First-Principles Calculation of Quantum Capacitance of Codoped Graphenes as Supercapacitor Electrodes

Because of their many advantages, graphene and graphene-based materials are used in supercapacitor electrodes. The main limitation of these electrodes is their low quantum capacitance, which is a direct result of the shortage of states near the Fermi level. Using first-principles density functional theory calculations, this report explored the quantum capacitances of Si-, S-, and P-doped graphenes and the same materials codoped with nitrogen. The findings imply that using phosphorus- and nitrogen-doped graphenes as electrode materials for supercapacitors could be a worthwhile strategy. Quantum capacitance calculations confirmed the greater advantage of some codoped graphenes compared with doped and pristine graphene.