Lithium! Is there a hotter element these days? The foundation of our attempt to move anyway from the use of petroleum products for energy sits, at least right now, on lithium and its use in batteries. Li-ion batteries are the core to electric cars, household electrical storage and pretty much any technology that requires the power for long periods. However, the lithium has to come from somewhere, just like all resources from our planet ... and unlike petroleum, it isn't life that is the ultimate source.
Lithium is a weird element. It is the third lightest, with a nucleus of 3 protons. Most of the lithium on Earth is an isotope called lithium-7, meaning the nucleus has 3 protons and 4 neutrons. A small fraction is lithium-6, which has one fewer neutrons.