustion engines.
The interior space is retained in full. As the energy accumulators/generators are integrated into the spacious sandwich floor, no compromises are necessary with respect to passenger space, luggage capacity or variability. The powertrain technology located in the sandwich floor and integrated directly at the front axle ensures a low centre of gravity and, consequently, extremely reliable and agile handling. Crash safety is of the extremely high standard associated with Mercedes thanks partly to the housing of the powertrain components between the axles.
Typically for this class of car, all three versions of the Concept BlueZERO are front-wheel drive models with an electric motor at the front axle. The batteries are located in the centre of the vehicle floor behind this, in a position which protects against intrusion in the event of a frontal or rear impact because the energy accumulators are located outside of the body's impact and deformation zones.
Mercedes-Benz will present two BlueZERO variants at the 2009 NAIAS show in Detroit: the BlueZERO E-CELL as a purely battery-powered vehicle and the fuel-cell version, the BlueZERO F-CELL – both of which are emission-free in local operation. Mercedes-Benz development engineers are also working on a third version with a range extender, the BlueZERO E-CELL PLUS. This is additionally equipped with a compact internal combustion engine as a generator that produces power during a journey.
All these models feature battery packs based on the latest lithium-ion technology. This new battery technology has decisive advantages over conventional battery types, among them very compact dimensions, significantly higher performance, excellent reliability and a long operating life. The common components used in the modular system also include the compact, permanent magnet synchronous electric motor, which operates at a maximum of 13,280 rpm.
It develops a peak output of 100 kW and a continuous output of 70 kW. Its peak torque is 320 Nm, while the continuous torque is 180 Nm. The maximum torque is available from the first revolution of the electric motor and exceeds the figure achieved by a current V6 petrol engine at 2500 rpm. ■