Modeling of Polyvinylidene Fluoride (PVdF) by Molecular Dynamics Simulation

Lithium rechargeable batteries are an alternative to the available options for sustainable and effective energy generation due to the high tension and numbers of charge and discharge cycles1,2. While searching for more efficient batteries, many studies have modified the polymeric matrix, in order to build safer electrochemical devices3. In this context, PVdF and PVdF-HFP copolymers stands out as good candidates for working as polymer matrix in solid polymer electrolyte (SPE)4. In this study, it was used GROMACS5 package and Byutner et al.6 force field for the computational simulations of pure PVdF. The same protocol was followed to validate the polymer model. NPT simulations (constant number of particles N, pressure P and temperature T), in 5 different temperatures (333, 373, 413, 453, 493K), were accomplished, with 5 ps and 1 ps as coupling time for pressure and temperature, respectively. Figure 1 presents density values in 5 different temperatures referenced above, comparing with the result obtained by Byutner and the experimental values presented by Zoller and Walsh7. With the validated model, the next steps include the characterization of the polymers’ structure and then addition of ionic liquid for applications in lithium batteries prototype. We have calculated thermodynamics, structural and dynamics properties and will be able to give a better comprehension of the ion mobility, supporting possible future modifications and the way to improve polymer electrolyte efficiency based on PVdF.