Investigation of Lithium Transference Number in PMMA Composite Polymer Electrolytes Using Monte Carlo (MC) Simulation and Recurrence Relation

In this study, Monte Carlo (MC) simulation is conducted with recurrence relation to study the effect of SiO2 with different particle size and their roles in enhancing the ionic conductivity and lithium transference number of PMMA composite polymer electrolytes (CPEs). The MC simulated ionic conductivity is verified with the measurements from Electrochemical Impedance Spectroscopy (EIS). Then, the lithium transference number of CPEs is calculated using recurrence relation with the MC simulated current density and the reference transference number obtained. Incorporation of micron-size SiO2 (≤10 ㎛) fillers into the mixture improves the ionic conductivity from 8.60×10-5 S/cm to 2.35×10-4 S/cm. The improvement is also observed on the lithium transference number, where it increases from 0.088 to 0.3757. Furthermore, the addition of nano-sized SiO2 (≤12 nm) fillers further increases the ionic conductivity up towards 3.79×10-4 S/cm and lithium transference number of 0.4105. The large effective surface area of SiO2 fillers is responsible for the improvement in ionic conductivity and the transference number in PMMA composite polymer electrolytes.