Ionic Conductivity Enhancement of Polymer Electrolytes with Ceramic Nanowire Fillers

TLDR

Solid‑state electrolytes offer improved safety and electrochemical stability over liquid electrolytes, yet their practical use is limited by low lithium‑ion mobility, and incorporating ceramic nanoparticles into polymer matrices has been shown to enhance conductivity, though forming efficient conduction networks remains challenging. This study demonstrates that ceramic nanowire fillers can create efficient ionic conduction networks in polymer‑based solid electrolytes, boosting conductivity by three orders of magnitude. By embedding Li₀.₃₃La₀.₅₅₇TiO₃ nanowires into a polyacrylonitrile–LiClO₄ matrix, the authors engineered surface‑mediated ion transport pathways that dramatically increase ionic mobility. The 15 wt % Li₀.₃₃La₀.₅₅₇TiO₃ nanowire composite polymer electrolyte achieved an unprecedented room‑temperature ionic conductivity of 2.4 × 10⁻⁴ S cm⁻¹ and an expanded electrochemical stability window, demonstrating that nanowire‑mediated conduction networks markedly improve solid‑state electrolyte performance and guiding future high‑performance designs.

Abstract

Solid-state electrolytes provide substantial improvements to safety and electrochemical stability in lithium-ion batteries when compared with conventional liquid electrolytes, which makes them a promising alternative technology for next-generation high-energy batteries. Currently, the low mobility of lithium ions in solid electrolytes limits their practical application. The ongoing research over the past few decades on dispersing of ceramic nanoparticles into polymer matrix has been proved effective to enhance ionic conductivity although it is challenging to form the efficiency networks of ionic conduction with nanoparticles. In this work, we first report that ceramic nanowire fillers can facilitate formation of such ionic conduction networks in polymer-based solid electrolyte to enhance its ionic conductivity by three orders of magnitude. Polyacrylonitrile-LiClO4 incorporated with 15 wt % Li0.33La0.557TiO3 nanowire composite electrolyte exhibits an unprecedented ionic conductivity of 2.4 × 10(-4) S cm(-1) at room temperature, which is attributed to the fast ion transport on the surfaces of ceramic nanowires acting as conductive network in the polymer matrix. In addition, the ceramic-nanowire filled composite polymer electrolyte shows an enlarged electrochemical stability window in comparison to the one without fillers. The discovery in the present work paves the way for the design of solid ion electrolytes with superior performance.