Vertically Aligned Ion Pathways for Fast Conduction and Uniform Lithium Deposition in Solid-State Batteries

Abstract

The random distribution of one-dimensional nanofillers in composite polymer electrolytes (CPEs) typically results in tortuous ion transport pathways, severely limiting ionic conductivity and Li⁺ flux uniformity. Herein, an innovative electric field-assisted strategy is proposed to construct vertically aligned ion channels in CPEs using lithiated halloysite nanotubes (HNTs–SO₃Li) embedded within a polyurethane acrylate/polyethylene glycol diacrylate (PUA/PEGDA) matrix. Under an alternating electric field, the nanotubes orient perpendicularly, forming continuous, low-tortuosity pathways that significantly enhance room-temperature ionic conductivity. The aligned structure not only shortens Li⁺ transport distances but also homogenizes ion flux at the electrode interface, effectively suppressing lithium dendrite growth. Electrochemical characterization reveals exceptional stability. Three-dimensional structural reconstruction and ion transport simulations further demonstrate that the ordered channels promote uniform Li⁺ distribution and faster ion kinetics compared to disordered systems. This study provides a scalable and efficient approach to designing high-performance CPEs for next-generation solid-state batteries, addressing critical challenges in ionic conductivity, interfacial stability, and dendrite suppression.

Keywords

alignment / composite polymer electrolytes / fast Li⁺ conduction / uniform lithium deposition

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