Dovetail Electric Aviation is working with cooling specialist Engineered Fluids to develop a new immersion-cooled battery suitable for multiple aircraft applications. The companies announced their partnership on June 12 in Australia.
The DovePack batteries being developed by Dovetail for various battery- and hydrogen-electric regional aircraft will use Engineered Fluids’ proprietary AmpCool cooling fluid. According to the companies, the immersion cooling technology will deliver a breakthrough in safety and thermal stability for aircraft batteries.
In contrast to traditional air- or cold plate-cooled systems, Engineered Fluids says that AmpCool allows direct cooling by surrounding each battery cell with a non-conductive, non-flammable, and chemically stable fluid. The Florida-based company says this supports a 1,000-fold improvement in thermal conductivity compared with air cooling processes, while also providing a built-in fire suppressant by isolating and containing failed cells without pressure relief systems or external cooling.
Lighter, Smaller Batteries
The use of immersion cooling is also expected to do away with the need for heavy and complex heat sinks around batteries, as well as fans, pumps, and tubing. Dovetail believes the resulting size and weight savings will be especially beneficial for new electric aircraft, and it is already testing the technology at its facilities in Australia and Spain.
Last year, Crisalion Mobility agreed to use Dovetail battery packs for its planned five-passenger Integrity eVTOL aircraft. Dovetail is also working on plans to convert existing turboprop models to electric propulsion, including the Cessna Caravan, the DHC Twin Otter, the Beechcraft King Air, and the Casa C212.
“Electric aviation cannot scale without better thermal management at a battery level,” said Lars Heeg, Engineered Fluids’ director for Europe, Middle East, and Asia. “By fully immersing battery cells in AmpCool, we can deliver dramatically better heat dissipation, prevent thermal runaway propagation, and extend battery performance in the most demanding environment imaginable [for] flight.”
The DovePack battery systems have an energy density of between 260 and 270 Wh/kg, with 403 maximum volts, and maximum charge and discharge rates of 60 amps and 80 amps, respectively. Dry weight of the full system is 31 kilograms (68 pounds).