Analysis of a Li-Ion Nanobattery with Graphite Anode Using Molecular Dynamics Simulations

Molecular dynamics simulations were performed to investigate the initial charging of a Li-ion nanobattery with a graphite anode and lithium hexaflourphosphate (LiPF6) salt dissolved in ethylene carbonate (CO3C2H4) solvent as the electrolyte solution. The charging was achieved through the application of external electric fields simulating voltage sources. A variety of force fields were combined to simulate the materials of the nanobattery, including the solid electrolyte interphase, metal collectors, and insulator cover. Some of the force field parameters were estimated using ab initio methods, and others were taken from the literature. We studied the behavior of Li-ions traveling from cathode to anode through electrolyte solutions of concentrations 1.15 and 3.36 M. Time-dependent variables such as energy, temperature, volume, polarization, and mean square displacement are reported; a few of these variables, as well as others such as current, resistance, current density, conductivity, and resistivity are r...