Why does graphite conduct electricity?

Why Graphite Conducts Electricity

Structure and Bonding

Graphite is composed of carbon atoms arranged in a hexagonal lattice structure.

Each carbon atom in graphite forms three covalent bonds with neighboring atoms, leaving one delocalized electron per atom.

The delocalized electrons are free to move within the layers of the graphite structure, allowing for easy flow of electric current.

Semi-Metal Nature

Graphite is classified as a semi-metal or semiconductor due to its ability to conduct electricity, although not as efficiently as metals.

The presence of delocalized electrons gives graphite its semi-metallic properties, allowing it to conduct electricity.

Anisotropic Conductivity

Graphite exhibits anisotropic conductivity, meaning it conducts electricity more effectively in certain directions compared to others.

The conductivity is highest within the layers of graphite (in-plane conductivity) and lower perpendicular to the layers (out-of-plane conductivity).

Van der Waals Forces

Weak van der Waals forces hold the layers of graphite together.

These forces allow for easy separation of layers, facilitating the use of graphite as a lubricant and in applications like pencil lead.

Interesting Facts

Graphite’s ability to conduct electricity was discovered in the early 19th century by scientist Humphry Davy.

The unique structure of graphite also imparts properties like high thermal conductivity and lubricity, making it useful in various industrial applications.

Graphite is commonly used as an electrode material in batteries, fuel cells, and electrical contacts due to its conductivity and stability.