GM Announces Supply Deal with Wolfspeed for Silicon Carbide (SiC) Chips for its Future EVs

author: Eric Walz   

General Motors on Monday announced a strategic supplier agreement with North Carolina-based semiconductor company Wolfspeed Inc. to develop and provide silicon carbide (SiC) power solutions for GM's future electric vehicles. 

As a part of the agreement, GM will participate in the "Wolfspeed Assurance of Supply Program" (WS AoSP), which is intended to secure domestic, sustainable and scalable materials for EV production.

The silicon carbide technology supplied by Wolfspeed will be used in the integrated power electronics of GM's new Ultium Drive units that will be used to power the company's next-generation EVs. Wolfspeed's silicon carbide devices will enable GM to develop more efficient EV propulsion systems that can extend the range of its future EVs.

Silicon carbide has benefits over traditional silicon chips, including better conductivity and cooling performance in high temperature environments, which makes them well suited for electric vehicles.  

"Our agreement with Wolfspeed represents another step forward in our transition to an all-electric future," said Shilpan Amin, GM vice president, Global Purchasing and Supply Chain. "Customers of EVs are looking for greater range, and we see silicon carbide as an essential material in the design of our power electronics to meet customer demand. Working with Wolfspeed will help ensure we can deliver on our vision of an all-electric future."

The widespread adoption of silicon carbide as an industry standard semiconductor can help support the auto industry's rapid transition to EVs. Many EV manufacturers, including Tesla and Chinese EV startup NIO Inc., are working to introduce silicon carbide technology for the inverters in their electric vehicles.

In an electric vehicle, the inverter converts direct current (DC) to alternating current (AC) and controls the flow of electricity from the battery or from the battery pack to the electric motor(s). More importantly, the silicon carbide inverter delivers a more rapid flow of power if the driver demands it, such as during hard acceleration. 

By using a silicon carbide inverter to control the current flow, more power is made available at the wheels. This allows automakers the option of using smaller electric motors without sacrificing power output. But the motors can also be made lighter and operate more efficiently, which can increase range. 

Silicon carbide inverters also offer higher efficiency gains, because they produce less heat and are less temperature-sensitive, which is important for higher RPM high voltage electric motors to help prevent overheating. These inverters also have lower cooling demands and a smaller form factor, making them ideal for electric vehicles where size and weight are concerns.  

Tesla became the first automaker to add SiC metal-oxide-semiconductor field-effect transistors (MOSFETs) to an inverter design the company sourced from its supplier STMicroelectronics in the Model 3.

For the Model 3, the use of SiC in the inverter reduced its overall weight of the inverter to 4.8kg, which is less than half the weight of the inverter in the 2019 Nissan Leaf, which weighs in at 11.1kg. 

Chinese EV startup NIO also plans to use a new silicon carbide (SiC) electric drive system in its future EVs, beginning with the forthcoming ET7. In June, NIO announced that the first C-Sample of its new SiC powertrain rolled off the assembly line.

The silicon carbide power device solutions for GM will be produced at Wolfspeed's Mohawk Valley Fab in Marcy, New York, which is the world's largest silicon carbide fabrication facility. The facility is currently under construction as is expected to go online in early 2022. 

The highly automated fabrication facility will increase capacity for Wolfspeed's SiC business, which is growing rapidly due to increased demand for EV components, as well as for other advanced technology sectors around the world, the company said.

GM is investing $35 billion in electrification and autonomous driving technologies through 2025 as it plans for an all-electric future with dozens of new battery-powered models in the works. 

Supply deals like the one with WolfSpeed will help ensure that GM has the advanced components its needs to deliver more efficient EVs that can travel longer between charges.

Eric Walz

Originally hailing from New Jersey, Eric is a automotive & technology reporter covering the high-tech industry here in Silicon Valley. He has over 15 years of automotive experience and a bachelors degree in computer science. These skills, combined with technical writing and news reporting, allows him to fully understand and identify new and innovative technologies in the auto industry and beyond. He has worked at Uber on self-driving cars and as a technical writer, helping people to understand and work with technology.