Graphite is made of carbon hexagonal plane layer structure. Layers of carbon atoms in the plane by strong covalent bond, and van der Waals forces between layers combine with very weak, and the distance between layers is bigger. Therefore, under the right conditions, acid, alkali, salts and other chemical substances can be inserted between graphite layers and combines with the carbon atoms to form new chemical-graphite intercalation compounds (Graphite Intercalation on Compounds, referred to as GIC). In this compound when heated to the right temperature, instantly breaks down quickly, produce a lot of gas, graphite along the axis direction of swells into a worm-like new material, namely, exfoliated graphite. This expansion is expandable graphite graphite intercalation compound.