A Universal Magnetic Alignment Strategy for Composite Solid-state electrolytes with Vertically Aligned High-Ionic-Conductivity Pathways

Abstract

The low ionic conductivity of polymer-based solid electrolytes limits their application. Conventional enhancements by adding inorganic fillers typically requires material-specific modifications or complex processing. Here, we report a universal magnetic alignment strategy using field-responsive “guide” nanorod to construct vertically aligned transport channels (VATC) of Li+ in poly(ethyleneoxide) (PEO)-based composite electrolytes. Via magneto-mechanical coupling, these “guide” nanorods spatially organize non-magnetic Li7La3Zr2O12 (LLZO) fillers without direct magnetic modification. The resulting composite with low-tortuosity pathways achieves an ionic conductivity of 1.2×10-4 S·cm-1 at 30 °C, doubling that of randomly dispersed counterpart. In LiFePO4||Li all-solid-state cells, it simultaneously delivers improved rate capability and cycling stability. This work demonstrates a simple, scalable, and material-agnostic route to high-performance solid electrolytes, promising for next-generation energy storage.