US Military Edging Closer To Electric Vehicles, One Step At A Time

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The US Department of Defense has been achingly slow to add electric vehicles to its massive fleet. However, signs of activity have been stirring among automotive and battery stakeholders with an interest in defense contracts. The latest example is the US silicon battery firm Amprius Technologies, which has nailed down a slot in the xTechPrime Competition hosted by the US Army.

Award-Winning Batteries For Electric Vehicles, Eventually

To be clear, the XtechPrime award does not mean that the US Army is ready to run right out and buy a whole fleet of new electric vehicles equipped with silicon batteries. Amprius makes silicon lithium-ion batteries for various applications that are relevant to DOD applications, but not electric vehicles — yet.

“Amprius Technologies’ high-performance lithium-ion batteries are currently being used in premium and mission critical applications and will soon expand to EV and consumer applications as our manufacturing capacity grows,” the company states on its website.

That day appears to be edging closer, based on Amprius’s track record to date. “Our commercially available 370 Wh/kg silicon anode battery demonstrated extreme fast charge rate of 0-80% state of charge in less than six minutes,” Amprius adds.

Meanwhile, the xTechPrime award has supported a $1.9 million contract for Amprius to develop its 500 Wh/kg SiMaxx™ cell for electric mobility applications in the defense sector.

For the time being, that probably means aircraft. Amprius has partnered with the US firm AeroVironment to integrate the new battery into its solar-powered, autonomous high altitude pseudo satellite (HAPS).

“Our partnership with Amprius allows AV to field our solar stratospheric platforms with the highest payload capability in its class: 150 lb mass and 1500W continuous power,” explains the VP and General Manager of AeroVironment’s HAPS division.

How Serious Is The US Army About Electric Vehicles?

Still, the availability of a fast charging, 500 Wh/kg battery suggests that military electric vehicles are closer than they were just a couple of years ago. After all, the point of the xTechPrime Competition is to encourage small businesses to contribute to the modernization goals of the US Army, including vehicle electrification.

“Amprius’ industry-leading 500 Wh/kg, 1300 Wh/L SiMaxx cell… provides approximately double the energy compared to conventional cells,” Amprius emphasizes.

“The continued partnership with the Department of Defense accelerates the development of critical capabilities and strengthens the U.S. supply chain,” they add.

If you caught that thing about continued partnership, that’s a reference to an ongoing DOD portable battery modernization project that involves Amprius.

“Although the Army has been slow to adopt battery-powered electric vehicles, it is constantly on the lookout for opportunities to lighten the heavy load of portable batteries carried around by the modern soldier to power their increasingly large stock of portable electronic gear,” CleanTechnica noted earlier this year, adding that drone technology has also stimulated the demand for next-generation batteries that weigh less and last longer.

The Silicon Solution

Both the Defense Department and the US Department of Energy have been focusing the search for better batteries on silicon, as a higher-performance replacement for the graphite commonly used in battery anodes.

There being no such thing as a free lunch, silicon is not a magic potion. It has taken some time to develop a silicon-based material that can withstand hundreds of charging cycles. The Energy Department’s Pacific Northwest National Laboratory, for example, was working on a silicon “sponge” all the way back in 2010.

All that hard work is beginning to pay off. In 2021, Amprius Technologies won a contract with the Rapid Capabilities and Critical Technologies Office of the US Army to develop its silicon battery for use in drones. The contract also included developing silicon battery cells that complement the Army’s new form-fitting battery vests.

A significant milestone occurred in 2022, when the battery passed a required nail penetration test.

More Silicon Batteries For Electric Vehicles

The xTechPrime Competition also yielded another indication of the Army’s interest in electric vehicles. Among the other awardees is the 100% silicon anode specialist GDI, which partnered with the leading defense battery contractor Navitas Systems to enter the competition.

“GDI’s silicon anode can increase the energy density of Li-ion batteries by over 30% and triple their charging speed compared to those with graphite-based anodes,” GDI explains. “The anodes can operate in low temperatures and will enable increased safety of cells, as demonstrated in recent 3rd party nail penetration testing.”

In addition to electric vehicles, GDI is aiming to electrifying everything from aviation to yard equipment.

Whether or not the Defense Department is ready to up the ante on electric vehicles, GDI is prepping for the market. The firm, which is headquartered in New York, has set up a pilot scale, roll-to-roll production facility in the Netherlands in partnership with the high tech materials firm AGC, as a first step to commercial-scale production in Lauenförde, Germany.

What About Fuel Cell Electric Vehicles?

Yes, what about them? Signs of US military interest in fuel cell electric vehicles have emerged now and then over the years. In 2017 the Department of Energy took note of the Defense Department’s hydrogen fuel cell activities, though not much progress on the application to fuel cell electric vehicles has crossed the CleanTechnica radar to date.

One interesting development occurred back in 2018, when the US Army Tank Automotive Research, Development and Engineering Center (TARDEC) deployed a General Motors Chevrolet Colorado ZH2 fuel cell vehicle to get some additional soldier feedback.

“Previous ZH2 evaluations involved Soldiers at the squad and platoon levels, while this latest exercise involved an entire battalion-sized element,” TARDEC explained.

“The ZH2, fitted with a hydrogen fuel cell and electric drive, has a stealthy drive system which produces a very low smoke, noise, odor and thermal signature. This allows Soldiers to conduct silent watch and silent mobility missions on the battlefield,” TARDEC added.

I’ll be reaching out to TARDEC to see if there was a follow-up program. Meanwhile, the ZH2 got props for exporting enough power to run the squadron Tactical Operations Center while parked, providing a noise-free, easier-to-maintain alternative to diesel generators.

That was not the end of GM’s interest in fuel cell electric vehicles,. Earlier this year the company provided an update on a fuel cell pilot project aimed at eliminating pollution at worksites, centered on a fleet of medium-duty hydrogen fuel cell trucks and green hydrogen production.

“Built on a similar frame to the 2024 Chevrolet Silverado 5500 MD, these field evaluation fleet trucks will be powered by HYDROTEC fuel cell systems,” GM explained.

“Since fuel cells are lightweight and enable large payloads, excellent range, quiet operation and rapid refueling, they can meet the needs of the heaviest duty applications,” GM elaborated.

If the Chevy Silverado rings a bell, GM’s Defense branch pitched a fuel cell version of the vehicle to the Army about six years ago, as a successor to the Colorado demonstration project. That idea also seems to have fallen by the wayside, though the Army began showcasing a prototype fuel cell electric vehicle for emergency response last year, engineered by the new Accelera branch of Cummins.

Opportunities for producing  green hydrogen on site could help stimulate more activity in the military fuel cell field, so stay tuned for more on that.

Image (cropped) The Defense Department has been slow to adopt electric vehicles, but new silicon EV battery technology could help speed things up (courtesy of Pacific Northwest National Laboratory).