I have just scanned the article to see if there are some relevant facts. There are not, but I agree, that the issue is the battery. Given current technological progress around batteries, the “flying EV” is maybe feasible for small (1-3 passenger + pilot), private planes, but is still too heavy for any sort of commercial type of plane. While kerosene has energy density 42MJ/kg or 11,7kWh/kg, the battery cell used today has energy density 300Wh/kg. Challenger 600, consumes 260 gallons/1000l/800kg per hour. Hence we talk about 9,4 MWh, electricity engine would be maybe 20% more efficient, but still, that is lot of batteries to carry around for a plane. And here comes my regular “infrastructure argument”: how do they want to charge 5-10 planes like that at the same time?