Realizing highly conductive “polymer in salt” electrolytes through Li-ion-highway for room temperature all-solid-state Li-S batteries

Abstract

“Polymer in salt” electrolytes (PISEs) have great application prospects because of their higher ionic conductivity than conventional solid polymer electrolytes (SPEs) at room temperature. However, it is still a challenge to realize both high ionic conduction and mechanical properties for PISEs. Here we address the issue by comprising interconnected ultra-long MnO2 nanowires modified with (3-Aminopropyl)trimethoxysilane (AMW) in PAN-LiTFSI-based PISEs. The presence of AMW reinforces the mechanical properties and aids Li-ion migration between ionic aggregates through a “hand-to-hand” mode. The resulting electrolyte (PIS-AMW) exhibits a high tensile strength of 2.77 MPa, ionic conductivity of 4.44 × 10−4 S cm−1 and Li-ion transference number of 0.61 at 25 °C. Li symmetric cells assembled with PIS-AMW demonstrate satisfactory cycling stability for up to 600 h. All-solid-state lithium‑sulfur batteries assembled with this electrolyte exhibit a capacity of 643 mAh g−1 at 0.05C and 25 °C after 80 cycles. The strategy effectively resolves the dilemma between long-range ionic conduction and mechanical properties in PISEs, which have potential applications in high-energy-density solid-state batteries.