Molecular Structure at the Cathode-Electrolyte Interface

The equilibrium structures of the glassy polymer cathode (cathode shown in black, with sulfur atoms in yellow) in contact with different solvents (DME in red and DOL in blue) are presented for three systems: (a) pure DME, (b) mixed DME/DOL, and (c) pure DOL. The structural differences along the z-axis arise from variations in solvent density and packing in the bulk phases. For each system, the corresponding simulation box length along the z-direction is shown. These configurations highlight how solvent composition influences interfacial layering, polymer exposure, and the overall organization of the cathode–electrolyte boundary.

How does a lithium ion dance with a conjugated polymer?

Cation-π interactions - attractions between Li⁺ and the π-electron cloud of a conjugated polymer - play a vital role in energy storage and charge transport. Yet classical force fields usually ignore them. In this study, we explicitly incorporated these interactions into the OPLS-AA force field. The video illustrates how including cation–π physics  strengthens the nonbonded attraction between Li⁺ ions and the aromatic sites of the polymer, revealing interfacial behaviors that standard models fail to capture.