Bye Aerospace in Denver makes compact electric aircraft. These are typically unmanned airplanes for geospatial roles, and light vehicles for flight training. George E Bye funded the company in 2010 hence the name. At the time he probably did not envisage saying bye to lithium ion. However, in the world of batteries change can happen fast.
So Will It Be Bye to Lithium Ion Permanently?
Bye Aerospace had early successes with a proof-of-concept electric Cessna in 2011. Then it launched Sun Flyer One, a modified PC-Aero Elektra One in 2015. It had been quietly working on a Sun Flyer Two through a subsidiary. Then it brought the project in-house in 2018.
At that stage Bye Aerospace appeared unready to say bye to lithium ion. However, on August 6, 2019 the Aircraft Owners and Pilots Association AOPA dropped a modest bombshell. They announced Bye had turned its attention to lithium sulfur power. We have known the potential of the latter for a while. In a nut-shell, lithium sulfur batteries are lighter, denser and more powerful than lithium ion.
So Why The Need to Change Lithium Horses Now?
The twin-seater Sun Flyer Two will weigh in at about 2,700 pounds. It should have a maximum flying speed of 165 knots and have just over 4 hours flight endurance. However, Bye Aerospace was apparently experiencing problems meeting all three goals.
Therefore lithium sulfur batteries would have presented a more convincing alternative. That’s because they produce more energy per unit of weight that lithium ion batteries. The battery supplier speaks of a potential 400 watt hours per kilogram. This seems like case closed, given a comparison lithium ion battery only managed 260 watt-hours per kilogram.
George E Bye told an AOPA journalist lithium sulfur cells “have the potential to greatly enhance the quality, cost and performance … of our aircraft projects”.
Related
Lithium-Sulfur Batteries Tap Transport’s Door
What are Lithium-Sulfur Batteries?
Preview Image: Promise of a Silent Falcon
