BU-310: How does Cobalt Work in Li-ion?

Cobalt was discovered by Swedish chemist Georg Brandt in 1739. It is a hard, lustrous, silver-gray metal that is extracted as a by-product when mining nickel and copper. Besides serving as a cathode material of many Li-ion batteries, cobalt is also used to make powerful magnets, high-speed cutting tools, and high-strength alloys for jet engines and gas turbines. Cobalt compounds have been employed for centuries to color porcelain, glass, pottery, tile and enamel; it is also important in human nutrition as part of vitamin B12. Figure 1 illustrates the breakdown of cobalt uses.

Cobalt is mostly retrieved as a byproduct from copper and nickel production. High cost entices battery manufacturers to seek alternatives, but cobalt cannot be entirely eliminated.

Being mostly a byproduct in the production of copper and nickel, the pricing follows the demand of these primary metals. This can lead to an over-supply of cobalt, as was the case in 2015. Cobalt prices were higher in 2010 and they are expected to pick up as the demand for large Li-ion batteries increases. Even at reduced prices, a ton of high grade cobalt runs at about US $28,000. This compares to US $6,000 for a ton of lithium carbonate (estimated 2015 prices). Lithium carbonate is a crystalline salt that is also used in glass and ceramic industries, as well as in medicine.

According to the British Geological Survey (2014), the Democratic Republic of Congo has a 50 percent share of worldwide cobalt production; China, Canada, Australia and Russia are also major contributors. Cobalt in developing countries is often mined under life threating working conditions by adults and children with low pay.

Cobalt is an essential element for good health but too has a poisoning effect that can reflect in heart problems, damaged vision and cancer. Contact with cobalt can occur by ingestion, breathing cobalt contaminated air, or by constant skin contact. Cobalt poisoning has also been reported from the wear and tear of some cobalt/chromium metal-on-metal hip implants

The reuse of cobalt by recycling Li-ion batteries is only partially successful because of the refinements needed to bring the material back to battery-grade. (See also BU-705: How to Recycle Batteries) There should be no shortage of cobalt as the world has ample reserves.

Cobalt was the first cathode material for commercial Li-ion batteries, but a high price entices manufacturers to substitute the material. Cobalt blended with nickel, manganese and aluminum creates powerful cathode materials that are more economical and offer enhanced performance to pure cobalt. (See also BU-205: Types of Lithium-ion)

References

[1] Source: CDI, Roskill, MMTA, Industry Sources