The article sites out of date numbers for the world reserves. The USGS number is about 13 million tons (metric) of lithium, but that was 2009 (that number jives with the 365 X 37000 tons in the article). Much more has been found since, Wyoming is estimated to have 18 million tons alone. Current estimates of world reserves is around 39 million tons.
Lithium - Wikipedia, the free encyclopedia
Lithium is extremely common in the universe and we have just begun to prospect for mine-able deposits. At one time John D Rockefeller said that he would personally drink any oil found west of the Mississippi. This was a year or two before Spindletop (the first big find in Texas).
We also don't know for sure that EV batteries in the distant future will use lithium. It's possible lithium will continue to be used for hundreds of years or it could be an obsolete chemistry in 50 years. Add to that in the next century we will be able to mine the asteroids for minerals. Elon is targeting getting humans to Mars in his lifetime, but once we have the tech to get people to Mars and back, we will have the tech to get mining ships to the asteroid belt too. The asteroids are further out, but you don't have to contend with a gravity well when you get there.