Lithium ion transportation in lignin infused polyvinyl alcohol based eutectogel: A molecular dynamics framework

Eutectogels are an arising material in the field of energy storage applications like high-energy Lithium-Ion batteries (LIBs) due to their properties like higher ionic conductivity, environment friendly and enhanced safety. However, it is important to understand the working mechanism of eutectogels at an atomistic level with the help of Molecular Dynamics (MD) simulations, in order to enhance their performance as electrolytes for LIBs. Eutectogels are formed by integrating deep eutectic solvent (DES) involving Lithium Chloride (LiCl) and ethylene glycol (EG) in the molar ratio of 1:5 with the polymeric matrix of Polyvinyl alcohol (PVA) chains considered for this study. Thereafter, lignin molecules are induced in the eutectogel system to improve the characteristics of an eutectogel. The elaborate study of the effect of lignin on the lithium ions movement through the lignin-added-eutectogel is involved in this work. The increase in hydrogen bonds among PVA polymeric chains and lignin molecules show the strength enhancement. From the Radial Distribution Function results it is derived that the lithium ions are showing enhanced interactions with chlorine ions than any other component of the system. Mean Square Displacement gives an idea about diffusivity of lithium ions through the systems and it suggests that the Li⁺ ion diffusivity is improved after Lignin imposition. On the basis of findings from this work, the modified Lignin infused PVA based eutectogel can be the potential candidate for the battery and energy storage applications.