Your numbers are off. Tesla requires 9kg of lithium per 10kWh. If 85kWh model has in reality 95kWh, then you'd need 85kg lithium per car. World reserves of lithium are roughly 16 million tons, so, it would suffices for a bit under 200 million Teslas.

Lithium production was 43000 tons last year, which would produce 500.000 cars, even if we wouldn't need lithium for anything else.

https://electrek.co/2016/11/01/breakdown-raw-materials-tesla...

https://www.statista.com/statistics/268790/countries-with-th...

https://www.statista.com/statistics/606684/world-production-...