Interface-Regulated Nanofillers for Improved Multi-Scale Zn 2+ Transport and Interfacial Stability in Solid-State Zinc-Ion Electrolytes

Solid-state zinc-ion batteries (SSZIBs) offer intrinsic safety and low cost, yet their practical deployment is severely constrained by the low ionic conductivity and unstable Zn/electrolyte interfaces of existing solid polymer electrolytes. Herein, we report a composite polymer electrolyte with enhanced performance, fabricated by integrating ZIF-8@TiO 2 core–shell nanofillers into a PEO-PVDF matrix. The conformal TiO 2 shell reinforces the structural stability of ZIF-8 and establishes chemically robust polymer-filler interfaces, enabling interconnected Zn 2+ -preferential transport pathways within a mesoporous, cross-linked ion-conduction network. Benefiting from this synergistic architecture, the optimized LZPV-9 electrolyte delivers a high room-temperature ionic conductivity of 4.74 × 10 –4 S cm −1 , a Zn 2+ transference number of 0.51, and stable cycling performance, retaining 88.37% of its initial capacity after 100 cycles. The Zn|LZPV-9|MnO 2 cell further achieves over 1000 h of stable plating/stripping at 0.2 mA·cm −2 under ambient conditions without short circuit. This work demonstrates a nanoscale interfacial-engineering strategy to stabilize MOF-based fillers and provides a promising pathway toward durable, high-conductivity solid-state zinc-ion batteries.