Polyrotaxane-engineered dynamically adaptive slide-crosslinked polymer electrolyte enabling high-performance...

The electrolyte of solid-state lithium metal batteries (LMBs) is challenged by lithium dendrites growth and repeated volume expansion and contraction of Li anodes. Conventional crosslinked polymer electrolytes struggle to meet the requirements of high-safety and long-cycling due to the inherent compromise between mechanical rigidity and ion transport. Herein, we report a dynamically adaptive slide-crosslinked polymer electrolyte (PPRx-PVC) synthesized via in-situ copolymerization of vinyl-functionalized pseudopolyrotaxane (PPRx=, x represents the molecular weight of PEG in PPRx=) and vinylene carbonate (VC). The molecular pulley mechanism of polyrotaxane enables synergistic enhancement of mechanical robustness (Young's modulus >2 GPa) and energy dissipation capacity via reversible sliding of threaded cyclodextrin rings along the guest polymer. Systematic optimization of PPRx= molecular weight (Mn ≈ 20,000 g mol^-1) reveals a critical interplay between ion interaction and network dynamics, achieving an exceptional Li⁺ transference number of 0.78 and electrochemical stability window of 4.85 V. The optimized PPR20000-PVC electrolyte demonstrates suppressed dendrite growth through adaptive stress redistribution during 1300 h Li plating/stripping at 0.5 mA cm^-2, enhanced interfacial durability against Li anode volume changes via dynamic network reconfiguration, and superior performance in Li||LiFePO₄ (LFP) with 93.2 % capacity retention over 200 cycles at 0.5C.This work provides new design of polymer electrolyte for high-performance LMBs that concurrently address mechanical durability, interfacial compatibility, and ion transport challenges in LMBs.