Carbon fibres could work as battery electrodes in cars and planes, claim researchers

Research opens up new possibilities for structural batteries, where the carbon fibre forms part of the energy system

Carbon fibres can work as battery electrodes, storing energy directly, according to a new study by scientists at the Chalmers University of Technology in Sweden.

The findings could open up new opportunities for structural batteries, where the carbon fibre becomes part of the energy system, the researchers suggested, and could contribute to a significant weight-reduction in the aircraft and vehicles of the future.

A car body would then be not simply a load-bearing element, but also act as a battery

The scientists say that this is a key challenge for electrification, as passenger aircraft need to be much lighter than they are today if they are to be powered by electricity. A reduction in weight is also important for vehicles in order to extend the driving range per battery charge.

Professor of material and computational mechanics at the University, Leif Asp, conducted research into the ability of carbon fibres to perform more tasks than simply to act as a reinforcing material, adding that they can store energy, for example.

"A car body would then be not simply a load-bearing element, but also act as a battery," he said.

"It will also be possible to use the carbon fibre for other purposes, such as harvesting kinetic energy, for sensors or for conductors of both energy and data. If all these functions were part of a car or aircraft body, this could reduce the weight by up to 50 per cent."

It will also be possible to use the carbon fibre for other purposes, such as harvesting kinetic energy

Asp and his team of researchers studied the microstructure of different types of commercially available carbon fibres. They discovered that carbon fibres with small and poorly oriented crystals have good electrochemical properties but a lower stiffness in relative terms.

"We now know how multifunctional carbon fibres should be manufactured to attain a high energy storage capacity, while also ensuring sufficient stiffness," Asp explained.

"A slight reduction in stiffness is not a problem for many applications such as cars. The market is currently dominated by expensive carbon fibre composites whose stiffness is tailored to aircraft use. There is therefore some potential here for carbon fibre manufacturers to extend their utilisation."

We now know how multifunctional carbon fibres should be manufactured to attain a high energy storage capacity

In the study, the types of carbon fibre with good electrochemical properties had a slightly higher stiffness than steel, whereas the types whose electrochemical properties were poor are just over twice as rigid as steel.

Now, the researchers are collaborating with both the automotive and aviation industries, the latter of which Asp said it may be necessary to increase the thickness of carbon fibre composites, to compensate for the reduced stiffness of structural batteries.

This would, in turn, also increase their energy storage capacity, he added.

The Computing Technology Product Awards 2018 are coming!

Recognising the very best in technology talent, the Awards will recognise innovation and technology excellence across the range of mobility, software, infrastructure, security, cloud computing - and people.

To find out more, to enter and to reserve your table at the Awards on 30 November, check out our dedicated Computing Technology Product Awards website