The Next Frontier of EV Innovation: The Powertrain!

Batteries have owned the public's mind share when it comes to boosting performance and decreasing the cost of electric vehicles. And for good reason. The battery accounts for roughly half the total cost of an EV. Batteries have been undergoing significant innovations recently, with startups such as QuantumScape and Ample looking into solid-state lithium batteries and modular designs.

General Motors' planned $650 million investment into lithium production company Lithium Americas further spotlights the increasing demand for EV batteries and the chemicals that make them a reality. A Reuters study in October found that automakers had committed $1.2 trillion to invest in batteries and other EV parts through 2030.

But for EVs to work at scale, we need to focus on another component — the powertrain.

An electric vehicle’s powertrain is exactly what it sounds like. These components give the vehicle power, i.e. its motor, transmission, driveshaft, AC/DC converter, and control unit. We’re talking about the control systems determining an EV’s performance, range, and efficiency. Or, for even more context, the parts that account for 10-25% of an EV’s total cost.?

There has been some innovation in the space, most notably with companies exploring the use of new materials, such as silicon carbide . But the truth is that a massive opportunity exists for startups to make a splash by coming up with solutions to the market’s biggest barriers. Let’s look at some of the challenges and the opportunities to address them.?

Fundamentally different

In many ways, the powertrain of an EV is much simpler than that of an internal combustion-powered vehicle. EV powertrains are made of far fewer components — 60 percent less — than vehicles that run on internal combustion.

Other fundamental differences pertain to the types of transmissions and torque delivery used. In internal combustion-powered vehicles, the transmission system distributes power from the engine to the wheels, while power management in an EV is governed by the drive inverter regulating power flow from the battery to the motor. As a result, EV drivers experience improved acceleration and a more enjoyable ride overall.

However, while EV powertrains provide breakthroughs with getting from 0 to 60 mph faster, there's still work to be done with transmission system efficiency. Most EVs still use a dated platform of 400 volts, but a minimum 800-volt platform would reduce joule losses and allow high-voltage cabling to be downsized, improving efficiency and cutting weight.

Lucid's 924-volt platform is one reason the automaker has been able to achieve a 520-mile range, and now GM, Hyundai and Volkswagen are transitioning to 800-volt platforms. The improved efficiencies delivered by an 800-volt platform mean the industry can increase driving range and decrease charging time, significant barriers to EVs working at scale. By eliminating range anxiety, we can quash the next stifler of EV adoption, which is price.

The average new EV sells for significantly more than its internal combustion counterpart. Developing more efficient powertrains won't solve this issue by itself, but improving the technology so these vehicles can use less energy and smaller batteries and travel farther on a single charge is a critical step in making EVs more accessible.

Specific parts of an EV powertrain, including motors and inverters, need attention. Recent deal activity in this space — such as Yasa Motors ' acquisition by Mercedes-Benz and Turntide Technologies ' rapid ascension to unicorn status with nearly $500 million worth of capital raised — is evidence of the sheer scale of the opportunity that's out there. But there's still room for improvement.

What the three main types of EV motors — permanent magnet synchronous motor, induction motor and switched reluctance motor — all have in common is that they're radial motors, meaning their magnetic fields are oriented in a radial direction relative to their rotation axis. While radial motors have proven to be reliable and efficient, they could benefit from development in terms of performance, size and cost. In fact, motor manufacturers have been operating somewhat with their backs up against a wall as they've been forced to focus largely on cost reduction vs. performance improvement.

Motor innovation

There have been some exciting innovations in axial flux motors, an alternative to radial flux motors. An axial flux motor has a magnetic field running parallel to the axis of rotation. This is the type of motor that Yasa Motors produces, meaning it is what Mercedes AMG vehicles will use in the future.

Axial flux motors are becoming more popular because they have a higher power density than radial flux motors, meaning they can produce more power for their size and weight. They also have a lower cogging torque, making them smoother and more efficient at low speeds.

But compared with radial flux motors, axial flux motors can have more complex designs and be more challenging to manufacture, making them more expensive. They require neodymium magnets, which are rare earth minerals. Developing a viable alternative that doesn't rely on this type of magnet would be a game changer and sure to catch the attention of EV makers and investors alike.

When it comes to developing better motors, location also matters. There are two main options today. In-hub placement means the motor is in the wheel's hub, while a central drive unit placement puts the motor in the center of the vehicle and power is transferred to the wheels. An in-hub motor eliminates the need for a transmission, driveshaft, and differential, but it is typically not as efficient. A central drive unit, on the other hand, requires a driveshaft and differential and, in some cases, a transmission, allowing an EV to operate at optimal efficiency. This placement also results in better insulation through the suspension system and from the weather.

The inverter space offers another opportunity for startup innovation. Most EVs use voltage-source inverters, which are simple and inexpensive but limited in performance and efficiency. Developing more advanced inverter technologies, such as current-source inverters, can significantly improve performance and efficiency.

In addition to the other obstacles innovators face, the auto industry is a highly regulated industry. The lengthy certification process for new motor and inverter components can be a major barrier for companies looking to bring innovative new products to market. But for startups with the resources to disrupt the status quo, there is a massive opportunity out here to focus on innovation in this space.

This article was originally published in Automotive News