Density functional theory study of doped coronene and circumcoronene as anode materials in lithium-ion batteries.

Density functional theory calculations are carried out to investigate the adsorption properties of Li and Li on twenty-four adsorbents obtained by replacement of C atoms of coronene (CH) and circumcoronene (CH) by Si/N/BN/AlN units. The molecular electrostatic potential (MESP) analysis show that such replacements lead to an increase of the electron-rich environments in the molecules. Li is relatively strongly adsorbed on all adsorbents. The adsorption energy of Li (E) on all adsorbents is in the range of - 42.47 (BHN) to - 66.26 kcal/mol (m-CHBN). Our results indicate a stronger interaction between Li and the nanoflakes as the deepest MESP minimum of the nanoflakes becomes more negative. A stronger interaction between Li and the nanoflakes pushes more electron density toward Li. Li is weakly adsorbed on all adsorbents when compared to Li. The adsorption energy of Li (E) on all adsorbents is in the range of - 3.07 (BHN) to - 47.79 kcal/mol (CHSi). Assuming the nanoflakes to be an anode for the lithium-ion batteries, the cell voltage (V) is predicted to be relatively high (> 1.54 V) for CH, CHSi, BHN, CHSi, and BHN. The E data show only a small variation compared to E, and therefore, E has a strong effect on the changes in V.