Two-dimensional silica enhanced solid polymer electrolyte for lithium metal batteries

Solid polymer electrolytes (SPEs) are promising substitutes for current flammable liquid electrolytes to achieve high-safety and high-energy-density lithium metal batteries. Polyethylene oxide (PEO) based solid polymer electrolytes have attracted increasing attention because of their excellent flexibility, manufacturability, light weight, and low-cost processing, while they often suffer from low ionic conductivity at room temperature, low lithium transference number and unsatisfactory interfacial resistance, which largely restrain their practical application.

Herein, two-dimensional holey silica nanosheets (2D-HSN) as the fillers, together with LiNO3 as the electrolyte additive, are introduced in a PEO/poly(vinylidene fiuoride-co-hexafluoropropylene) (PVDF-HFP) blended polymer matrix to obtain a SPE. The incorporation of HSN filler creates supplementary channels for lithium ion migration and lowers the crystallinity of the polymer, thereby facilitating the movement of lithium ions.