You are dismissive of one technology (which the article never implies is ready), then bring up a battery technology that is even more irrelevant (for the reasons you state).

> Lithium will be a huge cost even in LFP batteries as you can't take it out.

The figure I have heard is ~5% of the battery cost is related to the cost of Lithium. The cost of the raw Lithium compounds is not a dominant factor in the cost of most Lithium batteries, for example see https://pdf.sciencedirectassets.com/271367/1-s2.0-S037877531... I did some googling to find something recent that could compare the raw costs of materials, but they usually only break it down to the cost of the cathode material rather than individual metal compounds. https://www.crugroup.com/knowledge-and-insights/spotlights/n... imply that Nickel and Cobalt costs dominate currently.