Category Archives: Hybrid
The car will make its appearance at the Geneva motor show in March next month
Volkswagen has confirmed its XL1 hybrid for production, which will make its appearance at the Geneva motor show next month.
The two-seat Volkswagen XL1 has a plug-in diesel hybrid system that allows it to achieve 314 MPG and 31 miles on electric power alone. The CO2 emissions sits at 21 g/km, and it is considered the most aerodynamic car with a Cd figure of 0.189. It’s also very light at just 1,752 pounds.
The XL1 hybrid features a 47 bhp 0.8-litre, two-cylinder diesel engine with a 27 bhp electric motor and 5.5 kWh battery pack. According to VW, the XL1 can go from 0-62 MPH in 12.7 seconds with a top speed of 98 MPH.
The XL1 also has some other interesting features, such as a design that completely covers the rear wheels to reduce drag; a pair of rear-facing mirrors on the side of the car instead of door mirrors; wing doors that swivel upwards and forwards, and slightly offset seats for the most interior space possible.
As mentioned, the XL1 is very light at just 1,752 pounds because it is mainly made of carbon monocoque. Aluminum is used on the suspension and dampers as well as ceramic for the brakes and magnesium wheels.
KERS system will propel the vehicle from a stop
In the automotive world, a lot of manpower and money is being put into research and development of systems to help boost fuel economy. The most common system today is a hybrid arrangement that uses batteries and electric motors to help propel the vehicle. Another green system is a KERS flywheel like the one used on the Porsche 918 RSR racecar.
The KERS system on the Porsche is activated with a push button to give the car added performance. Volvo is set to start testing its own version of KERS on the public roads of Sweden after receive a grant from the Swedish Energy Agency.
“Our aim is to develop a complete system for kinetic energy recovery. Tests in a Volvo car will get under way in the second half of 2011. This technology has the potential for reducing fuel consumption by up to 20 percent. What is more, it gives the driver an extra horsepower boost, giving a four-cylinder engine acceleration like a six-cylinder unit,” relates Derek Crabb, Vice President VCC Powertrain Engineering.
The KERS flywheel that Volvo will use spins at up to 60,000 RPM and gets its energy for the forces created when braking. That rotational inertia is then transferred to the rear wheels via a special transmission. In the Volvo system, the combustion engine will be switched off as soon as braking starts and then the energy in the flywheel will be used to propel the vehicle from a stop and help it accelerate.
This sort of system will be most effective in stop and go city driving. Volvo estimates that the combustion engine might be able to be turned off as much as half the time. When combined with the combustion engine the energy in the flywheel could add as much as 80hp to the vehicle and increase performance while allowing the car to be more fuel-efficient.
The Volvo flywheel will be made from carbon fiber instead of steel for maximum efficiency. The flywheel measures a diameter of 20cm and weighs 13 pounds. It also spins in a vacuum to minimize losses.
Article Continues -> Volvo to Test KERS Flywheel Tech with Grant from Swedish Government
Battery prototype: Two sludge-like electrode materials are fed into the device shown here. The anode material flows into the top half, and the cathode flows into the bottom. Lithium ions pass from one material to the other, and electrons flow through the black and red leads. Credit: Yet-Ming Chiang
A startup hopes to commercialize a novel design that features a liquid electrolyte.
Last year, the battery startup A123 Systems spun out another company, called 24M, to develop a new kind of battery meant to make electric vehicles go farther and cost less. Now a research paper published in Advanced Energy Materials reveals the first details about how that battery would work. It also addresses the challenges in bringing the battery to market.
A big problem with the lithium-ion batteries used in electric vehicles and plug-in hybrids is that only about 25 percent of the battery’s volume is taken up by materials that store energy. The rest is made up of inactive materials, such as packaging, conductive foils, and glues, which make the batteries bulky and account for a significant part of the cost.
24M intends to greatly reduce the inactive material in a battery. According to estimates in the new paper, its batteries could achieve almost twice the energy densities of today’s vehicle battery packs. Batteries with a higher energy density would be smaller and cheaper, which means electric and hybrid cars would be less expensive. The paper estimates that the batteries could cost as little as $250 per kilowatt hour—less than half what they cost now.
A conventional battery pack is made up of hundreds of cells. Each cell contains a stack of many thin, solid electrodes. These electrodes are paired with metal foil current collectors and separated from each other by plastic films. Increasing the energy storagerequires adding more layers of electrode material—which in turn requires more layers of metal foil and plastic film.
24M’s design makes it possible to increase energy storage without the extra metal foil and plastic film. The key difference is that the electrodes are not solid films stacked in a cell, but sludge-like materials stored in tanks—one for the positive electrode material and another for the negative electrode.
The materials are pumped from the tanks into a small device, where they move through channels carved into blocks of metal. As this happens, ions move from one electrode to the other through the same kind of separator material used in a conventional battery. Electrons make their way out of the material to an external circuit. In this design, increasing energy storage is as simple as increasing the size of the storage tanks—the device that allows the electrodes to interact stays the same size. The design also does away with the need to wire together hundreds of cells to achieve adequate energy storage.
Story Continues -> A car battery at half the price