Project Title: Next-Generation Lithium Metal Anode Cells for Electric Aviation

Location: Cambridge, MA

Award Amount: $11,922,264

24M Technologies Website



Lithium-ion (Li-on)-based energy storage systems have advanced in energy density while also greatly reducing in cost over the last decade. The current generation of high-nickel cathodes paired with graphite anodes are approaching the measurable limits of their performance, however.

Lithium metal anodes are the highest energy density anodes but the processibilities of thin foil and safety control for production is a big drawback to its use in transportation applications.

Technical Approach

24M’s manufacturing process is a simple, space-efficient, low-cost, modular approach to Li-ion battery manufacturing. The process is designed around the use of standard Li-ion supply chain materials, which results in significant OPEX and CAPEX savings versus a conventional manufacturing line.

24M’s SemiSolid cell manufacturing with a binder-free electrode process and platform gives rise to a new class of low-cost, high-energy density, extremely safe, and reliable lithium-ion cells that accelerate the path to a better energy future.

The 24M team will develop and scale up batteries incorporating a lithium electrode sub-assembly (LESA) and SemiSolid cathode that deliver lower cost energy storage (<70 $/kWh), superior power (>1.5 kW/kg), and improved energy density (450 Wh/kg) for electric aviation. The 24M Technologies team will develop and scale up a commercial, modular large-pilot line (1 MWh/y) for customer validation with a clear path to GWh/y production capacity of new Li metal-based batteries.


LESAs, developed during the IONICS program, provide a demonstrated pathway to stable Li metal anodes in which dendrite growth is mitigated by an in-situ corrosion prevention process with a chemo-mechanically tunable polymer–ceramic interlayer. Our team includes leading commercialization partners that bring exacting product specifications for reliable downstream product validation alongside domestic (Albemarle, Sepion) manufacturing and battery pack design (And Battery Aero) partners to meet the aggressive goals of SCALEUP while increasing battery production in the United States.

ARPA-E Mission Alignment

Achieving energy densities over 300 Wh kg while massively reducing cost to under 70$/kWh will require rethinking conventional technologies. Building on foundational work completed by members of our team under the ARPA-E Batteries for Electrical Energy Storage in Transportation (BEEST) and Integration and Optimization of Novel Ion-Conducting Solids (IONICS) programs, we enable new development and scale-up activities for lithium metal-based energy storage incorporating 24M’s unique SemiSolid cathode alongside LESAs to demonstrate an electric aircraft transportation with extended range and reduced cost.


ARPA-E SCALEUP 2019 24M Pouch Cell

24M Pouch Cell

ARPA-E SCALEUP 2019 24M Unit Cell Manufacturing Line

24M Unit Cell Manufacturing Line