Reversible lithium storage capacity on carbon nitride by electric field

Graphitic carbon nitride (g-C3N4) has attracted enormous interest because of its prominent photocatalytic performance. Due to the planar it conjugation structure which should provide good binding energy for adsorption of metal atoms including lithium (Li) and sodium (Na), g-C3N4 also possesses great application potential in ion batteries. Here, first-principles calculations are performed to investigate its application in lithium ion batteries (LIBs), focusing on the electric field effect on the Li storage. Our results revealed that Li adsorbed C3N4 (Li-C3N4) exhibits good modulation of its Li binding energy by applying external vertical electric field. The Bader charge analysis and charge density difference calculations provide a deep insight into the tunable Li adsorption to C3N4 sheets. Our theoretical results suggest that C3N4 is a suitable anode material for LIBs.