Magnetic concrete could make wireless EV charging affordable

March 12, 2018 // By Christoph Hammerschmidt
With a material that is rather unusual in electrical engineering start-up company Magment plans to revolutionize the inductive charging of electric vehicles: Magnetizable concrete. Above all, this would make automatic charging by means of coils in the roadway affordable. The technology is already being tested in several research projects.

Magnetizable concrete, advertises Magment founder and CEO Mauricio Esguerra, offers one major advantage over other materials in electrical engineering: it is unbeatable value for money. "Concrete is the most cost-effective material on the market," says Esguerra. This price advantage applies not only to its manufacture but also to its processing. The magnetizable concrete developed by Magment can be processed in exactly the same way as conventional concrete - the same machines, the same processes. This already reveals an important field of application for this material: automatic charging of electric cars by means of inductors embedded in the road infrastructure. Even charging while driving is possible.

The technology of magnetic concrete is based on the research work of Esguerra and his team at former Siemens Spinoff Epcos. The company developed and produced passive components. Esguerra succeeded in producing a concrete of very homogeneous quality by mixing ferrite particles in cement. "We can control the magnetic parameters very precisely”, says Esguerra.

Magnetizable concrete can be brought into all conceivable forms by pressureless processing. For wireless charging, Magment has developed a kind of tile in which an electrical conductor is embedded. Primary and secondary coils are charged in "a kind of resonance" at 85 kHz. Esguerra says "a kind of resonance", because the field of resonance charging area is occupied by large companies like Qualcomm; Magment wants to set itself apart from these rivals technically. At a distance of 20 cm, however, his technique can achieve an efficiency of 95%, assures Esguerra.