Project invents crash-safe battery housing for EVs

A mass-producible, crash-safe housing for electric vehicle (EV) batteries has been developed by Fraunhofer researchers using fibre-reinforced composite materials.

Experts from the Fraunhofer Institute for Chemical Technology, along with colleagues from other Fraunhofer Institutes, used a modified Artega GT sports car fitted with an electric drive and an electric motor in the rear for the project.

The result is a 35kg housing that does not affect the stability or the safety of the passenger.

‘Traditional solutions made of steel weigh up to 25 per cent more,’ said Manfred Reif, project manager in the project. ‘The battery housing can withstand a crash, assuming a ten-fold gravitational acceleration.’

If a sharp object collides with the housing at 45mph, the battery within the housing remains intact. In addition, the 16 lithium-ion modules are protected from humidity and a semi-permeable membrane equalises pressure.

According to a statement from Fraunhofer, it must be possible to mass-produce the housing in order to make it feasible.

‘It must be possible to mass-produce the lightweight components,’ explained Reif. ‘Up to now, this has not been possible in this form.’

The scientists have developed a special process chain with cycle times that make the production of high unit counts possible.

‘The process chain is designed so that many steps can be run simultaneously,’ said Reif.

The plastic is heated up parallel to the production step, and elements are prepared that ensure load and tensile strength or the attachment to the storage in the rear of the Artega.

This includes, for example, directionally oriented fibreglass structures or custom-made metal inserts. All the individual components are then assembled and pressed together in a ‘one-shot process’.

Currently, the battery box must still be secured with transverse attachments in the rear of the Artega; however, a replacement is being sought.