Lithium ion batteries provide improved levels of capacity combined with reliable operation when compared to other forms of cell and battery technology including Nickel Cadmium, Ni-Cd and Nickel Metal Hydride, NiMH.
As a result of their characteristics, Lithium Ion, or Li-ion batteries have become the battery technology of choice in a variety of areas. Li-ion batteries are used almost exclusively in mobile phones, laptops, e-readers and many other electronic gadgets. In addition to this, Li-ion technology is also used being used for power applications - everything from the smallest electronic gadgets, through mobile phones, laptops, etc to power tools and there are even lithium ion car batteries for powering electric cars.
A lithium ion battery, or cell of whatever form has four main constituents:
Cathode: This is the positive electrode and it is typically made from a lithium based metal oxide of some form. There are several different lithium ion battery technologies, so the exact format will change from one type to the next.
Anode: This is the negative electrode of the lithium ion battery and it is generally made from carbon, normally in the form of graphite.
Electrolyte: The electrolyte is the located between the two electrodes within the cell. It is often a mixture of organic carbonates such as ethylene carbonate, diethyl carbonate, etc.
Separator: In order to prevent the two electrodes touching a separator is placed between the anode and cathode. This absorbs the electrolyte, and enables the passage of ions, but prevents the direct contact of the two electrodes within the lithium in cell.
During the overall cycle there are two processes associated with movement of the lithium ions:
Intercalation : The process where the lithium ions in the lithium ion battery are inserted into the electrode is called intercalation.
Deintercalation : This is the reverse process and occurs when lithium ions are extracted from the electrode, i.e. they move back out.
