Battery density doubled in the last ten years:
https://www.westchestercleanenergy.com/post/lithium-battery-...
Density is going up exponentially in the graph because it has been improving 18% for every doubling of the number shipped. Global EV market share is projected to cross 25% this year, so we should expect two more 18% improvements as it approaches 100%. That should improve density 39%. Then (ignoring batteries sold so far, and assuming there are no new markets for lithium batteries), we’ll see another 18% in 2 years (164% of current density), 4 (193%) 8 (228%), and so on until some theoretical limit is hit.
In all likelihood, some other technology will replace lithium batteries at some point. That further improves the density numbers.
And that's great, lets assume that continues, which there is no guarantee of, when would batteries be in the same ballpark as jet fuel?
Lets call current batteries 300 Wh/kg and jet fuel 12,000 Wh/kg, that means, according to you, development would look something like:
Battery Density: 2035 - 600 Wh/kg 2045 - 1200 Wh/kg 2055 - 2400 Wh/kg 2065 - 4800 Wh/kg 2075 - 9600 Wh/kg
So in half a century we may see batteries approaching the power density needed.
There are physical limits to Moore's-like laws for chip densities and chemical power densities. We can't be too far from those for lithium.