Weak-Solvation Molecular Ion Gates Enabling Multipath Li⁺ Hopping and Air Stability in Garnet/Poly(ethylene oxide) Electrolytes

Additionally, the −CF₃ groups enhance LiTFSI dissociation, weaken Li⁺-EO and Li⁺-TFSI^– interactions, and accelerate coordination exchange and interfacial hopping. Simultaneously, the ether-oxygen moieties provide Li⁺ -transport sites at the LLZTO/PEO interface, activating polymer, interfacial, and garnet-associated Li⁺ transport regions. As a result, the composite electrolyte delivers a Li⁺ transference number of 0.622 and an electrochemical stability window of 5.38 V (vs Li⁺/Li).

Li||Li symmetric cells cycle stably for over 2000 h at 0.2 mA cm^–2 and 0.2 mAh cm^–2, and LiFePO₄||Li full cells retain 87.8% of their initial capacity after 1100 cycles at 1 C. The WSMI strategy proposed in this work provides valuable insights into tailoring interfacial chemical environments for all-solid-state batteries.