Lithium and Sodium Storage on Graphitic Carbon Nitride

Abstract

We present results from density functional theory calculations of the lithium adsorption onto 2D graphitic carbon nitride membranes, C3N4 and C6N8 and bulk C3N4. We find that lithium adsorbs preferentially over the triangular pores with a high adsorption energy. We also find that lithium adsorption severely distorts the membrane and bulk material. The lithium mainly interacts with the pyridinic nitrogen in the material, which enables a large lithium uptake. However, the pyridinic nitrogen is also responsible for the instability of the material. We also present experimental results on the charge and discharge capacities of C6N8. These mirror the theoretical prediction that the material shows a high lithium uptake which is, however, irreversible.