According to the Pennsylvania State University (Penn State) researchers, batteries for eVTOL vehicles have special requirements. Given these requirements, the scientists say the batteries will be built with these specific specifications in mind.

The Penn State researchers reported their findings alongside prototype eVTOL battery designs in a June 7 study published in Joule. They noted that eVTOL vehicles "have attracted considerable interest as a disruptive technology to transform future transportation systems." However, the researchers acknowledged that the batteries' unique operating profiles and requirements pose hurdles to be overcome by future battery technologies.

Study author Chao-Yang Wang said: "I think flying cars have the potential to eliminate a lot of time, increase productivity and open the sky corridors to transportation. Commercially, I would expect these vehicles to make 15 trips twice a day, during rush hour, to justify the cost of the vehicles. The first use will probably be from a city to an airport, carrying three to four people about 50 miles."

But Wang acknowledged that creating batteries to match the needs of eVTOL vehicles is not a walk in the park. "Batteries for flying cars need very high energy density so that [they] can stay in the air. [They] also need very high power during takeoff and landing. It requires a lot of power to go vertically up and down," he said.

The study author also noted that eVTOL vehicle batteries must have the ability to be recharged rapidly to match vehicles' frequent takeoffs and landings. A battery typically charges easily when empty, but charging takes longer and becomes more difficult as it stores more energy. Heating the battery, however, keeps the battery charging time short.