last sentence, "The lithium battery was invented by a research scientist at Exxon in the 1970s but the oil giant ultimately didn't pursue the technology."
It's got a lot in common with sodium, being just over it in the periodic table. So just like how you have NaCl, you'll find LiCl too, in a dissolved salt form. You'll not really find it in the pure metallic form because it reacts quickly and violently with water in that form, just like sodium. And earth is pretty wet.