If you extract enough energy from pedaling to charge a battery while also travelling, you’ll definitely end up using more power than less. Which absolutely defeats the purpose.
All these “smart” ideas would already be implemented if they were actually clever and deployable. The reason no one does it is because physics doesn’t work that way.
Dynamo lights work off a similar principle. It extracts energy from pedaling or the wheels spinning to power lights on the bike. You can feel the drag and it’s probably about 5w of power. Really not a whole lot. About the same energy you’d save from wearing smooth socks or cleaning the chain for some perspective.
The extra weight required to implement a solution like yours would probably rob the rider of any gains. But in a very theoretical sense it could work if the material weighed an insignificant amount.