This analysis only looks at vehicle batteries, but there are a ton of technologies that aren't suitable for vehicles that _are_ suitable for the grid due to weight concerns and a lot of them have room to become significantly cheaper than lithium.

I just don't think the grid storage market is going to be leftover vehicle batteries. The demand will be big enough that battery technology will be tailored toward grid storage; cheaper batteries that are less dense, super-high lifecycle numbers that cars don't need, less need for high charge and discharge rates.