gen-define-intercalation-and-give-one-short-worked-example-487e

Define intercalation and give one short worked example.

# Intercalation **Definition:** Intercalation is the reversible insertion of molecules, ions, or atoms into layered host structures without significantly disrupting the host's framework. The guest species occupy spaces between the layers while the basic structure remains intact. ## Worked Example: Lithium Intercalation in Graphite **Process:** Li⁺ ions intercalate into graphite (used in lithium-ion battery anodes) **Reaction:** ``` C₆ + Li⁺ + e⁻ ⇌ LiC₆ ``` **What happens:** - Graphite consists of stacked carbon sheets with van der Waals gaps (~3.35 Å) - Lithium ions insert between these carbon layers during charging - Each Li⁺ typically associates with 6 carbon atoms - The layer spacing expands slightly (~10%) to accommodate Li⁺ - The graphite structure remains intact and the process is reversible **Result:** Maximum theoretical capacity is LiC₆ (372 mAh/g), where one lithium atom is stored per six carbon atoms. This intercalation mechanism is what makes rechargeable lithium-ion batteries possible!