Evaluations of Highly Stable Derivatives of Polycyanated Tricyclic[10]annulene Anions as Efficient Halogen-Free Electrolyte for Lithium- and Sodium-Ion Batteries.

Abstract

Polycyanated tricyclic[10]annulene and the benzene derivatives, namely polycyanated Rees hydrocarbons, exhibit properties of organic superacids in the gas phase because they generate highly stable anions after deprotonation. Stable anions can prospectively be used as electrolytes in lithium- and sodium-ion batteries (LIBs and NIBs, respectively). This study investigates the stability of polycyanated benzo-fused tricyclic[10]annulene anion and polycyanated tricyclic[10]annulene anion and discusses their potential as halogen-free electrolytes in LIBs and NIBs using density functional theory calculations. The calculated energy for binding of an electron to the polycyanated Rees hydrocarbon anions in the gas phase is larger than that of recently developed, efficient, halogen-free electrolytes. The binding energy of Li⁺ and Na⁺ with the polycyanated Rees hydrocarbon anions is smaller than that of the electrolyte B₁₂H₁₂ ^2-, as well as the currently used electrolytes, but is comparable to that of the electrolytes B₁₂(CN)₁₂ ^2- and CB₁₁(CN)₁₂ ^2-. The present calculations suggest that polycyanated Rees hydrocarbon anions can be used as halogen-free electrolytes in LIBs and NIBs. This study paves the way for the synthesis of stable anions derived from organic superacids with potential applications as halogen-free electrolytes in metal-ion batteries.