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RESEARCHERS at Imperial College London, UK are developing a prototype material which stores energy and could be used to make car bodies.

A team led by Emile Greenhalgh from Imperial’s aeronautics department, working in conjunction with various partners including Volvo, are responsible for the patented material. It is a supercapacitor and is composed of woven carbon and glass fibres mats embedded in a polymer resin. The glass fibre mat is the insulator between the carbon fibre layers, which act as the anode and cathode. As the material does not store energy chemically, it can be charged and discharged faster than a conventional battery and does not degrade so quickly.

Alexander Bismarck, a professor in advanced materials at Imperial and a member of the team which developed the composite tells tce that the most difficult part of the project so far was finding a polymer resin that was flexible enough to allow ions but still able to provide mechanical stability to the system.

The team say the material is lightweight but strong enough to be used to make car body panels and components. The latest stage of the project has secured €3.4m ($4.7m) worth of funding from the European Union. The team will look at developing the composite so it can be used to replace flooring in a car’s boot, specifically the wheel well where the spare wheel is stored. They estimate that this would reduce the car’s weight by 15% and could mean the number of batteries required could be reduced. A hybrid petrol-electric car requires several batteries to store energy which are heavy and bulky and lower its efficiency. Volvo is looking at using the material in a prototype car.

The composite could be charged conventionally from a household power supply, but the team are also investigating the possibility of recycling power from the brakes.

As part of the development the team will grow carbon nanotubes on the surface of the material to increase the surface area which will improve the storage capacity. The capacity of supercapacitors is directly proportional to the surface area. They will also investigate suitable commercial production techniques.

“So far we have only made 10cm by 10cm samples,” says Bismarck. “We have been working on the project for five years but it is only now that we have been able to get the funding to develop it further.”

Greenhalgh.says: “The future applications for this material don’t stop there – 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. We’re at the first stage of this project and there is a long way to go, but we think our composite material shows real promise.”

Other project partners include Imperial’s chemistry and chemical engineering departments, Swerea SICOMP, INASCO Hella, Advanced Composites Group, and Nanocyl.