One of the keys to unlocking the potential of electric vertical takeoff and landing (eVTOL) aircraft is developing lightweight lithium-ion batteries that pack enough energy density. Ideally, an effective battery system would offer eVTOLs the required range and fast recharging time to make this entirely new form of air transport scalable as well as commercially viable.
For years, the battery industry talked about reaching a higher gravimetric energy density—a so-called “magic number” of 450 watt hours per kilogram, which some experts said would break the sector wide open and spur the emerging eVTOL industry forward.
For comparison, a typical off-the-shelf electric vehicle (EV) battery has an energy density of 250 to 350 watt hours per kilogram. But in November 2021, a company called Amprius announced it was developing the first commercially…