A Multi-Topologically Superposed Mechanically Interlocked Polymer

Mechanically interlocked structures (MIS) provide a powerful platform for creating advanced materials with unprecedented topological architectures. Nevertheless, current related studies have predominantly focused on the construction of MIS with single topological motifs, and the integration of multiple topologies into a single MIS remains a grand challenge. Herein, we harness ligand conformational constraints to regulate the flexible coordination behavior of alkali metal ions, enabling the construction of a multi-topologically superposed mechanically interlocked polymer (MIP) featuring the unprecedented incorporation of four distinct topological motifs. This incorporation imparts MIP with exceptional mechanical strength and efficient Na⁺ transport capability. As an artificial solid electrolyte interphase (ASEI) for sodium metal batteries, MIP delivers remarkable ultralong cycling stability, maintaining 87.8% capacity retention after 10 000 cycles at 20 C. This work breaks the boundaries of conventional MIS by enabling the creation of multi-topologically superposed MIS, thereby unveiling new topological landscapes and opening unexplored opportunities for advanced functions.