A novel SiO2 nanofiber-supported organic–inorganic gel polymer electrolyte for dendrite-free lithium metal batteries

Abstract

The ever-growing dendrite lithium is a hazardous behavior for lithium metal batteries due to triggering safety issues. Gel-based polymer electrolyte, which possesses high ionic conductivity, chemical stability, and high-level safety, has a great potential to substitute traditional liquid electrolyte to avoid electrolyte leakage, electrolyte decomposition, and interface issues. In this work, precursor solution which consists of polyethylene glycol 2000, isocyanate-ended tri-hydroxyl polyether polyols, and LiPF6 is in situ polymerized in SiO2 nanofiber membrane to prepare SiO2 nanofiber-supported organic–inorganic gel polymer electrolyte. In this polymer electrolyte, the inorganic SiO2 nanofiber framework is endued with good mechanical properties for polymer electrolyte, while the ether-rich polymer chains have superior compatibility with electrolyte, acting as ionic transportation network. The synergistic effect between organic and inorganic part induces uniform lithium deposition, thus resulting in remarkable lithium dendrite resistance and electrochemical performances including ionic conductivity, interfacial resistance, charge/discharge capacities, rate behavior, and long-term cyclic life span.