[Bicycle Bob]

Wikipedia says:
Lithium is widely distributed on Earth,[11] however, it does not naturally occur in elemental form due to its high reactivity. Estimates for crustal content range from 20 to 70 ppm by weight.[6] In keeping with its name, lithium forms a minor part of igneous rocks, with the largest concentrations in granites. Granitic pegmatites also provide the greatest abundance of lithium-containing minerals, with spodumene and petalite being the most commercially-viable mineral sources for the element.[6] A newer source for lithium is hectorite clay, the only active development of which is through Western Lithium Corp in the USA. [12]
According to the Handbook of Lithium and Natural Calcium, "Lithium is a comparatively rare element, although it is found in many rocks and some brines, but always in very low concentrations. There are a fairly large number of both lithium mineral and brine deposits but only comparatively a few of them are of actual or potential commercial value. Many are very small, others are too low in grade."[13] The most important deposit of lithium is in the Salar de Uyuni area of Bolivia, which holds half of the world's reserves.[14]
[edit]Applications

Because of its specific heat capacity, the highest of all solids, lithium is often used in heat transfer applications.
It is an important ingredient in anode materials, used in Lithium-ion batteries because of its high electrochemical potential, light weight, and high current density.

Another source estimated the world supply of affordably-extracted lithium to be too small to equip a significant percentage of vehicles with lithium batteries.