Synthesis and molecular dynamic simulation of a novel single ion conducting gel polymer electrolyte for lithium-ion batteries

Abstract

Single ion conductor has been realized as a new path to reduce polarization and improve electrochemical performance of the lithium ion batteries (LIBs). In this work, a novel single ion conductor gel polymer electrolyte (SIGPE) was designed via free radical polymerization, co-electrospinning and plasticizing process. The molecular structure information of the single ion polyanionic salt P(MPEGA-AMPSLi) of the SIGPE is carefully verified. The SIGPE shows high ionic conductivity of around 2.8 × 10−5 S/cm at 25 °C, high lithium ion transference number of 0.75, wide electrochemical window of 4.7 V as well as a stable cycle performance at 25 °C and 60 °C. The plasticizing mechanism of the gel polymer electrolyte has also been modeled and studied theoretically by molecular dynamics simulation. The results display a positive effect of the plasticizing in promoting the ionization of Li ions, increasing the diffusion coefficient of Li ions from 8.05 × 10−11 cm2/s to 1.37 × 10−9 cm2/s.