From grain for horses to JP-8 fuel for jets, energy has long been the fundamental currency of the battlespace. ExPEDitions is a DARPA effort to leapfrog operational energy limitations, demonstrating a new chemistry for electrically rechargeable batteries and fuel cells able to achieve both high energy and power density.
Balancing energy and power
“Energy” is like the size of your bank account; “power” is how fast you can spend it. A sensor array and a vertical-takeoff-and-land drone might have similar total energy needs, but one spends the energy over months, the other in minutes or hours.
The advent of affordable lithium-ion batteries has provided ubiquitous portable power at unprecedented energy densities, but hydrocarbon fuel power systems outstrip these energy densities by a factor of 10. ExPEDitions looks to match fuel energy density but in a battery form factor that will enable electrical rechargeability and complete independence from fuel supply lines in hotly contested environments.
Achieving high energy, stability, endurance
ExPEDitions is building on a promising rechargeable carbon-air system developed in the DARPA ExCURSion program (Expeditionary Carbon Utilization for Energy Resilience and Stabilization). ExCURSion’s novel chemistry shows high specific energy and high stability, making it a favorable system-level alternative to hydrocarbons for endurance missions and commercial applications alike (e.g. drones with hundreds of additional miles of range; electric vehicles that don’t risk bursting into flame).
In its first 18 months, ExPEDitions aims to create a battery solution ready for testing in real-world devices (e.g. drones, heavy machinery, etc.) to create a pathway for near-term adoption and maturation in commercial markets.
Overcoming power density limitations
In ExPEDitions’ second 18-month phase – in addition to moving the initial battery solutions towards integration into real world devices – ExPEDitions will focus on using recent advancements in oxygen electrochemistry (or other novel approaches) to at least triple the peak specific power of the batteries, opening up new approaches to frontline capabilities.
Combining high energy and power density in a rechargeable solution could dramatically simplify battlespace logistics, particularly for contested environments. It could also help rapidly accelerate the commercial innovation and adoption around new energy solutions for an almost unlimited array of real-world applications.
