Title: A safe, flexible, and high-performing gel-polymer electrolyte for rechargeable lithium metal batteries

Abstract

The use of gel polymer electrolytes (GPEs) is of great interest to build high-performing rechargeable lithium metal batteries (LMBs) owing to the combination of the good electrochemical properties coming from the liquid and improved safety of the polymer host. In this work, we report a facile and scalable one-pot preparation method of a GPE based on a highly safe polyethylene glycol dimethyl ether (PEGDME) plasticizer in a poly (vinylidenefluoride-co-hexafluoropropylene) (PVDF-HFP) polymer matrix. The prepared GPE exhibits excellent safety (non-flammability and thermal stability up to 250ºC), and outstanding electrochemical properties at room temperature (high ionic conductivity of 3.4×10−4 S cm−1). Moreover, GPE delivers good C-rate response and high capacity (ca. 1 mAh cm−2 at C/10). Notably, the prototype pouch cell (ca. 19 mAh at C/10) provides remarkable safety, mechanical flexibility, and strong tolerance towards bending and cutting. These results suggest that the prepared GPE is a promising candidate for the development of high-performance, flexible and safe LMBs that operate at room temperature.