Phenylboronic Acid Functionalized Calix[4]pyrrole‐Based Solid‐State Supramolecular Electrolyte

Abstract Solid‐state polymer electrolytes (SPEs) suffer from the low ionic conductivity and poor capability of suppressing lithium (Li) dendrites, which limits their utility in the preparation of all solid‐state Li‐metal batteries (LMBs). It is reported here a flexible solid supramolecular electrolyte that incorporates a new anion capture agent, namely a phenylboronic acid functionalized calix[4]pyrrole (C4P), into a poly(ethylene oxide) (PEO) matrix. The resulting solid‐state supramolecular electrolyte demonstrates high ionic conductivity (1.9 × 10⁻³ S cm⁻¹ at 60 °C) and a high Li⁺ transference number ( = 0.70). Furthermore, the assembled Li|C4P‐PEO‐LiTFSI|LiFePO₄ cell allows for stable cycling over 1200 cycles at 1 C at 60 °C, as well as good rate performance. The favorable performance of the C4P‐PEO‐LiTFSI SPE leads to suggest it can prove useful in the creation of high energy density solid‐state LMBs.