Enhanced Electrochemical Properties and Optimized Li⁺ Transmission Pathways of <scp>PEO</scp>/<scp>LLZTO</scp>‐Based Composite Electrolytes Modified by Supramolecular Combination

Poly(ethylene oxide) (PEO) and Li6.75La3Zr1.75Ta0.25O12 (LLZTO)-based composite polymer electrolytes (CPEs) are considered one of the most promising solid electrolyte systems. However, agglomeration LLZTO within PEO lack Li+ channels result in poor electrochemical properties. Herein, a functional supramolecular combination (CD-TFSI) consisting active β-cyclodextrin (CD) with self-assembled LiTFSI salt is selected as an interface modifier to coat fillers. Benefiting from vast H-bonds formed between β-CD matrix and/or LLZTO, homogeneous dispersion tight contact obtained. Moreover, 6Li NMR spectra confirm new transmission pathway ceramic then as-prepared PEO/[email protected] CPEs due typical cavity structure β-CD. As proof, conductivity increased 5.3 × 10−4 S cm−1 8.7 at 60 °C, transference number enhanced 0.38 0.48, stability window extended 5.1 V versus Li/Li+. Li‖LiFePO4 CR2032 coin full cells pouch prove practical application CPEs. This work offers strategy modifying fillers optimize PEO/LLZTO for lithium batteries.