I have looked into this quite a bit.

Non of the materials in the battery are really scares. Building up the capacity both in terms of mining and refining will likely be slower then demand growth however, so in the next 5-10 years its hard to say raw material input prices coming down a huge amount. This effectively generates a lower bound in the mid term for battery prices.

However, its not as bad as it sound. Depending on how you build your battery, the inputs are much cheaper. Iron Phosphate cathodes (LFP) are much, much cheaper. Manganese cathodes are also quite cheap and will be entering the market soonish. Cobalt has already been largely phased out, because it was to expensive.

Beyond that, localization of mining can add a lot of value. Currently a nickel atom travels a long time before it end up in your driveway. So without actually improving mining, a lot of cost can be removed.

There are however huge improvements to the chemical and the manufacturing aspects being made. Over the next decade the manufacturing of the cells will be so fast, that it will be a small part of the cost. Tesla I think is the most advanced in this right now, the assembly lines they presented are quite insane in terms of output per investment. And others are working on things like that too.

There are huge inefficiency still in the chemical processing, both in terms of how it is done, and how much its transported.

This video shows how the current cathode manufacturing works (from a company that wants to improve it but still): https://www.youtube.com/watch?v=4i1T6s_NdAQ

Once you get all of those cost out, reaching as low as 30-40$/kwh is achievable even for a high nickel cathode, and significantly less for a LFP battery or Manganese heavy cathodes. Tesla Battery Day target is for 56$/kwh (educated guessing by people) for high nickel but that is for the next 5 years.

There is significant further upside potential even then. Eliminating transition free metals from the cathode would cut cost significantly if it could be replaced with much cheaper materials. This is very active target of research right now, including by a Tesla funded high-reputation university lab.

Removing graphite and increasingly replacing it with silicon and eventually with nothing (using Lithium form the cathode to plate an anode) has a lot of potential as well to reduce cost.

Once we are talking 20 years, Lithium Sulfer is a great candidate both for automotive and long distance planes. These batteries would be incredibly cheap because Sulfer is waste material now.

Lithium is unlikely to go away anytime soon. There are potentially superior materials out there, but lithium has a lot of places to go still.

You might want to watch:

- The Limiting Factor (exactly about your question basically) https://www.youtube.com/channel/UCIFn7ONIJHyC-lMnb7Fm_jw

- EV Stock Channel (mostly about supply chain) https://www.youtube.com/channel/UCMfEjqHQS4u8W5etV0uAG_A

- Benchmark Minerals (lots of free contend and talks from companies in the supply chain) https://www.benchmarkminerals.com/

- Cell Ciders podcast (https://podcasts.apple.com/us/podcast/cell-siders/id15584413...)

Also, consider watching Tesla Battery Day and pay attention to detail, they actually do a really great job explaining the costs and how to improve them in the next 2-7 years.