Effects of carbon surface topography on the electrode/electrolyte interface structure and relevance to Li–air batteries

Abstract

This work is focused on the effect of the electrode/electrolyte interface restructuring under the variation of carbon surface topography, as one of the possible factors determining the electrochemical activity of different carbon materials in Li-air batteries. Molecular dynamics simulation was used to investigate an acetonitrile-based electrolyte in contact with the following carbon surfaces: graphene plane, single-layer graphene edge, and multi-layer graphene edge. It was shown that the surface topography strongly influences the electrolyte structure at the interface. Acetonitrile has a layered structure at the plane and the edge of graphene nanoribbons and a qualitatively different chessboard structure at the multi-layer graphene edge. It was found from the potentials of mean force that the variation of the surface topography induces the redistribution of the reactants Li and O near the surface and influences their adsorption rate. This should affect the kinetics of the oxygen reduction reaction and may explain massive deposition of discharge products on graphene edges in Li-air batteries.

Electrode/Electrolyte Interface in the Li–O2 Battery: Insight from Molecular Dynamics Study

“…However, additional study should be conducted on the influence of surface defects and angstrom-scale roughness. Some relevant attempts have been made recently 41 , unfortunately electrode potential (and/or charge) was not taken into account, which is of high importance for modeling Li-O2 system according to our findings. Also we do understand that adsorption of DMSO molecules on the electrode surface can be influenced by quantum effects that are not captured by molecular dynamics simulation.…”

Coordination Numbers of Bivalent Ions in Organic Solvents

“…Ion solvation affects charge transfer [2,3], interaction with surfaces [4], and the kinetics of chemical interactions [5]. The properties of the solvation shells in solutions based on organic solvents are especially critical in the development of batteries [6][7][8][9][10][11].…”

Fast Method for Calculating Spatially Resolved Heterogeneous Electron-Transfer Kinetics and Its Application to Graphene with Defects

“…The rate constant in eq can be used for an exchange current density estimation across the whole interface where e is the charge of an electron, S is the surface area, and C ( ) is the concentration distribution of the reactant at the interface, which can be obtained from MD simulations, as in our previous works. − …”