Composite Polymer Electrolytes With Hierarchical Confinement of Anions and Solvents for Stable Solid‐State Li Metal Batteries

Abstract

Solid‐state lithium‐metal batteries leveraging solid polymer electrolytes (SPEs) represent a promising technological pathway. Among these, polyvinylidene fluoride (PVDF)‐based SPEs are particularly noteworthy, yet they face a fundamental dilemma: electrode/electrolyte interfacial degradation from solvent‐dominated Li+ coordination versus constrained Li+ transport under solvent‐deficient conditions. To resolve this paradox, a 3D porous few‐layered MoS2 was synthesized and employed as the filler in PVDF‐based SPEs. The fillers concurrently weaken Li+ coordination with both FSI− and solvent through targeted dipole interactions, thereby enhancing Li+ migration rate and inducing structural reorganization to anion‐dominated Li+ solvation. The optimized PVDF‐based electrolyte demonstrates record‐breaking ionic conductivity (1.13 mS cm−1), Li+ transference number (0.68), and exceptional compatibility with lithium metal anodes under solvent‐lean conditions. The LiNi0.8Co0.1Mn0.1O2||Li cell demonstrates exceptional cycling stability, achieving a record‐high capacity retention of 90.5% after 1500 cycles at 2 C. Furthermore, practical applicability is confirmed through a 54 mAh pouch cell configuration. The ultra‐stable interfacial characteristics establish new performance benchmarks, demonstrating a viable pathway toward practical solid‐state batteries with minimal solvent dependence.