Sadly, this is not very practical. A lithium cell in itself is a chemical time bomb: if it gets mechanically damaged or short-circuited, it has enough oomph to burn your device, skin or house. For factory-produced battery packs this effect is mitigated by having protective circuits that monitor charge level, temperature and a bunch of other parameters, cutting off the power if the cell is deemed too dangerous. But once you take a random lithium cell off the street and try to revitalize it, you are opening a can of worms: depending on how it was used, it might be full of dendrites [0], ready to cause a fiery short-circuit a few charges after. It might have structural damage due to gas buildup, or someone literally stepping on it. It could have been under direct sunlight for longer than it should, and so on.
It's fine to tinker around with it for your own experiments, but you don't want to ship it to anybody who's not going to be using it in a fireproof lab wearing eye protection.
A better idea would be to find a way to properly recycle the raw materials (i.e. extract the lithium from a dead cell), but that could be several orders of magnitude more challenging.
[0] https://www.batterypoweronline.com/news/a-look-inside-your-b...