Okay so these are lithium-air batteries, they pull oxygen from the air so they don't need to carry as much weight. Presumably they're heavier when discharged because they're carrying a bunch of oxygen with them.
The problem is impurities in the air poison the chemistry. So the challenge is getting the air perfect.
Currently there has been a lab demonstration of a 1.2kwh/kg battery with 1000 cycles of lifespan.
12kwh/kg is really just a theoretical maximum for the chemistry.
CATL is saying "this is the future", and since they're the biggest battery maker in ... the world (?) ... that probably means there's going to be a whole lot of R&D pushed at this.
So 12kwh/kg has not actually been shown by anyone, but the way battery density competition has been going so far, we should expect that batteries will cross over the 1kw/kg line in the decade. And given they're about 0.3 now, that's a big improvement already. Enough for short haul aviation.
By about 3 or 4 kw/kg, they're going to be competitive with jet fuel given the losses of a jet engine. At this point there will really be no reason not to electrify aircraft since fuel is dominant in the cost of flight.
