Modelling of Li⁺ and Na⁺ Conduction Under Electric Fields in Organic Ionic Plastic Crystals

Solid electrolytes are a promising topic, which could replace the flammable solvents currently used for both Li-ion battery electrolytes, and their Na-counterpart (still under development). Thus the transport properties of such solid electrolytes must be understood. Here, we studied the effect of applying an external electric field to an organic ionic plastic crystal, P1224PF6, previously reported to have interesting alkali-ion transport properties[i]. The study employed molecular dynamics (using a previously reported force field[ii]). The roles of electric field strength and Li+/Na+ concentration were explored. Furthermore, system polarisation was explored by adding a surface/electrode to the system. This was done both on the basis of an external electric field and one due to electrode charge. [i] Chen, F., Pringle, J.M., Forsyth, M. Chem. Mater. 2015, 27, 2666-2672. [ii] Chen, F., Jin, L., de Leeuw, S.W., Pringle, J.M., Forsyth, M. J. Chem. Phys. 2013, 138, 244503.