Battery Metals (Lithium, Cobalt)
Lithium (Li) is a soft, silver-white metal belonging to the alkali metal group of chemical elements. Under standard conditions, it is the lightest metal and the least dense solid element. Like all alkali metals, lithium is highly reactive and flammable.
Lithium occurs in a number of pegmatitic minerals, but due to its solubility as an ion, is present in ocean water and is commonly obtained from brines and clays. On a commercial scale, lithium is isolated electrolytically from a mixture of lithium chloride and potassium chloride.
Lithium has many applications, but the growth in demand for this metal in recent years has been connected to its use as an important component of battery electrolytes and electrodes, because of its high electrode potential. Because of its low atomic mass, it has a high charge- and power-to-weight ratio. A typical lithium-ion battery is rechargeable and can generate approximately 3 volts per cell, compared with 2.1 volts for lead-acid or 1.5 volts for zinc-carbon cells.
Cobalt (Co) is found in the Earth's crust only in chemically combined form, save for small deposits found in alloys of natural meteoric iron. The free element, produced by reductive smelting, is a hard, lustrous, silver-gray metal.
Cobalt is primarily used in the preparation of magnetic, wear-resistant and high-strength alloys. Demand for it is increasing, however, as a component of batteries. Lithium cobalt oxide is widely used in lithium-ion battery cathodes. Nickel-cadmium (NiCd) and nickel metal hydride (NiMH) batteries also include cobalt to improve the oxidation of nickel in the battery.
Most of the world’s cobalt comes from Central Africa, often from countries with unstable systems of government. To ensure a steady cobalt supply to meet the growing demand of today’s technologies, stable sources of cobalt are being increasingly developed.