https://davidfmayer.substack.com/p/batteries-except-possibly-hydrogen/comments
Batteries (except possibly hydrogen fuel batteries) will NEVER power 747 size aircraft.
For those of you expecting electric aircraft to replace 747 type machines, FORGET IT.
Here are the relevant figures.
Hydrogen 33,313 watt hours / kilogram
Methane 15,444 watt hours / kilogram
Jet fuel 12,200 watt hours / kilogram
Best lithium-air battery, rechargeable 2,500 watt hours / kilogram
Even best lithium-air battery possible (which is unavailable) carries only ONE FIFTH the energy per unit weight of jet fuel. OK, now here is MORE bad news. Lithium-air batteries GAIN WEIGHT as they discharge, nearly doubling in weight when fully discharged. The reason for this is that such batteries work by using oxygen from the air to oxidize the anode from Li to Li2O, which is nearly twice as heavy. The oxidation produce remains in the battery, greatly increasing weight.