The ones actually being used in California for grid storage are iron chemistries; so far as I'm aware, the sodium-ion ones are only being used in China at this point.
Extraction of lithium from old batteries is five times more expensive than mined lithium.[21] However, lithium extraction from Li-ion batteries has been demonstrated in small setups by various entities [16][22][17] as well as in production scale by battery material recycling companies like Electra Battery Materials[23] and Redwood Materials, Inc.[24]
So, probably not great. But recycling should be more ecologically friendly.
Lithium mining isn't great for the environment. And there are a lot human rights abuses involved in some of the mining. Which is probably why it is cheaper than recycling.
All pipe dreams:
I hope international pressure and regulations can pull the cost of extraction inline with it's ACTUAL cost.
And I hope the cost of recycling lion batteries will come down, so that the cost of recycling is comparable enough that regulations regarding recycling them (and using recycled lithium) can pass. Best case would be that recycling lithium is cheaper than extracting it.
Edit:
Chances are that as this is a commercial application, with known spec of the batteries. So the recycling of them is probably cheaper than dealing with consumer recycling
Redwood materials is a big player in this space. Don't forget, the larger the cells, the easier they are to recycle. Tiny cellphone packs are hard to stretch out and scrape, comparatively.