Sequential Co-Click Reactions with Poly(glycidyl propargyl ether) toward Single-Ion Conducting Electrolytes

We utilize the direct, monomer-activated anionic ring-opening polymerization of glycidyl propargyl ether (GPE) to obtain a clickable polyether backbone [(P(GPE)] with high molecular weights and narrow distributions. First, P(GPE) was individually clicked with three different azide-functionalized pendant groups: LiTFSI-N3, EG3-N3, and Bn-N3. LiTFSI serves as a lithium ion source with immobilized anion, tri(ethylene glycol) as an additional source of ion-conductive medium, and the benzyl substituent is used to improve the mechanical properties. To combine all these properties in one single polymer electrolyte, we sequentially co-clicked the named azides onto P(GPE). The final material composition, the [O]/[Li] ratio, as well as the glass transition temperature can be adjusted via the azide feed ratios. A self-standing electrolyte material with close-to-unity lithium transport number and very high electrochemical stability was obtained. We present an innovative clickable PEG platform to synthesize a ready-to-use anion-immobilized solid polymer electrolyte with tunable thermal properties in a single, sequential reaction step.