Gel Polymer Electrolyte Based on Tetraethylene Glycol Dimethyl Ether Used As a Stable Electrolyte for Lithium Oxygen Batteries with Enhanced Cycling Performances

Free-standing gel polymer electrolytes with poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) matrix plasticized with tetraethylene glycol dimethyl ether (TEGDME) were prepared and investigated. The as-prepared gel polymer electrolytes exhibited good reversibility of Li⁺ plating and striping, large operating window, and acceptable ionic conductivity. When applied in lithium-oxygen (Li-O₂) batteries, the gel polymer electrolyte exhibited a high initial discharge capacity of 2,988 mAh g^-1. Furthermore, the battery with gel polymer electrolyte can last at least 50 cycles in the fixed capacity cycling, displaying an excellent stability.Detailed study reveals that the gelling process is essential for the cycling stability enhancement. With excellent electrochemical properties, the free-standing gel polymer electrolyte presented in this investigation have great application potentials in long-life Li-O₂ batteries.