Cobalt -Oxide-Lithium Batteries
Mechanism
The basic structure of these includes the anode, or negative terminal, which is often made of graphite, a cathode, or positive terminal, which is made from lithium-cobalt oxide. and a separator that prevents the terminals from touching, but is permeable to the lithium ions that float freely between the terminals in a solution called electrolyte. The LiCoO2 present in these, has a two-dimensional structure in layers of cobalt oxide, among which are the lithium ions, which move during the discharge of the anode to the cathode. On the other hand, during charging, the negative electrode of the cell is electrochemically reduced, i.e., the lithium ions are inserted into the chemical structure traveling from the positive electrode to the negative of the graphite.
Capacities and life cycle
These batteries have a relatively short life cycle of between 500 and 1000 charge/discharge cycles, which is due to the presence of the graphite anode which limits cycle life by changing the solid electrolyte interface, thickening at the anode and lithium coating while rapidly charging and discharging at low temperature. In addition to this, these devices possess very high specific energy and limited specific power so their use has been in decline in recent years. The price of these batteries has been increasing due to an increase in the price of cobalt currently hovering between $100 and $200 per kWh.
Applications
Among the main applications in which these types of batteries are used are cell phones, laptops, cameras and tablets.
Advantages
Among the advantages of these can be mentioned that they have no memory effect, have the highest density and specific energy of the market, have discharge rates below 10% and are not toxic.
Disadvantages
While in the disadvantages it can be mentioned that cobalt is an expensive and scarce raw material which raises its price before fluctuations in the price of cobalt, they have a limited discharge capacity and finally, its use at high temperatures is not recommended because it has low thermal stability.