Helios Horizon made aviation history on June 5 with the first flight of a human-piloted electric airplane powered by solid-state batteries. According to the company, the batteries provide double the range and flight times possible with conventional electric-vehicle batteries.
Founder and chief test pilot Miguel Iturmendi designed the Helios Horizon aircraft around a Pipistrel Taurus airframe. The aircraft is equipped with “unique systems for power delivery, battery management, propulsion and thermodynamic control,” the company said. The airframe was also modified with wing extensions and solar panels.
The test flights performed by Iturmendi at Zephyrhills Municipal Airport (KZPH) in Florida were done to validate the weight and balance of the aircraft after incorporation of the new batteries.
According to the company, unlike the lithium-ion cells previously used by Helios Horizon and by almost all electric vehicles, solid-state batteries are smaller and offer greater energy density.
Lithium-ion batteries contain a liquid electrolyte. Next-generation solid-state batteries replace some or all of that liquid with solid materials, reducing fire risk and allowing more energy to be stored in the same amount of space. According to Helios, in testing, solid-state batteries have shown greater resistance to damage, overheating, and thermal runaway than conventional lithium-ion batteries.
Helios Horizon’s previous lithium-ion batteries provided 260 watt-hours per kilogram. The new solid-state batteries yield 410 Wh/kg. Solid-state batteries can be charged from almost empty to 80 percent in less than 15 minutes.
“For the first time, we have a battery technology that yields the range and charging times necessary to make commercial electric aviation viable, while providing the safety the flying public will demand,” Iturmendi said.
Helios Horizon holds the world altitude record for an electric aircraft in its weight class and has been designed to fly into the stratosphere. While it has reached 24,000 feet on previous flights, the team is targeting altitudes over 40,000 feet, higher than most passenger airliners.
With the introduction of solid-state batteries into Helios Horizon’s unique power management and propulsion systems, Iturmendi expects to easily complete stratospheric flights on a single charge.
The team will be making more test flights later in the year.