Battery developer Oxis Energy will work with Bye Aerospace to produce a lithium-sulfur battery cell for a high-voltage battery pack system for possible use in the US aircraft maker’s electric aircraft.
The Colorado-based aircraft maker is working with UK-based Oxis on a variant of the chemistry for its eFlyer 4 and future air taxi aircraft designs’ performance. The project will start next month.
In European ground tests, Oxis reports its battery achieved a discharge three-times longer than the previously used lithium nickel manganese cobalt oxide technology.
An Oxis spokesman told BEST Battery Briefing that they were unable to disclose more information about discharge times without prior consent from the customer as they were tied to specific aircraft designs.
However, the firm predicts its technology will achieve twice the discharge duration of Bye’s lithium-ion batteries, for the same weight.
The mission (or discharge) profile for Bye was performed as a bench laboratory assessment as the test continues until the battery is fully discharged.
Test records were constructed using actual data measured from an aircraft to provide a realistic discharge profile.
The spokesperson told BBB: “Each application has a different mission profile. In the first phase, we will determine how the lithium-sulfur cells and modules perform in terms of discharge duration and provide engineering design information such as thermal management.
“We are working with Bye with the goal that a high-voltage lithium-sulfur battery will be used on its range of aircraft.”
Oxis’ cells have reached 400Wh/kg and the company expects to achieve 500Wh/kg by early next year— a year later than its 2016 prediction— through improvements to the cell, including the anode, the cathode, the separator and the electrolyte formulation.
Bye’s Sun Flyer 2 aircraft uses six lithium-ion batteries— 80kW combined— from Electric Power Systems.
Over the next 18 months, Oxis aims is to move towards the production of commercial cells and battery systems in order to meet the volume roll-out criteria set by Bye Aerospace.