Dynamic Migration‐Pulling Polymer Electrolyte Design Strategy for Low‐Temperature Lithium–Sulfur Batteries

Abstract

Quasi-solid-state lithium-sulfur batteries exhibit significant promise as safe, high-energy electrochemical storage technology, yet their performance remains constrained by polysulfide accumulation and exacerbated shuttle effects due to sluggish redox kinetics and inefficient charge transport. Here, a dynamic migration-pulling strategy is proposed to accelerate polysulfide redox kinetics by dynamically restructuring the solvated structure of Li⁺, which is validated on a GPE incorporating boronic ester dynamic covalent bonds and polar side chains (BE-GPE). Theoretical calculations and experiments revealed that the desolvation barrier for Li⁺ is significantly reduced, while the ligand groups were pulled out from the solvated shell assisted by the migration of dynamic covalent bonds. Rapid charge transfer kinetics are attainable via designed electrolyte. Consequently, BE-GPE based lithium-sulfur batteries delivered high reversible capacity of 1446 mAh g^-1 at 0.1 C and long-term cycling stability with an average capacity decay of 0.04% during 1000 cycles at 0.5 C. The initial capacity at 0.5 C is up to 920 mAh g^-1 and remains stable for 200 cycles at 0 °C. Successfully realized the energy storage of quasi-solid-state Li-S batteries under low-temperature conditions.