The question is "how much will lithium cost?"
It can be extracted from the ocean, there are undeveloped known mineral deposits and you always expect there are unknown deposits to be found. Production will grow as demand grows, when there is lag because new sources take time to develop and proven demand is needed before someone spends a lot of money developing a new source there will be cost growth, when new sources, recycling, etc. develop, prices will drop.
In 20-30 years one of the alternatives (like sodium batteries, we'll never run out of sodium) aren't so unlikely to be found.