Dual Dynamic Supramolecular Interaction-Enhanced All-Solid-State Electrolyte for High-Performance Lithium Metal Batteries

Poly(ethylene oxide) (PEO)-based polymer electrolytes exhibit great potential for application in all-solid-state batteries. However, the insufficient Li⁺ transport efficiency has hindered the large-scale development of PEO. To address these challenges, we introduced a dual supramolecular interaction strategy for the preparation of PEO-based electrolytes, where tetrafluoroterephthalonitrile (TFTPN) complexes with Li⁺ and phenylenediboronic acid (PBA) as anion capturer were engaged. Through the synergistic effects of Lewis acid-base interactions between TFTPN and Li⁺, and hydrogen bonding-derived anchoring for bis(trifluoromethylsulfonyl)imide (TFSI^-) anion by boronic acid moieties in PBA, the Li⁺ transport efficiency was significantly enhanced with ionic conductivity of 6.14 × 10^-4 S cm^-1 and Li⁺ transference number of 0.6 at 50 °C (1.01 × 10^-4 S cm^-1 at 25 °C). PEO-TFTPN-PBA-based cell enabled a maximum discharge specific capacity of 130.7 mAh g^-1 at 2 C, and a high retention rate of 81.7% after 200 cycles. This study will provide an effective approach and a synergistic material design strategy for leveraging dynamic supramolecular interactions within PEO-based solid polymer electrolytes.