Mechanically Interlocked Polymer Electrolyte with Built‐In Fast Molecular Shuttles for All‐Solid‐State Lithium Batteries

The mobility of molecular shuttles inside a mechanically interlocked polymer (MIP) can improve the ionic conductivity and electron transport capacity of a solid polymer electrolyte (SPE) and maintain a mechanically tough structure. The polyrotaxane‐based MIP electrolyte with a necklace‐like molecular structure exhibits high ionic conductivity (σ = 5.93 × 10 −3 S cm −1 at 25 °C and 1.44 × 10 −2 S cm −1 at 60 °C), a high Li + ion transference number ( t + = 0.71), and high electrochemical oxidation stability (≈4.7 V vs Li + /Li). When SPEs are used in Li‐based batteries, a high Coulombic efficiency (≥98.5%), an excellent rate capability, and fast charging (≥2C) can be achieved using a “built‐in molecular shuttle” design.