I could see a non-rechargeable electric battery (but refillable, ala jet fuel) such as aluminum-air maybe working. The round trip efficiency would be similar t

I could see a non-rechargeable electric battery (but refillable, ala jet fuel) such as aluminum-air maybe working. The round trip efficiency would be similar to diesel (since you are re-smelting rather than recharging), but the effective energy density on the plane could actually be much better than jet fuel.