Lithium was an element with three protons and three electrons. It was used in glass and batteries.
Lithium was discovered in the early 1800s by two scientists who isolated the element from petalite ore. Then, in 1821, pure lithium was isolated from lithium salts. The first application of lithium was in grease for aircraft engines. Then, during the Cold War, lithium was used to make hydrogen for hydrogen bombs. This required fission which was controversial anyway. After the Cold War, the demand for lithium fell. However, it would go up again.
Tech Level: 10
In the mid-1990s, scientists learned how to extract lithium from brine. This was less expensive than mining for lithium. This was used to create lithium oxide, a widely used flux in glass. Lithium oxide was also used in ovenware. This was by far the most common application of lithium. The second most common was lithium-ion batteries.