A computational study on the potential application of carbon nitride nanosheets in Na-ion batteries.

In the current study, the C3N monolayer, as a two-dimensional material, was considered as a suitable anode material in sodium-ion (Na-ion) batteries (NIBs) by performing first-principles density functional theory (DFT) computations. It was shown that the metallic feature of the Na-ion is retained after its adsorption onto various sites on the surface of the C3N monolayer. The C3N monolayer has negative adsorption energy values for the Na-ion. Afterwards, the C3N monolayer was shown to have a greater maximum theoretical capacity of 543.89 mAh/g for the Na-ion in comparison with other materials based on our computations. Due to the low activation energy barrier of approximately 0.112 eV, migration of the Na-ion, which includes diffusion on the surface of the C3N monolayer, is rapid, demonstrating its great capability for fast charge-discharge processes. Ultimately, it was shown that, for the Na, the C3N monolayer possesses a low average open-circuit voltage, i.e., 0.83 V. These results show that it is possible to utilize the C3N monolayer in NIBs as an anode material.