Yeah, but if all the grid storage and powerwall production could go sodium, that would free up lithium for the places it's needed.
The same argument could be made for nickel-iron batteries, though. They're heavy and bulky, but they last literally forever, and their source materials are ludicrously abundant. Why don't we see nickel-iron grid-scale storage? I'd love to know.
They are relatively expensive, they have fairly high self-discharge rates and aren’t very efficient. Last I checked, they had on the order of 1%/day discharge (some versions are as low as ~20%/month). They also are not very efficient in the charge/discharge cycle, losing 30-40% of the power put in. Lithium currently is around 10%.
Their primary use is in applications where their long lifetimes outweigh all other considerations.
The same argument could be made for nickel-iron batteries, though. They're heavy and bulky, but they last literally forever, and their source materials are ludicrously abundant. Why don't we see nickel-iron grid-scale storage? I'd love to know.