The problem is clear. Hybrid cars and EVs rely on batteries for power, but batteries are bulky and heavy, causing the car to use up more energy. But what if a car's bodywork was made of a strong, lightweight material that could store and discharge electrical energy just as a conventional battery does? In pursuing this goal, researchers at the Imperial College London are developing a key building block for the hybrid car of the future, and the implications go way beyond automobiles - think wafer thin mobile phones and laptops that don't need a separate battery because they draw power from their casing.

Imperial College has been working on the idea as part of a €3.4 million 3 year European Union-funded project which includes researchers from a number of European partners, including automotive firm Volvo. The prototype material is a composite of carbon fibers and a polymer resin which can store and discharge large amounts of energy much faster than conventional batteries. Unlike these there is little degradation in the material over time because there is no chemical process involved, and this also aids more rapid recharging. It is lightweight and strong enough to make car body parts, and could be plugged into the household power supply for recharging.

Researchers say the next stage is to further develop the composite in order to store more energy. This may be achieved by growing carbon nanotubes on the surface of the carbon fibers which will increase the surface area, thus improving its storage capacity. They also hope to find alternative options for recharge such as recycling energy created during braking while the car is on the move. Their first test in-situ will be to exchange the metal floor in the car boot, or wheel well, for the composite, and Volvo is investigating the possibility of rolling this out in prototype cars for testing purposes. The addition of the composite combined with a reduced need for heavy batteries could see the car's overall weight drop by up to 15%, consequently increasing the range of future hybrids.

The most effective method for manufacturing the composite material at an industrial level is also being investigated. Project co-coordinator, Dr Emile Greenhalgh, from the Department of Aeronautics at Imperial College London, says: “We are really excited about the potential of this new technology. We think the car of the future could be drawing power from its roof, its bonnet or even the door, thanks to our new composite material. Even the Sat Nav could be powered by its own casing. 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.”

The future for the Hybrid car looks bright... and batteries are definitely not included.