Investigation on bare ZnO nanotubes and nanosheet as electrode materials for potassium-ion batteries: A DFT search

Abstract

Within this work, the possibility of using (5,0), (6,0), (7,0), (8,0), and (9,0) zigzag ZnO nano-tubes and a ZnO nano-sheet (ZnONS) was investigated in potassium-ion batteries (KIBs) through the B3LYP-gCP-D3/6-31G* scheme. The cell voltage, ion diffusion coefficient, the maximum energy barrier for the migration of K+ and the adhesion energies of K+ and K of (5,0) nano-tube were 0.93 V, 5.31 × 10−8 cm2/s, –33.4 kcal/mol, respectively. The results showed that the impact of the dispersion term (D3) on the K and K+ adhesion energies was more than that of the gCP (basis set superposition error). A reduction in the curvature of the ZnONS dramatically weakened the interaction of the K atom, whereas it had a slight impact on the interaction of K+. Therefore, a decrease in the curvature of the ZnONS increased the cell voltage to 1.21 V. We can use ZnO nano-structures as a promising anode for KIBs.