The improvement in electrochemical properties with the addition of SiO2 into PMMA/PLA-LiBOB Gel Polymer Electrolytes Based Lithium Ions Battery

Abstract The present work investigates the impact of SiO₂ nanofiller on the electrochemical properties of gel polymer electrolytes (GPEs) composed of PMMA/PLA-LiBOB. The study encompasses two distinct systems: PMMA/PLA-LiBOB (System I) and PMMA/PLA-LiBOB-SiO₂ (System II). Nyquist plots were generated to analyze the samples' bulk resistance (Rb), and it was found that Rb value shows a decreasing trend with the incorporation of SiO₂. The ionic conductivity increases from 1.69×10⁻⁶ S cm⁻¹ to 1.37×10⁻³ S cm⁻¹ at room temperature, with the highest composition achieved at 6 wt.% of SiO₂. Dielectric properties revealed that the addition of SiO₂ nanofiller led to the enhancement of dielectric constant (ε′) and dielectric loss (ε″), attributed to SiO₂ nanofiller with high orientation polarizability and space charge polarization effects. Linear Sweep Voltammetry (LSV) measurements from both GPE samples are 4.1 V (System I) and 4.7 V (System II). Comparative electrochemical performances of the batteries assembled in System I and System II were conducted, demonstrating the superiority of System II in terms of stability and cycling performance. The differential capacity analysis further supported the enhanced electrochemical activity upon SiO₂ nanofiller incorporation.