The effect of Cl encapsulation and hydrogenation process on the performance of ZnO nanocluster as an anode in Na-ion batteries

Abstract

Density functional theory (DFT) computations are performed for probing the application of a Zn12O12 nanocage as well as its geometrically engineered forms as an anode material in Na-ion batteries (NIBs). The performance of the pure Zn12O12 nanocage was low and its cell voltage (Vcell) was approximately 1.06 V. Therefore, in order to enhance the performance, two methods were projected, namely encapsulation of an anion inside the nanocage and hydrogenation of Zn atoms of the cage. The second method was unsuccessful since it demonstrated a negative Vcell, which was due to the fact that interaction between the atomic Na and the hydrogenated nanocage was stronger than the cationic Na. However, the encapsulation of a chloride inside the Zn12O12 nanocage led to a dramatic increase in the Vcell from 1.06 to 2.96 V, which was greater than the Vcell anticipated for carbon nano-tubes and C24 fullerene.