The sheer economic force behind electric flight is insane. It’s like an ocean behind a glass wall. Any crack and it will rush in to take advantage of it.
Boeing and Airbus spend literal tens of billions for single-digit efficiency gains. Think what 50-60% efficiency gains are worth.
Liquid Hydrogen:
2.6 kWh/L Volumetric Energy Density
39 kWh/kg Gravimetric Energy Density
Lithium Ion:
0.693 kWh/L Volumetric Energy Density
0.340 kWh/kg Gravimetric Energy Density
Conclusion:
Liquid Hydrogen is 3.75x more energy dense by volume.
Liquid Hydrogen is 114.7x more energy dense by weight.
Gravimetric energy density cannot be understated, weight is immensely important for aircraft. Planes can easily be grown to increase fuel storage as long as weight is kept low (hence why blimps are a thing). Weight is directed related to buoyancy.
The only real barrier is cost of fuel. Airbus as well as other manufactures are working on Hydrogen planes with electric motors, so yes Hydrogen planes are still electric.
Large scale air transport isn’t going to benefit from electric flight until they switch to zeppelins or we somehow master beamed power from space. The difference in energy density between batteries and combustible fuel is simply too great. If commercial aviation is going to become carbon neutral in our lifetimes it’s going to be through carbon neutral fuels. Can those be made cheap enough? Maybe.
General aviation on the other hand (“doctor killers”) could go electric. The range requirements and the size of the aircraft are much smaller. We already have solar powered drone aircraft; scaling those up to something that can hold a small number of people is a matter of refining the technology, which engineers do very well.
Maybe, like gliders and rockets, we’ll solve the BEV aircraft problem by using multiple stages: a tow plane with enough battery and engine power to get the plane aloft will spend most of its energy at the source airport doing that, and once at altitude it will disengage and return. That would greatly decrease the amount of battery that the main aircraft would need.
Or maybe the first stage is a zeppelin? I still don’t think you could have a BEV 737-sized vehicle but that might work with a smaller but still commercially-sized aircraft.