Effect of carbon cathode morphology on the electrode/electrolyte interface structure

Abstract

The study has focused on identifying possible factors that determine differences in electrocatalytic activity between carbon cathodes with different morphologies in Li–air batteries. The structure of the aprotic solvent dimethyl sulfoxide at carbon surfaces, such as nanotube, graphene plane, and single- and multilayer graphene edges, has been investigated using molecular dynamics simulation. It has been found that the solvent has a layered structure near the graphene plane, the graphene edge, and the nanotube. Moreover, the sharpness of the solvent layers decreases with the increasing surface curvature. The interface structure at the edge of the multilayer graphene has a qualitatively different, chessboard structure. It has been assumed that the observed differences in the interfacial solvent structure can influence the concentration distribution of the Li⁺ and O₂ reactants and in their adsorption rates, thereby affecting the kinetics of the oxygen reduction reaction.