Jet packs, robotic maids and flying vehicles are all guaranteed for the twenty first century. We got a mechanized, autonomous vacuum cleaner as an option. Now a group of researchers at Penn State is exploring requirements for the design and testing of electrical vertical takeoff and touchdown (EVTOL) auto and potential battery power sources.
Mechanical Engineering’s William E. “I think flying vehicles have the potential to eliminate a lot of time and increase productivity and open sky corridors for transportation,” said Chao-Yang Wang, Diffender Chair and Director of Electrochemical Engine Heart. Penn State. “Although electric vertical takeoff and touchdown are very difficult for the auto battery.”
Researchers outline technical requirements for flying automotive batteries and report on prototype batteries on June 7, 2021 in Joule.
“Batteries intended for flying vehicles need very high power densities to keep them in the air,” Wang said. “They also require a lot of energy during take-off and touchdown. It requires a lot of energy to go up and down vertically.”
Wang notes that the batteries also need to be recharged quickly enough to generate immense income during rush hours. He sees these vehicles doing frequent take-offs and landings and recharging rapidly and repeatedly.
“Commercially, I expect these vehicles to make 15 trips twice a day during rush hour to justify the cost of the vehicles,” Wang said. “Primary use will probably take three to four people about 50 miles from a city to an airport.”
Weight may be a consideration for these batteries as the car must lift and unload the battery. As the EVTOL flies, depending on the wang, typical speeds on short trips can be 100 mph and longer trips are 200 mph.
The researchers experimentally tested two energy-dense lithium-ion batteries that can recharge with enough power for a 50-mile EVTOL journey in 5 to 10 minutes. These batteries can sustain over 2,000 fast-charges over their lifetime.
Wang and his team used the technology for electric car batteries. The bottom line is to heat the battery to allow it to charge faster without the formation of lithium spikes that sag and are harmful to the battery. It seems that overheating the battery causes a rapid discharge of the power held in the battery allowing take off and landing.
The researchers heat the battery by incorporating a nickel foil that quickly brings the battery down to 140 levels Fahrenheit.
“Under normal circumstances, three properties are important for an EVTOL battery to work against each other,” Wang said. “Extreme power density reduces quick charging and quick charging in general reduces the variety of possible recharge cycles. However we are in a position to do all three in a single battery.”
A completely distinctive side of flying vehicles is that the batteries must at all times retain some cost. For example, unlike cellphone batteries, which work best when fully discharged and recharged, a flying car battery can never be allowed to fully discharge in the air as it stays in the air and takes off. Energy is required for this. A flying automotive battery should have a margin of safety at all times.
When the battery is empty, the internal resistance to charge is low, although the larger the remaining cost, the harder it is to push extra power into the battery. Sometimes, recharging slows down due to the battery being full. Nevertheless, by heating the battery, recharging can last within five to ten minute intervals.
“I hope the work we’ve done on this paper will give people a strong concept that we don’t want these vehicles for another 20 years,” Wang said. “I think we’ve shown that EVTOL is commercially viable.”
Additionally engaged in this venture are Xiao-Guang Yang and Shanhai Ge, each assistant analysis professor in mechanical engineering, and Teng Liu, a doctoral scholar in mechanical engineering at Penn State; and Eric Roundtree, EC Energy, State Faculty, Pennsylvania.
Power effectiveness and workplaces of the US Division of Renewable Energy, the US Air Power Small Enterprise Specialization Switch Program and the William E. The Diefenderfur Endowment funded this analysis.