Helpful. To quote the comment...
My question still remains about whether it opens up sources of supply as well.
I think it would, a lot of refining is currently done in China, so Tesla would need to buy the refined Lithium carbonate for Chinese suppliers and that is what most of the industry is doing.
If they do refining, Tesla can buy the raw material in different grades direct from the mine. If Tesla develops a supper efficient refining process, they might be able to use lower grade ore, in part because they have cut out the middle man, and some of the sea miles. Or they can use new North American mines, cutting out a lot of sea miles and transport delays.
Tesla might even be able to use the process they intend to use for extracting lithium for clay, I have previously guessed that might be using electricity to plate Lithium.
Why I say this is a lot of mining processing uses complex chemical flowsheets that are often tailored fairly specifically to the output of a particular mine.
In contrast a "first principles" approach using electricity to plate Lithium. might work for any Lithium source.
From a mission point of view, that works best if Tesla can use electricity generated on-site to plate Lithium.
Lithium plating would work, it is just a question of the efficiency of the process, and the volumes it could produce, no point in doing it if the Lithium it produces isn't a sufficient quantity.
Lithium also reacts with water producing some heat and hydrogen, that reaction is far less violent that the sodium + water reaction. Perhaps some of the heat/hydrogen can be used for some industrial process at the factory, or to make electricity. I'm not sure how useful the heat is.
I should stress this is just a hunch, I like to think the odds on my hunches are 50/50, but in truth they are lower.