Melt‐Intercalated Montmorillonite Composite Electrolytes Enabling Interlayer‐Interface Dual Conduction Networks for Stable Solid‐State Lithium Metal Batteries

The sluggish ion transport kinetics within solid‐state electrolytes and the consequent heterogeneous lithium deposition represent core bottlenecks impeding high‐energy‐density lithium metal batteries. Such uneven deposition originates from restricted ion transport networks and fragile contact at electrode/electrolyte interfaces. Constructing long‐range continuous fast ion transport networks effectively regulates microscopic ion flux, enabling uniform lithium plating/stripping. Herein, we propose an innovative solvent‐free melt coordination intercalation strategy, combined with electrospinning and in‐situ thermal polymerization, to construct composite solid electrolytes featuring dual‐ion conduction channels using 2D layered montmorillonite as the functional skeleton. The highly conductive interlayer confinement transport channels of montmorillonite and the continuous montmorillonite/polymer amorphous interfaces synergistically constitute interconnected “interlayer‐interface” dual‐conduction networks for Li + . Consequently, the resulting electrolyte exhibits a high room‐temperature ionic conductivity of 1.6 mS·cm −1 and an outstanding Li + transference number of 0.68. Meanwhile, uniform ion transmission across the electrode/electrolyte interface is guaranteed. The Li||Li symmetric cells demonstrate long stable cycling of over 6000 h at 0.1 ‍mA·cm −1 . Furthermore, LiFePO 4 ||Li full cells retain ∼70% of their initial capacity after 3000 cycles at 2 C rate. This work simultaneously achieves efficient ion transport and enhanced interfacial stability, providing a promising avenue for high‐performance solid‐state lithium metal batteries.