Engineers at Imperial College London are developing a composite material that can store and discharge electrical energy, but is also strong and lightweight enough to be used for car parts.
Automotive engineers are eager to use more composite materials to reduce weight and eliminate corrosion. In the future, composite parts may even do double duty and serves as batteries on hybrid and electric vehicles.
Engineers at Imperial College London, working in conjunction with several partners such as Advanced Composites Group Ltd. and Volvo Car Corp., are developing a prototype material that can store and discharge electrical energy but is also strong and lightweight enough to be used for car parts.
“We are really excited about the potential of this new technology,” says Emile Greenhalgh, a professor in the Department of Aeronautics at Imperial College. “We think the car of the future could be drawing power from its roof, its [hood] or even its door, thanks to our new composite material. Even the [GPS system] could be powered by its own casing. We’re at the first stage of this project and there is a long way to go, but we think our material shows real promise.”
Greenhalgh and his colleagues are planning to develop the composite material (in addition to a cost-effective way to mass-produce it) so that it can be used to replace the metal flooring that traditionally holds a spare tire in the car trunk. “Replacing a metal wheel well with a composite one could enable [automakers] to reduce the number of batteries needed to power an electric motor,” says Greenhalgh. “This could lead to a 15 percent reduction in overall weight, which should significantly improve the range of future hybrid cars.”
The composite material is made of carbon fibers and a polymer resin. It can store and discharge large amounts of energy much more quickly than conventional batteries. In addition, the material does not use chemical processes, making it quicker to recharge than traditional batteries. The recharging process also causes little degradation in the composite material, because it does not involve a chemical reaction, whereas conventional batteries degrade over time.
According to Greenhalgh, the material could be charged by plugging a hybrid car into a household power supply. The engineers are also exploring other alternatives for recharging, such as recycling the energy created when a car brakes.
Current hybrid cars consist of an internal combustion engine, which is used when the driver accelerates the car, and an electric motor powered by batteries, which turns on when the car is cruising. The cars need a large number of batteries to power the electric motor, which makes the vehicle heavier.
Greenhalgh and his colleagues are planning to further develop their composite material so that it can store more energy. For instance, the team will improve the material’s mechanical properties by growing carbon nanotubes on the surface of the carbon fibers, which should increase the surface area of the material and improve its capacity to store more energy.
In addition, the engineers believe the new material, which has been patented by Imperial College, could potentially be used for the housing of portable electronic devices, such as cell phones and computers, so that they would not need a separate battery.
“This would make such devices smaller, more lightweight and more portable,” Greenhalgh points out. “You might have a mobile phone that is as thin as a credit card because it no longer needs a bulky battery, or a laptop that can draw energy from its casing so it can run for a longer time without recharging.”
New Composite Material Doubles as a Battery
June 18, 2010