The only way to know whether any battery recycling can be considered an environmentally friendly process is to perform life cycle assessment (LCA) including end-of-life (EOF) phase. By quantifying the life cycle impact categories (LCIA) of at least two batteries recycling technologies, you can compare which is the most environmentally friendly option.
There are a few LCA software that you can download at no cost to perform this assessment like OpenLCA platform. You're welcome to download my published research on LCA and LCIA to get an idea. You can find these papers in the profile at ResearchGate.net.
Hope this helps answer your question and good luck!
The hydrometallurgical methods are environmentally freindly methods for batteries recycling. In these methods, the batteries are leached with suitable acids, after grinding. The metals then are recovered from solution by different methods such as solvent extraction, cementation and ... You can find lots of papers in this topic.