>Lithium-ion specific energy density < 1 MJ/kg i think battery swapping is much more realistic for planes than for cars and that would allow to use non-recharg

>Lithium-ion specific energy density < 1 MJ/kg i think battery swapping is much more realistic for planes than for cars and that would allow to use non-rechargeable or factory rechargeable batteries like the metal-air ones (my favorite is Al-air) which is order of magnitude better than rechargeable Li-ion, and that really gets us close to the gas/jet capabilities given the low thermodynamic efficiency (or extremely high price and complexity) of the combustion based engines. >In short we need much better batteries and much lighter motors. This is not going to happen anytime soon. this is exactly what is happening right now in front of our eyes :)