Plastic Electric Motor May Help EVs Reduce Weight

Developed by the Fraunhofer Institute for Chemical Technology, it is also cheaper to build.

Mass, aerodynamics, and powertrain efficiency are the three pillars of a more efficient combustion engine vehicle. Although electric cars already have the most energy-efficient engine man has ever created, it also pursues low weight. And more aerodynamic designs, as pop-out door handles and cameras instead of rear-view mirrors clearly demonstrate. But they also have room for improvement. Curiously, one of these opportunities has been found on the most unlikely element: the electric motor. What if its housing is made of plastic in place of metal? This is what the Fraunhofer Institute for Chemical Technology (ICT) and the Karlsruhe Institute of Technology (KIT) have recently proposed in Germany.

“An electric motor consists of a rotating rotor and a static stator. The stator contains the copper windings that the electricity flows through – and this is where the majority of electrical losses occur”, says Robert Maertens, a researcher at Fraunhofer ICT. Maertens refers to the 10 percent of losses that happen through the heat in an electric motor. This is why electric cars are so efficient: 90 percent of the electric energy becomes movement, while the very best combustion engines can only turn 40 percent of the chemical energy contained in fuels to work.