The Polymer Society of Korea

Abstract

Lithium metal batteries (LMBs) are characterised by their high theoretical capacity (3860 mAh/g) and low redox potential (-3.045V vs. SHE). However, dendrite formation and interfacial instability hinder practical use.
In this work, we propose a polymer composite electrolyte based on polyacrylonitrile (PAN) and azide-functionalised mesoporous silica nanoparticles (MSNs), chemically crosslinked via tetrazole ring formation through cycloaddition. The cationic-tetrazolium ring facilitates lithium-ion transport by affecting anion mobility, similar to single-ion conductors.
The tetrazolium electrolyte exhibits a high lithium-ion transference number (tLi+ =0.91) and ionic conductivity (2.7 mS/cm at 80°C). In LiFePO₄ half-cell tests, it demonstrates long-term cycling stability (140.4 mAh/g over 290 cycles at 1C). This work demonstrates an approach in composite electrolytes to enhance ionic transport and stable electrochemical performance of LMBs.