Simulation of long range ordering in an ionic liquid using molecular dynamics

In the last few years, a startling amount of electronic devices have been recalled due to issues regarding the safety of the battery. This is because the current electrolytes in batteries are volatile and flammable. Ionic liquids are currently being explored as possible alternatives to current electrolytes in lithium ion batteries. As a result, it is important to understand the structure of ionic liquids when lithium is added. Experimental structure factors of N-alkyl-N-methylpyrrolidinium and bis(trifluoromethylsulfonyl)imide (TFSI) from x-ray diffraction data show three peaks at low wavenumber values: a prepeak, a second peak due to charge alternation, and a third peak due to charge adjacency. Molecular dynamics computer simulations were used to calculate structure factors and investigate why the charge alternation peak disappears after adding LiTFSI.