Battery manufacturer Amprius Technologies has delivered the first examples of its latest 450-Wh/kg, 1150-Wh/L high-energy-density lithium-ion cells. Compared with commonly available 300-Wh/kg batteries, the new cells, which use the U.S. company’s Si-Nanowire anode technology, represent a further improvement on the 405-Wh/kg product unveiled as recently as last November.
The first of the cells went to a company that makes high-altitude pseudo satellites. Amprius COO Jon Bornstein said that the increased performance will support aerospace products with higher power needs, including new eVTOL aircraft, for which the batteries could extend flight endurance as power will not deplete so quickly during takeoff. He said that the company expects to produce the first 500-Wh/kg cells later this year.
The keys to the improved technology are the silicon-based anodes and the vertically orientated nanowires used by Amprius. “Traditional electrodes have particles that have to interact, but we have a straight path that means lower resistance and higher power,” Bornstein explained to FutureFlight. That, plus the strong material capacity of silicon has resulted in a tenfold improvement over graphite-based anodes.
In December 2021, Amprius Technologies announced a breakthrough in battery charging rates, with a 0 to 80 percent charge rate for its cells in just six minutes. It is working to achieve mass-production rates for its cells of hundreds of megawatt-hours per year and expects to initiate a major ramp-up in 2024.
According to Bornstein, Amprius is developing cells for drone delivery applications. Other possible applications for improved batteries could include uncrewed air systems for military operations.
“This could be a game-changer for eVTOL aircraft,” Bornstein declared, arguing that battery-electric propulsion is the most viable solution for most eVTOL aircraft intended for urban air mobility services carrying up to six passengers.
Amprius already has a development contract with an undisclosed leading aerospace group that is working on an all-electric eVTOL air taxi vehicle. It has previously provided batteries for the Zephyr solar-powered drone developed by Airbus, which has invested in the company.