Stability of acceptor graphite intercalation compounds: The key role of the anion ionization potential

The stability of acceptor graphite intercalation compounds (GICs) with Brönsted acids is the key point of their utility in various fields; many of them are unstable and are rapidly decomposed even at room temperature. A theoretical model of the first decomposition stage is proposed for this type of GIC. Using quantum-chemical methods in terms of this model, we show that the ionization potential of the intercalant anion is the key factor governing the stability of such compounds. The role of anion solvation, hydrogen bonding, and Coulomb interactions in the stability of GICs is analyzed.