Volvo turns car body into a battery

October 17, 2013 // By Christoph Hammerschmidt
Car batteries are heavy and clumsy, right? Along with research partners, Volvo has developed a concept to integrate the batteries into the car structure. With innovative materials and form factors, the batteries would claim much less space. Further down the road, the concept could significantly reduce the weight of future electric vehicles.

Volvo's new energy storage systems consist of carbon fibres, nano structured batteries and supercapacitors. The project team identified a feasible alternative to the heavy weight, large size and high costs associated with the batteries seen in hybrids and electric cars today, whilst maintaining the efficient capacity of power and performance. The answer was found in the combination of carbon fibres and a polymer resin, creating an advanced nanomaterial, and structural super capacitors. The reinforced carbon fibres sandwich and the new battery are moulded and formed to fit around the car's frame, such as the door panels, the boot lid and wheel bowl, releasing the space normally occupied by the batteries (without sucpercaps) in the floor structure of the car or in the trunk. The carbon fibre laminate is first layered, shaped and then cured in an oven to set and harden. The super capacitors are integrated within the component skin. This material can then be used around the vehicle, replacing existing components, to store and charge energy.

The material is recharged and energised by the use of brake energy regeneration in the car or by plugging into a mains electrical grid. It then transfers the energy to the electric motor which is discharged as it is used around the car.

But it is not only the form factor that gives this concept an edge over conventional lithium-ion batteries. The new material also charges and stores faster than conventional batteries. And it is also strong and pliant.

Today, Volvo has evaluated the technology by creating two components for testing and development. These are a boot lid and a plenum cover, tested within the Volvo S80.

The boot lid is a functioning electrically powered storage component and has the potential to replace the standard batteries seen in today’s cars. Though it contains a battery, it is lighter than a standard boot lid, saving on both volume and weight.

The new plenum demonstrates