Super-Toughness Self-Healing MOF-Based Composite Solid Electrolyte with Reaction-Transport Coupling Regulates Transportation of Ions and Polysulfides in High-Performance Solid-State Li–S Batteries

Abstract Lithium–sulfur batteries have emerged as a promising candidate for next-generation energy storage systems due to high theoretical energy density and low cost. However, the practical application is severely hindered by issues such as the polysulfide shuttle effect, sluggish ion transport, and lithium dendrite growth. Here, we proposed a synergistic strategy based on nanoconfinement polymerization and self-healing dynamic cross-linking to successfully fabricate a self-healing composite solid electrolyte, composed of PVDF-HFP, graphene oxide, UiO-66, linear polydopamine chains, and a boronic ester cross-linked network. The electrolyte demonstrates high ionic conductivity (1.7 × 10–4 S cm–1), good puncture resistance (9.7 N), high elongation at break (335%), and superior capacity retention (a capacity decay rate of 0.0276% per cycle over 500 cycles). Even under a high sulfur loading of 4 mg cm–2, the capacity retention remained as high as 94.8%, which exceeds previously reported electrolytes. This strategy offers a new pathway to designing advanced solid electrolytes for high-energy batteries.