Propel Aero is a Sunnyvale, California-based company developing a sodium-air fuel cell for electric aviation. The system is refueled with liquid sodium metal rather than recharged, targeting system-level energy density near 1,000 watt-hours per kilogram (stack-level prototypes demonstrated about 1,700 Wh/kg, roughly three times that of lithium-ion batteries), while its sodium-oxide byproduct reacts with atmospheric CO2 to form benign sodium carbonate. The company was formed by battery researchers including MIT professor Yet-Ming Chiang and Venkat Viswanathan to commercialize research published in Joule in May 2025, starting with brick-sized refuelable cells for large drones, and was incubated at The Engine, the MIT startup incubator.
1
Round
1
Industry
5
Tags
Oct 21, 2026
Latest raise
Funding activity · 1 round
Oct 21, 2026
$4.9M
Seed
Article coming soon.
Pricing
Public hubs orient you on the raise. Paid plans unlock live AI adoption signals across your market.
For individuals and small teams getting started with AI buyer intelligence.
$149
/month
Features
For outbound teams and agencies that need more coverage and faster signal cadence.
$249
/month
Features
Act on this raise
Funding is the starting point. VeilStrat shows whether capital is showing up as hiring, tools, and web activity you can sell into.
