Graphite Cathode for Li-Ion Batteries
Graphite is a gray crystalline allotropic form of carbon that occurs as a mineral in some rocks and can be made from coke. It is used as a solid lubricant, in pencils and as a moderator in nuclear reactors.
Compared to other electrodes, graphite is highly conductive. This is because the graphitic atomic structure allows electrons to migrate between different layers of the material. It is also very inexpensive and robust and can be sourced easily, making it one of the most widely used electrodes in Li-ion batteries.
The graphite cathode is a high-performance electrode in Li-ion batteries and has many advantages, such as being cheap and being easy to access. Graphite is often found in combination with lithium fluoride (LiF) in lithium-ion batteries because of its excellent electrochemical performance, including high capacity and long cycling stability at low voltages.
In addition to its conductive properties, graphite is also an excellent conductor of electricity. This is due to the presence of a large number of free electrons that can move freely between the graphite layers, thus transferring energy to the electrical grid.
An ex situ X-ray diffraction study on graphite electrodes was performed at various charging and discharging voltages with a Bruker D8-advanced instrument. The ex situ XRD patterns were then analyzed using a computer program. The results showed that the surface layer of graphite electrodes exhibited a thickness increase when the upper cutoff voltage was increased to 4.6 V. Moreover, XPS revealed that more -CO3, -CO2 and LiF species were present on the surface of the graphite electrodes.
