Li_6.7La₃Zr_1.7Ta_0.15Nb_0.15O₁₂ enhanced UV-cured poly(ethylene oxide)-based composite gel polymer electrolytes for lithium metal batteries

A composite gel polymer electrolyte (CGPE) based on cross-linked poly (ethylene oxide) with excellent comprehensive properties for the application of lithium metal battery was prepared by UV curing. The cubic Li_6.7La₃Zr_1.7Ta_0.15Nb_0.15O₁₂ (TN) micron sized powder was used as an enhancer. Among them, the CGPE membrane with 10% TN filler has the best performance. While it has excellent mechanical properties and thermal stability, the corresponding room temperature ionic conductivity is as high as 3.5 mS cm⁻², the lithium ion migration number is 0.55, the electrochemical stability window is about 5.5 V, and shows excellent stability to lithium metal. At the same time, the lithium metal battery based on the electrolyte film has good rate performance and cycle stability (143.6 mA h g⁻¹ with capacity retention of 91.6% after 175 cycle at 0.2 C and 91.8% capacity retention after 100 cycle at 1.0 C), indicating it has practical application prospect.