I suspect hybrids will be developed first. Basically an APU sending power to the main motor + a relatively small battery. The 'APU' can be relatively compact and deliver a lot of power, with less engineering requirements (can place it anywhere, doesn't need to interface with a prop). If it fails you have some emergency battery power. Electric motors are incredibly strong and have very few moving parts, so reliability is higher. They are also light.
Net net, there's some complexity and the combined equipment may be heavier (may! existing powerplants are some heavy beasts) but there's probably advantages.
Certification would be horrendous, I imagine.
In my vision a compact rotary (that inside-out rotary patent a few years ago looked even more promising) would recharge the battery subsystem. Or maybe a fuel cell.
The same would probably work for GA. Really, hybrids will work regardless of the battery tech for the next couple decades.
Hybrid planes would be quite attractive, but of course the certification bareer which might be too large
So you effectively electrify 5x the number of cars...
But, that opportunity has passed, at least we are moving towards electrification.
I know that paragliding and hang gliding exist, but those are a bit out of my comfort (and safety) zone.
https://en.wikipedia.org/wiki/Ikarus_C42
Technically it is a microlight but top speed and handling are much closer to a regular GA craft. I absolutely loved it and if my eyesight was better I'd definitely go for a license.