I just read this, which could be total horseshit, but it looks reasonable:
Lithium only accounts for 3% of the cost of a battery. Recycled lithium is 5 times more expensive than 'new' lithium.
I think they said that recycling's biggest economic benefit is stabilizing the price fluctuation in lithium if demand for 'new' lithium exceeds resource output. I don't know if there's a point at which you don't need much new lithium for batteries because basically you will have built all the lithium batteries you will ever need and as you need new batteries you will just be using recycled lithium already mined.
I could see where battery storage gets good and cheap enough that, when coupled with solar, reaches the point where you get close enough to practical off-grid that the promise of free solar (minus capital investment) causes people to get more energy efficient.
If I could have 500kWh of lithium in my house and my daily solar production average was 5kw over my all day consumption, then having deep battery reserves would more than cover a run of bad weather. You could drop 10kWh negative for a couple of months and just draw down your battery to make up the difference and then slowly recharge back up in better weather.
Even with best case solar, I'd be under water by 10kWh now. My summer power bill tells me I'd need nearly 60kWh per day and I would bet that's a lot of periods of over 5kW when the central AC runs.