Analysis of the Ordering Effects in Anthraquinone Thin Films and Its Potential Application for Sodium Ion Batteries

Abstract

The ordering effects in anthraquinone (AQ) stacking forced by thin-film application and its influence on imer solubility and current collector adhesion are investigated. The structural characteristics of AQ and its chemical environment re found to have a substantial influence on its electrochemical erformance. Computational investigation for different charged tates of AQ on a carbon substrate obtained via basin hopping lobal minimization provides important insights into the hysicochemical thin-film properties. The results reveal the ideal tacking configurations of the individual AQ-carrier systems and how ordering effects in a periodic supercell environment. The atter reveals the transition from intermolecular hydrogen bonding oward the formation of salt bridges between the reduced AQ units nd a stabilizing effect upon the dimerlike rearrangement, while the strong surface-molecular interactions in the thin-film eometries are found to be crucial for the formed dimers to remain electronically active. Both characteristics, the improved current ollector adhesion and the stabilization due to dimerization, are mutual benefits of thin-film electrodes over powder-based systems. This hypothesis has been further investigated for its potential application in sodium ion batteries. Our results show that AQ thin-film lectrodes exhibit significantly better specific capacities (233 vs 87 mAh g-1 in the first cycle), Coulombic efficiencies, and long-Term ycling performance (80 vs 4 mAh g-1 after 100 cycles) over the AQ powder electrodes. By augmenting the experimental findings via omputational investigations, we are able to suggest design strategies that may foster the performance of industrially desirable owder-based electrode materials.