Image source: topwar.ru
The Office of Advanced Research Projects of the US Department of Defense (DARPA) is promoting a program to create next-generation military batteries aimed at increasing specific energy above 2 kWh/kg. This is 10 times higher than the best modern lithium-ion batteries (about 0.25–0.3 kWh/kg).
DARPA has set the task for researchers to radically improve the mechanism of battery systems. Applications for participation in the program are accepted this month, and ready proposals are expected in August 2026. The project will be implemented for 36 months, starting in January 2027.
Several key American technology companies from the commercial and defense sectors have already achieved specific laboratory and pre-production results that serve as a starting point for meeting the extreme requirements of the DARPA program.
A number of companies leading developments in the field of solid-state batteries intend to replace the traditional graphite anode with lithium metal. QuantumScape manufactures prototype batteries in 24 layers with an ultra-thin ceramic separator that provide 10% to 80% charging in less than 15 minutes while maintaining high capacity. Solid Power has already launched a pilot production line for full-size cells with sulfide solid electrolyte and is supplying them for testing to BMW and Ford automakers. Developments on their thin-film separators can become a good basis for the implementation of the DARPA request.
Amprius Technologies, which has focused on silicon anodes, has created the densest commercially available batteries to date. It mass-produces cells with an anode made of 100% silicon nanowires. Their achieved rate is 0.5 kWh/kg. Their batteries are already being purchased by the US Army and manufacturers of stratospheric drones (for example, the Airbus Zephyr). For DARPA, this is a significant achievement, proving that nanostructured materials can hold extreme amounts of energy.
Sila Nanotechnologies, which studies silicon composites, has developed a powdered silicon material called Titanium Silicon, which replaces graphite. Her main achievement is to solve the problem of catastrophic expansion of silicon (up to 300%) during charging by creating special nanoscale "pockets". The technology is already being implemented in consumer electronics and electric vehicles, providing a 20-40% increase in energy density without the risk of battery destruction.
PolyPlus Battery, a leading researcher in lithium-air and lithium-sulfur systems, is a pioneer in the development of protected lithium metal anodes. She was the first in the United States to coat pure lithium with an ultrathin layer of waterproof glass electrolyte. This made it possible to create stable laboratory samples of lithium-air batteries that do not collapse upon contact with air moisture.
DARPA intends to bring all these individual successes together in order to force companies to move from the current ceiling of about 0.5 kWh/kg to the revolutionary 2 kWh/kg and above.
