Effects of Methoxy Substituents in Contorted Polycyclic Aromatic Hydrocarbons for Pseudocapacitive Charge Storage

Abstract

We investigate the potential of a methoxy-group-coordinated contorted hexabenzocoronene (OCH3- cHBC) derivative as a promising pseudocapacitive Li-ion hosting organic electrode. By inserting a polar methoxy group at the end of each peripheral aromatic ring of cHBC, the strong negative electrostatic potential near the oxygen atom enabled us to modulate the pseudocapacitive characteristics of the OCH3-cHBC electrode with enhanced specific capacity. Particularly, benefiting from the electron-donating group, a Li-ion capacitor (LIC) consisting of an OCH3-cHBC anode with a double-layer capacitor cathode could be readily fabricated. It exhibited reliable energy and power densities as well as an ultralong lifetime of over 13000 cycles without significant degradation. The promising electrochemical results enriched the strategic molecular approach of polycyclic aromatic hydrocarbons, altering the electrochemical energy storage systems and ensuring advanced LIC electrodes.