Lithium Cobalt Oxide

Crystalline solid used as a compound in the cathodes of some Lithium-Ion (Li-Ion) batteries

What is a lithium cobalt oxide battery ?

A lithium-cobalt oxide battery is part of the larger group of lithium-ion (Li-Ion) batteries. It is the circulation of lithium ions (Li+) between two electrodes that allows the battery to be discharged or recharged.

In this type of Li-Ion battery, cobalt and lithium oxide are used in the composition of the positive electrodes called cathodes. The introduction of cobalt as a complement to lithium allows for better energy performance in these batteries using lithium in ionic form.


The specificities of cobalt and lithium oxide

Lithium cobalt dioxide is a chemical compound with the formula LiCoO2. It is sometimes called lithium cobalt mixed oxide or lithium cobaltite. This bluish-grey crystalline solid is commonly used in rechargeable Li-Ion batteries.

Introduced in the positive electrodes in lamellar form, cobalt improves the stability and power of Lithium-ion (Li-Ion) batteries thanks to its good conductivity.

However, the use of cobalt is now being questioned. First, because its extraction methods are controversial. Secondly, because cobalt and its derivatives are toxic to humans and their environment. In addition, its costs are high and volatile.

Manufacturers are now looking for ways to avoid, or at least reduce, the use of cobalt in batteries.


Examples and practical application

Cobalt and lithium oxide batteries are still widely used in smartphones, laptops and cameras. They are also used in car batteries.

To replace or reduce the use of cobalt in Li-Ion batteries, research has turned to nickel. A new generation of Li-Ion batteries has been developed.

These lithium batteries, known as ternary batteries, always work on the same electrochemical principle of Li+ ion exchange. But instead of Cobalt alone, the electrodes incorporate polymers containing 3 metallic elements:

  • nickel, manganese, and cobalt in NMC cathodes ;
  • nickel, cobalt, and aluminium in NCA cathodes.

Over time, the share of cobalt tends to decrease in these batteries in favour of other components.

Whilst the energy performance of nickel-cobalt-aluminium oxide cathodes is higher than that of cobalt and lithium oxides, the batteries are also more expensive to manufacture.

While looking to use less cobalt in electrodes, researchers are exploring the possibility of reprocessing old batteries to extract reusable elements. Recycling could allow the cobalt to be recovered for re-injection into new batteries.