Boron Nitride-Reinforced Gel Polymer Electrolyte for Lithium Metal Batteries: Enhanced Dendrite Suppression and Ultra-long Cyclability

초록

Lithium metal batteries (LMBs) have emerged as promising next-generation energy storage systems owing to their exceptionally high theoretical capacity (3860 mAh g− 1) and low electrochemical potential (− 3.04 V vs. SHE). However, practical implementation of LMBs remains severely limited by unstable lithium interfaces, dendrite formation, and parasitic reactions associated with liquid electrolytes. Herein, we developed a stabilized gel polymer electrolyte by incorporating boron nitride nanotubes (BNNTs) into a poly(vinylidene fluoride-co-hexafluoropropylene) matrix. The resulting BNNT-reinforced gel polymer electrolyte (BNGPE) exhibited enhanced electrolyte wettability, reduced interfacial resistance, a wide electrochemical stability window (~ 5.4 V), and outstanding thermal durability (up to 200 °C). Symmetric Li/BNGPE/Li cells demonstrated stable cycling performance with uniform lithium deposition, effectively suppressing dendrite formation over 5500 h without short-circuiting. Moreover, full-cell testing employing a LiFePO₄ cathode and lithium metal anode delivered a stable, high specific capacity (~ 163 mAh g− 1) and superior rate performance, especially under elevated-temperature conditions. These results clearly indicate that optimized BNNT-enhanced gel electrolytes effectively address critical limitations of conventional electrolyte systems, significantly improving safety, interfacial stability, and electrochemical performance. Thus, this study presents a viable pathway toward commercializing advanced, high-energy–density, and thermally resilient lithium metal battery technologies.

키워드