Rice husk-derived porous silicon dioxide fillers for enhancing ionic conductivity in a solid-state electrolyte of lithium–sulfur batteries under molecular dynamic calculation

Abstract

High cost, low ionic conductivity, and low mechanical strength remain formidable challenges to the practical application of solid electrolyte materials. Rice husk-derived silicon dioxide (abbreviated as RH_SiO2) is prepared and incorporated into a polyethylene oxide (PEO) polymer to form a low-cost, high-performance composite polymer electrolyte (CPE). The RH_SiO2 particles possess highly porous channels that allow the PEO to create fast three-dimensional Li-ion pathways for improving ionic conductivity and enhancing the fire resistance and mechanical strength of CPE. Molecular dynamics calculation reveals that under the incorporation of the RH_SiO2, the ionic conductivity is considerably enhanced as the RH_SiO2 content increases. At room temperature, the 10 wt% RH_SiO2 CPE demonstrates the highest ionic conductivity of 1.1 × 10⁻⁴ S cm⁻¹; this is 26.7 times that of the filler-free SPE. The experimental result is consistent with the theoretical calculation. Moreover, the stability and cyclability are considerably improved. The findings demonstrate the excellent commercialization potential of high-energy, all-solid-state Li–S batteries, supporting the possibility of a circular economy.