The recharging of the future will have to be fast, and therefore also wireless. American researchers at Oak Ridge National Laboratory, an institute in Tennessee funded by the US Department of Energy, have set a new power record for inductive charging of electric cars.

They recharged the battery of a zero-emission car to 100 kW with 96% efficiency. To achieve this, they used multiphase electromagnetic coupling coils with rotating magnetic fields.

A solution protected by a patent

The American scientists have already patented the technology used. In fact, to charge the Hyundai Kona EV used for the laboratory experiment, they chose a route similar to that used to charge smartphones and other consumer electronic devices.

Omer Onar, one of the researchers involved in the project, said:

"We have achieved the world's highest power density for a wireless charging system for electric cars. Our technology enables us to achieve a power density 8 to 10 times greater than that of a conventional coil".

la ricarica wireless di tesla è in arrivo

Tesla is also working on wireless charging

50% charge in less than 20 minutes

With a charging power of 100 kW, this new induction charging plate achieved a 50% charge in less than 20 minutes. The real innovation lies in the fact that, thanks to the polyphase coupling coils, considerable power can be achieved with very small appliances. The disc used to charge the battery measures just 35 centimetres in diameter.

This is a size/charge speed ratio that is unthinkable with conventional coils. In the past, wireless charging power of 120 kW has been achieved at Oak Bridge National Laboratory, but using conventional technology, the entire charging device was bulkier and more difficult to install.

"With this technology, we have achieved a revolutionary breakthrough that paves the way for fast and efficient wireless charging for electric passenger vehicles."

With such power and efficiency, mobile wireless charging can also enjoy considerable benefits.