deintercalation

Deintercalation is the process of removing intercalated species from a material that has hosted guest ions, atoms, or molecules between the layers of a host lattice. It is the reverse operation to intercalation and can significantly alter the structural, electronic, and chemical properties of the material.

Layered materials commonly subject to deintercalation include graphite and graphite intercalation compounds, transition metal dichalcogenides, layered oxides, and clays. The intercalated species may be ions, neutral atoms, or small molecules, and their removal leaves the host framework with reduced interlayer occupancy and often different lattice parameters.

The mechanism involves diffusion of the guest species out of the interlayer galleries, driven by changes in chemical potential, temperature, redox state, or solvent conditions. Deintercalation can be reversible or irreversible, depending on the strength of guest-host interactions, framework rigidity, and whether the structure undergoes phase transitions or stacking changes during extraction.

Methods to induce deintercalation include thermal treatment, chemical reactions, and electrochemical extraction. In energy storage, deintercalation corresponds to charging or delithiation/desodiation of electrode materials, where guest ions are removed from the host lattice.

Characterization typically uses X-ray diffraction to monitor interlayer spacing, thermogravimetric analysis to quantify remaining guest content, and spectroscopy to identify residual species. Deintercalation is a key concept in studies of intercalation compounds and affects applications ranging from batteries to catalysis and environmental remediation.

See also: intercalation, delithiation, exfoliation, intercalation compound.