I'm interested in the development of electric small airplanes with 4 or 6 seats, that could really happen in the following decades.
One of the main problems related to this project would be the specific energy of the batteries used on these airplanes. Batteries should have a good energy storage to make the range of the aircraft reasonable, and they also need to be light, to make the lift possible.
I saw in this article that the specific energy of the Li-ion batteries could reach 300 Wh/kg until 2030, but it's still a little bit low for a small aircraft. I did some more research, and I found that new different type of batteries are being developed, like lithium-air batteries, that in practice can get a specific energy of 1700 Wh/kg (just read this). I found also that glass batteries could be a thing too (read this), which could have specific energy several times greater that the recent Li-ion batteries and could work at low temperatures (which is good for high altitude flight).
I've little knowledge about chemistry of batteries, and so I'm requesting someone that has good formation in this area to share an opinion about the possibility of existence of batteries like lithium air or glass batteries at 2030 for example, and which value of specific energy could be a good prevision around that year.