PVDF-HFP-modified gel polymer electrolyte for the stable cycling lithium metal batteries

Gel polymer electrolytes (GPEs) is a promising electrolyte due to its processability and flexibility. However, the low ionic conductivity of GPEs remains huge challenges to hinder their development. Herein, a novel composite gel polymer electrolytes membrane consisting of Li1.7Al0.3Ti1.7(PO3)4 (LATP) ceramic powders, poly (propylene carbonate) (PPC) and poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) is designed and constructed via a solution-casting method. The morphology, structure and electrochemical properties of the gel polymer electrolyte modified by LATP are characterized by scanning electron microscope (SEM), X-ray diffraction (XRD) and electrochemical technology. It has been found that the as-prepared composite GPEs exhibit the higher ionic conductivity of 9.4 x 10-4 S cm-1 at 30 celcius, a wider electrochemical window of 5.2 V and a higher lithium-ion transference number of 0.66 than currently reported other analogous electrolytes. In the same time, it also shows good mechanical properties. As a result, LiFePO4|Li battery with PVDF-HFP-based membrane delivers excellent cycling stability. Therefore, the study indicates that PVDF-HFP-based composite GPEs possesses the potential application prospect in high performance lithium metal batteries (LMBs).

Automated summary

The novel composite gel polymer electrolytes membrane modified by LATP shows higher ionic conductivity, wider electrochemical window, higher lithium-ion transference number, and good mechanical properties. Therefore, PVDF-HFP-based composite GPEs have potential application prospects in high-performance lithium metal batteries.