Authors: Christofer Sångeland
Title: The formation of electrode-electrolyte interphases in polyester-based solid polymer electrolytes for solid-state LIBs
Affiliation: Uppsala University
Abstract
The efficiency and lifetime of lithium-ion batteries is largely dependent on the formation of stable and highly ion-conductive electrode-electrolyte interphases. It has been shown that incorporating a flexible poly(caprolactone) (PCL) moiety in poly(trimethylene carbonate)-based solid polymer electrolyte (SPE) is beneficial in terms of ionic conductivity, however, the effect of PCL on the electrode-electrolyte interphase has yet to be investigated. In this work, the Electrochemical Stability Window and formation of interfacial resistances in the PCL-LiTFSI-based SPE was studied using EIS at different potentials. Using post mortem XPS, we hope to identify compositional changes in the interface which are responsible for changes in frequency-impedance response. In order to facilitate separation of the layers for post mortem XPS analysis, we have synthesized a high molecular weight PCL and opted for lower salt concentrations to obtain a material which is less adhesive.