Well, yes and no. You're absolutely right that the weight is bad, it's like 10x as bad. But on the other side of things, something like 2/3rds of the cost of a plane ticket is just going straight to fuel, so if you can find a way to replace that fuel with electricity, you're taking maybe 20-30% off the cost of the flight, so the pot of gold at the end of that rainbow is so rich that you start re-thinking the definition of "viable"...
In terms of actual physics viability, it's "borderline". You can get up in the air for an hour or maybe 2 with electricity, which for a lot of short haul, tourist stuff, etc is potentially enough. And if it's "potentially enough" then it's 100% worth it because of the aforementioned fuel cost...
Now what I'm talking about is that blue thing that runs the length of the wing. That has to be frustratingly strong because the whole airplane hangs off of it. So I'm thinking something like pic 2 with two battery tubes, having periodic spacer tubes, and then the whole thing is wrapped up in carbon fiber like it was a Christmas present - and that outer wrapping prevents the two from racking.
https://pkteerium.xyz/media/57bfc234905a917698c1d9c5fb1f357088b11f68da4fbe10fadb47c01824cacd.JPG
