At a Washington Post Live virtual conference, General Motors President Mark Reuss provided more details about GM’s next-generation Ultium lithium metal battery and announced a joint development agreement with lithium metal battery innovator SES (formerly known as SolidEnergy Systems) (earlier post).

GM’s lithium metal battery with a protected anode will feature a combination of affordability, high performance and energy density. The initial prototype batteries have already completed 150,000 simulated test miles at research and development labs at GM’s Global Technical Center in Warren, Michigan, demonstrating real-world potential.

GM’s prototype lithium metal batteries were developed at the company’s research and development labs in Warren, Michigan. To accelerate lithium metal battery commercialization, GM announced a joint development agreement with lithium metal battery innovator SES. (Photo by Steve Fecht for General Motors)

To accelerate Li-Metal battery commercialization, GM is working with several innovative companies and making investments that will allow the company to scale quickly.

GM Ventures was an early investor six years ago in MIT spin-out SES, a research, development and manufacturing leader of Li-Metal technology and AI-powered battery management software to optimize performance and safety. The 2015 investment was the start of a close working relationship between SES and General Motors’ research and development organization.

Today’s joint development agreement is the next progression of that ongoing collaboration. As part of the agreement, GM and SES plan to build a manufacturing prototyping line in Woburn, Massachusetts, for a high-capacity, pre-production battery by 2023.

Affordability and range are two major barriers to mass EV adoption. With this next-generation Ultium chemistry, we believe we’re on the cusp of a once-in-a-generation improvement in energy density and cost. There’s even more room to improve in both categories, and we intend to innovate faster than any other company in this space.

—Mark Reuss

The expected battery energy density increase could enable higher range in a similarly sized pack or comparable range in a smaller pack. The weight and space savings from smaller battery packs could help with vehicle lightweighting or create more room for additional technology.

Part of the foundation of GM and SES’ collaboration on Li-Metal prototype batteries is GM’s extensive lithium metal battery experience. The company’s expertise in this field has resulted in 49 patents granted and 45 patents pending. SES will also bring its own lithium metal intellectual property to the collaboration.

GM announced this rapid technical progress for possible use in future Ultium-based vehicles just one year after the reveal of the first-generation Ultium Platform. The first Ultium-based products are expected to go on sale later this year.

GM has said that the second-generation Ultium cells would reduce costs for EVs such as the Chevrolet Bolt by 60% by mid-decade.

Although it began by pursuing a solid-state Li-metal solution, SES altered its approach to develop a safe electrolyte paired with an ultra-thin Li-metal anode. The electrolyte greatly enhances battery safety, and the ultra-thin Li-Metal anode reduces battery weight and production costs. The company says that its SES Li-metal cells can deliver 400-500 Wh/kg and more than 1000 Wh/L.

SES is offering Li-Metal cells in three formats:

• Hermes Cell (for drone applications)
• Hermes Module (for drone applications)
• Apollo Cell (for automotive applications) (coming in 2022)