Composite polymer electrolyte for highly cyclable room-temperature solid-state magnesium batteries

Developing an electrolyte candidate with a wide voltage window, highly reversible cycling with Mg-metal anode, and without the use of any flammable solvents is a major challenge for rechargeable Mg batteries. While there have been several reports on Mg2+-conducting polymer electrolytes with high ionic conductivities, studies to determine their cycling performance and Mg-deposition overpotentials have been scarce. Here, we report a composite polymer electrolyte that exhibits a highly reversible cycling with Mg-metal anode at room temperature. The synthesized polymer electrolyte has a high conductivity of 0.16 mS cm-1 at room temperature, and the galvanostatic cycling tests of Mg