ORNL wireless charging breakthrough unplugs electric vehicles from the grid

I’ve been saying for some time now during my keynotes, like the ones recently at GITEX in Dubai, and RWE in Germany that Lithium Ion batteries in electric vehicles will face a comparatively short lived future before polymers, that can charge EV’s in seconds, on or near road wireless charging systems, and then ultimately batteryless cars, like Lambourghini’s Terzo Millenio concept, which will be made from energy storing composites called structural batteries, appear and then become the norm. Because let’s face it plugging in your future electric car into a future electric supercharger network and hanging around for twenty or so minutes watching paint dry will still be as much of a nuisance as it is today.

And I’m not the only one to think so. The US Department of Energy's Oak Ridge National Laboratory (ORNL) who built and demonstrated a massive 20 kW wireless car charging system back in 2016 have now taken another giant leap in helping companies like BMW who are already starting to take the first step of this journey by developing wirelessly charged cars, realise their dreams with the creation of a 120 kW system that can charge cars fast and without the need for that darned charging cable.

As you’d expect ORNL's latest compact wireless charging system takes energy from the grid, converts it to high-frequency AC before using a coiled copper cable, like the one used to wirelessly charge your smartphone but larger, to transfer power across a 6 inch air gap to a secondary coil, where it's stored in a battery pack.

"It was important to maintain the same or smaller footprint as the previous demonstration to encourage commercial adoption," said project lead Veda Galigeker. "We used finite element and circuit analyses to develop a novel co-optimization methodology, solving the issues of coil design while ensuring the system doesn't heat up or pose any safety issues, and that any loss of power during the transfer is minimal."

In its laboratory demo, the project team managed to transfer 120 kW of power with 97 percent efficiency, which is comparable to the plug-in fast chargers in operation today. But the researchers are not stopping there. They plan to look for ways to increase power transfer to 200 kW and beyond, eventually delivering 350 kW systems capable of charging an electric vehicle in 15 minutes or less.

There's also talk of developing dynamic charging systems, where wireless charging pads are installed under road surfaces, perhaps even solar powered road surfaces like the ones in France, that will allow for top-ups at highway speeds as electric vehicles are driving over them.

So while the end of the dreaded charging cables won’t come too soon, it does look like it will come one day...

Source: ORNL