German startup’s groundbreaking motor holds promise of cheaper EVs with more range

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A technician works on DeepDrive GmbH's dual rotor technology on a test bench.Courtesy of manufacturer

While we wait for solid-state batteries, which are widely believed to be the next great leap in electric vehicle technology, others are seeking different ways to drive down the price and increase the range of EVs.

DeepDrive GmbH, a high-tech startup headquartered in Munich, has created a new electric motor that it says will pave the way for more affordable electric vehicles, thanks to its low cost of production and high efficiency.

The motors, which use dual-rotor technology, are ultracompact and designed to fit inside a wheel hub, unlike most EV motors today, which sit between the wheels and use axles to transfer torque. DeepDrive is working with eight leading car companies and has garnered support from high-profile investors that include BMW i Ventures and Continental AG's corporate venture capital unit. In its latest round[2] of funding, the company picked up an additional EUR30-million (£45-million), led by Leitmotif, a U.S. venture capital fund dedicated to decarbonization investments.

DeepDrive says it will use the funds to build in-house production lines and industrialize the technology.

Carola Mauck, a spokeswoman for DeepDrive, says that the German company is focused on large-scale projects for the mass market, with the aim of enhancing the economic feasibility of electric cars by bringing down their price. With the majority of new EVs priced at more than £50,000 and many closer to the six-figure range, DeepDrive's technology, if successful, could offer some light at the end of the tunnel for the average car buyer. At a time when many automakers are scaling back EV production citing lack of demand and increased costs, and seemingly moving backward by introducing more gas-electric hybrids, these new motors could disrupt the EV industry enough to secure its future.

That's certainly the goal of the founders who came together from leading companies like Audi and Bosch to form DeepDrive in 2021.

Deep Drive's central drive unit. The company developed a new electric motor that it hopes will pave the way for more affordable electric vehicles, thanks to its low cost of production and high efficiency.Courtesy of manufacturer

It's not every day that small startups can capture the attention of companies like BMW. The auto giant discovered DeepDrive at the 2021 Munich International Motor Show and has been collaborating with the company since then.

In a press release[4], Karol Virsik, head of research vehicle concepts and technologies at BMW Group, said, "DeepDrive's prototype parts largely exceeded our specifications. That's really unusual at such an early stage and with a completely new technology." He added, "DeepDrive has developed an exciting vision for the electric drive of the future."

Most EVs today use electric motors that consist of a stator and a rotor. The stator remains still while the rotor rotates inside it.

The stator contains copper coils or "windings" that generate a magnetic field. This causes the rotor to spin, producing the torque needed for acceleration. All well and good.

But the transfer of that electrical energy from stator to rotor - its magnetic flux - isn't perfectly efficient. And that is where DeepDrive saw room for improvement.

"The magnetic flux lines [in conventional motors] cause core [electrical energy] losses that reduce overall efficiency," Mauck says. "These motors also have complex cooling and structural support requirements, increasing their weight and manufacturing costs."

To avoid these core losses, DeepDrive's motor replaces the stationary stator with a second rotor. The outer rotor resembles a cake pan and spins simultaneously with a ring-shaped internal rotor.

The stator, which looks like a copper ring, sits in between the two rotors. The rotors allow more space for magnets, which are surface-mounted as opposed to being embedded, and the stator uses windings laid out in an innovative wave pattern. Mauck says this reduces production costs and eliminates the need for the complex assembly processes required by traditional motors.

The Drive-Brake Unit developed by Deep Drive and Continental.

The company says it is on track to start producing its motors by 2026.Courtesy of manufacturer

Four in-wheel motors are not required. In a performance application, four motors would be a good thing, but most cars can run on just one. For more mainstream applications, DeepDrive's central drive motor, which uses the same technology, can take the place of current EV motors that sit on the axles.

The pancake-shaped in-wheel motor is ultracompact, with a diameter of 19 or 20 inches, depending on the model.

Ranging from 32 to 37 kilograms, the motors are also lightweight and produce up to 30-per-cent more torque than the leading single-rotor design, owing to the large size of the outer rotor. In its most powerful configuration, each motor can produce a staggering 1,770 lb-ft of torque. DeepDrive says it's also 30-per-cent more energy efficient compared to a conventional motor in a typical drive cycle, which contributes to increased range.

This high efficiency allows for a 20-per-cent smaller battery, according to the company, and that is expected to lower the charging costs. Even with current battery technology, the company says its motors can allow EVs to drive up to 800 kilometres or more on a single charge. Most EVs today can drive about 400 - 500 kilometres on a single charge.

Compared with conventional electric motors, DeepDrive says its motor uses up to 80-per-cent less electrical steel and 50-per-cent less magnet material while avoiding the use of expensive rare earth minerals such as dysprosium and terbium, which are almost exclusively sourced from China. "By combining reduced material usage, cost-effective manufacturing techniques and the ability to use a smaller battery, DeepDrive's motor technology lowers production costs," Mauck says. "This contributes to making the entire vehicle more affordable."

DeepDrive says it is on track to start producing its motors by 2026.

After seeing the initial testing of the dual-rotor technology, BMW has said it plans to officially field test them in its vehicles. Spy photos[6] have already caught BMW testing a sporty-looking prototype equipped with what appear to be in-wheel motors.

Though BMW has remained officially tight-lipped, M boss Frank van Meel did hint to reporters recently that it was testing a quad-motor prototype that would be "typical M."

With the anticipated delivery of this groundbreaking dual-rotor motor closer than ever, it would seem some of the biggest innovations in EVs are coming from small, independent companies like DeepDrive - companies that have small, highly focused teams that can specialize in one area.

Even when it comes to solid-state batteries, companies like Volkswagen have chosen to invest in startups like QuantumScape Corp., which has developed a proprietary solid-state lithium-metal battery.

Volkswagen says it will redefine the future of battery technology.

If DeepDrive's new motors can enable EVs equipped with conventional batteries to travel 800 kilometres on a single charge, imagine the possibilities when the next generation of batteries arrives on the market.

References

1. ^ Open this photo in gallery: (www.theglobeandmail.com)
2. ^ latest round (www.deepdrive.tech)
3. ^ Open this photo in gallery: (www.theglobeandmail.com)
4. ^ press release (www.press.bmwgroup.com)
5. ^ Open this photo in gallery: (www.theglobeandmail.com)
6. ^ Spy photos (www.bmwblog.com)