[jillesvangurp]

Especially when considering that most of that 13 Wh/kg for petrol is typically delivered as waste heat. You can get a decent estimate of how bad it is comparing miles per kwh for an EV to miles per gallon for a typical petrol car. It's about 3-4 miles per kwh vs. about 20 miles per gallon. EVs just use their kwh a lot more efficiently than petrol cars. Because batteries and electrical motors are just really efficient.

An 11 wh/kg battery would result in a battery that delivers about 5-6 times more miles per kg of battery than petrol. You get weight parity around 3-4 kg. If you factor in the weight of the engine (they can be quite heavy) it gets a little better. Of course the weight matters far less than people think. The amount of energy needed to move a vehicle does not necesseily scale linearly with weight of the vehicle. Which is why a heavy cyber truck and much lighter / smaller EVs can have miles per kwh metrics that aren't that far apart. Same with petrol cars. Halving the weight doesn't given them twice as much range. Heavy batteries are not that big of a deal. Unless you put them in a plane. Weight matters a lot in planes.

So, a battery like this would be amazing news for battery electric planes that currently fly with 200-300 wh/kg batteries (at best). 11kwh/kg would be a 70x improvement in energy density. That's a lot of range. Even a small fraction of that would be a massive improvement. 700wh/kg more than doubles the range already.

I think we'll see batteries break 1kwh/kg next decade or so. 500 wh/kg is already on its way to production. So, a doubling is only a modest step up. At 1kwh/kg, most GA flight will become electric. 3-6 hours of range with dirt cheap electricity turns a 100$ hamburger into a Starbucks coffee run. That's game over for ICE engines in small planes.