Constructing Non‐Confined Fast Lithium‐Ion Transport Highway in Metal‐Phosphonate‐Organic Framework Through Solvent‐Free Eutectic Dissociation Strategy

Abstract Solvent‐free all‐solid‐state electrolytes offer compelling advantages, yet the simultaneous achievement of efficient salt dissociation and rapid unrestricted conduction remains a challenge. Herein, fast non‐confined lithium‐ion conduction is constructed in dry‐processed metal‐phosphonate organic framework (MPOF)‐based electrolytes via a eutectic dissociation strategy, which unlocks ion dissociation through dynamic ion‐ligand interaction sites. The inherent abundance of phosphonate groups and oxygen vacancies within amorphous MPOF's spatially loose nano‐channels drives the dissociation of lithium salt, where Li ⁺ ions coordinate with phosphonate groups and TFSI ⁻ is immobilized by oxygen vacancies. Impressively, the alternating negatively charged phosphonate groups and positively charged oxygen vacancies establish a continuous ligand channel within the porous matrix, enabling efficient and rapid Li ⁺ transport. Thus, the obtained MPOF@Li electrolyte provides an exceptional ionic conductivity (1.1 × 10 ⁻⁴ S cm ⁻¹ at 30 °C) and a high lithium‐ion transference number of 0.75. Consequently, with the MPOF@Li electrolyte, the symmetric cell exhibits long cycle life of over 7500 h, and the full cell with LiFePO ₄ cathode demonstrates an excellent capacity retention of 95% after 1000 cycles at 0.5 C. Surprisingly, the MPOF@Li electrolyte allows operation at low temperatures (−10 °C), achieving stable cycling in symmetric cells and maintaining ≈70% of room‐temperature capacity in full cells.